Whey processed food product

Abstract

To provide a whey processed food product having excellent mouthfeel.SOLUTION: The processed food product contains lactose at a proportion of 20 mass% or more, where: the proportion of lactose crystals in the whey processed food product is 3-5%; the proportion of coarse lactose crystals among the lactose crystals in the whey processed food product is 10% or less; and the proportion of fine lactose crystals among the lactose crystals in the whey processed food product is 70% or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a whey processed food produced using whey as a raw material. [Background technology]

[0002] Raw milk is processed into various dairy products such as milk, cheese, yogurt, butter, and cream through processing technology, and is consumed by people. However, in the cheese manufacturing process, only about 10% of raw milk becomes cheese, and the remaining 90% is discharged as whey. As whey is a by-product of the cheese manufacturing process, it contains a large amount of various essential amino acids, proteins, vitamins, and sugars, and is also a nutritionally excellent food material. However, whey is not fully utilized in the food field because it is easily deteriorated, has low preservation properties, and has a unique flavor. For this reason, whey used industrially is only 59% of the total whey discharged worldwide, and the remaining 41% is used as livestock feed or agricultural fertilizer, or is treated as industrial waste. For this reason, making effective use of whey and expanding its uses is an important issue, especially as a responsibility of companies that manufacture dairy products, in aiming to realize a sustainable society, such as making effective use of unused dairy resources and reducing waste to protect the environment.

[0003] One of the alterations of whey is the alteration of lactose contained in whey. It is generally known that in foods and beverages with a high lactose concentration, lactose crystals are generated and grow to a large size, which causes a rough feeling on the tongue and a loss of smooth texture. This phenomenon occurs more significantly as the lactose concentration increases. It has been pointed out that lactose crystals have an effect on the texture of brown whey cheese, which is one of the whey processed foods with a high lactose concentration, and it is known that the ideal crystal size is 20-30 μm, and that when the crystal size exceeds 100 μm, the tongue feels rough (Non-Patent Document 1). For this reason, in order to effectively use whey containing a large amount of lactose as a food ingredient, it is necessary to prevent the crystallization and growth of lactose contained in whey and maintain a good texture.

[0004] As a method for suppressing the crystallization of lactose in whey, a method is known in which whey is desalted by nanofiltration and then lactose is decomposed using a lactase (Patent Document 1). According to this method, it is possible to obtain lactose-decomposed and desalted whey, which has a good flavor due to the desalting, a low viscosity even when concentrated by decomposing lactose, and does not induce lactose crystallization during transportation of the concentrated liquid. In addition, although it is not a method for suppressing lactose crystallization, a method for suppressing mannitol crystallization is known in which a non-crystalline carbohydrate is used as a crystal precipitation regulator (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-129579 A [Patent Document 2] JP 2007-215450 A [Non-patent literature]

[0006] [Non-Patent Document 1] Siv Skeie, Roger K. Abrahamsen, “Chapter 45: Brown Whey Cheese”, Cheese 4th edition: Chemistry, Physics and Microbiology Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide a whey processed food with a good texture in order to effectively utilize whey and expand its applications. More specifically, the present invention aims to provide a whey processed food that is smooth to the touch with little roughness on the tongue, has little adhesion to the teeth when chewed, and has a good crispness. [Means for solving the problem]

[0008] The present inventors have conducted intensive research to solve the above problems, and have found that in whey processed foods containing lactose at a high concentration of 20% by mass or more, reducing the lactose crystal content makes the food smooth to the touch without roughness, but it has a problem of high adhesion to teeth when chewed, making it difficult to chew. Therefore, further research was conducted to obtain a whey processed food with a good texture that is both smooth and crisp. As a result, it was found that this can be achieved by reducing the lactose crystal content to 3-5% and appropriately adjusting the ratio of coarse crystals and fine crystals in the lactose crystals.

[0009] The present invention has been completed based on these findings and further research, and includes the following embodiments. Item 1: A whey processed food containing 20% ​​by mass or more of lactose, The percentage of lactose crystals in the whey processed food is 3-5%; and Whey processed foods in which the proportion of coarse lactose crystals in the lactose crystals in the whey processed foods is 10% or less and the proportion of fine lactose crystals is 70% or more; Here, the ratio of lactose crystals is a ratio calculated from the area of ​​the peak at the corresponding position obtained for the test whey processed food, based on the area of ​​the main peak of lactose monohydrate crystals (standard) detected in the range of 2θ = 19.9 to 20.4 ° in the X-ray diffraction pattern measured by an X-ray diffractometer; The proportion of coarse lactose crystals and fine lactose crystals in the lactose crystals is determined by observation with a phase contrast microscope and is the ratio of the total area of ​​coarse lactose crystal particles and the ratio of the total area of ​​fine lactose crystal particles to the total area of ​​lactose crystal particles (100%) in the test whey processed food. Item 2: The whey processed food according to Item 1, wherein the whey processed food is brown whey cheese, brown cheese, yeast, brnost, or caramel. Item 3: A method for making a whey processed food containing 20% ​​by mass or more of lactose smooth to the tongue and reducing adhesion to teeth when chewed, comprising: The method comprises reducing the rate of lactose crystals in the whey processed food to 3 to 5%, and The method as described above, characterized in that the proportion of coarse lactose crystals in the lactose crystals in the whey processed food is 10% or less and the proportion of fine lactose crystals is 70% or more; Here, the ratio of lactose crystals is a ratio calculated from the area of ​​the peak at the corresponding position obtained for the test whey processed food, based on the area of ​​the main peak of lactose monohydrate crystals (standard) detected in the range of 2θ = 19.9 to 20.4 ° in the X-ray diffraction pattern measured by an X-ray diffractometer; The proportion of coarse lactose crystals and fine lactose crystals in the lactose crystals is determined by observation with a phase contrast microscope and is the ratio of the total area of ​​coarse lactose crystal particles and the ratio of the total area of ​​fine lactose crystal particles to the total area of ​​lactose crystal particles (100%) in the test whey processed food. Effect of the Invention

[0010] According to the present invention, it is possible to provide a whey processed food that is smooth to the touch with less roughness on the tongue, has less adhesion to the teeth when chewed, and has a good crispness. According to the present invention, it is possible to effectively use whey as a food ingredient by solving the problem that whey, which is nutritionally excellent but could not be effectively used in the past. [Brief description of the drawings]

[0011] [Figure 1] 4 shows the X-ray diffraction patterns of the whey processed foods A to E prepared in Experimental Example 1. The main peak detected in the range of 2θ=19.9 to 20.4° was used to calculate the proportion of lactose crystals. [Diagram 2] 1 shows an image of the cross-sectional tissue of a slice of whey processed food I prepared in Experimental Example 1, observed under a phase contrast microscope (objective magnification ×10). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (I) Whey processed foods The whey processed food of the present invention (hereinafter also referred to as "the food") is a food produced using whey as a raw material. Whey is a by-product of cheese production, with most of the fat and casein removed from mammalian milk. Whey includes sweet whey, acid whey, whey concentrates obtained by concentrating these wheys, and whey powders obtained by drying and powdering these wheys. Examples of mammals from which milk is derived include cows, buffaloes, goats, and sheep, but cows, particularly dairy cows, are preferred.

[0013] The present food product is produced using the above-mentioned whey as a raw material and is characterized by having the following properties: (1) Lactose content: 20% by mass or more, (2) Lactose crystal content: 3-5% (3) The proportion of coarse lactose crystals in the lactose crystals in whey processed foods: 10% or less The proportion of fine lactose crystals in whey processed foods: 70% or more.

[0014] These characteristics are explained below. In this specification, "solid content" refers to the components excluding water. In this specification, "solid content concentration" refers to the proportion of solid content contained in the target object (e.g., whey processed food), and is expressed as the proportion (mass %) of solid content in the total amount when the total amount (wet mass) of the target object is taken as 100 mass %. In addition, in this specification, the "solid content equivalent amount" of a component refers to the content of the corresponding component in the target object (e.g., whey processed food) converted to solid content. Specifically, when the total amount (dry mass) of solid content of the target object is taken as 100 mass %, it refers to the proportion (mass %) of the corresponding component in the total amount of solid content.

[0015] (1) Lactose content The lactose content in whey processed foods can be measured using high performance liquid chromatography. The detailed measurement method and conditions will be described in the experimental examples below. The lactose content of the whey processed food may be 20% by mass or more. The lower limit is not limited, but may be, for example, 30% by mass, 35% by mass, 39% by mass, or 40% by mass. The upper limit is not limited, but may be, for example, about 60% by mass, 51% by mass, or 49% by mass. The lactose content of the whey processed food may be appropriately set within the range of 20 to 60% by mass. Although not limited, the range is preferably 20 to 51% by mass, more preferably 30 to 51% by mass, even more preferably 35 to 51% by mass, and particularly preferably 39 to 49% by mass.

[0016] The lactose content, calculated as solid content, can be 27% by mass or more, preferably 29 to 67% by mass, more preferably 40 to 64% by mass, and more preferably 47 to 54% by mass. The lactose content calculated as solid content in the present food can be calculated from the lactose content in the present food and the solid content concentration of the present food determined by the normal pressure heating and drying method (sand mixing method) described later.

[0017] (2) Ratio of lactose crystals The ratio of lactose crystals in a whey processed food according to the present invention is determined from the area of ​​the peak at the position corresponding to the main peak of lactose monohydrate crystals (α type) (standard) detected in the range of 2θ=19.9 to 20.4° in an X-ray diffraction pattern measured by an X-ray diffractometer, which is obtained by the same method for the target whey processed food. Details of the measurement and calculation methods will be described in Experimental Example 1 below.

[0018] As for the method of preparing the test sample (measurement sample) to be used for the measurement, for example, a hard solid whey processed food with a solid content concentration of 80% by mass or more can be prepared by slicing it to a thickness of 0.5 mm as in Experimental Example 1. On the other hand, for example, a semi-solid or soft solid whey processed food with a solid content concentration of less than 80% by mass can be prepared according to the Front loading method, which is one of the sample preparation methods used for powder X-ray diffraction measurement. Specifically, the test sample is filled into the sample filling part of a glass sample holder having a square columnar depression (sample filling part) with a depth of 0.5 mm and a bottom surface of 20 mm x 20 mm, and the surface is scraped off with the edge of another glass plate to make the surface of the test sample to be used for X-ray diffraction even (smooth and uniform), and then cooled at 5°C. The percentage of lactose crystals in whey processed foods is preferably 3 to 5%, and can be appropriately set within this range.

[0019] (3) The proportion of coarse and fine lactose crystals in the lactose crystals in whey processed foods The ratio of coarse lactose crystals and fine lactose crystals to the lactose crystals in the whey processed food in the present invention is determined by phase contrast microscopy. Specifically, it is the ratio of the total area of ​​coarse lactose crystal particles and the ratio of the total area of ​​fine lactose crystal particles to the total area of ​​100% of the lactose crystal particles contained in the whey processed food, determined by phase contrast microscopy. Details of the measurement and calculation methods, including the preparation method of the test sample (measurement sample) to be used for the measurement, will be described in Experimental Example 1 below.

[0020] In the present invention, coarse lactose crystals refer to crystals having a circle-equivalent diameter of 30 μm or more calculated from the horizontal projected area of ​​particles (lactose crystal particles) observed when whey processed foods are observed under a phase contrast microscope. Similarly, fine lactose crystals refer to crystals having a circle-equivalent diameter of 10 μm or less calculated from the horizontal projected area of ​​particles (lactose crystal particles) observed when whey processed foods are observed under a phase contrast microscope. The method for measuring the horizontal projected area of ​​particles using a phase contrast microscope and the method for calculating the circle-equivalent diameter are also described in detail in Experimental Example 1 below.

[0021] The proportion of coarse lactose crystals in the total lactose crystals is 10% or less in terms of the total area of ​​the corresponding crystal particles. Although there is no particular limitation as long as it is 10% or less, it is preferably 8% or less, more preferably 5% or less, particularly preferably 3% or less, and even more preferably 0%.

[0022] The proportion of fine lactose crystals in the total lactose crystals is 70% or more in terms of the total area of ​​the corresponding crystal particles. Although there is no particular limitation as long as it is 70% or more, it is preferably 72% or more, more preferably 80% or more, particularly preferably 90% or more, and even more preferably 95% or more.

[0023] The method for producing the whey processed food of the present invention is not particularly limited as long as it can produce a whey processed food having the above-mentioned characteristics using whey as a raw material. For example, a method can be used in which lactose crystal formation is suppressed by performing lactose decomposition processing using the lactase described in Patent Document 1, which is listed as a prior patent, and the ratio of lactose crystals and the ratio of coarse lactose crystals and fine lactose crystals in the lactose crystals (hereinafter, these are also collectively referred to as "characteristics of lactose crystals") are adjusted to be within the range of the present invention described above. Similarly, a crystal precipitation regulator described in Patent Document 2 can be used to suppress the crystal formation of lactose, thereby adjusting the lactose crystals to have the above-mentioned characteristics. As the crystal precipitation regulator, starch syrup, reduced starch syrup, reduced maltose starch syrup, coupling sugar, oligosaccharides, polysaccharides, etc. described in Patent Document 2 can be used, but trehalose, which has a high glass transition temperature and an ice crystal growth inhibitory effect, can also be used. Trehalose is preferable, as shown in the experimental example described below.

[0024] The details of the method for producing the whey processed food of the present invention using trehalose as a crystal precipitation regulator are as described in the experimental examples. As described there, the whey processed food of the present invention having the above-mentioned lactose crystal properties can be prepared by adjusting the blending ratio of trehalose and adjusting the mixing conditions (agitation speed, temperature, pressure) of the composition containing whey and trehalose. As an example, a whey preparation containing at least whey, trehalose, and water and having a lactose content of 20% by mass or more is concentrated under reduced pressure while being stirred and heated until the solid content is 75% by mass or more, and then subjected to a pressurized heat treatment, and then subjected to continuous shearing under heating conditions using a twin-screw kneader (kneading treatment), and then extruded by an extruder (extruder treatment). Note that any method may be used as long as it can produce the whey processed food of the present invention having the above-mentioned lactose crystal properties, and the present invention is not limited by its manufacturing method. Whether or not the whey processed food of the present invention has been obtained can be confirmed by measuring the lactose content and proportion of lactose crystals in the whey processed food, as well as the proportion of coarse lactose crystals and fine lactose crystals in the lactose crystals, using the methods described above.

[0025] The whey processed food of the present invention may be a solid or semi-solid food having the above-mentioned characteristics, and may be prepared by blending other ingredients as raw ingredients other than whey. Examples of other ingredients include raw milk, cow's milk or dairy products (skim milk, concentrated milk, reconstituted milk, whole milk powder, skim milk powder, cream, butter, butter oil, milk proteins such as casein, etc.), goat's milk, reducing sugar, gelatin, stabilizers, etc.

[0026] In the present invention, the term "solid" refers to a shape that does not deform under its own weight even when left to stand for at least 24 hours under conditions of 25°C and atmospheric pressure. The term "semi-solid" refers to a shape that deforms under its own weight in the above-mentioned case. The whey processed food of the present invention may have a solid concentration of 55% by mass or more, and includes paste-like (semi-liquid, non-formed), soft solid, and hard solid. Although not limited thereto, examples of the solid content concentration of the whey processed food in the paste-like, soft solid, and hard solid form are about 55 to less than 75% by mass, about 75 to less than 80% by mass, and about 80 to 90% by mass, respectively.

[0027] The solid content of the test sample (whey processed food) can be determined by the normal pressure heat drying method (mixed sand method). Specifically, after a constant weight is determined with sea sand and a glass rod placed in a weighing dish, the test sample and distilled water are added and the dish is dried in a dryer at 99°C for 4 hours. The moisture content of the test sample is then determined from the difference in weight of the test sample before and after drying. From the moisture content thus measured, the mass of solids contained in the test sample (before drying) can be determined, and the solid content concentration can be calculated from this.

[0028] In the present food product, the content of protein contained as a component other than lactose is not limited, but can be in the range of 7 to 12% by mass, preferably 7% or more and less than 10% by mass, and more preferably 8 to 9% by mass, calculated as solid content. The total amount of protein contained in this food can be measured using the Kjeldahl method. Details will be explained in the Examples section. The solid content equivalent of protein in this food can be calculated from the total protein content in this food and the solid content concentration of this food determined by the normal pressure heating drying method (sand mixing method) described above.

[0029] In addition, the whey processed food of the present invention may contain lipids as components other than lactose and whey, as long as the above-mentioned lactose content and lactose crystal properties are not impaired. The lipid content is not limited, but can be appropriately selected from a range of 9% by mass or more in terms of solid content. The range is preferably 22 to 41% by mass, more preferably 26 to 29% by mass. The lipid content in the present food can be measured by the Roese-Gottlieb method. Details will be explained in the Examples section. The lipid solids content in the present food can be calculated from the lipid content in the present food and the solids concentration of the present food determined by the normal pressure heating and drying method (sand mixing method) described above.

[0030] The whey processed foods covered by the present invention include, but are not limited to, the following brown whey cheese, yeast, caramel, etc. Although not limited thereto, these whey processed foods are known to be the following foods.

[0031] Brown whey cheese: A food product made by adding whey to milk and cream, then heating and concentrating it, with a solids concentration of 70-85% by mass and a fat content of 10-30% by mass. Note that in some countries and regions, brown whey cheese is also called brown cheese or brunost, but all of these are the same whey processed food products.

[0032] Yetost: A food product obtained by adding milk and cream to whey, then heating and concentrating it, with a solids concentration of 70-85% by mass and a lipid content of 10-30% by mass, in which all or part of the milk used is derived from goat's milk.

[0033] Caramel: A soft candy-like structure made from dairy ingredients and flavored with a milky taste, with whey processed food used as part of the dairy ingredients.

[0034] Also included are products obtained by adding milk or milk fat to whey, either concentrated or dried, which have the following characteristics: (a) The milk fat content is 5% by mass or more of the total dry weight (solid content equivalent); (b) The solid content is 70% by mass or more and 85% by mass or less by total weight (solid content concentration); (c) It is molded or capable of being molded.

[0035] (II) Method for improving the texture of whey processed foods The present invention also provides a method for making whey processed foods containing 20% ​​by mass or more of lactose smooth to the touch and reducing adhesion to teeth when chewed. As described above, this method can be carried out by adjusting the lactose crystal ratio of whey processed foods containing 20% ​​by mass or more of lactose as follows: (1) Lactose crystal content: 3-5% (2) The proportion of coarse lactose crystals in the lactose crystals in whey processed foods: 10% or less The proportion of fine lactose crystals in whey processed foods: 70% or more. The preferred ranges are as described in (I), and all of them are incorporated herein by reference. The explanations of the terms described herein, and the methods for adjusting the lactose content and the ratio of various lactose crystals are also as described in (I), and all of them are incorporated herein by reference.

[0036] As described above, in this specification, the terms "comprise" and "contain" include the meanings of "consisting of" and "consisting essentially of".

[0037] (Contribution to Sustainable Development Goals (SDGs)) The present invention can be utilized as a means for achieving the Sustainable Development Goals (SDGs). By utilizing the present invention, it is possible to contribute to the achievement of the Sustainable Development Goals (SDGs) and targets.

[0038] Specifically, the Sustainable Development Goals (SDGs) are as follows (Transforming our world: the 2030 Agenda for Sustainable Development, Ministry of Foreign Affairs, Internet <URL: https: / / www.mofa.go.jp / mofaj / gaiko / oda / sdgs / pdf / 000101402.pdf>): Goal 1. End poverty in all its forms everywhere. Goal 2. End hunger, achieve food security and improved nutrition and promote sustainable agriculture. Goal 3. Ensure healthy lives and promote well-being for all at all ages. Goal 4. Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all. Goal 5. Achieve gender equality and empower all women and girls. Goal 6. Ensure availability and sustainable management of water and sanitation for all. Goal 7. Ensure access to affordable, reliable, sustainable and modern energy for all. Goal 8. Promote inclusive and sustainable economic growth, full and productive employment and decent work for all. Goal 9. Build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation. Goal 10. Reduce inequality within and among countries. Goal 11. Make cities and human settlements inclusive, safe, resilient and sustainable. Goal 12. Ensure sustainable consumption and production patterns. Goal 13. Take urgent action to combat climate change and its impacts. Goal 14. Conserve and sustainably use the oceans, seas and marine resources for sustainable development. Goal 15. Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss. Goal 16. Promote peaceful and inclusive societies for sustainable development, provide access to justice for all and build effective, accountable and inclusive institutions at all levels. Goal 17. Strengthen the means of implementation and revitalize the global partnership for sustainable development.

[0039] The present invention can particularly contribute to the achievement of Goal 2 (end hunger, achieve food security and improved nutrition, and promote sustainable agriculture) and Goal 3 (ensure healthy lives and promote well-being for all at all ages). That is, by providing whey, a nutritionally excellent food ingredient containing large amounts of various essential amino acids, proteins, vitamins, and sugars, as a whey processed food, it can contribute to supplying safe and sufficient food to all people, including young women, pregnant and lactating women, and the elderly.

[0040] Furthermore, the present invention can particularly contribute to the achievement of Goal 9 (Build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation). In other words, by creating new added value for whey using this technology that suppresses the deterioration of whey, it is possible to promote technological development, research, and innovation such as industrial diversification and the creation of added value for products, thereby improving resource utilization efficiency and expanding and improving the efficiency of industrial processes, thereby promoting innovation in a sustainable and resilient manner.

[0041] Furthermore, the present invention can particularly contribute to the achievement of Goal 12 (ensuring sustainable consumption and production patterns). That is, by effectively utilizing whey, which was often discarded in the cheese manufacturing process by cheese manufacturers, as whey processed foods, food waste in production and supply chains can be reduced. Furthermore, by halving food waste, sustainable development and development in harmony with nature can be carried out, ensuring sustainable consumption and production patterns.

[0042] Furthermore, the present invention can also contribute to achieving the targets associated with each of the goals set out in "Transforming our world: the 2030 Agenda for Sustainable Development". EXAMPLES

[0043] In the following, the present invention will be described using experimental examples to aid in understanding the configuration and effects of the present invention. However, the present invention is not limited by these experimental examples. The following experiments were carried out at room temperature (25±5°C) and atmospheric pressure conditions unless otherwise specified. In the following, "%" means "% by mass" and "parts" means "parts by mass" unless otherwise specified.

[0044] Experimental Example 1 Nine types of whey processed foods A to I were produced, and the lactose content (mass%), lactose crystal ratio (%), and crystal size (μm) of each whey processed food were measured. In addition, the texture (feel on the tongue, crispness) of these whey processed foods A to I was evaluated.

[0045] The raw materials used in the production of whey processed foods are as follows: Whey powder: Dried whey powder (100% whey), lactose content 80%, protein content 12%, manufactured by Meiji Co., Ltd. Cream: Made by Meiji Co., Ltd., fat content 47%, lactose content 3% In addition, cream falls under the provision of the Ministerial Ordinance on the Compositional Standards of Milk and Dairy Products (Milk Ordinance), which states that "cream is obtained by removing all ingredients other than milk fat from raw milk, cow's milk or special cow's milk." Trehalose: Manufactured by Hayashibara Co., Ltd. The standards used to measure the lactose content and the rate of lactose crystals are as follows: Lactose monohydrate crystals (α-type): Lactose monohydrate (100%), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Hereinafter referred to as "lactose crystals (standard product)."

[0046] (1) Manufacture of whey processed foods A to I Whey preparations A to E were prepared by mixing the ingredients in the ratios shown in Table 1. The lactose content in the whey preparations was 29%.

[0047] [Table 1]

[0048] The obtained whey preparation was heated to 60-70°C in a continuous heating vacuum cooker device (manufactured by Mihama Co., Ltd.) while stirring at 20-60 rpm, a rotation radius of 0.175 m, and 0.37-1.1 m / s, and concentrated under reduced pressure for 5-60 minutes until the solid content reached 80% under vacuum (reduced pressure) pressure conditions (gauge pressure [relative pressure] of the device: -20 kPa to -50 kPa, absolute pressure: about 80 kpa to 50 kpa). After concentrating to a solid content concentration of 80%, the whey preparation concentrate was heated to 110-120°C under pressurized conditions (gauge pressure [relative pressure] of the device: 10 kPa to 20 kPa, absolute pressure: about 110 kpa to 120 kpa) until the whey preparation concentrate turned brown. Thereafter, the whey preparation concentrate was extruded by an extruder and cooled to 4°C or less to obtain solid whey processed foods A to E with a solid content concentration of 84%.

[0049] Separately, the whey preparation C (trehalose content: 5%) was subjected to the pressurized heating process among the above series of processing steps, and the preparation browned at 4°C before cooling was kneaded in a twin-screw kneader (manufactured by Irie Shokai Co., Ltd., with blades of diameter 60 mm, shaft distance 50 mm, and twist angle 60°. Rotation direction is the same) under a temperature condition of 60 to 80°C (rotation conditions: whey processed food F: 0 rpm, G: 10 rpm, H: 50 rpm, I: 100 rpm). Then, it was extruded by an extruder to obtain solid whey processed food products F to I (solid content concentration 84%).

[0050] (2) Measurement of lactose content (mass%) in whey processed foods The lactose content in the whey processed food (100%) was measured using high performance liquid chromatography (HPLC). The whey processed foods A to I produced above were prepared into 10% solutions in Milli-Q water, passed through a 0.2 μm mesh filter, and then further diluted 10-fold with Milli-Q water to prepare test samples, which were subjected to HPLC under the following conditions.

[0051] [HPLC conditions] HPLC equipment: Agilent 1200 (Agilent) Stationary phase: SUPELCO apHeraTM NH2 HPLC Column Mobile phase: 68% acetonitrile Elution rate: 1.0 ml / min Detector: RI detector.

[0052] Based on a calibration curve (showing the correlation between the amount of lactose and its peak area) previously prepared using lactose crystals (standard material), the lactose content in the test sample was determined from the area of ​​the lactose peak obtained for the test sample, and the lactose content in the whey processed foods A to I was then calculated.

[0053] (3) Percentage of lactose crystals in whey processed foods (%) The whey processed foods A to I produced above were sliced ​​to a thickness of 0.5 mm and used as test samples, and the amount of lactose crystals was determined using an X-ray diffraction measurement device (SmartLab X-ray DIFFRACTOMETER, manufactured by Rigaku).

[0054] Specifically, the test sample (one piece) was placed on a glass cell attached to the device so that the 0.5 mm thickness was on the top and bottom, and the X-ray diffraction image was measured with the X-ray diffraction measurement device. When the X-ray diffraction image of lactose crystals (standard product) is measured with the X-ray diffraction measurement device, multiple peaks derived from lactose crystals are detected in the range of 2θ = 19.9 to 20.4 °, and the largest peak among them is set as the main peak. Next, the X-ray diffraction image obtained for the test sample was smoothed and the base portion was subtracted, and the area value of the peak corresponding to the main peak of lactose crystals (standard product) among the peaks detected in the range of 2θ = 19.9 to 20.4 ° was calculated.

[0055] Next, the area value of the main peak measured in the same manner for lactose crystals (standard product) was used as the basis to determine the ratio of the area value of the peak obtained for each whey processed food A to I according to the following formula, and the percentage (%) of lactose crystals contained in each whey processed food was calculated.

[0056] [Formula 1] Percentage of lactose crystals in whey processed foods (%) = B / A × 100 A: Area value of the main peak of lactose crystals (standard) at 2θ = 19.9 to 20.4° B: Area value of the peak corresponding to the main peak for the whey processed food (test sample)

[0057] (4) The proportion of coarse and fine lactose crystals in the lactose crystals in whey processed foods The whey processed food produced above was sliced ​​to a thickness of 0.5 mm and used as a test sample. Approximately 1 mg of the sample was placed on a slide glass and crushed with a cover glass (crushing method). The sample was then observed in 15 fields of view (15 fields of view) using a phase contrast microscope (objective magnification x10, total magnification x10). The images obtained by observing the 15 fields of view were binarized to separate the background and particles (particles of lactose crystals), and the total number of particles was counted. Next, the horizontal projection area of ​​each particle (each lactose crystal) was measured, and the equivalent circle diameter of each was calculated. Particles with an equivalent circle diameter of 30 μm or more were classified as coarse lactose crystals, and particles with an equivalent circle diameter of 10 μm or less were classified as fine lactose crystals, and the number of coarse lactose crystals and the number of fine lactose crystals were calculated.

[0058] Next, the horizontal projection area of ​​each particle (lactose crystal) included in the observation field was added up to obtain the total area of ​​all lactose crystal particles. This is also referred to as the "total lactose crystal area" in the present invention. In addition, the horizontal projection area of ​​each particle corresponding to coarse lactose crystals among all particles (lactose crystals) included in the observation field was added up to obtain the total area of ​​coarse lactose crystal particles. This is also referred to as the "total coarse lactose crystal area" in the present invention. In addition, the horizontal projection area of ​​each particle corresponding to fine lactose crystals among all particles (lactose crystals) included in the observation field was added up to obtain the total area of ​​fine lactose crystal particles. This is also referred to as the "total fine lactose crystal area" in the present invention.

[0059] The total area of ​​lactose crystals was set as 100% (standard), and the percentage of the total area of ​​coarse lactose crystals and the percentage of the total area of ​​fine lactose crystals were calculated to represent the percentage of coarse lactose crystals and the percentage of fine lactose crystals in lactose crystals, respectively.

[0060] (5) Protein content in whey processed foods: Kjeldahl method Approximately 1.5 g of the whey processed food produced above was precisely weighed, diluted or dissolved in warm water, transferred to a 100 ml measuring flask, cooled, and then adjusted to volume with water. 20 ml of this diluted solution was placed in a decomposition flask. To this was gradually added 12 ml of a decomposition accelerator (Keltab C) and sulfuric acid, and mixed, and then 8 ml of hydrogen peroxide was added and mixed. Next, the nitrogen was converted to ammonia by thermal decomposition in a decomposition apparatus. After the liquid in the decomposition flask became transparent and turned blue due to copper sulfate, it was cooled and then diluted by gradually adding 50 ml of water. Then, it was distilled in a Kjeldahl distillation apparatus.

[0061] Specifically, an excess amount of sodium hydroxide was added to the above decomposition liquid (H2SO4 containing (NH4)2SO4) to make it alkaline, then it was heated with steam to release ammonia again, and the liberated ammonia was steam distilled and collected in an aqueous boric acid solution. The resulting ammonia collection liquid was titrated with a standard sulfuric acid solution to determine the nitrogen content, and the protein mass was calculated by multiplying it by the nitrogen protein conversion factor (6.38).

[0062] (6) Lipid content in whey processed foods: Roese-Gottlieb method Approximately 1 g of the whey processed food produced above was dispersed in 2 ml of ammonia water, then 10 ml of ethanol was added, followed by extraction with 25 ml of diethyl ether and 25 ml of petroleum ether. The second extraction was performed with 15 ml of diethyl ether and 15 ml of petroleum ether. The collected extract was dried to dryness, and the weight of the dried matter was measured, which was used as the lipid content in the test sample.

[0063] (7) Texture evaluation of whey processed foods An analytical sensory evaluation panel of four experts (training period: 5 to 15 years) trained in-house was used to evaluate the "texture to the tongue" and "feel with the teeth" of the whey processed foods A to I produced above. Note that the whey processed foods A to I were stored for 1 hour under constant temperature and humidity conditions of a temperature of 10°C and a humidity of 50% before being subjected to texture evaluation.

[0064] The whey processed foods were evaluated for "texture" and "crispness" based on the following criteria. (i) Texture: The presence or absence of roughness or smoothness felt on the tongue when eating Evaluation based on the following 5-point scale 5 (best): No roughness at all, very smooth 4 (Good): Almost no roughness, very smooth 3 (Good): Slightly rough, but smooth 2 (bad): Feels rough and not smooth 1 (worst): Significantly rough and not smooth at all.

[0065] (ii) Crunchiness: The resistance to chewing caused by food sticking to the teeth when chewing 5 (best): Does not stick to teeth at all, no resistance to chewing (very good chewiness) 4 (Good): Almost no adhesion to teeth, almost no resistance to chewing (good chewiness) 3 (Good): Sticks to teeth slightly, but has almost no resistance to chewing (good chewiness) 2 (Bad): Sticks to teeth and is difficult to break into pieces (bad bite feeling) 1 (worst): The food sticks to the teeth significantly and is very difficult to break down (very difficult to break down).

[0066] In addition, when conducting the texture evaluation, the entire panel worked together to reach a common understanding of the characteristics of each evaluation item. Each evaluation was performed by each panel, and the results were then discussed by the entire panel, which was then used as the overall evaluation for the entire panel, forming the final result.

[0067] In addition, an overall evaluation was made based on the results of both texture and crispness, using the following criteria. [comprehensive evaluation] ◎: Texture is 5, crispness is 4 or above ○: Both texture and crispness are 4 △: At least one of the texture and crispness was rated 3 or less ×: At least one of the texture and crispness was rated 2 or less

[0068] (8) Experimental results The results of measuring the X-ray diffraction patterns of whey processed foods A to E are shown in Figure 1 (A to E are shown from the top). The lactose content (%), the percentage of lactose crystals (%), the percentage of coarse crystals and the percentage of fine crystals (%) in the lactose crystals, and the results of the texture evaluation are shown in Table 2. The lactose content of whey processed foods A to E was in the range of 39 to 49%.

[0069] [Table 2]

[0070] Next, the lactose content (%), lactose crystal ratio (%), and the ratio of coarse crystals and fine crystals (%) in the lactose crystals were measured for the whey processed foods F to I, and the texture was evaluated. These results are shown in Table 3. The lactose content was 54% (solid content equivalent), the protein content was 9% (solid content equivalent), and the lipid content was 26% (solid content equivalent) out of 100% by mass of solid content in these whey processed foods.

[0071] [Table 3]

[0072] As shown in Table 2, when the percentage of lactose crystals contained in whey processed foods is low, the roughness felt on the tongue tends to improve and the food becomes smoother, but when the percentage is extremely low, the food becomes smooth but tends to stick to the teeth when biting, making the food less crisp (see the results for whey processed foods D and E).The results in Tables 2 and 3 confirm that by adjusting the percentage of lactose crystals contained in whey processed foods to about 3-5%, it is possible to achieve both smoothness and crispness.

[0073] Furthermore, from the results in Table 3, it was confirmed that whey processed foods in which the percentage of lactose crystals contained in the whey processed foods was adjusted to about 3-5%, and in which the content ratios of coarse lactose crystals with lactose crystal sizes of 30 μm or more and fine lactose crystals with sizes of 10 μm or less, as described above, as observed under a phase contrast microscope, were 10% or less and 70% or more, respectively, calculated as total area relative to the total amount of lactose crystals, had a good crispness and an extremely smooth texture, making them the best whey processed foods that combine smoothness and crispness (see the results for whey processed foods H and I). Figure 2 shows an image of the structure of whey processed food I observed under a phase contrast microscope (objective magnification x10, total magnification x10).

[0074] In the above experimental example 1, the relationship between the proportion of lactose crystals in whey processed foods with a lactose content of 39 to 49% by mass, particularly whey processed foods with a lactose content of 45% by mass, and the proportion of coarse lactose crystals and fine lactose crystals in those lactose crystals, and the texture (smoothness and crispness) was shown.Similarly, for whey processed foods with a lactose content of 20 to 51% by mass, it was found that when the proportion of lactose crystals in the whey processed foods was 3 to 5%, the proportion of coarse lactose crystals in those lactose crystals was 10% or less, and the proportion of fine lactose crystals was 70% or more, a tendency was observed for a smooth, crisp, and good texture to be obtained.

[0075] In the above experimental example 1, the relationship between the proportion of lactose crystals in a whey processed food with a lipid content of 18 to 25% by mass (whey processed food with a cream content of 35%) and the proportion of coarse lactose crystals and fine lactose crystals in those lactose crystals, and the texture (smoothness and crispness) was shown.Similarly, for whey processed foods with a lipid content of 8 to 30% by mass, a tendency was observed that a smooth, crisp, and good texture could be obtained when the proportion of lactose crystals in the whey processed food was 3 to 5%, the proportion of coarse lactose crystals in those lactose crystals was 10% or less, and the proportion of fine lactose crystals was 70% or more. [Industrial Applicability]

[0076] The present invention can be used as a means for achieving the Sustainable Development Goals (SDGs), and can contribute to the achievement of the Sustainable Development Goals (SDGs) and targets. The present invention can particularly contribute to the achievement of Goals 2 and 3 of the Sustainable Development Goals. That is, by providing whey, which is a nutritionally excellent food material containing a large amount of various essential amino acids, proteins, vitamins, and sugars, as a whey processed food, it can contribute to supplying safe and sufficient food to all people, including young women, pregnant and lactating women, and the elderly. In addition, the present invention can particularly contribute to the achievement of Goal 9 of the Sustainable Development Goals. That is, by creating new added value of whey using this technology that suppresses the deterioration of whey, it is possible to promote technological development, research, and innovation such as diversification of industry and creation of added value for products, thereby improving resource utilization efficiency and expanding and improving the efficiency of industrial processes, thereby promoting innovation in a sustainable and resilient manner. In addition, the present invention can particularly contribute to the achievement of Goal 12 of the Sustainable Development Goals. In other words, by effectively utilizing whey, which is often discarded in the cheese manufacturing process, cheese manufacturers can reduce food waste in production and supply chains.Furthermore, by halving food waste, sustainable development and development in harmony with nature can be achieved, ensuring a sustainable production and consumption pattern.

Claims

1. A whey processed food containing lactose in an amount of 20% by mass or more, The percentage of lactose crystals in the whey processed food is 3-5%; and A whey processed food, in which the ratio of coarse lactose crystals to the total lactose crystals in the whey processed food is 10% or less and the ratio of fine lactose crystals is 70% or more; Here, the ratio of lactose crystals is a ratio calculated from the area of ​​the peak at the corresponding position obtained for the test whey processed food, based on the area of ​​the main peak of lactose monohydrate crystals (standard) detected in the range of 2θ = 19.9 to 20.4 ° in the X-ray diffraction pattern measured by an X-ray diffractometer; The proportion of coarse lactose crystals and fine lactose crystals in the lactose crystals is the ratio of the total area of ​​coarse lactose crystal particles and the ratio of the total area of ​​fine lactose crystal particles to the total area of ​​lactose crystal particles in the test whey processed food, which is 100%, as determined by observation with a phase contrast microscope.

2. 2. The whey processed food according to claim 1, which is brown whey cheese, yeast or caramel.

3. A method for making a whey processed food containing 20% ​​by mass or more of lactose smooth to the tongue and reducing adhesion to teeth when chewed, comprising the steps of: The method comprises reducing the percentage of lactose crystals in the whey processed food to 3-5%; and The method as described above, characterized in that the proportion of coarse lactose crystals in the lactose crystals in the whey processed food is 10% or less and the proportion of fine lactose crystals is 70% or more; Here, the ratio of lactose crystals is a ratio calculated from the area of ​​the peak at the corresponding position obtained for the test whey processed food, based on the area of ​​the main peak of lactose monohydrate crystals (standard) detected in the range of 2θ = 19.9 to 20.4 ° in the X-ray diffraction pattern measured by an X-ray diffractometer; The proportion of coarse lactose crystals and fine lactose crystals in the lactose crystals is the ratio of the total area of ​​coarse lactose crystal particles and the ratio of the total area of ​​fine lactose crystal particles to the total area of ​​lactose crystal particles in the test whey processed food, which is 100%, as determined by observation with a phase contrast microscope.

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