Method for evaluating the texture of food and beverages during swallowing, and method for manufacturing a formulation for improving the texture during swallowing.

Abstract

The present invention provides a method for evaluating the mouthfeel upon swallowing a food or beverage, which makes it possible to accurately evaluate a mouthfeel upon swallowing a food or beverage with a simple method using an elongation viscometer or the like. The present invention also provides a method for producing a formulation for improving a swallowing mouthfeel using the evaluation method, and a formulation for improving a swallowing mouthfeel.　The method for evaluating a mouthfeel upon swallowing a food or beverage comprises: a step for diluting the food or beverage or adding a thickening component thereto so as to adjust the viscosity to be a constant or a substantially constant shear viscosity; a step for using a capillary rupture type elongation viscometer to measure the filament diameter of the viscosity-adjusted food or beverage over time, and calculating elongation viscosity and elongation strain from a change in the filament diameter; a step for determining an index value that represents the elongation viscosity in a region in which the elongation strain is in a particular range; and a step for evaluating the quality of the mouthfeel at swallowing the food or beverage on the basis of the determined index value.

Description

[Technical Field]

[0001] This invention relates to a method for evaluating the texture of food and beverages during swallowing, which utilizes the results of physical tests; a method for manufacturing a formulation for improving the texture of food and beverages during swallowing, which utilizes this method; and a formulation for improving the texture of food and beverages during swallowing. [Background technology]

[0002] In recent years, with the increase in the elderly population, there has been a growing trend of people experiencing difficulties with chewing and swallowing, a phenomenon known as dysphagia. Consequently, various formulations have been developed to improve bolus formation and other properties by adding viscosity (thickness) to liquid foods, making them easier for people with dysphagia to consume. These are collectively called "thickened foods." In recent years, due to their palatability and functionality, thickening agents primarily composed of polysaccharides have been favored in thickened foods.

[0003] The requirements for thickening agents include properties related to viscosity development, such as good dispersibility, rapid viscosity development, and viscosity stability (stable viscosity development over time, with respect to solvent type, temperature, and pH changes) when added to liquid foods under loose stirring conditions, such as hand stirring. However, good taste, odor, color (transparency), and texture are also important. In particular, bolus formation (cohesion), residue in the mouth and pharynx (a feeling of clinging to the throat, or stringiness), and slipperiness (sliminess) are important factors not only for palatability but also for stable swallowing.

[0004] Food polysaccharides such as xanthan gum, guar gum, modified starch, and carrageenan, which are relatively easy to disperse at room temperature (20-25°C), have been used as the main ingredients for viscosity development in thickening foods. While these polysaccharides are excellent as thickening agents for people with chewing and swallowing difficulties in that they develop viscosity in a short time, they produce a sliminess and residue characteristic of polysaccharides. Foods and beverages prepared using such polysaccharides tend to remain in the pharynx, and in some cases have insufficient shape retention, resulting in poor cohesion in the bolus and difficulty in swallowing.

[0005] Traditionally, the indicator of swallowability of liquid foods has been "viscosity." For example, according to the standards set by the Ministry of Health, Labour and Welfare, liquid (sol) foods for people with chewing and swallowing difficulties are defined as having a viscosity (steady-state shear viscosity) of 1,500 mPa·s or higher (measurement temperature: 20±2℃) as measured by a Type B rotational viscometer (Non-Patent Literature 1). However, the residue of the aforementioned foods and beverages in the pharynx is a problem that is more likely to occur when the viscosity is too high, and the cohesiveness of the food bolus often does not correlate with viscosity. Therefore, in recent years, the prevailing opinion has been that it is difficult to objectively express "ease of swallowing" based solely on viscosity.

[0006] Conventionally, methods for determining the "cohesion" of liquid foods have included the ring method and the texture profile analysis (TPA) method for measuring "cohesion." The ring method involves filling a glass ring placed in the center of concentric circles marked at regular intervals with liquid food, and then determining the "cohesion" of the liquid food after a certain period of time following the removal of the ring (Non-Patent Literature 2). The TPA method for measuring "cohesion" involves determining the "cohesion" of a food from the ratio of the first and second compression energies when the food is compressed twice perpendicular to it (Non-Patent Literature 3).

[0007] Foods with high "cohesiveness" that are easy for people with dysphagia to swallow are expected to differ in their in-vivo behavior when swallowed, compared to foods that are difficult to swallow. For the purpose of evaluating food properties and human swallowing motor performance in relation to the action of a person swallowing food, attempts have been made to measure actual swallowing movements using various measuring devices. Methods for discriminating parameters such as "ease of swallowing", "difficulty of swallowing", "ease of eating", and "difficulty of eating", including "smoothness through the throat", "feeling of catching in the throat", "feeling of satisfaction in drinking", "feeling of satisfaction in eating", "ease of swallowing", "refreshing feeling through the throat", and "invigorating feeling through the throat", from signal waveforms of continuous swallowing behavior collected using myoelectric potential measuring devices and pressure sensors, have already been reported (Patent Documents 1 and 2). There is also a method of determining whether a food is suitable for persons with dysphagia by measuring the flow velocity of the food flowing through the pharynx using X-ray contrast, endoscopic observation, or an ultrasonic measuring device (Patent Document 3).

[0008] Furthermore, a method of evaluating "cohesiveness" and "ease of swallowing" by attaching a sound-collecting microphone and a vibration detector to the throat of a test subject, capturing the sound generated when swallowing food, i.e., "swallowing sound", and analyzing its waveform (Patent Document 4), and a method of attaching a laryngeal flexion sensor that converts a bending rate into electrical resistance to the laryngeal region of a test subject, measuring the electrical signal of the laryngeal flexion sensor generated when the test subject swallows food or drink (during swallowing), and using the obtained two-dimensional signal waveform or parameters determined from the waveform as an indicator to evaluate the swallowing sensation of the food or drink (Patent Document 5), are known.

[0009] Also known are a method of improving the adhesiveness of food and drink based on elongational viscosity (Patent Document 6), and a method of improving the swallowability of food and drink based on the relaxation time measured by a capillary break-up elongational viscometer (Patent Document 7). Note that none of these Patent Documents 6 to 7 describe any specific measurement results of elongational viscosity. [Prior Art Documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2006-95264 [Patent Document 2] Japanese Patent Publication No. 2009-39516 [Patent Document 3] Patent No. 4400981 [Patent Document 4] Patent No. 4011071 [Patent Document 5] Patent No. 5489846 [Patent Document 6] Patent No. 6133217 [Patent Document 7] Patent No. 6687320 [Non-patent literature]

[0011] [Non-Patent Document 1] Regarding the handling of labeling permits for foods for the elderly, see the attached document: Testing methods for foods for the elderly (Notification from the Director of the New Food Development and Health Measures Office, Food Safety Division, Life Hygiene Bureau, Ministry of Health, Labour and Welfare; February 23, 1994, Eishin No. 15). [Non-Patent Document 2] Journal of the Japan Society of Home Economics 57(5):263-270, 2006, Akiko Maruyama et al., "Examination of a simple objective evaluation method for the mechanical properties of viscous liquid foods." [Non-Patent Document 3] Bourne, MC (MC Bourne ed.), Food Texture and Viscosity: Concept and Measurement 2nd ed., Academic Press, pp. 182-186 (2002). [Overview of the project] [Problems that the invention aims to solve]

[0012] However, the ring method used to determine "cohesion" is judged as having "cohesion" if the ring does not spread much after a certain period of time, but its discriminatory ability is generally low, and it has the drawback that even liquid foods that are judged as "not cohesive" in sensory evaluation are often judged to have "cohesion," especially with highly adhesive liquid foods. Furthermore, in the TPA method, the "cohesiveness" of food is considered to be correlated with "cohesion," so this method is sometimes used as an indicator of "cohesion" in gel-like foods and paste-like foods, but it often does not correlate with the "cohesion" of liquid foods.

[0013] Methods for measuring actual swallowing movements using various measuring devices, as described in Patent Documents 1-3, have problems such as the devices themselves being complex and expensive, and the methods for discriminating between them requiring specialized techniques.

[0014] Methods such as those described in Patent Documents 4-5, which involve capturing "swallowing sounds" and analyzing the waveform, or methods that measure the electrical signals of a laryngeal flexion sensor, allow evaluation using relatively inexpensive and readily available general-purpose equipment, but they have the drawback of requiring multiple subjects for evaluation.

[0015] Furthermore, the methods described in Patent Documents 6-7 do not take into account the effect of extensional strain on extensional viscosity, so it is unclear whether the effect of thickening polysaccharides on improving swallowing characteristics can be clearly evaluated. Moreover, since the test results are not explicitly stated in the specification, the improvement effect is not clear.

[0016] Furthermore, the tendency of thickening agents to remain in the pharynx due to their stringy nature is generally evaluated using medical methods such as videofluoroscopic swallowing studies and endoscopic swallowing examinations. However, these methods require skilled evaluators with medical knowledge and qualifications, and also place a significant burden on the subjects, making them unsuitable for frequent use in evaluating thickening agents. Moreover, there is currently no known method that can accurately measure the sliminess of food and beverages based on human perception.

[0017] As described above, there are few suitable methods for objectively measuring important textures of food and beverages during swallowing, such as "cohesion," "stringiness," and "sliminess," and there is a strong need to establish measurement methods and techniques.

[0018] Therefore, the present invention aims to provide a method for evaluating the texture of food and beverages during swallowing, which can accurately evaluate the texture of food and beverages during swallowing using a simple method that utilizes an extensional viscometer or the like. Furthermore, the present invention aims to provide a method for manufacturing a formulation for improving the texture of food and beverages during swallowing, which can be efficiently selected using this evaluation method. Moreover, the present invention aims to provide a formulation for improving the texture of food and beverages during swallowing that meets the selection criteria in this manufacturing method and has a high effect in improving the texture of food and beverages during swallowing. [Means for solving the problem]

[0019] The inventors of this invention have found that by determining an index value representing extensional viscosity from the extensional viscosity and extensional strain calculated using a capillary fracture type extensional viscometer, a high correlation is found between the index value and the texture during swallowing. Based on this finding, the present invention has been completed.

[0020] The present invention includes the following embodiments; Section 1. A process of adjusting the viscosity of food and beverages to a constant or nearly constant shear viscosity by diluting or adding thickening agents, A step of measuring the filament diameter of the viscosity-adjusted food or beverage over time using a capillary fracture type extensional viscometer, and calculating the extensional viscosity and extensional strain from the change in the filament diameter, A step of determining an index value that represents the extensional viscosity in a region where the extensional strain falls within a specific range, A step of evaluating the quality of the texture of the food or beverage when swallowed based on the determined index value, A method for evaluating the texture of food and beverages containing [specific ingredients / components] during swallowing.

[0021] Section 2. The method for evaluating texture during swallowing according to item 1, wherein the specific range of the extensional strain for determining the index value is determined by the correlation between the sensory evaluation of texture during swallowing, which has been determined in advance, and the extensional viscosity in the extensional strain.

[0022] Section 3. The method for evaluating the texture of food and beverages during swallowing, as described in item 1, wherein the step of determining the index value is to determine the maximum extension viscosity in the region where the extension strain is 2 to 4 as the index value, and the texture being evaluated during swallowing is "cohesion".

[0023] Section 4. The method for evaluating the texture of food and beverages during swallowing according to item 1, wherein the step of determining the index value is to determine the extension viscosity at any extension strain in the region where the extension strain is 7 or more as the index value, and the texture being evaluated during swallowing is "stringy".

[0024] Section 5. The method for evaluating the texture of food and beverages during swallowing as described in item 1, wherein the step of determining the index value is to determine the maximum extension viscosity in the region of extension strain 2 to 4 as the index value for "cohesion," and to determine the extension viscosity at any extension strain in the region of extension strain 7 or more as the index value for "stringiness," and the texture during swallowing to be evaluated is "cohesion" and "stringiness."

[0025] Section 6. Furthermore, a method for evaluating the texture of food and beverages during swallowing, as described in any one of items 1 to 5, including a step of evaluating the "sliminess" from the friction characteristics of the food and beverages in tribological tests, based on the correlation between the friction characteristics in tribological tests and sensory evaluation determined in advance.

[0026] Section 7. The method for evaluating the texture of food and beverages during swallowing, as described in item 6, wherein the tribology test measures the coefficient of friction at a specific sliding speed when the rotating body is rotated while applying pressure to the food and beverages in the container, interposed between the rotating body and the receiving part.

[0027] Section 8. The process involves using a liquid sample of the candidate formulation as the food or beverage and performing the method for evaluating the texture of the food or beverage during swallowing described in any one of items 1 to 7, A step of selecting a formulation by determining the texture of the candidate formulation when swallowed based on one or more of the evaluation results of "cohesion," "stringiness," or "sliminess" obtained, A method for producing a formulation for improving the texture during swallowing, which includes the formulation.

[0028] Section 9. The liquid sample of the candidate formulation was dispersed in ion-exchanged water and subjected to a shear rate of 50s at 25°C. -1 This is a dispersion in which the shear viscosity is adjusted to 50-150 mPa·s. The method for producing a swallowing texture-improving formulation according to item 8, wherein the step of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2 to 4 is 2,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.22 or more, and is selected as a formulation with a high effect in improving the "cohesion," "stringiness," and "sliminess."

[0029] Section 10. The liquid sample of the candidate formulation was dispersed in ion-exchanged water and subjected to a shear rate of 50s at 25°C. -1 This is a dispersion liquid in which the shear viscosity is adjusted to 150-300 mPa·s. The method for producing a swallowing texture-improving formulation according to item 8, wherein the step of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2 to 4 is 5,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,500 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.20 or more, and is selected as a formulation with a high effect in improving the "cohesion," "stringiness," and "sliminess."

[0030] Section 11. The liquid sample of the candidate formulation was dispersed in ion-exchanged water and subjected to a shear rate of 50s at 25°C. -1 This is a dispersion liquid in which the shear viscosity is adjusted to 300-500 mPa·s. The method for producing a swallowing texture-improving formulation according to item 8, wherein the step of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2 to 4 is 8,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 3,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.18 or more, and is selected as a formulation with a high effect in improving the "cohesion," "stringiness," and "sliminess."

[0031] Section 12. A swallowing texture improving preparation containing a thickening polysaccharide, which satisfies all of the selection criteria in the method for producing a swallowing texture improving preparation described in any one of items 9 to 11. [Effects of the Invention]

[0032] According to the present invention's method for evaluating the texture of food and beverages during swallowing, by determining an index value representing the extensional viscosity in a region where the extensional strain falls within a specific range, based on the extensional viscosity and extensional strain calculated using a capillary fracture type extensional viscometer, the correlation between the texture of food and beverages during swallowing and the index value can be increased, thereby enabling accurate evaluation of the texture during swallowing. As a result, we have been able to provide a method for evaluating the texture of food and beverages during swallowing that allows for accurate evaluation of the texture of food and beverages during swallowing using a simple method that utilizes an extensional viscometer or the like.

[0033] The present invention provides a method for producing a formulation for improving the texture during swallowing. This method involves performing the evaluation method of the present invention using a liquid sample of a candidate formulation to determine the texture of the candidate formulation during swallowing, thereby selecting a formulation that has a high effect in improving the texture during swallowing.

[0034] The swallowing texture improvement formulation of the present invention can provide a swallowing texture improvement formulation with a high effect in improving the texture during swallowing by satisfying all the selection criteria in the manufacturing method of the present invention. [Brief explanation of the drawing]

[0035] [Figure 1A] This is a schematic perspective view showing the tribology measurement apparatus (setup) used in the example. [Figure 1B] This is a schematic front cross-sectional view showing the tribology measurement apparatus (setup) used in the example. [Figure 2] The graphs show the dependence of extensional viscosity on extensional strain in Example 1, with (a) being the graph for xanthan gum and (b) being the graph for locust bean gum. [Figure 3] The graphs show the dependence of the coefficient of friction on sliding speed in Example 1, with (a) being the graph for xanthan gum and (b) being the graph for locust bean gum. [Figure 4] This is a scatter plot showing the correlation between the maximum extension viscosity at extension strains 2-4 in Example 1 and the sensory evaluation value of "cohesion." [Figure 5] This is a scatter plot showing the correlation between extensional viscosity at extensional strain 8 and the sensory evaluation value of "stringiness" in Example 1. [Figure 6] This is a scatter plot showing the correlation between the coefficient of friction at point e (i.e., sliding speed of 0.006 m / s) and the sensory evaluation value of "slippery feeling" in Example 1. [Modes for carrying out the invention]

[0036] (Object to be evaluated) The present invention relates to a method for evaluating the texture of food and beverages during swallowing. The textures that can be evaluated during swallowing include the main textures of food and beverages during swallowing: "cohesion," "stringiness," "sliminess," "residual feeling," "adhesion," "stickiness," and "coating feeling." In particular, it is preferable that the evaluation includes one or more evaluation items consisting of "cohesion," "stringiness," or "sliminess."

[0037] In the present invention, it is also possible to evaluate foods and beverages to which components that affect swallowability, such as thickeners, dispersants, emulsifiers, and stabilizers, have been added. The evaluation method of the present invention is particularly effective as a method for evaluating the texture during swallowing of foods and beverages containing thickening components such as thickening polysaccharides. Furthermore, it is also effective as a method for evaluating the texture during swallowing of liquid samples of candidate formulations in order to select an effective formulation from among candidate formulations for improving the texture during swallowing.

[0038] Food and beverages include beverages and food, and refer to anything ingested orally, regardless of whether or not it is chewed. Thickening agents are components that increase viscosity, and refer to thickeners, additives added to food and beverages that impart viscosity, and viscous components contained in food and beverages.

[0039] While there are no particular limitations on food and beverages, as will be discussed later, care foods such as thickening agents play a crucial role. This is because, with the aging society, there is an urgent need to develop care foods such as thickening agents that slow down the rate at which liquids pass through the throat, in order to reduce the risk of accidentally entering the trachea (aspiration) when swallowed.

[0040] Such care foods include not only foods with added thickening agents, but also beverages other than food, such as water, tea, and juice, to which thickening agents have been added. Preparations for improving the texture during swallowing also contain ingredients that affect swallowing, such as thickeners, dispersants, emulsifiers, and stabilizers.

[0041] The main components of the thickeners and dispersants to be evaluated include, for example, xanthan gum, gellan gum, carrageenan, guar gum, guar gum hydrolysate, locust bean gum, alginic acid, alginate, glucomannan, starch, modified starch, modified starch, dextrin, tamarind seed gum, soybean polysaccharides, agar, tara gum, pectin, native gellan gum, deacyl gellan gum, cassia gum, psyllium seed gum, amazin seed gum, wormwood seed gum, tragacanth gum, karaya gum, Examples include gum arabic, ghati gum, ramzang gum, macrophomopsis gum, curdlan, pullulan, succinoglycan, chitin, chitosan, mannan, gelatin, cellulose, microcrystalline cellulose, microfibrous cellulose, fermented cellulose, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, water-soluble hemicellulose, plant fibers (such as citrus fiber), konjac powder, etc., or their decomposition products. When these components are used as thickeners or dispersants, they may be used individually or in combination of two or more types.

[0042] Even with the same thickening agent, the texture during swallowing can change depending on the manufacturing method, raw materials, and refining process. It is also possible to evaluate mixtures or modified versions of these agents. Furthermore, according to the evaluation method of the present invention, it is possible to evaluate the texture during swallowing of newly developed thickening agents, as well as changes in texture during swallowing that result from the interaction between the thickening agent and other components.

[0043] Examples of emulsifiers and stabilizers include glycerol fatty acid esters (e.g., monoglycerol fatty acid esters, diglycerol fatty acid esters, organic acid monoglycerides, polyglycerol fatty acid esters, polyglycerol condensed ricinoleic acid esters), sucrose fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, calcium stearate, polysorbate, lecithin, and saponins.

[0044] (Applicable food and beverages) There are no particular restrictions on the types of food and beverages, but specifically, examples of such food and beverages are: Water (including distilled water, ion-exchanged water, purified water, reverse osmosis treated water, and ultrapure water), milk, milk beverages, lactic acid bacteria beverages, fermented milk beverages, carbonated beverages, fruit beverages (e.g., fruit juice beverages, fruit juice soft drinks, fruit juice carbonated beverages, fruit pulp beverages), vegetable beverages, vegetable and fruit beverages, coffee beverages, cocoa beverages, powdered beverages, sports drinks, functional beverages, ion drinks, vitamin supplements, nutritional balance beverages, supplement beverages, and other beverages; Tea beverages such as black tea, green tea, and blended teas (Note that beverages and tea beverages are included in the category of "beverages"). Japanese sake, beer, sparkling wine, beer-flavored alcoholic beverages, shochu, whiskey, brandy, wine, spirits (rum, vodka, gin, tequila, etc.), liqueurs, ethanol, and other alcoholic beverages, as well as various cocktails made by combining the aforementioned alcoholic beverages, or fruit wines such as red wine obtained by fermenting fruit juice; Soups such as consommé soup, potage soup, cream soup, and Chinese soup; Liquid foods such as miso soup, clear soup, stew, curry, and gratin; Liquid condiments such as separate dressings, oil-free dressings, ketchup, sauces, soy sauce, and other dressings; Special foods and therapeutic diets such as protein, phosphorus, and potassium-controlled foods, salt-controlled foods, fat-controlled foods, intestinal regulating foods, calcium, iron, and vitamin-fortified foods, hypoallergenic foods, high-calorie liquid foods, blended foods, and chopped foods: It includes. The examples of food and beverages in question also include semi-finished and intermediate products of these items.

[0045] "Process for adjusting the shear viscosity of food and beverages" From the viewpoint of improving the accuracy of evaluating the texture during swallowing, the concentration of the liquid sample needs to be adjusted so that the liquid sample has an appropriate shear viscosity under a constant shear rate. In other words, in the evaluation method of the present invention, the shear viscosity usually changes depending on the concentration of the solute, etc., of the liquid sample, and the extensional viscosity may also change accordingly. Therefore, the texture during swallowing is evaluated using a liquid sample that has been adjusted to a constant or approximately constant shear viscosity.

[0046] Therefore, the present invention's method for evaluating texture during swallowing includes a step of adjusting the viscosity of the target food or beverage by diluting it or adding a thickening agent to achieve a constant or substantially constant shear viscosity. Here, the specified shear viscosity is defined as a shear rate of 50 s at 25°C. -1 Preferably, the pressure is 50-150 mPa·s, 150-300 mPa·s, or 300-500 mPa·s, more preferably 80-120 mPa·s, 160-240 mPa·s, or 320-480 mPa·s, and even more preferably 94-106 mPa·s, 192-208 mPa·s, or 385-415 mPa·s.

[0047] The shear viscosity of food and beverages can be adjusted by diluting them with liquid components (such as water) or by adding a thickening agent to increase their viscosity. As thickening agents, those containing the aforementioned "components of thickening agents and dispersants to be evaluated" are preferably used.

[0048] Furthermore, if the target food or beverage or thickener is solid, a liquid sample is prepared by dispersing or dissolving it using a solvent. When powdered or granular thickening components absorb water before they can disperse uniformly in the solvent, only the surface of the powder or granules is hydrated, making it difficult for water to penetrate to the parts that have not yet come into contact with water, thus inhibiting uniform dispersion, this state is called "clumping." However, it is preferable that no clumping occurs when dispersing solid food (solute). Also, even when the solute is completely hydrated (dissolved), it is preferable that it dissolves uniformly so that no concentration distribution occurs. As a solvent, it is preferable to use water from the viewpoint of minimizing the influence of components other than water, but it is particularly preferable to use ion-exchanged water, distilled water, reverse osmosis treated water, pure water, or ultrapure water.

[0049] The method for measuring shear viscosity is as described in the examples, for example, but it can be performed using a commonly used dynamic viscoelasticity measuring device.

[0050] Furthermore, if the viscosity of the food or beverage in question before adjustment is within the specified range of shear viscosity, this viscosity adjustment procedure can be omitted.

[0051] "Process for calculating extensional viscosity and extensional strain" The present invention provides a method for evaluating the texture during swallowing, which includes the step of measuring the filament diameter of viscosity-adjusted food and beverages over time using a capillary fracture type extensional viscometer, and calculating the extensional viscosity and extensional strain from the change in the filament diameter. By using a capillary fracture type extensional viscometer, the extensional viscosity and extensional strain of food and beverages can be calculated relatively easily and with good reproducibility.

[0052] A typical example of a capillary fracture extensional viscometer (CaBER) is a device that has sample holders positioned vertically with a gap between them. With a sample placed between them, the gap between the sample holders is widened at a predetermined speed, and the behavior of the sample as it is stretched (e.g., filament diameter) is measured using an observation means such as laser light.

[0053] In the extensional viscometer used in the examples, a sample is loaded between two 4 mm-diameter plates arranged parallel to each other in the vertical direction with an initial gap of 1 mm, and then the upper plate is linearly stretched in 50 ms to set the final gap to 4.1 mm. The sample is pulled and stretched by the plates, and then flows under its own surface tension to form hemispherical droplets at the top and bottom, during which process the sample contracts onto the filament, and the sample between the plates contracts into a filament shape. The diameter of the filament at the midpoint of the final gap height between the two upper and lower plates (D mid ) is measured using laser light, and the measurement is performed continuously from the initial diameter D0 (=4 mm) at time t0 (when the top plate starts moving) until time t b (when the filament breaks).

[0054] Although the measurement can be performed only once, it is preferable to repeat the measurement a plurality of times (for example, 5 times or more) for each sample from the viewpoint of improving the accuracy of evaluation of texture during swallowing.

[0055] As a method for calculating the extensional viscosity and the extensional strain from the change in the filament diameter, there are calculation methods corresponding to various models, and for example, the extensional viscosity η can be calculated using the formula (1). E In this model, the extensional viscosity η of the sample is calculated from the contraction behavior of the filament after the upper plate reaches the final gap. E In this model, the extensional viscosity η of the sample is calculated from the contraction behavior of the filament after the upper plate reaches the final gap. E to calculate the value.

[0056]

Formula

[0057] Here, σ is the surface tension of the sample, D mid (t) is the filament diameter at the midpoint of the final gap height at time t, and X is a geometric coefficient. This X is a coefficient that takes into account the shape of the filament during contraction due to inertial effects and gravitational effects, and it has been experimentally shown that X=0.7127 is an appropriate value for highly viscous fluids.

[0058] The surface tension σ of the sample can be measured using various surface tension measuring devices, and it is preferable to repeat the measurement multiple times at the same measurement temperature as the measurement using an extensional viscometer, and use the average value as the surface tension σ.

[0059] Extensional viscosity η in equation (1) E In calculating this, it is possible to use a differential approximation of the filament diameter at the midpoint, which can be calculated, for example, from equation (2).

[0060]

number

[0061] Here, t i is the measurement point (time) closest to any time t, and t i-1 is, t i This is the measurement point immediately preceding D. mid (t i ), D mid (t i-1 ) is the filament diameter at each measurement point. This gives the extensional viscosity η at time t. E It is possible to calculate this.

[0062] Furthermore, the extension strain ε (Hencky strain) can be calculated, for example, from equation (3).

[0063]

number

[0064] This allows us to calculate the extensional strain ε at time t, and the extensional strain ε and extensional viscosity η over time t. E The relationship can be calculated.

[0065] As described above, extensional viscosity and extensional strain can be calculated from the change in filament diameter measured over time using an extensional viscometer.

[0066] "The process of determining indicator values" The present invention provides a method for evaluating texture during swallowing, which includes a step of determining an index value that represents the extensional viscosity in a region where the calculated extensional strain falls within a specific range. By determining an index value that represents the extensional viscosity in a region where the extensional strain falls within a specific range, the correlation between the texture of food and beverages during swallowing and the index value can be improved. In other words, the texture during swallowing is related to a part of the extensional behavior measured by a capillary fracture type extensional viscometer, and it is important to limit the extensional strain related to that part of the behavior to a specific range and determine an index value that represents the extensional viscosity in that region.

[0067] For example, if the texture to be evaluated during swallowing is "cohesion," a representative index value for extensional viscosity can be determined in the extensional strain range of 1 to 5, but it is preferable to determine a representative index value for extensional viscosity in the extensional strain range of 2 to 4. Furthermore, a representative index value can be determined using an extensional viscosity of 1 or more in these ranges, but it is more preferable to determine the maximum extensional viscosity as the index value.

[0068] Furthermore, if there are multiple maximum values ​​(peak values) of extensional viscosity in the above-mentioned region due to extensional strain, it is also possible to determine the maximum value of the extensional viscosity with the smallest extensional strain as the index value, or to determine the average value of multiple maximum values ​​as the index value, instead of the maximum extensional viscosity.

[0069] Furthermore, if the texture being evaluated during swallowing is "stringy," an index value representing extensional viscosity can be determined in the region where the extensional strain is 7 or higher, but it is preferable to determine an index value representing extensional viscosity in the region where the extensional strain is between 7.5 and 10. Also, an index value representing extensional viscosity can be determined using one or more extensional viscosity values ​​in these regions, but it is preferable to determine the extensional viscosity at any of the extensional strains (for example, when the extensional strain is 8) as the index value. When determining an index value representing extensional viscosity using two or more extensional viscosity values, the average value of the multiple extensional viscosity values ​​may be taken, or a weighted average may be taken with weighting given to the more important extensional viscosity (for example, the extensional viscosity when the extensional strain is 8).

[0070] In the present invention's method for evaluating texture during swallowing, it is possible to evaluate texture during multiple swallowing stages based on the calculated extensional viscosity and extensional strain. For example, in the region where the extensional strain is 2 to 4, the maximum extensional viscosity can be determined as an index value for "cohesion," while in the region where the extensional strain is 7 or higher, the extensional viscosity at any extensional strain can be determined as an index value for "stringiness."

[0071] The extension strain value (or its range) for calculating the index value of the texture evaluation method during swallowing according to the present invention is preferably determined based on the correlation between the sensory evaluation of texture during swallowing, which has been determined in advance, and the index value. The evaluation method of the present invention is a method for predicting the results of sensory evaluation, and as long as a significant difference is obtained in the sensory evaluation, the sensory evaluation method itself is not limited in any way and can be used with any sensory evaluation method.

[0072] For sensory evaluation, a method that allows for detailed quantification of evaluation results is preferred, and the Visual Analog Scale (VAS) method is preferred as the evaluation method. Furthermore, it is preferable to have a sufficient number of subjects and to confirm that the oral sensations of all subjects have a certain level of accuracy.

[0073] The correlation can be determined by performing the steps described above to calculate extensional viscosity and extensional strain and determine index values ​​for multiple food and beverages with different textures during swallowing, as well as by performing a sensory evaluation of the same food and beverage, and then using the index values ​​and the results of the sensory evaluation. It is preferable that the conditions in each step when determining the correlation match the conditions when implementing the swallowing texture evaluation method of the present invention.

[0074] When seeking correlations between multiple food and beverage products, for example, when evaluating food and beverage products containing thickening agents, using food and beverage products with different types of thickening agents, not just varying the concentration, can lead to a more versatile method for evaluating texture during swallowing.

[0075] When determining the correlation between multiple food and beverage items, it is preferable to use two or more items, and more preferably three or more items, from the viewpoint of improving the accuracy of evaluating the texture of the food and beverage items during swallowing.

[0076] When seeking correlation, regression equations can be derived based on linear approximation, exponential approximation, logarithmic approximation, etc. For example, in Example 1, linear approximation was performed on the correlation between the maximum extensional viscosity at extensional strains 2-4 and the sensory evaluation value of "cohesion". Correlation coefficient: r = 0.944 (p < 0.05) This has been obtained. This confirms that the maximum extensional viscosity at extensional strains 2-4 is suitable as an indicator of "cohesion."

[0077] Furthermore, in Example 1, a linear approximation was performed on the correlation between extensional viscosity at extensional strain 8 and the sensory evaluation value of "stringiness". Correlation coefficient: r = 0.860 (p < 0.05) This has been obtained. This confirms that the extensional viscosity at extensional strain 8 is suitable as an indicator of "stringability".

[0078] When determining the extension strain value (or its range) for calculating an index value for a texture evaluation method during swallowing based on correlation, it is preferable to adopt a condition in which the absolute value of the correlation coefficient between the index value (extension viscosity value at a specific extension strain, etc.) and the sensory evaluation value is 0.8 or higher, more preferably 0.85 or higher, and even more preferably 0.9 or higher.

[0079] "A process for evaluating texture during swallowing." As described above, texture is evaluated using index values ​​obtained from a calculation method determined from the correlation with sensory evaluation values. That is, the texture evaluation method of the present invention includes a step of evaluating the quality of the texture of the food or beverage when swallowed, based on the determined index values. For example, a liquid sample of the candidate formulation is dispersed in ion-exchanged water and subjected to a shear rate of 50s at 25°C. -1 In the case of a dispersion whose shear viscosity is adjusted to 50-150 mPa·s, if the maximum extensional viscosity in the extensional strain range of 2-4 is 2,000 mPa·s or higher, the "cohesion" of all evaluated food and beverages is judged to be 50 or higher by the VAS method described above, i.e., good "cohesion." Furthermore, if the extensional viscosity at extensional strain 8 is 2,000 mPa·s or less, the "stringiness" of all evaluated food and beverages is judged to be less than 50 by the VAS method described above, i.e., low "stringiness," resulting in less residue in the throat.

[0080] "The process of evaluating the 'sliminess'" The present invention's method for evaluating texture during swallowing may include a step of evaluating "sliminess" from the frictional properties of food and beverages in a tribological test, based on the correlation between the frictional properties in a tribological test and the sensory evaluation, which have been determined in advance. Preferably, the tribological test involves measuring the coefficient of friction at a specific sliding speed when the rotating body is rotated while applying pressure to the food or beverage in the container, with the food or beverage interposed between the rotating body and the receiving part. Specifically, the tribological test described in the examples is an example.

[0081] Preferably, the correlation is determined by conducting tribology tests under multiple conditions and selecting the conditions that show a high correlation between the coefficient of friction and the sensory evaluation. For example, the coefficient of friction can be measured when the sliding speed is changed, and conditions that show a high correlation with the sensory evaluation of "slipperiness" can be selected. In particular, the coefficient of friction at e (i.e., 0.006 m / s), which is the point where the vehicle transitions from the "boundary lubrication region" to the "mixed lubrication region," showed a high value, making it a preferred condition for evaluating "slipperiness."

[0082] When seeking correlation, regression equations can be derived based on linear approximation, exponential approximation, logarithmic approximation, etc. For example, in Example 1, linear approximation was performed on the correlation between the coefficient of friction at a sliding speed of 0.006 m / s and the sensory evaluation value of "slippery feeling". Correlation coefficient: r = -0.895 (p < 0.05) This has been obtained.

[0083] Regarding the normal force (load) in tribology testing, a value of 0.1 to 1 N is preferable because it increases the correlation between the obtained frictional characteristics and the "slippery feeling," a value of 0.2 to 0.5 N is more preferable, and 0.3 N is the most preferable.

[0084] In the present invention, it is preferable to adopt tribological test conditions such that the absolute value of the correlation coefficient is 0.8 or higher, more preferably 0.85 or higher, and even more preferably 0.9 or higher.

[0085] Furthermore, as mentioned above, texture is evaluated using index values ​​obtained from a calculation method determined from the correlation with sensory evaluation values. For example, a liquid sample of the candidate formulation is dispersed in ion-exchanged water and subjected to a shear rate of 50s at 25°C. -1In the case of a dispersion whose shear viscosity is adjusted to 50-150 mPa·s, if the coefficient of friction at the aforementioned sliding speed of 0.006 m / s is 0.22 or higher, then the "sludgy" feel of all the food and beverages being evaluated will be judged to be less than 50 by the VAS method described above, i.e., they will be judged to have little "sludgy" feel.

[0086] "Method for manufacturing a preparation for improving the texture during swallowing" The present invention provides a method for producing a formulation for improving swallowing texture, comprising the steps of: performing the method for evaluating the swallowing texture of a food or beverage according to the present invention as described above, using a liquid sample of a candidate formulation as a food or beverage; and selecting a formulation by determining the swallowing texture of the candidate formulation based on one or more of the obtained evaluation results of "cohesion," "stringiness," or "sliminess."

[0087] In this case, it is preferable that one or more of the following criteria (a) to (c) be satisfied. (a) A liquid sample of the candidate formulation is dispersed in ion-exchanged water and sheared at 25°C at a rate of 50 s. -1 A dispersion in which the shear viscosity is adjusted to 94-106 mPa·s, and the process of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2-4 is 2,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.22 or more, as a formulation with a high effect in improving the "cohesion", "stringiness", and "sliminess", or (b) A liquid sample of the candidate formulation is dispersed in ion-exchanged water and the shear rate is 50 s at 25°C. -1 A dispersion in which the shear viscosity is adjusted to 192-208 mPa·s, and the process of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2-4 is 5,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,500 mPa·s or less, and the coefficient of friction at the sliding speed of 0.006 m / s is 0.20 or more, as a formulation with a high effect in improving the "cohesion", "stringiness", and "sliminess", or (c) A liquid sample of the candidate formulation is dispersed in ion-exchanged water and the shear rate is 50 s at 25°C. -1 The dispersion is adjusted to have a shear viscosity of 385-415 mPa·s, and the process of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2-4 is 8,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 3,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.18 or more, as a formulation that has a high effect in improving the "cohesion," "stringiness," and "sliminess."

[0088] "A preparation for improving the texture of food during swallowing" The swallowing texture improving preparation of the present invention contains a thickening polysaccharide and satisfies all of the selection criteria in the above-mentioned method for producing the swallowing texture improving preparation.

[0089] Specifically, it must satisfy one or more of the following criteria (a) to (c). (a) Disperse the candidate formulation in ion-exchanged water and set the shear rate to 50 s at 25°C. -1 For a dispersion whose shear viscosity is adjusted to 50-150 mPa·s, does it satisfy all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2-4 is 2,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.22 or more? (b) Disperse the candidate formulation in ion-exchanged water and set the shear rate to 50 s at 25°C. -1 For a dispersion whose shear viscosity is adjusted to 150-300 mPa·s, does it satisfy all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2-4 is 5,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,500 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.20 or more? (c) Disperse the candidate formulation in ion-exchanged water and set the shear rate to 50s at 25°C. -1For a dispersion whose shear viscosity is adjusted to 400-500 mPa·s, all of the following criteria are met: the maximum extensional viscosity in the extensional strain range of 2-4 is 8,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 3,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.18 or more.

[0090] Preparations for improving the texture during swallowing may also contain ingredients that affect swallowability, such as thickeners like polysaccharides, dispersants, emulsifiers, and stabilizers. Specifically, examples include one or more of the above-mentioned ingredients.

[0091] The following methods can be used to adjust the system in order to satisfy one or more of the criteria (a) to (c) above. (1) When the extensional strain preferentially increases the maximum extensional viscosity in the range of 2 to 4, for example, by adding a material with a higher potency than normal, such as heat-treated xanthan gum or high acylgellan gum, or by increasing its content. (2) In order to preferentially reduce the extensional viscosity in extensional strain 8, add materials containing insoluble dietary fiber such as citrus fiber, or polysaccharides with surfactant properties such as gum arabic, ghati gum, soybean polysaccharides, sugar beet pectin, or increase their content. (3) When preferentially increasing the coefficient of friction at a sliding speed of 0.006 m / s, remove or reduce the amount of gum arabic, soybean polysaccharides, etc., which do not produce much viscosity relative to the amount added.

[0092] Of course, by appropriately mixing elements that satisfy each parameter, it is possible to satisfy one or more of the above criteria (a) to (c) through trial and error. [Industrial applicability]

[0093] The present invention provides a simple, rapid, and objective method for evaluating the "cohesion," "residual feeling," and "sliminess" in the throat, which are important parameters of the "ease of swallowing" of food and beverages, particularly liquid food and beverages. Furthermore, the present invention can provide a method for evaluating whether a liquid composition is an easily swallowable liquid composition suitable for the elderly or those with dysphagia, using the above method. Moreover, the present invention can provide a method for selecting an easily swallowable liquid composition suitable for the elderly or those with dysphagia from among test liquid compositions, using the above method, and can provide an easily swallowable liquid composition selected by said method. [Examples]

[0094] The present invention will be described below with reference to examples, but the scope of the present invention is not limited thereto. Unless otherwise specified, "%" means "mass%".

[0095] Example 1 (Evaluation of the texture of thickening polysaccharides during swallowing) (Thickening polysaccharides) SunSupport® S-15 (San-Ei Gen F.F.I. Co., Ltd., Osaka, Japan), which is xanthan gum: XG, and SunSupport® S-21 (San-Ei Gen F.F.I. Co., Ltd., Osaka, Japan), which is locust bean gum: LBG, were used as food polysaccharides.

[0096] (Preparation of polysaccharide solution) Ten types of polysaccharide solutions were used: XG dispersions with concentrations of 0.2%, 0.4%, 0.6%, 0.8%, or 1.0%, and LBG solutions with concentrations of 0.3%, 0.4%, 0.45%, 0.5%, or 0.55%. 200g of deionized water was placed in a glass beaker and heated to 80°C. While stirring at 1,000 rpm using a 60mm diameter, four-bladed propeller, 0.4g, 0.8g, 1.2g, 1.6g, or 2.0g of XG, or 0.6g, 0.8g, 0.9g, 1.0g, or 1.1g of LBG were added. After heating and stirring for 10 minutes to dissolve, the dispersion weight was adjusted to 200g by correcting for evaporation with deionized water, and then cooled in a 20°C water bath. XG dispersions with polysaccharide concentrations of 0.2%, 0.4%, 0.6%, 0.8%, or 1.0% (hereinafter referred to as XG solutions; each concentration of XG solution will be referred to as X-1, X-2, X-3, X-4, and X-5 in order) or LBG dispersions with concentrations of 0.3%, 0.4%, 0.45%, 0.5%, or 0.55% (hereinafter referred to as LBG solutions; each concentration of LBG solution will be referred to as L-1, L-2, L-3, L-4, and L-5 in order) were prepared. These polysaccharide solutions were stored overnight at 5°C and then heated to 25°C in a constant temperature water bath before use, immediately before the rheological, tribological, and sensory evaluations described below.

[0097] (Shear viscosity measurement) The steady-state flow viscosity and dynamic viscoelasticity of beverage samples at 25°C were measured using a fluid rheometer ARES-LS1 (TA Instruments, DE, US). A 50 mm diameter resin cone-plate plunger was used with a gap of 0.05 mm, and the strain rate was set to 0-50 s. -1 It increases linearly over 1 minute, 50s -1 The steady-state flow viscosity was measured after the flow was stabilized at a constant velocity for one minute after reaching the target point.

[0098] (Extensional viscosity measurement (CaBER1 measurement)) The extensional rheology of the polysaccharide solution was measured at 25°C using an extensional viscometer CaBER1 (Thermo Haake GmbH, Karlsruhe, Germany). The principle of this method involves loading the sample between two 4mm diameter plates, positioned parallel to each other with an initial gap of 1mm, using a plastic pipette. The upper plate is then linearly stretched for 50ms to a final gap of 4.1mm. The polysaccharide solution is stretched by the plates, but then flows due to its own surface tension, forming hemispherical droplets. During this process, it contracts into a filament, and the solution between the plates shrinks into a filamentous structure. The diameter of the filament at the midpoint of the final gap between the two plates (D) is measured. mid The initial diameter D0 (=4mm) at time t0 (when the top plate starts moving) is measured using laser light, and the time t until the filament breaks is calculated from the initial diameter D0 (=4mm) at time t0 (when the top plate starts moving). b Measurements were taken continuously until the filament broke. The measurement was repeated five times for each polysaccharide solution.

[0099] Extensional viscosity of polysaccharide solution η E This can be calculated using equation (1), derived by McKinley and Tripathi, from the filament shrinkage behavior after the upper plate reaches the final gap.

[0100]

number

[0101] Here, σ is the surface tension of the polysaccharide solution, D mid (t) θ is the filament diameter at time t, and X is a geometric coefficient. This X is a coefficient that takes into account the shape of the filament during contraction due to inertial and gravitational effects, and it has been experimentally shown that X = 0.7127 is an appropriate value for highly viscous fluids.

[0102] The differential approximation of the diameter at the midpoint of the filament was calculated from equation (2).

[0103]

number

[0104] Here, t i is the measurement point (time) closest to any time t, and t i-1 is, t i This is the measurement point immediately preceding D. mid (t i ), D mid (t i-1 ) represents the filament diameter at each measurement point.

[0105] Furthermore, the extension strain ε (Hencky strain) was calculated from equation (3).

[0106]

number

[0107] The surface tension of each polysaccharide solution was measured at 25°C using a high-performance surface tension measuring device DY-500 (Kyowa Interface Science Co. Ltd, Saitama, Japan). The measurement was repeated three times, and the average value was taken as the surface tension σ of each polysaccharide solution.

[0108] (Measurement of friction coefficient) For measuring the coefficient of friction, a Modular compact rheometer MCR302 (Anton Paar GmbH, Graz, Austria) equipped with a tribology measurement device (setup) was used. As shown in Figures 1A and 1B, this device has a base surface with three cylindrical polydimethylsiloxane (PDMS) pins 2 with a diameter of 6 mm arranged in an inverted cone-shaped container 1 with a diameter of 20 mm and a vertex angle of 90° (only two pins 2 are visible in Figure 1B, but there is actually another pin 2 further inside). A 1 ml polysaccharide solution was placed in this cone-shaped container 1, and a plunger 4 fitted with a spherical ground glass 3 with a diameter of 12.7 mm was pressed vertically from above against the PDMS pins 2, applying a vertical load (F NA force of 0.3N was applied, and the plunger 4 was rotated around its handle as the axis of rotation. Temperature: 25℃, sliding speed: 10 -7 The coefficient of friction was measured three times when the machine was rotated at approximately 1 m / s, and the third measurement was used.

[0109] (Sensory evaluation) Twelve healthy dentitioned individuals (8 males, 4 females, mean age 32.3 ± 5.4 years) were included as subjects. First, 10 ml of polysaccharide solution was poured into the floor of each subject's mouth in a randomized order using a 20 ml syringe (Terumo Corporation, Tokyo, Japan). The subjects were instructed to swallow the entire volume in one gulp without chewing, and were asked to identify the XG and LBG solutions in order of decreasing viscosity. It was confirmed that all subjects provided the correct answers. This trial confirmed that all subjects possessed a certain degree of accuracy in their oral sensation and that all samples exhibited discriminable physical differences in viscosity.

[0110] Next, subjects were asked to subjectively evaluate the texture of polysaccharide solutions, specifically "cohesion," "stringiness," and "sliminess," after swallowing them using the same method as described above. The Visual Analog Scale (VAS) method was used for evaluation. Specifically, each subject was given a sheet with a 100mm long line segment drawn on it, where the left end was defined as the minimum sensory evaluation value and the right end as the maximum sensory evaluation value. They were asked to mark the point on the line segment corresponding to their evaluation of each polysaccharide solution, and the distance from the left end was measured in units of 1mm. This distance was defined as the texture evaluation value (VAS value, dimensionless) for each sample.

[0111] In this study, foods that flow as a single mass when passing through the throat were defined as having high cohesion, foods that leave a residue in the oral cavity and throat were defined as having high stringiness, and foods that provide a slippery sensation in the oral cavity and throat were defined as having high sliminess. Each subject was given one trial for sensory evaluation of one sample. In terms of texture during swallowing, foods with high cohesion, low stringiness, and low sliminess are considered preferable.

[0112] (Results for shear viscosity and extensional viscosity) Shear rate of each polysaccharide solution: 50s-1 Table 1 shows the shear viscosity at , the maximum extensional viscosity value at extensional strains 2-4, and the extensional viscosity at extensional viscosity 8.

[0113] [Table 1]

[0114] For both XG and LBG, the shear viscosity increased with increasing concentration. Of the polysaccharide solutions used in this study, the steady-state flow viscosities of the five pairs of beverage samples—X-1 and L-1, X-2 and L-2, X-3 and L-3, X-4 and L-4, and X-5 and L-5—were all approximately the same.

[0115] Figure 2 shows the dependence of extensional viscosity on extensional strain (Hencky strain). (a) shows the results for the XG solution using xanthan gum, and (b) shows the results for the LBG solution using locust bean gum. As shown in Figure 2, a positive peak was observed in all polysaccharide solutions between extensional strains 2 and 4, followed by a decrease in viscosity, with a bottom in viscosity reduction between extensional strains 4 and 6. Subsequently, the extensional viscosity increased with increasing extensional strain until the filament broke. The maximum extensional viscosity values ​​for extensional strains 2 to 4 increased in a concentration-dependent manner for both the XG and LBG solutions, but when comparing solutions with similar shear viscosities, the XG solution tended to have a higher extensional viscosity. The extensional viscosity at extensional strain 8 also increased in a concentration-dependent manner, but when comparing solutions with similar shear viscosities, the LBG solution tended to have a higher extensional viscosity.

[0116] (Results of the coefficient of friction) Figure 3 shows the dependence of the coefficient of friction of XG and LBG solutions on sliding speed. (a) shows the results for the XG solution using xanthan gum, and (b) shows the results for the LBG solution using locust bean gum. This graph is called the Stribeck curve and shows the interaction between PDMS as a flooring material, frosted glass balls as plungers, and polysaccharide solutions.

[0117] The symbols a to f are also added to this graph for explanatory purposes. The coefficient of friction for all concentrations of XG solution is the sliding speed 1 × 10⁻⁶ -7 From approximately 4 x 10 -6 It rises sharply in m / s (ab region), and then increases by approximately 6 × 10⁻⁶. -5 There is a region where the increase or decrease is small up to m / s (bc region), and then approximately 5 × 10 -4 It drops to m / s (cd region), and then further to 6 × 10 -3 After rising to m / s (de region), it showed a tendency to rapidly decrease to 1 m / s (ef region).

[0118] On the other hand, the coefficient of friction of the LBG solution is 1 × 10⁻⁶ of the sliding speed. -7 From approximately 6 x 10 -5 The rate increases more slowly in m / s (ab region) than in the case of XG solution, and then increases by approximately 3 × 10⁻⁶. -4 There is a region where the increase or decrease is small up to m / s (bc region), and then approximately 1 × 10⁻⁶ -3 It increases to m / s (cd region), and then further increases to 6 × 10 -3 After a region where there was little increase or decrease up to m / s (de region), it showed a tendency to decrease sharply down to 1 m / s (ef region).

[0119] Furthermore, similar to the XG solution, a decrease in the coefficient of friction was observed as the LBG concentration increased across almost the entire shear velocity range. The coefficient of friction at the point where the region in the figure changes (be) is shown in Table 2. In addition, a decrease in the coefficient of friction was observed as the concentrations of XG and LBG increased across the entire shear velocity range of be.

[0120] [Table 2]

[0121] (Results of sensory evaluation) Table 3 shows the sensory evaluation values ​​for each texture—"cohesion," "stringiness," and "sliminess"—when 12 subjects swallowed a polysaccharide solution.

[0122] [Table 3]

[0123] The "cohesion" of the XG solution was generally higher than that of the LBG solution. Furthermore, the "cohesion" of the XG solution tended to increase with increasing concentration. On the other hand, the "cohesion" of the LBG solution was generally lower than that of the XG solution, and no consistent trend was observed. The "stringiness" of both the XG and LBG solutions tended to increase in a concentration-dependent manner, but the LBG solution showed a larger value than the XG solution at all concentrations. The "sludgy" of both the XG and LBG solutions also tended to increase in a concentration-dependent manner, but the rate of increase decreased as the concentration increased.

[0124] (Correlation between sensory evaluation and elongation rheology) Figure 4 shows a scatter plot illustrating the correlation between the maximum extensional viscosity and the sensory evaluation value of "cohesion" for each polysaccharide solution at extensional strains 2-4 in extensional viscosity measurements using CaBER1. The correlation coefficient was found to be very high, r=0.944 (p<0.05). In extensional viscosity measurements using CaBER1, there is a region where the filament contraction rate decreases after forced displacement by the plunger, and this is observed as an increase in extensional viscosity at extensional strains 2-4. When humans swallow, the tongue sends the solution to the pharynx, which forcibly displaces the solution. It is expected that the decrease in fluidity at this time, i.e., the increase in extensional viscosity, is perceived by the subject as the "cohesion" of the solution.

[0125] Furthermore, the viscosity of the LBG solution, which was generally evaluated as having high "stringiness" in sensory evaluation, tended to be higher in the high extension strain (8 or higher) region compared to the XG solution. Table 4 shows the correlation between the extensional viscosity value and the sensory evaluation value of "stringiness" for the total polysaccharide solution at extension strains of 3 to 9.

[0126] [Table 4]

[0127] "Stringiness" was found to have a high correlation with extensional viscosity in the high-strain region, with the highest correlation coefficient being r=0.860 (p<0.05) at extensional strain 8. Figure 5 shows a scatter plot illustrating the correlation between extensional viscosity at extensional strain 8 and the sensory evaluation value of "stringiness".

[0128] From the above results, it was confirmed that by using a capillary fracture type extensional viscometer to measure the diameter of the liquid filament over time at 25°C, calculating the extensional viscosity and extensional strain from the rate of change of the diameter, determining the maximum extensional viscosity at extensional strains of 2 to 4, and using this as an indicator of "cohesion," and determining the extensional viscosity at any one point above extensional viscosity 7, and using this as an indicator of "stringiness."

[0129] (Correlation between sensory evaluation and tribology) Table 5 shows the correlation between the coefficient of friction and the "slippery feeling" at points b to e in Figure 3.

[0130] [Table 5]

[0131] A high negative correlation was observed between "slipperiness" and the coefficient of friction at all points, but the correlation coefficient at point e (i.e., 0.006 m / s), which is the point of transition from the "boundary lubrication region" to the "mixed lubrication region," showed the highest value at r = -0.895 (p < 0.05). Figure 6 shows a scatter plot illustrating the correlation between the coefficient of friction at e (i.e., 0.006 m / s) and the sensory evaluation value of "slipperiness."

[0132] It is thought that humans perceive the lubricating effect of polysaccharide solutions as "sliminess" because a certain amount of the solution penetrates between the tongue and palate, forming a film that reduces the surface roughness of biological tissue. In other words, it was confirmed that "sliminess" is highly correlated with the coefficient of friction at the point of transition from the "boundary lubrication region" to the "mixed lubrication region," and that this can be used as an indicator to evaluate the texture of polysaccharide solutions and liquid foods containing them.

[0133] Example 2 (Evaluation of the texture of commercially available thickening food solution during swallowing) (Preparation of thickening agent for food solutions) Using five major commercially available thickening agents (a-e, all granular products primarily intended for use by individuals with swallowing difficulties, and using xanthan gum as the main thickening ingredient), a thickening agent solution was prepared without the formation of lumps by adding the thickening agent to 100g of deionized water while stirring by hand at a speed of 4 rotations per second until the weight of the thickening agent listed in Table 6 was reached, and then stirring at the same speed for 30 seconds.

[0134] [Table 6]

[0135] (Sensory evaluation, measurement of shear viscosity, extensional viscosity, and friction coefficient) Each of the above-mentioned thickening food solutions was left to stand in a 25°C constant temperature bath, and after 30 minutes, the shear viscosity, extensional viscosity, and friction coefficient were measured using the same method as in Example 1. Sensory evaluation of each thickening food solution was also performed using the same method as in Example 1, and the results (VAS values) are listed in Table 7 along with the shear viscosity.

[0136] [Table 7]

[0137] Thickening food solution a-1~e-1 50s -1 The shear viscosity in all samples was approximately 100 mPa·s. Using a VAS value of 50 as the baseline for sensory evaluation, a higher value (i.e., 50 or higher) indicates better "cohesion," while lower values ​​(i.e., less than 50) indicate a better texture for "stringiness" and "sliminess." For example, a-1 was evaluated as having good "sliminess," but not good "cohesion" or "stringiness." In Table 7, the sensory evaluation values ​​for each texture that were good are shown in bold.

[0138] Also, the sliding speed of the thickening food solution was 50s.-1 Table 8 shows the shear viscosity at 0, the maximum extensional viscosity at extensional strains of 2-4, the extensional viscosity at extensional strain 8, the coefficient of friction at a sliding velocity of 0.006 m / s, and the characteristics of the texture of each solution.

[0139] [Table 8]

[0140] Here, the thickening agent for the food is measured at 25°C and a shear rate of 50s. -1 For dispersions (a-1 to e-1) whose shear viscosity is adjusted to 50 to 150 mPa·s, the maximum extensional viscosity in the extensional strain range of 2 to 4 is 2,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.22 or more. Furthermore, for the dispersion (a-2 to e-2) whose shear viscosity is adjusted to 150 to 300 mPa·s, the maximum extensional viscosity in the extensional strain region of 2 to 4 is 5,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,500 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.20 or more. Furthermore, for dispersions (a-3 to e-3) whose shear viscosity was adjusted to 300 to 500 mPa·s, if the maximum extensional viscosity in the extensional strain range of 2 to 4 was 8,000 mPa·s or higher, the extensional viscosity at extensional strain 8 was 3,000 mPa·s or lower, and the coefficient of friction at a sliding speed of 0.006 m / s was 0.18 or higher, the respective measured values ​​in Table 8 were indicated in bold. In addition, in the sensory evaluation (Table 7), if the "cohesion" was judged to be good, a circle was added to the right of the measured value of "maximum extensional viscosity at extensional strain 2 to 4"; if the "stringability" was judged to be good, a circle was added to the right of the measured value of "extensional viscosity at extensional strain 8"; and if the "slipperiness" was judged to be good, a circle was added to the right of the measured value of "coefficient of friction at sliding speed of 0.006 m / s". The bolded sections and circled items in this table are identical, confirming that the quality of the texture of food and beverages can be clearly estimated by the extensional viscosity or friction parameters defined for each shear viscosity range.

[0141] Example 3 (Preparation of a formulation for improving the texture during swallowing) In Example 2, the same thickening food a or e was used, and heat-modified xanthan gum was added in the amounts shown in Table 9. This was then added to 100g of deionized water while stirring by hand at a speed of 4 rotations per second. After that, the mixture was stirred at the same stirring speed for 30 seconds to prepare thickening food solutions A-1 to A-3 without the formation of lumps. The sliding speed of this thickening food solution A-1 was 50s. -1 The shear viscosity was 100.5 mPa·s (target value 94-106 mPa·s). The preparation methods for heat-treated xanthan gum and heat-modified xanthan gum (with metaphosphate added) are shown below.

[0142] <Thermal-modified xanthan gum> Xanthan gum (SunSupport [registered trademark] P-180, San-Ei Gen F.F.I. Co., Ltd., Osaka, Japan) was supplied to the hopper of a twin-screw extruder at a raw material feed rate of 10 g / min. Furthermore, the extruder process was carried out while adding ion-exchanged water (20°C) at a rate of 20 g / min.

[0143] The extruder used had 8 barrels (including the discharge port), a screw diameter of 11 mm, and a circular discharge nozzle with a hole diameter of 2.0 mm. The temperature of each barrel was set to 70°C for the barrel closest to the hopper and 90°C for the barrel on the discharge nozzle side, which included the mixing section. The screw rotation speed was adjusted to 150 rpm, and the mixing time was 60 seconds. The heated molten mixture obtained from the discharge nozzle was collected and dried at 60°C for 20 hours. After drying, it was pulverized using a small high-speed pulverizer (Wonder Blender WB-1, manufactured by Osaka Chemical Co., Ltd.), and pulverized material (150-250 μm) with a 60-mesh pass and 100-mesh on was collected.

[0144] <Thermally modified xanthan gum (with metaphosphate added)> Xanthan gum (SunSupport [registered trademark] P-180, San-Ei Gen F.F.I. Co., Ltd., Osaka, Japan) was supplied to the hopper of a twin-screw extruder at a raw material feed rate of 10 g / min. Furthermore, the extruder process was carried out while adding 20 g / min of water (20°C) containing 5% by mass of sodium hexametaphosphate.

[0145] The extruder equipment used (barrel, screw diameter, discharge nozzle shape), temperature settings for each barrel, screw rotation speed, mixing time, drying, sieving, and recovery processes were the same as those used for the previously processed thermally modified xanthan gum.

[0146] [Table 9]

[0147] Thickening food solutions A-1 to E-3 were left to stand in a constant temperature bath at 25°C, and after 30 minutes, the shear viscosity, extensional viscosity, and friction coefficient were measured using the same method as in Example 1, and the results are summarized in Table 10. Furthermore, similar to Table 8, for dispersions (A-1, E-1) with shear viscosity adjusted to 50-150 mPa·s, the maximum extensional viscosity in the extensional strain range of 2-4 was 2,000 mPa·s or higher, the extensional viscosity at extensional strain 8 was 2,000 mPa·s or lower, and the friction coefficient at a sliding velocity of 0.006 m / s was 0.22 or higher. The dispersion (A-2, E-2) whose shear viscosity is adjusted to 150-300 mPa·s has a maximum extensional viscosity of 5,000 mPa·s or more in the extensional strain range of 2-4, an extensional viscosity at extensional strain 8 of 2,500 mPa·s or less, and a coefficient of friction of 0.20 or more at a sliding speed of 0.006 m / s. For dispersions (A-3, E-3) whose shear viscosity was adjusted to 300-500 mPa·s, if the maximum extensional viscosity in the extensional strain range of 2-4 was 8,000 mPa·s or more, the extensional viscosity at extensional strain 8 was 3,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s was 0.18 or more, the respective measured values ​​in Table 10 are shown in bold.

[0148] Furthermore, for the sensory evaluation values ​​evaluated using the same method as in the examples, a circle (○) was added to the right of the measured value of "maximum extensional viscosity at extensional strain 2-4" when it was judged that the "cohesion" was good (VAS value of 50 or higher), to the right of the measured value of "extensional viscosity at extensional strain 8" when it was judged that the "stringiness" was good (VAS value of less than 50), and to the right of the measured value of "coefficient of friction at sliding speed of 0.006 m / s" when it was judged that the "slippery feel" was good (VAS value of less than 50).

[0149] [Table 10]

[0150] In Example 3, all of the thickening food solutions (A-1 to E-3) prepared showed that the maximum extensional viscosity in the extensional strain range of 2 to 4, the extensional viscosity at extensional strain 8, and the coefficient of friction at a sliding speed of 0.006 m / s all fell within the aforementioned ranges. Furthermore, all of the thickening food solutions exhibited excellent texture, being well-structured, with little stringiness (residual feeling) that clings to the throat, and little unpleasant sliminess in the oral cavity.

Claims

1. A process of adjusting the viscosity of food and beverages to a constant or nearly constant shear viscosity by diluting or adding thickening agents, A step of measuring the filament diameter of the viscosity-adjusted food or beverage over time using a capillary fracture type extensional viscometer, and calculating the extensional viscosity and extensional strain from the change in the filament diameter, A step of determining an index value that represents the extensional viscosity in a region where the extensional strain falls within a specific range, A method for evaluating the texture of food or beverages during swallowing, comprising the step of evaluating the quality of the texture of the food or beverages during swallowing based on the determined index value.

2. The method for evaluating texture during swallowing according to claim 1, wherein the specific range of extensional strain for determining the index value is determined by the correlation between a pre-determined sensory evaluation of texture during swallowing and the extensional viscosity in the extensional strain.

3. The method for evaluating the texture of food or beverages during swallowing according to claim 1, wherein the step of determining the index value is to determine the maximum extension viscosity in the region where the extension strain is 2 to 4 as the index value, and the texture to be evaluated during swallowing is "cohesion".

4. The method for evaluating the texture of food or beverages during swallowing according to claim 1, wherein the step of determining the index value is to determine the extension viscosity at any extension strain in the region where the extension strain is 7 or more as the index value, and the texture during swallowing to be evaluated is "stringy".

5. The method for evaluating the texture of food and beverages during swallowing according to claim 1, wherein the step of determining the index value is to determine the maximum extension viscosity in the region of extension strain 2 to 4 as the index value for "cohesion," and to determine the extension viscosity at any extension strain in the region of extension strain 7 or more as the index value for "stringiness," and the texture during swallowing that is evaluated is "cohesion" and "stringiness."

6. Furthermore, the method for evaluating the texture of food and beverages during swallowing according to any one of claims 1 to 5, further comprising the step of evaluating the "sliminess" from the friction characteristics of the food and beverages in tribological tests, based on the correlation between the friction characteristics in tribological tests and sensory evaluation determined in advance.

7. The method for evaluating the texture of food or beverages when swallowed, according to claim 6, wherein the tribology test measures the coefficient of friction at a specific sliding speed when the rotating body is rotated while applying pressure to the food or beverages in the container, interposed between the rotating body and the receiving part.

8. The step of performing the method for evaluating the texture of food or beverages during swallowing according to any one of claims 1 to 7, using a liquid sample of a candidate formulation as the food or beverage, A method for producing a formulation for improving swallowing texture, comprising the step of selecting a formulation by determining the texture of the candidate formulation during swallowing based on one or more of the obtained evaluation results of "cohesion," "stringiness," or "sliminess."

9. The liquid sample of the candidate formulation was dispersed in ion-exchanged water and measured at a shear rate of 50 s at 25°C. －１ A dispersion liquid in which the shear viscosity is adjusted to 50 to 150 mPa·s. The method for producing a swallowing texture-improving formulation according to claim 8, wherein the step of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain region of 2 to 4 is 2,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,000 mPa·s or less, and the coefficient of friction at the sliding speed of 0.006 m / s is 0.22 or more, as a formulation with a high effect in improving the "cohesion," "stringiness," and "sliminess."

10. The liquid sample of the candidate formulation was dispersed in ion-exchanged water and measured at a shear rate of 50 s at 25°C. －１ A dispersion liquid in which the shear viscosity is adjusted to 150 to 300 mPa·s. The method for producing a swallowing texture-improving formulation according to claim 8, wherein the step of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain region of 2 to 4 is 5,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 2,500 mPa·s or less, and the coefficient of friction at the sliding speed of 0.006 m / s is 0.20 or more, and is selected as a formulation with a high effect in improving the "cohesion," "stringiness," and "sliminess."

11. The liquid sample of the candidate formulation was dispersed in ion-exchanged water and measured at a shear rate of 50 s at 25°C. －１ A dispersion in which the shear viscosity is adjusted to 300-500 mPa·s. The method for producing a swallowing texture-improving formulation according to claim 8, wherein the step of selecting the formulation is to select a formulation that satisfies all of the following criteria: the maximum extensional viscosity in the extensional strain range of 2 to 4 is 8,000 mPa·s or more, the extensional viscosity at extensional strain 8 is 3,000 mPa·s or less, and the coefficient of friction at a sliding speed of 0.006 m / s is 0.18 or more, as a formulation with a high effect in improving the "cohesion," "stringiness," and "sliminess."

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