TWI700042B - Process for preparing whey protein gel - Google Patents

Abstract

A low acidity preparation process for whey protein gel includes adding citric acid, sodium citrate, potassium citrate and sodium carbonate followed by sterilization to form a whey protein gel without adding a thickener or gelling agent and having a high content of whey protein and desired properties such as hardness, water retention, and gel strength, and palatability.

Description

Method for preparing whey protein gel

The invention relates to a preparation method of whey protein gel, in particular to a low acid preparation method of whey protein gel.

Whey protein refers to the general term of the remaining protein in the whey after precipitation of casein at pH 4.6. Because of its rich nutritional value and special functionality, it has been widely used in various food fields. In recent years, the rise of sports trends has caused the output value of products such as whey protein powder, whey protein food and whey protein bars to continue to rise in the sports nutrition supplement market.

Whey protein is usually heated to above 70°C in a low acid environment (>pH4.6) to form aggregates or gels, but the formed gel has voids and undesirable properties (hardness, hardness, Water retention and gel strength), so it is not conducive to heat sterilization. At present, the whey protein gel prepared by the acidification process (under pH 4.6) can lower the threshold of heat sterilization (the sterilization can be completed at about 95°C) and avoid serious denaturation of whey protein, but in order to increase whey protein curdling For the stability of the gel, other edible gels will be added in the process to gel together.

A main purpose of the present invention is to provide a low-acid preparation method of whey protein gel without thickener or gelling agent.

Another object of the present invention is to provide a low-acid preparation method for whey protein gel, which has a pH of 5.9-7.5, a gel strength of 25.10-158.6 g, and a hardness of 8.15-134.726 g. And 24.12-68.99% water retention.

Another object of the present invention is to provide a simple low-acid preparation method for whey protein gel, in which only four commonly used methods such as citric acid, sodium citrate, potassium citrate and sodium bicarbonate are used in addition to whey protein. Edible ingredients.

Another object of the present invention is to provide a low-acid preparation method of whey protein gel, which can be used for commercial sterilization at 121°C without adversely affecting the properties of whey protein gel (hardness, water retention, and coagulation). Glue strength) and palatability.

A low acid preparation method of whey protein gel completed according to the present invention includes the following steps: (1) Disperse or dissolve 8%-15% by weight of whey protein powder in water or an aqueous citric acid solution, and the lemon The acid aqueous solution has less than 0.5% by weight of citric acid; (2) 0-0.5% by weight of sodium citrate, 0-0.5% by weight of potassium citrate, and 0-0.5% by weight are added to the dispersion or aqueous solution obtained in (1) above % Sodium bicarbonate, wherein the amount of sodium citrate and potassium citrate cannot be 0 at the same time; when one of sodium citrate and potassium citrate is 0, the above (1) must use citric acid aqueous solution; and the bicarbonate Sodium is selectively added; (3) The intermediate product obtained in (2) above is subjected to heat sterilization heat treatment, and then cooled to form a whey protein gel. All of the above weight% is added with water, citric acid, and citric acid. The weight sum of sodium, potassium citrate and sodium bicarbonate is the basis.

The addition of sodium bicarbonate in the method of the present invention can adjust the pH value of the formed whey protein gel, and can also adjust the hardness of the formed whey protein gel.

Preferably, 0.1% to 0.5% by weight of sodium bicarbonate is added in the foregoing step (2).

Preferably, the heat sterilization heat treatment of the aforementioned step (3) is heated at 100-140°C for 1-20 minutes. More preferably, heat at 121°C for 10 minutes.

Preferably, in the foregoing step (1), 8% by weight of whey protein powder is dispersed or dissolved in water or an aqueous citric acid solution.

Preferably, the aforementioned step (1) disperses 8%-15% by weight of whey protein powder in water; step (2) adds 0.05-0.5% by weight of sodium citrate, and to the dispersion obtained in (1) above 0.05-0.5% by weight of potassium citrate, but without sodium bicarbonate.

Preferably, the aforementioned step (1) disperses 8%-15% by weight of whey protein powder in water; step (2) adds 0.05-0.5% by weight sodium citrate, 0.05% by weight to the dispersion obtained in (1) above -0.5% by weight potassium citrate, and 0.1% to 0.5% by weight sodium bicarbonate.

Preferably, the aforementioned step (1) dissolves 8%-15% by weight of whey protein powder in an aqueous citric acid solution; step (2) adds 0.05-0.4% by weight sodium citrate to the aqueous solution obtained in (1) above, And 0.05-0.4% by weight potassium citrate, but without sodium bicarbonate.

Preferably, the aforementioned step (1) dissolves 8%-15% by weight of whey protein powder in an aqueous citric acid solution; step (2) adds 0.05-0.4% by weight sodium citrate to the aqueous solution obtained in (1) above, 0.05-0.4 wt% potassium citrate, and 0.1 wt% to 0.5 wt% sodium bicarbonate.

Preferably, the whey protein gel formed in the aforementioned step (3) has a pH value of 5.9-7.5, a gel strength of 25.10-158.6 g, a hardness of 8.15-134.726 g, and a water retention of 24.12-68.99%.

The present invention provides a low-acid preparation method of whey protein gel, in which the protein is formed into a gel by shielding the hydrophobic interaction of electrons or special ions by adding mineral salt ions. The concentration and type of mineral salt play an important role in the structure, spatial shape and gel characteristics of the protein gel. A lower mineral salt concentration can induce the formation of a transparent and filiform gel, while a relatively high mineral salt At concentration, a cloudy granular gel is formed. In the present invention, citric acid and its derivative salts, sodium bicarbonate are added to make the whey protein low-acid solution appear liquid during the process, and then the commercial sterilization treatment (121°C) is used to form a stable gel. The preparation process is simple And there is no need to add gel. The sterilized whey protein gel has stable quality and good palatability.

The formula of the invention is simple in composition and conforms to the trend of clean labeling with less addition. From the perspective of the manufacturing process, the present invention has only one heat treatment step for commercial sterilization after the components are mixed, and the procedure is simple.

Whey protein suitable for use in the present invention includes, but is not limited to, refined whey protein powder (whey protein content is more than 80% by weight), such as whey protein concentrate (available from, for example, FONTERRA Cooperative, New Zealand; Lactoprot , Germany (trade names LACTOMIN 80-S and LACTOMIN 80-S HG); Leprino Food, USA), and whey protein isolate (eg Bipro, USA).

The weight% of the raw materials used in the following examples is based on the weight sum of water, citric acid, sodium citrate, potassium citrate and sodium bicarbonate. Example 1 Preparation

(1) Simply use water or dissolve citric acid in water to prepare 0, 0.15% and 0.3% citric acid aqueous solutions; (2) Add 8% refined whey protein powder (FONTERRA, New Zealand); (3) Add 0, 0.25% and 0.5% sodium citrate, 0, 0.25% and 0.5% potassium citrate and 0, 0.25% and 0.5% sodium bicarbonate to the mixture of (2) above (4) The mixed whey protein solution of (3) above is subjected to commercial sterilization treatment (121°C, 10 minutes), and the whey protein gel is formed after cooling. Gel strength determination

Refer to international standards (ISO/GMIA; P/0.5&HDP/BJB), use standard probe P/0.5, press down speed 1 mm/sec, and press down to a maximum force of 4 mm. Hardness determination

Refer to the method of Cui et al. (Cui Xuhai et al., Chinese Agricultural Science, 41(3): 803-807, 2008), using probe P/0.5, pre-test speed: 5 mm/sec, test speed: 1 mm/sec, Speed after test: 10 mm/sec, the value measured by pressing down to the force (5 g) felt by the sample and then pressing down 4 mm. Water retention measurement

Refer to the method of Cui et al. (Cui Xuhai et al., Chinese Agricultural Science, 41(3): 803-807, 2008) for minor correction, weigh 4-5 g whey protein gel sample (W1), and wrap it with gauze Fix it in a 50 ml centrifuge tube and centrifuge at 3000 rpm for 6 minutes. Take out the sample from the gauze and measure the weight after centrifugation (W2), calculate the water retention according to the following, and repeat the experiment twice. Water retention (%)=[Sample weight after centrifugation (W2)/Sample weight before centrifugation (W1)]Í100

The raw materials used, dosage and texture test results (gel strength, hardness and water retention) are listed in Table 1.

Table 1 Group Citric acid% Potassium citrate% Sodium citrate% Sodium bicarbonate% PH value Gel strength g Hardness g Water retention% 1 0.3 0.25 0.25 0.5 6.606 40.05 34.23 48.75% 2 0.15 0.5 0 0.25 6.613 64.70 33.70 63.56% 3 0 0.25 0.5 0.25 7.215 44.95 13.08 53.78% 4 0.15 0.25 0.5 0.5 7.124 43.40 8.55 24.12% 5 0.15 0.25 0 0 5.736 104.20 58.49 44.54% 6 0.15 0.25 0.25 0.25 6.606 74.35 41.67 52.87% 7 0.3 0 0.25 0.25 5.974 148.15 101.99 49.35% 8 0 0.25 0.25 0.5 7.433 (Below the detection limit of the instrument) (Below the detection limit of the instrument) 24.78% 9 0.3 0.25 0.5 0.25 6.035 70.80 41.20 50.89% 10 0 0.5 0.25 0.25 6.523 25.10 11.65 64.38% 11 0.3 0.5 0.25 0.25 6.021 97.95 67.33 45.87% 12 0.15 0.25 0.5 0 6.488 65.05 44.30 62.73% 13 0.15 0.5 0.5 0.25 6.503 89.25 59.59 46.71% 14 0.15 0 0.25 0 5.646 62.15 58.64 53.06% 15 0.3 0.25 0.25 0 6.503 34.25 38.43 59.49% 16 0.15 0.5 0.25 0 5.829 90.95 57.78 42.05% 17 0.3 0.25 0 0.25 5.992 158.60 134.73 46.70% 18 0.15 0 0.5 0.25 6.48 78.75 32.79 59.70% 19 0 0.25 0.25 0 6.844 74.80 35.43 69.00% 20 0.15 0.5 0.25 0.5 6.905 27.65 8.15 25.50% Example 2

The composition of Table 2 below repeats the steps and measurements of Example 1. Table 2 also lists the measurement results.

Table 2 Material composition Proportion (%) Gel strength hardness Water retention pH water 91.51% Citric acid 0.00% 56.57 46.19 68.29% 6.65 Whey Protein Concentrate (FONTERRA, New Zealand) 8.00% Potassium citrate 0.32% Sodium citrate 0.17% Sodium bicarbonate 0.00% Example 3

The composition of Table 3 below repeats the steps and measurements of Example 1. Table 3 also lists the measurement results.

table 3 Material composition Proportion (%) Gel strength hardness Water retention pH water 91.32% Citric acid 0.00% 61.40 36.35 59.61% 6.90 Whey Protein Concentrate (LACTOMIN 80-S) 8.00% Potassium citrate 0.34% Sodium citrate 0.34% Sodium bicarbonate 0.000% Example 4

Except for further dissolving sugar and citric acid in water, the composition in Table 4 below repeats the steps and measurements of Example 1. Table 4 also lists the measurement results.

Table 4 Material composition Proportion (%) Gel strength hardness Water retention pH water 82.35% Citric acid 0.05% 81.10 99.13 69.0% 7.50 Whey Protein Isolate (Bipro, USA) 12.00% granulated sugar 5.00% Potassium citrate 0.05% Sodium citrate 0.05% Sodium bicarbonate 0.50% Example 5

Except for further dissolving sugar, liquid lemon flavor and honey together with citric acid in water, the composition in Table 5 below repeats the steps and measurements of Example 1. Table 5 also lists the measurement results.

table 5 Material composition Proportion (%) Gel strength hardness Water retention pH water 84.69% Citric acid 0.02% 73.75 109.10 66.28% 6.59 Whey Protein Concentrate (FONTERRA, New Zealand) 8.00% granulated sugar 5.00% Potassium citrate 0.32% Sodium citrate 0.17% Liquid Lemon Spice 0.30% honey 1.50%

Figures 1 to 4 show the appearance of the whey protein gel product prepared in Example 2-5, in which Figure 1, Figure 2 and Figure 4 are yellow and opaque whey protein gels, and Figure 3 is light yellow Transparent whey protein gel.

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Figure 1 is a photograph of a whey protein gel product prepared according to Example 2 of the present invention. Figure 2 is a photograph of a whey protein gel product prepared according to Example 3 of the present invention. Figure 3 is a photograph of a whey protein gel product prepared according to Example 4 of the present invention. Figure 4 is a photograph of a whey protein gel product prepared according to Example 5 of the present invention.

Claims (10)

A method for preparing whey protein gel with low acidity, comprising the following steps: (1) Dispersing or dissolving 8%-15% by weight of whey protein powder in water or an aqueous citric acid solution, the citric acid aqueous solution having a weight of less than 0.5 % Citric acid; (2) Add 0-0.5 wt% sodium citrate, 0-0.5 wt% potassium citrate, and 0-0.5 wt% sodium bicarbonate to the dispersion or aqueous solution obtained in (1) above, wherein The amount of sodium citrate and potassium citrate cannot be 0 at the same time; when one of sodium citrate and potassium citrate is 0, the above step (1) must use citric acid aqueous solution; when the above step (1) does not use lemon In the case of an aqueous acid solution, the amount of sodium bicarbonate used is less than 0.5% by weight; and the sodium bicarbonate is selectively added; (3) the intermediate product obtained in the above step (2) is subjected to heat sterilization heat treatment, and then cooled to form Whey protein gel, all of the above weight% is based on the combined weight of water, citric acid, sodium citrate, potassium citrate and sodium bicarbonate. According to the preparation method of claim 1, wherein in step (2), 0.1% to 0.5% by weight of sodium bicarbonate is added; when step (1) does not use citric acid aqueous solution, the amount of sodium bicarbonate is less than 0.5% by weight. The preparation method of claim 1, wherein the heat sterilization heat treatment of step (3) is heated at 100-140°C for 1-20 minutes. The preparation method of claim 1, wherein the heat sterilization heat treatment of step (3) is heated at 121°C for 10 minutes. The preparation method according to claim 1, wherein in step (1), 8% by weight of whey protein powder is dispersed or dissolved in water or an aqueous citric acid solution. The preparation method of claim 1, wherein step (1) disperse 8%-15% by weight of whey protein powder in water; step (2) add 0.05-0.5% by weight to the dispersion obtained in (1) above Sodium citrate, and 0.05-0.5% by weight potassium citrate, but sodium bicarbonate is not added. The preparation method of claim 1, wherein step (1) disperse 8%-15% by weight of whey protein powder in water; step (2) add 0.05-0.5% by weight to the dispersion obtained in (1) above Sodium citrate, 0.05-0.5 wt% potassium citrate, and 0.1 wt% to less than 0.5 wt% sodium bicarbonate. The preparation method of claim 1, wherein step (1) dissolves 8%-15% by weight of whey protein powder in an aqueous citric acid solution; step (2) adds 0.05-0.4 weight to the aqueous solution obtained in (1) above % Sodium citrate, and 0.05-0.4% by weight potassium citrate, but without sodium bicarbonate. The preparation method of claim 1, wherein step (1) dissolves 8%-15% by weight of whey protein powder in an aqueous citric acid solution; step (2) adds 0.05-0.4 weight to the aqueous solution obtained in (1) above % Sodium citrate, 0.05-0.4% by weight potassium citrate, and 0.1% to 0.5% by weight sodium bicarbonate. The preparation method of claim 1, wherein the whey protein gel formed in step (3) has a pH value of 5.9-7.5, a gel strength of 25.10-158.6g, a hardness of 8.15-134.726g, and 24.12-68.99% Water retention.

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