Special texture modifier for low-fatty acid emulsion and gradient application process of special texture modifier

Abstract

The invention provides a special texture modifier for low-fatty acid emulsion and a gradient application process of the special texture modifier. The special texture modifier for the low-fatty acid emulsion is prepared by taking lemon peel residues as raw materials through a ball milling-hydration synergistic modification process. The gradient application process specifically comprises the following steps: adding the texture conditioning agent into the production process according to 0.7-0.8% of the mass of the finished yoghurt, wherein the addition mass ratio of the proportioning process to the filling process is 4: 1. By applying the special texture regulator, the whey precipitation rate of the low-fatty acid milk can be reduced to 35.89%, the sense milk fat feeling is improved, and the texture and flavor of the product are synchronously improved. Gradient activation application of the lemon peel pomace in a dairy product system is achieved for the first time, traditional thickening agent compounding is replaced with physical modification, the problem that the utilization rate of agricultural product processing by-products is low is solved, the prepared regulator has ecological friendliness and economical efficiency, and a new scheme is provided for functional dairy product development.

Description

Technical Field

[0001] The present invention belongs to the field of food science, and particularly relates to a texture modifier special for low-fat yogurt and its gradient application process. Background Art

[0002] Low-fat yogurt has common problems such as increased whey separation rate, loose texture, and lack of milk fat feeling due to the reduction of fat content. The current industry solutions have double technical barriers: (1) Functional limitations: Traditional thickeners such as pectin and gelatin can only inhibit whey separation, but cannot compensate for the sensory defects caused by the reduction of fat, and there are religious dietary restrictions and allergy risks for animal-derived ingredients; (2) Defects in modification processes: The utilization of lemon peel residue mostly relies on chemical modifications such as acid-base hydrolysis, with complex processes and secondary pollution. Although the ultrafine grinding physical modification technology can improve the water-holding capacity of fibers, the existing technology has not solved the problem of the dispersion stability of modified fibers in the milk matrix, and has not constructed a gradient application system adapted to the production process. Therefore, there is an urgent need to develop a physical synergistic modification process based on agricultural by-products to simultaneously achieve the coordinated improvement of whey stability and sensory compensation while meeting the requirements of clean label and industrial production. Summary of the Invention

[0003] Technical problems to be solved: The technical problems to be solved by the present invention are to overcome the defects in the existing texture improvement technology for low-fat yogurt, such as single function, large pollution in the modification process, and low utilization rate of by-products, and to provide a texture modifier based on the physical modification of lemon peel residue and its gradient application process.

[0004] Technical solution: A preparation method of a texture modifier special for low-fat yogurt, comprising the following steps: S1. Ball milling treatment: Ball milling the dry lemon peel residue powder at a speed of 400 rpm for 1 h to obtain a modified powder; S2. Hydration treatment: Mix the modified powder with water at a volume ratio of 10%, and stir and hydrate at a speed of 250 rpm for 1 h to obtain the texture modifier special for low-fat yogurt. The texture modifier special for low-fat yogurt prepared by the above method. The gradient application process of the above texture modifier special for low-fat yogurt, comprising the following steps: Add the texture modifier special for low-fat yogurt to the production process in a total amount of 0.7%-0.8% of the mass of the finished yogurt, wherein the mass ratio of addition in the batching process to the filling process is 4:1. Brief Description of the Drawings Figure 1 It is a schematic diagram of the low-fat yogurt preparation process of the present invention; Figure 2 It is a sensory evaluation radar chart of the process optimization group of the present invention. Advantageous Effects: 1. By using the special texture regulator for low-fat yogurt in the present invention and combining with the gradient application process, the whey separation rate is reduced to 35.89%, while the sensory score of milk fat feeling is improved; 2. The physical modification in the present invention replaces the chemical colloid compounding, meeting the requirements of clean label. Specific Embodiments The present invention will be further described below in conjunction with embodiments. The following embodiments are explanations of the present invention and the present invention is not limited to the following embodiments: Embodiment 1 A gradient application process of a special texture regulator for low-fat yogurt includes the following steps: Step 1. Put the dry powder of lemon peel residue into a ball mill, and perform ball milling treatment at a speed of 400 rpm for 1 h to obtain a modified powder; Step 2. Respectively take 0.1 g, 0.75 g and 1.5 g of the modified powder of lemon peel residue, add 10 mL of water to each, and perform stirring and hydration treatment at a speed of 250 rpm for 1 h to obtain hydrated products for standby; Step 3. Measure 4 portions of 100 mL of low-fat milk base material, the temperature of the batching process is 50 °C and lasts for 10 min. Respectively take the hydrated products of 0.1 g, 0.75 g and 1.5 g of the modified powder of lemon peel residue in Step 2, and add them to the batching process at one time. The fourth portion of low-fat milk is not subjected to any treatment. Further perform homogenization treatment, heat up to 60 °C, and maintain the temperature for 5 min. Then perform secondary heat sterilization, the temperature is 95 °C and lasts for 5 min. Ferment at a temperature of 42 °C in a constant temperature incubator for 5 h, stir to break the emulsion and perform filling to prepare low-fat yogurt added with special texture regulators with different concentration gradients. Step 4. Compare the whey separation rates of low-fat yogurt added with special texture regulators with different concentration gradients. The specific test method is as follows: Take 5 g of low-fat yogurt sample in a 10 mL centrifuge tube, and centrifuge at 2500×g at 4 °C for 15 min. Determine the whey separation rate of low-fat yogurt with different lemon peel residue contents by calculating the ratio of the mass of the supernatant after centrifugation to the total mass of the sample. The calculation formula is as follows: We compared the whey separation rates of low-fat yogurt added with special texture regulators with different concentration gradients, and the results are as follows: Table 1 Whey separation rate of low-fat yogurt added with special texture regulators with different concentration gradients* * Different lowercase letters in the same column indicate significant differences, p < 0.05. Considering that a relatively high addition concentration of the special texture regulator in the actual process may cause excessive precipitation at the bottom of the yogurt, adding 0.75% of the special texture regulator can significantly reduce the whey separation rate of low-fat yogurt. Example 2 A special texture regulator for low-fat yogurt and its gradient application process, comprising the following steps: Step 1. Put the dry powder of lemon peel residue into a ball mill, and perform ball milling treatment at a rotation speed of 400 rpm for 1 h to obtain a modified powder; Step 2. Take 2 portions of 0.75 g of the modified lemon peel residue powder, add 10 mL of water to each, and perform stirring and hydration treatment at a rotation speed of 250 rpm for 1 h to obtain 2 portions of hydrated products for standby; Step 3. Measure 100 mL of low-fat milk base material, the temperature of the batching process is 50 °C and lasts for 10 min. Take 1 portion of the hydrated product in Step 2, add 80% of it to the batching process, and further perform homogenization treatment at a temperature of 60 °C for 5 min. Then perform secondary heat sterilization at a temperature of 95 °C for 5 min. Ferment at a temperature of 42 °C in a constant temperature incubator for 5 h, stir to break the emulsion and then fill. When filling, add the remaining 20% of the hydrated lemon peel residue product in Step 2 to prepare low-fat yogurt with a gradient addition of 0.75% of the special texture regulator. Step 4. Take another 2 portions of 100 mL of low-fat milk base material, the temperature of the batching process is 50 °C and lasts for 10 min. Take the second portion of the hydrated product in Step 2 and add it all at once to 1 portion of the low-fat milk base material during the batching process, and do not perform any treatment on the other 1 portion of the low-fat milk. Further perform homogenization treatment on both portions of the low-fat milk at a temperature of 60 °C for 5 min. Then perform secondary heat sterilization at a temperature of 95 °C for 5 min. Ferment at a temperature of 42 °C in a constant temperature incubator for 5 h, stir to break the emulsion and then fill to prepare low-fat yogurt with a non-gradient addition of 0.75% of the special texture regulator and ordinary low-fat yogurt without lemon peel residue. I. Comparison of whey separation rate Quantify the whey separation rate of the low-fat yogurt with a gradient addition of 0.75% of the special texture regulator in Step 3, the low-fat yogurt with a non-gradient addition of 0.75% of the special texture regulator in Step 4, and the ordinary low-fat yogurt without lemon peel residue. The test method is the same as Step 4 of Example 1. II. Comparison of milk fat feeling A double-blind treatment was carried out on the low-fat yogurt with 0.75% special texture modifier added to the gradient in step 3, the low-fat yogurt with 0.75% special texture modifier added non-gradiently in step 4, and the ordinary low-fat yogurt without lemon peel residue. A randomized three-digit coding system was used to anonymously label the samples. All samples to be tested were left to stand and equilibrate at room temperature before sensory evaluation. A specific expert group consisting of 10 professionally trained sensory evaluators was formed. Standardized sensory calibration training had to be completed before the evaluation. The buttery feeling was defined as the feeling related to the smooth, uniform and dense texture of the yogurt on the tongue. Using an improved scoring method, the scores were classified on a 10-point scale (9 points indicating approximate full-fat yogurt, 5 points indicating approximate low-fat yogurt, and 1 point indicating approximate skimmed yogurt). At the same time, this scoring method was also used to conduct sensory evaluations on the appearance color, milk fragrance, roughness, appearance whey separation, and overall acceptability of different yogurts. Strict oral cleaning procedures were implemented before each sample evaluation. The evaluators were required to clean their mouths with a 0.9% saline mouthwash before sample evaluation and maintain a 1-minute rest interval. Table 2 Whey separation rate and sensory scores of buttery feeling of different low-fat yogurts * * Different lowercase letters in the same column indicate significant differences, p < 0.05. The results showed that adding lemon peel residue after ball milling treatment to low-fat yogurt and through the gradient application process could reduce the whey separation rate and improve the buttery feeling. As described above, it is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, without departing from the spirit and technical solution of the present invention. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A preparation method of a texture modifier special for low-fat yogurt, characterized in that, It includes the following steps: S1. Ball milling treatment: Ball mill the dry powder of lemon peel residue at a rotation speed of 400 rpm for 1 h to obtain a modified powder; S2. Hydration treatment: Mix the modified powder and water at a volume ratio of 10%, and stir and hydrate at a rotation speed of 250 rpm for 1 h to obtain a texture modifier special for low-fat yogurt.

2. A texture modifier special for low-fat yogurt prepared by the method according to claim 1.

3. The gradient application process of the texture modifier specifically for low-fat yogurt according to claim 2, characterized in that It includes the following steps: Add the texture modifier special for low-fat yogurt to the production process in a total amount of 0.7%-0.8% of the mass of the finished yogurt product, wherein the mass ratio of addition in the batching process to the filling process is 4:1.

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