Encapsulated natural spicy cheese and method for making same

Abstract

The application provides a kind of encapsulated natural spicy cheese and its preparation method, the chili oil is added in the form of chili oil microcapsule in the spicy cheese, the chili oil microcapsule is prepared by complex coacervation method with the mixture of gelatin and chitosan oligosaccharide as wall material, chili oil as core material, Tween 80 as emulsifier. It is found by orthogonal experiment analysis that when the wall material concentration is 1%, the wall material / core material ratio is 1:1, the pH is 6.5, and the emulsifier Tween 80 content is 2.5%, the prepared chili oil microcapsule has a higher embedding rate of 68.25%. Further comparison by sensory evaluation found that adding chili oil in the form of microcapsule to cheese does not affect the physicochemical components and texture characteristics of cheese and has a positive effect on the flavor of cheese, among which the taste is improved by 13.25%, the flavor is improved by 16.04%, and the aroma is improved by 18.18%.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and specifically relates to an encapsulated natural spicy cheese and its preparation method. Background Technology

[0002] Cheese, also known as curd, is a fresh or fermented dairy product made from cow's milk, cream, partially skimmed milk, buttermilk, or a mixture of these products, through curdling and whey separation. Cheese is rich in high-quality protein, vitamins, minerals, and unsaturated fatty acids, among other beneficial substances. It plays a role in regulating blood lipids, promoting calcium and protein absorption, and preventing cardiovascular diseases; therefore, cheese is often referred to as "the gold of milk."

[0003] Chili peppers are a popular and important vegetable, enjoyed stir-fried, pickled, dried, and processed into condiments such as dried chili peppers, chili powder, chili sauce, and chili oil. They are sold domestically and exported to earn foreign exchange. Especially in recent years, the popularity of chili peppers has swept through the US, Japan, and Western Europe, making them a significant export commodity for my country's agricultural products. The main nutritional and health-promoting component of chili peppers is capsaicin. The biological effects of capsaicin have been extensively studied, revealing its anti-cancer, anti-diabetic, antihypertensive, anti-inflammatory, antibacterial, analgesic, and antioxidant properties. Studies have shown that among chili-consuming populations, most consumers prefer cheeses with a higher spiciness level and are also influenced by the visual appeal of spiciness. Therefore, combining chili peppers with cheese could improve the flavor of cheese and make it more widely accepted.

[0004] Existing spicy cheeses are the popular Mexican chili cheeses, which are fermented for six months, then emulsifiers, cheese starch, and Mexican-specific red and green chilies are added, followed by heating and stirring. This type belongs to the processed cheese category. Another method of making chili cheese abroad involves adding chili flakes or other spices to the curd before extrusion, resulting in a cheese with dispersed chili flakes. However, the addition of chili flakes can easily affect the curd, causing textural defects in the natural cheese. Since the main flavor compounds in chili oil are capsaicin and its homologues, capsaicin has high thermal stability and is insoluble in water. Furthermore, chili oil has hydrophobic properties and antibacterial activity, preventing it from being stably and evenly distributed in cheese and inhibiting its fermentation process.

[0005] Therefore, how to perfectly blend cheese and chili peppers to obtain natural cheese with high sensory quality that meets the preferences of Chinese people is a problem that needs to be solved. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention aims to provide an encapsulated natural spicy cheese and its preparation method, thereby solving the problem of uneven distribution of chili oil in cheese due to its hydrophobicity.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] The first aspect of this invention provides a method for preparing encapsulated natural spicy cheese, comprising the following steps:

[0009] Step 1, Preparation of microcapsules:

[0010] Chili oil microcapsules were prepared by complex coagulation method using a mixture of gelatin and chitosan oligosaccharide as the wall material, chili oil as the core material, and Tween 80 as the emulsifier.

[0011] Step 2, Cheese preparation:

[0012] After pasteurization, the raw milk is cooled and placed in a fermentation tank. Under constant temperature water bath conditions, a starter culture is added to the raw milk and stirred until evenly mixed. After fermentation for a certain period of time, the chili oil microcapsules prepared in step 1 are added. Then, rennet is added. After coagulation is complete, the curd is cut into cubes using a stainless steel cross and longitudinal cutter. After cutting, the cubes are left to stand for a certain period of time and then heated and stirred. When the cheese pH drops to 5.45, the whey is drained by stacking. Finally, the cubes are cut and shaped to obtain encapsulated natural spicy cheese.

[0013] Furthermore, the preparation steps of the microcapsules in step 1 are as follows:

[0014] S11, Emulsification: Take gelatin, chili oil, and emulsifier Tween 80, add them to distilled water and dissolve them at 50°C. After dissolving, emulsify them in a homogenizer to obtain the reaction solution.

[0015] S12, complex coagulation reaction; dissolve chitosan oligosaccharide in distilled water, add it to the reaction solution obtained in S11, adjust the pH of the reaction solution to 6.0-7.0 with NaOH solution, react at a constant temperature for a period of time, stir on a magnetic stirrer to obtain complex coagulation reaction solution;

[0016] S13, cross-linking; place the complex coagulation reaction solution obtained in S12 in an ice-water bath, add glutaraldehyde for cross-linking and adjust the pH to above 7.0, and cross-link and solidify for 1 to 1.5 hours under stirring. After the reaction is completed, centrifuge and take out the supernatant to obtain chili oil microcapsules.

[0017] Furthermore, in step 1, the mass ratio of gelatin to chitosan oligosaccharide is 1:2 to 2:1. Preferably, the mass ratio of gelatin to chitosan oligosaccharide is 1:1.

[0018] Further, in step 1, the wall material concentration is 1%–2%, the wall material / core material ratio is 1:1–1:3, the pH value is 6.0–7.0, and the Tween 80 emulsifier content is 2%–3%. Preferably, the wall material concentration is 1%, the wall material / core material ratio is 1:1, the pH value is 6.5, and the Tween 80 emulsifier content is 2.5%.

[0019] Furthermore, in step 2, the amount of chili oil microcapsules added during cheese preparation is 0.05%.

[0020] The second aspect of this invention provides an encapsulated natural spicy cheese prepared by the method described in the first aspect.

[0021] The advantages of this invention compared to the prior art are as follows:

[0022] 1. In the preparation of the encapsulated natural spicy cheese of the present invention, chili oil is added in the form of chili oil microcapsules. The chili oil microcapsules are prepared by complex coagulation method using a mixture of gelatin and chitosan oligosaccharide as the wall material, chili oil as the core material, and Tween 80 as the emulsifier. Orthogonal experimental analysis showed that when the wall material concentration is 1%, the wall material / core material ratio is 1:1, the pH is 6.5, and the Tween 80 emulsifier content is 2.5%, the encapsulation efficiency of the prepared chili oil microcapsules can reach 68.25%.

[0023] 2. Sensory evaluation comparison revealed that adding chili oil to cheese in microcapsule form does not affect the physicochemical composition and textural characteristics of the cheese and has a positive impact on the flavor of the cheese. Specifically, the texture was improved by 13.25%, the taste by 16.04%, and the aroma by 18.18%. This effectively solves the problem of uneven distribution of chili oil in the cheese due to its hydrophobicity when directly adding chili oil in the preparation of existing spicy cheeses. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0025] Figure 1 The potentials of chitosan oligosaccharide and gelatin at different pH values ​​are shown.

[0026] Figure 2 The potentials of chitosan oligosaccharide and gelatin crosslinked at different pH values ​​are shown.

[0027] Figure 3 The microscopic results of chili oil microcapsules are shown;

[0028] Figure 4 The particle size distribution of chili oil microcapsules is shown. Detailed Implementation

[0029] The detection methods involved in the following embodiments:

[0030] Moisture content determination: The moisture content is determined by direct drying method. The sample is placed in a crucible after constant weight and dried in a drying oven at 101-105℃ until constant weight. The weight is then recorded. The ratio of the mass difference before and after drying to the mass of the sample is the moisture content of the sample.

[0031] Determination of fat content: Soxhlet extraction method according to GB / 5009.6-2016 "National Food Safety Standard - Determination of Fat in Food".

[0032] Protein determination: GB / 5009.5-2016 "National Food Safety Standard - Determination of Protein in Food" uses the Kjeldahl method.

[0033] pH determination: The cheese sample was mixed with sterile physiological saline at a ratio of 1:2, centrifuged at 13000 rpm for 1 min, and the pH of the solution was measured using a pH meter.

[0034] Cheese texture determination: Four types of cheese samples were prepared into 1cm×1cm×1cm sizes, and their texture was analyzed using a physical property analyzer. A P / 36R probe was selected, with the following settings: probe descent speed before measurement 2.0mm / s, testing speed 2.0mm / s, probe return speed after measurement 5.0mm / s, downward deformation 50%, and trigger force 5.0N. The three cheese samples were measured in triplicate, and the average value was taken.

[0035] The raw materials used in the following examples are:

[0036] The raw milk (fat content 3.78%, protein content 3.28%, total solids content 12.58%) was sourced from Hunan New Hope Nanshan Liquid Emulsion Co., Ltd., and was stored at 4℃ and used within one day.

[0037] For the main reagents, see Table 1.

[0038] Table 1 Main Reagents

[0039]

[0040] Example 1

[0041] This embodiment provides a method for preparing encapsulated natural spicy cheese, including the following steps:

[0042] Step 1, Preparation of microcapsules:

[0043] Chili oil microcapsules were prepared by complex coagulation using a mixture of gelatin and chitosan oligosaccharide as the wall material, chili oil as the core material, and Tween 80 as the emulsifier. The specific steps are as follows:

[0044] (1) Emulsification: Take 1% gelatin, 1% chili oil and 2.5% emulsifier Tween80, add 50mL of distilled water and dissolve at 50℃. After dissolving, emulsify in a homogenizer at speed of the sixth gear (≥10000rpm) for about 10min to obtain the reaction solution.

[0045] (2) Complex coagulation reaction: Dissolve 1% chitosan oligosaccharide in 50mL of distilled water, add it to the emulsified reaction solution, and adjust the pH of the reaction solution to 6.5 with 10% NaOH solution. React at a constant temperature for a period of time, and stir on a magnetic stirrer for about 30 minutes to obtain the complex coagulation reaction solution.

[0046] (3) Crosslinking: The complex coagulation reaction solution was placed in an ice-water bath, 2 ml of glutaraldehyde was added for crosslinking and the pH was adjusted to above 7.0. The crosslinking was solidified for 1 to 1.5 h under stirring. After the reaction was completed, the supernatant was removed by centrifugation to obtain chili oil microcapsules.

[0047] The encapsulation rate of the chili oil microcapsules was found to be 68.25%.

[0048] Step 2, Cheese preparation:

[0049] 4 kg of raw milk was pasteurized at 63℃ for 30 min and then cooled to 32℃. The pasteurized raw milk was placed in a fermentation tank and then placed in a 32℃ water bath. R704 direct-inoculation starter culture was added to the raw milk and mixed thoroughly. The starter culture dosage was 0.1 g / L. When the raw milk fermented to pH 6.5, 0.05% chili oil microcapsules were added. Then, rennet was added at a dosage of 0.05 g / L of milk, mixed with distilled water at a ratio of 1:40, and added after 3 min. After coagulation, the curd was cut into 1.5 × 1.5 × 1.5 cm pieces using a stainless steel cross- and longitudinal cutter. 3 After cube-shaped cutting, the cheese was left to stand for 5 minutes. The temperature was then slowly increased from 32°C to 38°C at a rate of 5 minutes per °C. The cheese was then slowly stirred at 38°C until the pH dropped to 5.45. The cheese was then stacked to drain the whey and finally cut and shaped to obtain the encapsulated natural spicy cheese.

[0050] Example 2: Optimization of the wall material for chili oil microcapsules

[0051] This embodiment investigated the changes in zeta potential values ​​of chitosan oligosaccharide and gelatin at different pH values ​​with varying ratios. Specifically, the zeta potential values ​​of chitosan oligosaccharide and gelatin at different pH values ​​were measured to determine the isoelectric point and charge of gelatin. Gelatin and chitosan oligosaccharide were crosslinked at different pH values ​​in ratios of 1:1, 1:2, and 2:1 to find the pH range for crosslinking and the optimal ratio.

[0052] Depend on Figure 1It is known that the isoelectric point of gelatin is between pH 5 and 5.5. Gelatin carries a positive charge before its isoelectric point and a negative charge below it. Chitosan oligosaccharides, on the other hand, carry a positive charge at pH less than 8, and between pH 6 and 7, gelatin and chitosan oligosaccharides carry almost equal amounts of opposite charges. During cheese processing, the pH of cheese after whey drainage is below 5.5. At pH below 5.5, both chitosan oligosaccharides and gelatin carry a positive charge, weakening electrostatic attraction. When chili oil microcapsules are added to cheese, at this pH value, coagulation is disrupted, releasing chili oil into the cheese, which helps improve its texture and flavor.

[0053] In the Figure 2 Analysis revealed that cross-linking gelatin and chitosan oligosaccharides at different ratios and pH levels showed that when the pH was between 6 and 7, the potential value was around 0 mV when the ratio of gelatin to chitosan oligosaccharides was 2:1 and 1:1. Considering all factors, a ratio of 1:1 gelatin to chitosan oligosaccharides was used to prepare chili oil microcapsules.

[0054] Example 3: Particle size distribution of microcapsules

[0055] The size of fat globules in milk is approximately 1-10 μm. Therefore, it was considered to control the particle size of the microcapsules to be consistent with that of the fat globules, thereby avoiding adverse effects from subsequent cheese fermentation. Chili oil microcapsules were prepared using the method described in step 1 of Example 1, and their particle size was measured using a laser particle size analyzer to screen out microcapsules with a size of 1-10 μm.

[0056] Depend on Figure 3 It can be seen that the microscopic results of the microcapsules show a relatively uniform size. The prepared microcapsules meet the required particle size; when the wall material concentration is 1%, the core material ratio is 1:1, the pH is controlled at around 6.5, and the homogenizer speed is set to the sixth gear with a speed ≥10000 rpm, the resulting microcapsule particle size is between 1-10 μm. Figure 4 As shown, this indicates that when the wall material concentration is 1%, the core material ratio is 1:1, the pH is controlled at around 6.5, and the homogenizer speed is set to the sixth gear with a speed ≥10000 rpm, the prepared microcapsules meet the requirements, do not affect the fermentation of cheese, and can be used for addition to cheese.

[0057] Comparative example:

[0058] To investigate the effects of different chili oil addition methods on the physicochemical, textural, and sensory properties of cheese, this comparative example prepared cheese according to the method described in Example 1, with the following differences: when the raw milk fermented to pH=6.5, it was divided into four portions, and 0.05% chitosan oligosaccharide gelatin empty microcapsule solution, chili oil microcapsule solution (i.e., Example 1), and chili oil without encapsulation were added respectively, along with a blank control group.

[0059] The moisture, fat, protein, pH, and texture of the four types of cheese were measured, and sensory evaluation was further conducted.

[0060] 1. Physicochemical and textural properties of cheese:

[0061] Table 2 shows the various indicators of the four types of cheese: There were no significant differences in protein and fat content among the four cheeses (p > 0.05), but significant differences in moisture content and pH (p < 0.05). Specifically, in the cheese with added chili oil microcapsules, compared to the control group, its moisture content was not significantly different (p > 0.05), but its pH was significantly higher than the control group. This is presumably because the cheese with added chili oil microcapsules needs to form a stable network structure, resulting in a slightly slower curdling rate and a slower pH decrease, leading to a higher measured pH value. However, in the group with directly added chili oil, its moisture content was significantly lower than the control group. Increased fat content leads to decreased cheese hardness and increased fat globule size. As shown in Table 3, in this comparative example, the addition of chili oil microcapsules did not significantly affect the cheese hardness compared to the control group, nor did its elasticity and chewiness differ significantly (p > 0.05), but its cohesiveness and adhesiveness were significantly different compared to the control group (p < 0.05).

[0062] Table 2 Physicochemical components of different cheeses

[0063]

[0064] Note: Different letters in the same row indicate significant differences between groups (P < 0.05).

[0065] Table 3. Texture evaluation results of different cheeses

[0066]

[0067] Note: Different letters in the same row indicate significant differences between groups (P < 0.05).

[0068] 2. Sensory evaluation of cheese

[0069] A sensory evaluation team of 10 people, aged 18-25, was established. Internal screening and trial training of the evaluators were conducted in accordance with GB / T16291.1—2012 "General Guidelines for the Selection, Training and Management of Sensory Evaluators Part 1: Selection of Evaluators". Sensory evaluations were conducted in a designated laboratory with partitions separating the participants. Cheeses were scored according to the five indicators in Table 4, with a scoring scale of 0-20 points. Two samples of each of the four types of cheese were prepared. Each cheese was cut into a 3cm cube and placed in a covered 60mL soufflé cup. Paper ballots were used to collect scores. A mandatory 5-minute rest period was implemented between samples, and participants rinsed their mouths with deionized water.

[0070] Table 4 Descriptive Sensory Evaluation Form

[0071]

[0072] The sensory evaluation results of the four types of cheese are shown in Table 5 below. There were no significant differences in texture among the four cheeses (p > 0.05). In terms of taste, flavor, and aroma, the chili oil microcapsule cheese had a higher sensory evaluation score compared to the control group. The group with directly added chili oil also received a higher sensory evaluation score than the control group. However, there were significant differences in color among the four cheeses (p < 0.05). The chili oil microcapsule cheese, due to the addition of chili oil microcapsules, had a slightly yellow color and received a lower sensory evaluation score. The cheese with directly added chili oil remained milky white and received a higher sensory evaluation score. The presumably, this is because the casein emulsifying ability of the casein in the milk was not strong enough, leading to some chili oil being expelled with the whey during subsequent cheese making, while the remaining chili oil was unevenly dispersed in the cheese.

[0073] Table 5 Sensory evaluation results

[0074]

[0075] Note: Different letters in the same row indicate significant differences between groups (P < 0.05).

[0076] In summary, adding chili oil to cheese in microencapsulation does not affect the physicochemical composition and textural characteristics of the cheese and has a positive impact on its flavor. Specifically, the texture is improved by 13.25%, the taste by 16.04%, and the aroma by 18.18%. This effectively solves the problem of uneven distribution of chili oil in the cheese due to its hydrophobicity when directly adding it during the preparation of existing spicy cheeses.

[0077] Finally, it should be noted that the above description is only used to illustrate the technical solutions of the present invention and is not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention.

Claims

1. A method for preparing encapsulated natural spicy cheese, characterized in that, The preparation method includes the following steps: Step 1, Preparation of microcapsules: Chili oil microcapsules were prepared by complex coagulation method using a mixture of gelatin and chitosan oligosaccharide as the wall material, chili oil as the core material, and Tween 80 as the emulsifier. Gelatin has an isoelectric point between pH 5 and 5.5, while chitosan oligosaccharides are positively charged at pH less than 8. Step 2, Cheese preparation: After pasteurization, the raw milk is cooled and placed in a fermentation tank. Under constant temperature water bath conditions, a starter culture is added to the raw milk and stirred until evenly mixed. After fermentation for a certain period of time, the chili oil microcapsules prepared in step 1 are added. Then, rennet is added. After coagulation is complete, the curd is cut into cubes using a stainless steel cross and longitudinal cutter. After cutting, the cubes are left to stand for a certain period of time and then heated and stirred. When the cheese pH drops to 5.45, the whey is drained by stacking. Finally, the cubes are cut and shaped to obtain encapsulated natural spicy cheese.

2. The method for preparing encapsulated natural spicy cheese according to claim 1, characterized in that, Step 1: The preparation steps of the microcapsules are as follows: S11, Emulsification: Take gelatin, chili oil, and emulsifier Tween 80, add them to distilled water and dissolve them at 50°C. After dissolving, emulsify them in a homogenizer to obtain the reaction solution. S12, complex coagulation reaction; dissolve chitosan oligosaccharide in distilled water, add it to the reaction solution obtained in S11, adjust the pH of the reaction solution to 6.0-7.0 with NaOH solution, react at a constant temperature for a period of time, stir on a magnetic stirrer to obtain complex coagulation reaction solution; S13, cross-linking; place the complex coagulation reaction solution obtained in S12 in an ice-water bath, add glutaraldehyde for cross-linking and adjust the pH to above 7.0, and cross-link and solidify for 1~1.5 h under stirring. After the reaction is completed, centrifuge and take out the supernatant to obtain chili oil microcapsules.

3. The method for preparing encapsulated natural spicy cheese according to claim 1, characterized in that, In step 1, the mass ratio of gelatin to chitosan oligosaccharide is 1:2 to 2:

1.

4. An encapsulated natural spicy cheese prepared by any one of claims 1 to 3.

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