Liquid nutritional composition

Abstract

To provide a liquid nutritional composition that uses only plant-derived protein as a protein source, has high emulsification stability, and possesses a rich, milky flavor. [Solution] A liquid nutritional composition containing (A) a plant protein having a water-soluble nitrogen index (NSI) of 75 or higher and a TCA solubilization rate of 5% or less, and (B) a plant protein having a water-soluble nitrogen index (NSI) of 40 or higher and a TCA solubilization rate of 10% or higher and 20% or less, wherein the total content ratio of component (A) and component (B) is 3% by mass or higher and 14% by mass or lower.

Description

Technical Field

[0001] The present invention relates to a liquid nutritional composition.

Background Art

[0002] Protein is one of the three major nutrients and is a major component of various parts of the human body, including muscles, skin, nails, hair, and internal organs. Until not so long ago, the image of protein was strongly associated with what top athletes drank for muscle enhancement purposes, and it was mostly in powder form. However, in recent years, it has been increasingly used in the diets of the general public and the light layer, and its reach has been expanding. Along with this, there has been an increase in products of various forms of protein supplements, such as bar forms and jelly forms like baked confectionery and nougat, and many products appealing for protein can now be seen even in convenience stores. Among them, the RTD (Ready to Drink) form is a beverage that has already been prepared and can be drunk simply by pointing a straw. Due to this convenience of drinking, the RTD form is highly popular.

[0003] For such products that appeal for protein, milk-derived proteins (casein, whey protein) are used as protein sources from the nutritional perspective of containing essential amino acids in a well-balanced manner, the sensory perspective of having a good flavor, and the physical property perspective of having high emulsification stability.

[0004] On the other hand, there is a claim that in the world, there is a possibility of a so-called "protein crisis" where the balance between the demand and supply of protein for the future population will collapse. For sustainable food supply, an alternative from animal-derived proteins with a large environmental impact to plant-derived proteins with a small environmental impact is required. In response to this, in recent years, the development of foods using plant-derived proteins has been active, and the issue has become how to approximate the flavor and physical properties of foods using animal-derived proteins. Considering products in the RTD form, soy milk can be cited as a representative product using plant-derived proteins, but compared to milk, it has no richness and has a thin flavor.

[0005] Patent Document 1 describes how a rich flavor is achieved by combining milk-derived raw materials such as milk fat and milk protein with plant-derived raw materials such as vegetable oil and plant-derived protein. Patent Document 2 describes how a rich flavor is achieved by adding sulfites to a beverage containing plant-derived protein. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-107243 [Patent Document 2] Japanese Patent Publication No. 2023-129216 [Overview of the project] [Problems that the invention aims to solve]

[0007] In Patent Document 1, although the flavor is good, animal-derived protein is essential, making it difficult to produce a product with good flavor using only plant-derived protein, and the protein content is also low. In Patent Document 2, although the flavor is good, salts are added, resulting in poor emulsification stability and a low protein content.

[0008] As described above, it was difficult to achieve an RTD (Ready-to-Drink) beverage that uses only plant-derived protein as a protein source, has high emulsification stability, and possesses a rich, milky flavor.

[0009] The object of the present invention is to provide a liquid nutritional composition that uses only plant-derived protein as a protein source, has high emulsification stability, and possesses a rich, milky flavor. [Means for solving the problem]

[0010] The present invention is as follows: [1] A liquid nutritional composition containing (A) a plant protein having a water-soluble nitrogen index (NSI) of 75 or higher and a TCA solubilization rate of 5% or less, and (B) a plant protein having a water-soluble nitrogen index (NSI) of 40 or higher and a TCA solubilization rate of 10% or higher and 20% or less, wherein the total content ratio of component (A) and component (B) is 3% by mass or higher and 14% by mass or lower. [Effects of the Invention]

[0011] The liquid nutritional composition of the present invention uses only plant-derived protein as a protein source, has high emulsification stability, and possesses a rich, milky flavor.

[0012] The present invention provides a liquid nutritional composition with high emulsification stability and a rich, milky flavor by combining specific amounts of plant proteins with different water-soluble nitrogen index (NSI) and TCA solubilization rates, such as (A) a plant protein with a water-soluble nitrogen index (NSI) of 75 or higher and a TCA solubilization rate of 5% or less (hereinafter also simply referred to as "protein (A)"), and (B) a plant protein with a water-soluble nitrogen index (NSI) of 40 to 60 and a TCA solubilization rate of 10% to 20% (hereinafter also simply referred to as "protein (B)"). The mechanism is not clearly understood, but the following is considered possible.

[0013] A liquid nutritional composition containing only plant protein (A) with a water-soluble nitrogen index (NSI) of 75 or higher and a TCA solubilization rate of 5% or less has high water solubility and resistance to heat denaturation, resulting in high emulsification stability, but it does not have the rich, milky flavor. On the other hand, a liquid nutritional composition containing only plant protein (B) with a water-soluble nitrogen index (NSI) of 40 to 60 and a TCA solubilization rate of 10% to 20% has low emulsification stability because the plant protein is prone to aggregation, and it does not have the rich, milky flavor. In contrast, a liquid nutritional composition containing both plant protein (A) and plant protein (B) exhibits high emulsification stability. By using plant protein (A) and plant protein (B) in combination, the aggregated plant protein (B) was stabilized by electrostatic or hydrophobic interactions between the different plant proteins, resulting in a nutritional composition with high emulsification stability.

[0014] Furthermore, while plant-based protein (A) and plant-based protein (B) alone do not produce a milky richness, using both plant-based protein (A) and plant-based protein (B) together creates a milky richness. By creating two peaks with different particle sizes in the particle size distribution graph, the smaller particle size plant-based protein passes through the taste pores quickly, allowing the flavor to be perceived immediately after drinking, while the larger particle size plant-based protein passes through the taste pores more slowly, allowing the flavor to be perceived several seconds after drinking. This allows for a longer-lasting flavor experience, resulting in a milky richness.

[0015] As described above, the liquid nutritional composition of the present invention is obtained by using a combination of a plant protein (A) that is highly water-soluble and has a low degree of decomposition, and a plant protein (B) that is less water-soluble and has a high degree of decomposition, thereby obtaining a liquid nutritional composition with high emulsification stability and a rich, milk-like flavor. [Modes for carrying out the invention]

[0016] <Liquid Nutritional Composition> The present invention will be described in more detail below. The liquid nutritional composition of the present invention contains (A) a plant protein having a water-soluble nitrogen index (NSI) of 75 or higher and a TCA solubilization rate of 5% or less, and (B) a plant protein having a water-soluble nitrogen index (NSI) of 40 or higher and a TCA solubilization rate of 10% or higher and 20% or less, wherein the total content ratio of component (A) and component (B) is 3% by mass or higher and 14% by mass or lower.

[0017] <Plant-based protein> The liquid nutritional composition of the present invention is characterized by containing plant protein (A) and plant protein (B). Examples of raw materials for the plant protein of the present invention include isolated plant protein, granular plant protein, and hydrolyzed plant protein (hydrolyzed plant protein, plant peptides), obtained by crushing plants, removing fiber, adding acid to the resulting sap to precipitate, neutralizing, and drying the mixture. The plant protein-containing material contains not only plant protein but also water, lipids, carbohydrates, ash, etc. The plant protein-containing material used in the present invention is preferably not hydrolyzed, and more preferably is isolated plant protein. The source raw material for the plant protein of the present invention is not particularly limited and can be any plant protein that can be used for food purposes, such as soybeans, peas, wheat, broad beans, rice, almonds, peanuts, edamame, chickpeas, etc. In particular, soybeans and peas are preferred from the standpoint of emulsification and flavor.

[0018] <Plant-based protein (A) and plant-based protein (B)> <Water Soluble Nitrogen Index (NSI)> NSI indicates the amount of water-soluble nitrogen relative to the total nitrogen content. In other words, it is an indicator of the water solubility of plant proteins; the higher the water solubility, the greater the amount of water-soluble nitrogen, and therefore the higher the NSI. It is also known that water-soluble proteins become insoluble when they are denatured. Insolubilization reduces the amount of water-soluble nitrogen, resulting in a lower NSI. Therefore, NSI can also be an indicator of the degree of denaturation of plant proteins. In this invention, by using two or more types of plant proteins with different NSIs in combination, the average particle size tends to be smaller, the emulsification stability tends to be higher, and a milky richness is more easily perceived. Plant protein (A) is preferably soluble in water, has an NSI of 75 or higher, is preferably soluble in water, has a small average particle size, has high emulsification stability, and a milky richness is more easily perceived. Preferably, NSI is between 78 and 100. The plant protein (B) is preferably NSI of 40 to 60, as this provides moderate water solubility, tends to result in smaller average particle size, higher emulsification stability, and a richer, milk-like flavor. Preferably, it is 40 to 55, and more preferably 46 to 55.

[0019] <0.22M trichloroacetic acid (TCA) solubilization rate> The TCA solubilization rate indicates the solubility of vegetable protein in 0.22 M trichloroacetic acid (TCA). As protein hydrolysis progresses, it becomes easier to dissolve in TCA, so the value of the TCA solubilization rate increases. Therefore, the TCA solubilization rate is an index indicating the degree of degradation. When protein degradation progresses, it may be denatured by heat during the production (formulation, sterilization) of the liquid nutritional composition, leading to poor physical properties. In the present invention, by using two or more types of vegetable proteins with different TCA solubilization rates in combination, it becomes easier to feel a milky texture. Vegetable protein (A) preferably has a TCA solubilization rate of 5% or less. Since the degree of degradation is small, it is difficult to denature by heat, the average particle size tends to be small, the emulsification stability tends to be high, and it is preferable because it becomes easier to feel a milky texture, and preferably 3% or less. Vegetable protein (B) preferably has a TCA solubilization rate of 10% or more and 20% or less. Since it has an appropriate degree of degradation, the average particle size tends to be small, the emulsification stability tends to be high, and it is preferable because it becomes easier to feel a milky texture, preferably 14% or more and 20% or less, and more preferably 15% or more and 18% or less.

[0020] The total content ratio of vegetable protein (A) and vegetable protein (B) contained in the liquid nutritional composition of the present invention is 3.0% by mass or more and 14.0% by mass or less. By setting it within this range, the average particle size tends to be small, the emulsification stability tends to be high, and it becomes easier to feel a milky texture. More preferably, it is 5.0% by mass or more and 12.0% by mass or less.

[0021] The mass ratio of vegetable protein (A) and vegetable protein (B) contained in the liquid nutritional composition of the present invention is preferably (A):(B) of 1:5 to 5:1. By setting it within this range, it becomes easier to feel a milky texture. More preferably, it is 1:2 to 2:1.

[0022] The liquid nutritional composition of the present invention contains water. Examples of water include tap water (municipal water), well water, spring water, groundwater, hard water, soft water, natural water, mineral water, deep ocean water, etc. As long as it is water that can be used for food, it is not particularly limited and can be used. In the liquid nutritional composition, the amount of water is preferably 80% by mass or more and 97% by mass or less, more preferably 86% by mass or more and 97% by mass or less.

[0023] <Liquid oil and fat> It is preferable that the liquid nutritional composition of the present invention contains liquid oil and fat. By containing liquid oil and fat, the viscosity tends to be lowered, precipitation is less likely to occur, and the emulsification stability of vegetable protein tends to be improved. The liquid oil and fat used in the liquid nutritional composition of the present invention is an oil and fat that is liquid at normal temperature and has a structure in which three fatty acids are ester-bonded to a glycerin backbone. Examples include soybean oil, rapeseed oil, corn oil, safflower oil, edible sunflower oil, sesame oil, cottonseed oil, medium-chain fatty acid oil (MCT), rice bran oil, olive oil, coconut oil, perilla oil, fish oil, etc. As long as it is a liquid oil and fat that can be used for food, it is not particularly limited and can be used.

[0024] In the liquid nutritional composition of the present invention, when containing liquid oil and fat, the liquid oil and fat is preferably 0.1% by mass or more and 7.0% by mass or less. More preferably, it is 0.5% by mass or more and 6.0% by mass or less, and most preferably 1.0% by mass or more and 6.0% by mass or less. When the liquid oil and fat is within this range, the viscosity tends to be lowered, precipitation is less likely to occur, and the emulsification stability of vegetable protein tends to be improved.

[0025] <Emulsifier> It is preferable that the liquid nutritional composition of the present invention contains an emulsifier. Examples of the emulsifier include polyglycerol fatty acid ester, organic acid monoglyceride, sucrose fatty acid ester, and lecithin. Among them, decaglycerol decaoleate, which is a polyglycerol fatty acid ester, is more preferable.

[0026] <Other raw materials> In addition to the essential components mentioned above, the liquid nutritional composition of the present invention may further contain other components commonly used in liquid nutritional compositions, such as dietary fiber, thickening polysaccharides, minerals, vitamins, fruit juice, flavorings, and colorings, to the extent that they do not impair the effects of the present invention.

[0027] The liquid nutritional composition of the present invention is a liquid and fluid nutritional composition. The basic composition preferably includes a plant protein-containing substance, including plant protein, and further preferably includes an emulsifier and liquid oil. In addition, other components commonly used in liquid nutritional compositions, such as dietary fiber, thickening polysaccharides, minerals, vitamins, fruit juice, flavorings, and colorings, can be included.

[0028] <Method for producing liquid nutritional composition> Liquid nutritional compositions can be manufactured by performing a blending process and a filling process. Homogenization and sterilization processes may be performed after the blending process as needed.

[0029] [Blending process] The compounding process involves dissolving each raw material in water. Water is placed in a manufacturing container, the raw materials are added, and they are dissolved by propeller agitation. If the raw materials are difficult to dissolve, they are dissolved using a high-speed agitator or a dissolution pump such as a powder blender. The water temperature at this time is preferably 25-80°C. Increasing the water temperature allows for more efficient dissolution of the raw materials.

[0030] [Homogenization process] In the homogenization process, it is preferable to use homogenizers such as high-speed homomixers, Gorin homogenizers (low-pressure homogenizers, high-pressure homogenizers), and microfluidizers to refine the emulsion particles. High-pressure homogenizers are preferred due to their homogenization capacity, processing capacity, and manufacturing cost. The homogenization pressure is preferably 0.5 to 100 MPa.

[0031] [Sterilization process] For the sterilization process, heat sterilization such as boiling, retort sterilization, and UHT sterilization is preferably used, but UHT sterilization is more preferable considering the deterioration of flavor and nutritional components. UHT sterilization has direct and indirect methods, and the indirect method has plate type and tubular type. Direct methods are preferable because they are highly effective in suppressing the deterioration of nutritional components, but in order to achieve the objectives of the present invention, the indirect method is preferred for the liquid nutritional composition of the present invention due to the effect of the indirect method, which suppresses the coarsening of emulsion particles and improves emulsion stability. For UHT sterilization, it is preferable to process at 120 to 160°C for 1 to 60 seconds.

[0032] [Filling process] In the filling process, for boiling sterilization and retort sterilization, the product is filled and sealed into containers before sterilization, and in the case of UHT sterilization, it is filled and sealed into containers aseptically after sterilization. Examples of sealed containers include cans, aluminum pouches, and soft bags for boiling sterilization and retort sterilization, and Tetra Pak®, Brick Pack, Carton, and PET bottles for UHT sterilization. The sealed container for the liquid nutritional composition of the present invention is not particularly limited. [Examples]

[0033] The present invention will be specifically described below with reference to examples.

[0034] <Preparation of plant-based protein> A plant-based protein-containing material was prepared, containing the following plant-based proteins. The protein content, NSI, and TCA solubilization rate were measured using the method described later. Soy protein-containing substance (1) ("Prolina RD-01" manufactured by Fuji Oil Co., Ltd., protein content 86% by mass, NSI: 79.6, TCA solubilization rate: 2.5%) Soy protein-containing substance (2) (SSPI-90D6H manufactured by Nissei Kyoei Co., Ltd., protein content: 86% by mass, NSI: 54.6, TCA solubilization rate: 17.3%) Soy protein-containing substance (3) (Willpro S615 manufactured by Nippon Shinyaku Co., Ltd., protein content: 86% by mass, NSI: 46.7, TCA solubilization rate: 15.0%)

[0035] <Protein content> Quantitative analysis was performed using the Kjeldahl method.

[0036] <Water Soluble Nitrogen Index (NSI)> NSI represents the amount of water-soluble nitrogen relative to the total nitrogen content. Specifically, 5.0 g of a plant protein-containing substance is added to 200 ml of water, stirred with a propeller at 37°C for 1 hour, then diluted to 250 ml with water, centrifuged at 3,000 rpm for 10 minutes, and the supernatant is collected. The nitrogen content of this supernatant is measured using the Kjeldahl method. Simultaneously, the amount of nitrogen in the sample is measured using the Kjeldahl method, and the amount of nitrogen in the supernatant (water-soluble nitrogen) relative to the total nitrogen in the sample is calculated and defined as the NSI.

[0037] <0.22M trichloroacetic acid (TCA) solubilization rate> The TCA solubilization rate indicates the solubility of plant protein in 0.22 M trichloroacetic acid (TCA). Specifically, 5.0 g of plant protein-containing material was added to 50 g of water, stirred with a propeller at 37°C for 1 hour, and then filtered to obtain a filtrate. An equivalent volume of 0.44 M trichloroacetic acid solution was added to the obtained filtrate and filtered again. The nitrogen content in the obtained filtrate was measured using the Kjeldahl method, and the amount of nitrogen soluble in TCA relative to the nitrogen content of the plant protein itself was calculated and defined as the TCA solubilization rate.

[0038] <Examples and Comparative Examples> <Manufacturing of liquid nutritional composition> 1760g of warm water (55°C) was placed in a stainless steel beaker, and while stirring with a propeller, the following ingredients were added in order: 100g of soy protein-containing material (1) (Fuji Oil Co., Ltd. "Prolina RD-01", protein content: 86%) as vegetable protein (A), 100g of soy protein-containing material (2) (Nissei Kyoei Co., Ltd. "SSPI-90D6H", protein content: 86%) as vegetable protein (B), 36g of corn oil (NOF Co., Ltd. "C-Oil") as liquid oil, and 4g of emulsifier (decaglycerin decaoleate, Taiyo Kagaku Co., Ltd. "Q-1710S"). The mixture was stirred and held at 55°C for 15 minutes to obtain the formulation. Next, the formulation was homogenized once at a pressure of 50MPa using a high-pressure homogenizer (Sanwa Engineering Co., Ltd. H20-H2). After homogenization, the mixture was placed in a stainless steel beaker, immersed in a tray of water, and cooled to 20°C. Then, it was sterilized using a UHT sterilizer (RMS-2S-T / P, manufactured by Hisaka Works Co., Ltd.) (tube-type indirect UHT sterilization). Ten pre-sterilized conical tubes were aseptically filled with 100g of the mixture and sealed to obtain the liquid nutritional composition of Example 1. Examples 2-7 were prepared similarly using the formulations shown at the top of Table 1. Comparative Examples 1-4 were prepared similarly using the formulations shown at the top of Table 2. For each liquid nutritional composition, five conical tubes were used for evaluation immediately after preparation, while the remaining five conical tubes were stored upright at 60°C for three days and used for the following evaluations.

[0039] <Evaluation of liquid nutritional compositions> The obtained liquid nutritional compositions were evaluated, and the results are shown in Tables 1 and 2 (bottom). The evaluation items and methods are as follows.

[0040] <Average particle size> Average particle size is an important indicator of emulsification stability, and from the viewpoint of emulsification stability, a smaller average particle size is desirable. The emulsification stability of a liquid nutritional composition includes not only emulsification in the narrow sense, where lipid particles are uniformly dispersed, but also in the broad sense, where all components are uniformly dispersed, such as without aggregation of proteins. The average particle size of the liquid nutritional composition immediately after manufacturing was measured using a laser diffraction / scattering particle size analyzer (LA-950, manufactured by Horiba, Ltd., dispersion medium: filtered water, sample refractive index: 1.6-0.00i / 1.333, particle size reference: volume). In addition, the number of peaks in the particle size distribution in this invention was evaluated. The particle size distribution of the liquid nutritional composition immediately after manufacturing was calculated using a laser diffraction / scattering particle size analyzer (LA-950, manufactured by Horiba, Ltd., dispersion medium: filtered water, sample refractive index: 1.6-0.00i / 1.333, particle size reference: volume), a graph showing the particle size distribution was created, and the number of peaks was measured. Since peaks tend to indicate a rich, milky flavor, it is desirable to have two or more peaks.

[0041] <Emulsification stability> The evaluation criteria for emulsification stability were determined by assessing creaming and precipitation after storage at 60°C for 3 days, and were evaluated using the following methods and criteria. Creaming refers to the separation in which a white layer forms near the liquid surface due to the rise of oil, while precipitation refers to the formation of a solid layer near the bottom due to the settling of insoluble proteins. After storing containers of liquid nutritional composition at 60°C for 3 days, the containers were opened, and creaming was evaluated. The liquid portion was then gently transferred to another container, and the accumulated sediment near the bottom of the container was visually inspected. Containers showing creaming or sediment were shaken 10 times by hand and re-evaluated in the same manner. For creaming, "◎" indicated good results with no sediment; "〇" indicated good results with sediment present but uniform after shaking; "△" indicated results with sediment present and creaming / sediment occurring even after shaking, but the container could be consumed by tilting it; and "×" indicated results with sediment present, creaming / sediment occurring even after shaking, remaining in the container even after tilting, and unsuitable for consumption. "◎" or "○" were the passing criteria, with "◎" being preferred.

[0042] <Milk-like richness> A sensory evaluation of the milk-like rich flavor of the present invention was conducted. Six panelists, A to F, aged 20 to 50, participated. They poured 50 mL of the liquid nutritional composition, stored at 25°C for 3 days after production, into a paper cup and drank it to perform a sensory test. The sensory test was also performed in comparison with milk ("Delicious Milk" manufactured by Meiji Co., Ltd.) and soy milk ("Delicious Unadjusted Soy Milk" manufactured by Kikkoman Corporation). The evaluation items were assessed according to the following criteria. A four-level rating system was used to evaluate the products: "1" for those with a similar richness to milk, "2" for those with less richness than milk but more rich than soy milk and with a lingering richness, "3" for those with less richness than milk but more rich than soy milk and with a richness that quickly disappears from the tongue, and "4" for those with a similar richness to soy milk. The average score of the evaluations from the six participants was rounded to two decimal places to calculate the final score. Products with an average score of 1.0 to 1.5 were marked with "◎" as they had a richness comparable to milk and were good; products with an average score of 1.1 to 2.5 were marked with "〇" as they were below milk but had a richer taste than soy milk and a lingering richness; products with an average score of 2.6 to 3.5 were marked with "△" as they were below milk but had a richer taste than soy milk and a richness that quickly disappeared from the tongue; and products with an average score of 3.6 to 4.0 were marked with "×" as they had a richness comparable to soy milk.

[0043] [Table 1]

[0044] [Table 2]

[0045] From the evaluation results of Examples 1 to 7, it was found that the liquid nutritional composition of the present invention uses only plant-derived protein as a protein source, has high emulsification stability, and possesses a rich, milky flavor.

[0046] Comparative Example 1 differs from Example 1 in that it uses only plant protein (A) and not plant protein (B). As a result, a milk-like richness was not achieved, and the target liquid nutritional composition was not obtained.

[0047] In Comparative Example 2, compared to Example 1, the formulation used only plant protein (B) and not plant protein (A). As a result, the emulsification stability was low, the milk-like richness was not obtained, and the target liquid nutritional composition was not achieved.

[0048] In Comparative Example 3, the total amount of plant protein (A) and plant protein (B) was reduced to 1.7% by mass compared to Example 1. As a result, the emulsification stability was low, and the target liquid nutritional composition could not be obtained.

[0049] In Comparative Example 4, the total amount of plant protein (A) and plant protein (B) was increased to 15.5% by mass compared to Example 1. As a result, the emulsification stability was low, and the target liquid nutritional composition could not be obtained.

Claims

[Claim 1] A liquid nutritional composition comprising (A) a plant protein having a water-soluble nitrogen index (NSI) of 75 or higher and a TCA solubilization rate of 5% or less, and (B) a plant protein having a water-soluble nitrogen index (NSI) of 40 or higher and a TCA solubilization rate of 10% or higher and 20% or less, wherein the total content ratio of component (A) and component (B) is 3% by mass or higher and 14% by mass or lower.

Images