CN106880032A - A kind of compound lactalbumin gel of Lotus Root Starch and preparation method - Google Patents

Abstract

The invention relates to a whey protein gel compounded with lotus root starch. The strength of the whey protein gel is greater than 100.0g, the water holding capacity is greater than 75.0%, and the storage modulus is greater than 3780.0Pa. The preparation steps of the whey protein gel are as follows: (1) prepare whey protein stock solution with isolated whey protein and deionized water; (2) prepare lotus root starch stock solution with lotus root starch and deionized water; (3) ) Mix the whey protein stock solution and the lotus root starch stock solution in a certain volume ratio, add calcium chloride and deionized water, and adjust the pH value with acid or alkali; The whey protein gel compounded with lotus root starch was obtained. The solvent used in the preparation process of the present invention is water, and the cost is low; the preparation process is heated in a hot water bath at 95°C to form a gel, the process is simple, the process is controllable, safe and environmentally friendly, and it is beneficial to form a gel with high strength, good elasticity, and good water retention. gel.

Description

A kind of whey protein gel compounded with lotus root starch and its preparation method

technical field

The invention belongs to the technical field of milk protein processing, and in particular relates to a whey protein gel compounded with lotus root starch and a preparation method thereof.

Background technique

Lotus root (scientific name Nelumbo nucifern), a perennial aquatic plant of the genus Nelumbo, is widely distributed in subtropical countries, such as China, Australia, and Italy. According to statistics, the total planting area of lotus root in China reaches 330,000 hectares. Relevant studies have shown that lotus root contains a lot of nutrients such as starch, dietary fiber, protein, amino acid, reducing sugar, minerals, carotene and vitamins, so lotus root is often used as an important raw material for salads, candies and fried foods. In addition, lotus root is also used as a folk remedy for fever, dysentery, dizziness, heat stroke, and gastrointestinal ailments. Among all nutrients, starch is the most abundant component in lotus root, including amylose and amylopectin. At present, lotus root starch is mainly used in catering, traditional candy and food additives. However, there are few reports on the deep processing and application of lotus root starch.

Whey protein is a by-product of the cheese production process. It has certain nutritional and biological activities. It is often used as a food additive to improve the processing characteristics of food raw materials and has a wide range of applications in the food industry. Whey protein also has gelling, emulsifying, and foaming properties, and gelling is the most widely used property. In recent years, people have conducted a lot of research on the formation mechanism of whey protein gels, and revealed that heat-induced gelation is the most common gelation method. The heat-induced gelation process includes the initial denaturation of proteins, structure unfolding, and aggregation formation. A gel network with a certain spatial structure. However, the existing whey protein gels are poor in strength, elasticity and water retention, which directly affects the texture and mouthfeel of protein gel foods.

As a biomacromolecular polysaccharide, starch can interact with proteins to improve the gel properties of proteins. At present, these studies mainly focus on wheat starch, corn starch and potato starch. The research on lotus root starch mainly focuses on the physical and chemical properties, granule morphology and thermal properties, but there are no related reports on the application of lotus root starch in whey protein gel at home and abroad.

Contents of the invention

In order to further improve the strength, elasticity and water retention of whey protein gel, the invention provides whey protein gel compounded with lotus root starch and a preparation method.

The whey protein gel compounded with lotus root starch has strength greater than 100.0g, water holding capacity greater than 75.0%, and storage modulus greater than 3780.0Pa.

The operation steps of preparing a whey protein gel compounded with lotus root starch are as follows:

(1) Preparation of whey protein stock solution

Whey protein isolate and deionized water were magnetically stirred and mixed evenly at room temperature, and allowed to stand at 4°C for 10-12 hours to obtain a whey protein stock solution with a mass concentration of 20%.

(2) Preparation of lotus root starch stock solution

Stir and mix the lotus root starch and deionized water evenly under heating conditions, and let stand at 4°C for 2 to 3 hours to obtain a lotus root starch stock solution with a mass concentration of 5%;

(3) Preparation of whey protein gel compounded with lotus root starch

Mix the whey protein stock solution and the lotus root starch stock solution, add deionized water to dilute, and add calcium chloride according to the mass volume ratio of 5.55-22.2g/L, and then use acid or alkali to adjust the pH value to 5-9, A mixed solution is obtained; the mass concentration of whey protein in the mixed solution is 10%, and the mass concentration of lotus root starch is 0.50-1%; heated in a water bath, rapidly cooled in an ice-water bath, and stabilized for more than 20 h at 4°C to obtain lotus root starch Complex whey protein gel.

Further defined technical solutions are as follows:

The whey protein isolate in step (1) is bovine whey protein isolate.

Magnetic stirring in step (1): magnetic stirring for 2-3 hours at a temperature of 20° C. and a rotational speed of 500 r/min.

The lotus root starch described in step (2) is the lotus root starch purchased from supermarkets.

Heating and stirring in step (2): stirring for 0.5 to 1 hour at a temperature of 80° C. and a rotational speed of 500 r/min.

The acid in step (3) is hydrochloric acid (HCl) with a concentration of 0.1 M; the base is sodium hydroxide (NaOH) with a concentration of 0.1 M.

In step (3), heat in a water bath at a temperature of 95°C for 25-35 min.

Beneficial technical effect of the present invention is embodied in the following aspects:

1. The strength of the whey protein gel compounded with lotus root starch of the present invention is greater than 100.0g, the water holding capacity is greater than 75.0%, and the storage modulus is greater than 3780.0Pa. The strength of the whey protein gel in the prior art is less than 100.0g, The water holding capacity is less than 70.0%, and the storage modulus is less than 3000.0Pa.

2. The solvent used in the preparation process of the present invention is water, and the cost is low; the preparation process is to form a gel by heating in a hot water bath at 95°C. Sexy gel.

detailed description

Below in conjunction with embodiment, the present invention will be further described.

The source of raw materials used in the following examples is described as follows:

Bovine whey protein isolate was purchased from Sangon Bioengineering (Shanghai) Co., Ltd., and lotus root starch was purchased from Carrefour Supermarket in Hefei.

Example 1

The operation steps of preparing the whey protein gel compounded with lotus root starch are as follows:

Step 1: Prepare Whey Protein Stock Solution

Weigh 20 g bovine whey protein isolate powder into 100 ml deionized water, stir magnetically at 500 r/min for 2 h at room temperature, and then prepare whey protein stock solution with a mass concentration of 20% at 4 °C for 12 h.

Step 2: Preparation of lotus root starch stock solution

Weigh 5 g of lotus root starch into 100 ml of deionized water, heat and stir at 80 °C for 0.5 h, and prepare a stock solution of lotus root starch with a mass concentration of 5%.

Step 3: Prepare lotus root starch complex whey protein

Measure respectively 50 ml of the whey protein stock solution obtained in step 1 and 10 ml of the lotus root starch stock solution obtained in step 2 with a graduated cylinder and place in a 200 ml beaker, add 0.555 g of calcium chloride solid therein, and then add Dilute to 100 ml with deionized water, adjust the pH value of the mixed solution to 5 with 0.1 M HCl solution at the same time, and prepare a mixture with a whey protein mass concentration of 10%, lotus root starch mass concentration of 0.50%, and a calcium chloride concentration of 0.05 M. Liquid 100 ml.

Step 4: Heat the mixture obtained in step 3 in a water bath at 95°C for 30 min, place it in an ice-water bath for rapid cooling, and finally stabilize it at 4°C for 24 h to obtain a whey protein gel compounded with lotus root starch.

The strength of the whey protein gel compounded by lotus root starch is 143.7g, the water holding capacity is 77.5%, and the storage modulus is 3781.0Pa; this method obtains the strength, water retention and energy storage of the whey protein gel compounded by lotus root starch The modulus is improved relative to whey protein gels in the prior art.

Example 2

The operation steps of preparing the whey protein gel compounded with lotus root starch are as follows:

Step 1: Weigh 20 g of whey protein isolate powder into 100 ml of deionized water, stir magnetically at 500 r/min at room temperature for 2 h, and then prepare whey protein stock solution with a concentration of 20% at 4°C for 12 h.

Step 2: Weigh 5 g of lotus root starch in 100 ml of deionized water, heat and stir at 80°C for 0.5 h, and prepare a stock solution of lotus root starch with a concentration of 5%.

Step 3: Take respectively 50 ml of the whey protein stock solution obtained in step 1 and 15 ml of the lotus root starch stock solution obtained in step 2 with a graduated cylinder and place in a 200 ml beaker, add 1.11 g of calcium chloride solid therein, and then add to the mixture Add deionized water to the solution and dilute to 100 ml, and adjust the pH value of the mixed solution to 9 with 0.1 M NaOH solution at the same time, make the whey protein mass concentration 10%, lotus root starch mass concentration 0.75%, and calcium chloride concentration of 10%. 0.10 M mixed solution 100 ml.

Step 4: Heat the mixture obtained in step 3 in a water bath at 95°C for 30 min, place it in an ice-water bath for rapid cooling, and finally stabilize it at 4°C for 24 h to obtain a whey protein gel compounded with lotus root starch.

The strength of the whey protein gel compounded with lotus root starch is 256.8g, the water holding capacity is 83.2%, and the storage modulus is 7383.8Pa; the strength and water retention of the whey protein gel compounded with lotus root starch obtained by this method are relatively high , the storage modulus is relatively large.

Example 3

The operation steps of preparing the whey protein gel compounded with lotus root starch are as follows:

Step 1: Weigh 20 g of whey protein isolate powder into 100 ml of deionized water, stir magnetically at 500 r/min at room temperature for 2 h, and then prepare whey protein stock solution with a concentration of 20% at 4°C for 12 h.

Step 2: Weigh 5 g of lotus root starch in 100 ml of deionized water, heat and stir at 80 °C for 0.5 h, and prepare a stock solution of lotus root starch with a concentration of 5%.

Step 3: Measure 50 ml of the whey protein stock solution obtained in step 1 and 20 ml of the lotus root starch stock solution obtained in step 2 with a measuring cylinder respectively and place in a 200 ml beaker, add 1.665g of calcium chloride solid therein, and then add to the mixing Add deionized water in the solution and dilute to 100 ml, adjust the pH value of the mixed solution with 0.1 M NaOH solution at the same time to be 7, make the whey protein mass concentration 10%, lotus root starch mass concentration 1%, calcium chloride concentration 1%. 0.15 M mixed solution 100 ml.

Step 4: The mixture obtained in step 3 was heated in a water bath at 95°C for 30 min, then placed in an ice-water bath for rapid cooling, and finally stabilized at 4°C for 24 h to obtain a whey protein gel compounded with lotus root starch.

The strength of the whey protein gel compounded with lotus root starch is 359.4g, the water holding capacity is 94.8%, and the storage modulus is 16468.3Pa. The whey protein gel compounded with lotus root starch obtained by this method has high strength and good water retention. The storage modulus is large.

Claims (7)

1. A whey protein gel compounded with lotus root starch, characterized in that: the strength of the whey protein gel is greater than 100.0g, the water holding capacity is greater than 75.0%, and the storage modulus is greater than 3780.0Pa. 2. prepare the method for the compound whey protein gel of a kind of lotus root starch described in claim 1, it is characterized in that operating steps are as follows: (1) Preparation of whey protein stock solution Whey protein isolate and deionized water were magnetically stirred and mixed evenly at room temperature, and allowed to stand at 4°C for 10-12 hours to obtain a whey protein stock solution with a mass concentration of 20%. (2) Preparation of lotus root starch stock solution Stir and mix the lotus root starch and deionized water evenly under heating conditions, and let stand at 4°C for 2 to 3 hours to obtain a lotus root starch stock solution with a mass concentration of 5%; (3) Preparation of whey protein gel compounded with lotus root starch Mix the whey protein stock solution and the lotus root starch stock solution, add deionized water to dilute, and add calcium chloride according to the mass volume ratio of 5.55-22.2g/L, and then use acid or alkali to adjust the pH value to 5-9, A mixed solution is obtained; the mass concentration of whey protein in the mixed solution is 10%, and the mass concentration of lotus root starch is 0.50-1%; heated in a water bath, rapidly cooled in an ice-water bath, and stabilized for more than 20 h at 4°C to obtain lotus root starch Complex whey protein gel. 3. The method for whey protein gel compounded with lotus root starch according to claim 2, characterized in that: the whey protein isolate in step (1) is bovine whey protein isolate. 4. A method for whey protein gel compounded with lotus root starch according to claim 2, characterized in that: magnetic stirring in step (1): magnetic stirring for 2 to 3 hours at a temperature of 20°C and a rotational speed of 500r/min . 5 . The method of whey protein gel compounded with lotus root starch according to claim 2 , characterized in that: heating and stirring in step (2): stirring at a temperature of 80° C. and a rotational speed of 500 r/min for 0.5 to 1 hour. 6. The method for whey protein gel compounded with lotus root starch according to claim 2, characterized in that: the acid in step (3) is hydrochloric acid (HCl) with a concentration of 0.1 M; the alkali is a concentration of 0.1 M M Sodium Hydroxide (NaOH). 7. The method for whey protein gel compounded with lotus root starch according to claim 2, characterized in that: in step (3), heating in a water bath at a temperature of 95°C for 25-35 min.