Ready-to-eat small crispy meat with Tibetan tea flavor and preparation method thereof

Abstract

The invention relates to instant small crispy meat with Tibetan tea flavor and a preparation method thereof. The preparation process comprises the following steps: pickling streaky pork, and soaking the streaky pork with a functional emulsion constructed by using tea polyphenol, tea polysaccharide, Tibetan tea and avocado as main components; a double-layer powder coating process is adopted, the first layer is composed of high-viscosity modified starch, egg white powder and Tibetan tea powder, and a moisture barrier layer is formed through hot oil presetting; the secondary layer adopts pregelatinized hydroxypropyl starch, wheat protein and a calcium carbonate cross-linking agent to construct a fragile framework, so that the oil absorption rate is remarkably reduced, and the crispness is enhanced. The tea polyphenol and the tea polysaccharide synergistically improve the oxidation resistance, the antibacterial activity and the meat water binding capacity, phospholipid / sterol in the avocado is used as a natural emulsifier of the emulsion, and the phospholipid / sterol and polyunsaturated fatty acid in the edible oil balance pork saturated fat. In addition, the Tibetan tea not only gives Tibetan tea flavor to the small crispy meat, but also is rich in various lipases and rich fibers, and has the effects of reducing moisture permeation and balancing the absorption of cholesterol and fat, so that the instant small crispy meat is more delicious and healthy.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to instant Tibetan tea flavored crispy pork and a preparation method thereof. Background Art

[0002] Crispy pork is a common traditional snack in China, boasting a golden, crispy exterior and a savory, flavorful interior. Its primary ingredients are pork, typically pork belly and tenderloin. Pork belly, with its blend of fat and lean meat, retains its juiciness and tenderness during frying, making it the preferred choice for crispy pork. While ingredients vary by region, crispy pork generally includes eggs, flour, starch, scallions, ginger, and garlic. It comes in a variety of flavors, including original, peppery, three-fresh, sour soup, sweet and sour pineapple, and stir-fried dried tofu. Crispy pork is generally considered delicious, especially when served hot. However, it can also be quite greasy, which is inconsistent with current health-conscious practices. Furthermore, while its preparation is simple, it uses a high amount of oil, making it inexpensive to produce in small batches. Overcooking can also lead to poor flavor after cooling, and reheating can cause the batter to become hard and tasteless. Therefore, many consider crispy pork a "traditional Chinese New Year dish," reserved for Lunar New Year.

[0003] Tibetan tea, a dark tea, is one of China's six major tea categories and boasts a rich history and culture. Tibetan tea is often praised for its sweetness and viscosity, often accompanied by the saying, "I'd rather go without food for a day than without tea," and "Tea is essential for digesting fishy meats, and tea is essential for relieving the heat of barley." Furthermore, Tibetan tea can be used to make the traditional Tibetan snack, ghee tea. Research has shown that only Tibetan tea effectively dissolves ghee, a feat unmatched by other teas. This is due to the deep fermentation of Tibetan tea, which contains a high concentration of lipase, which breaks down fat, converting the ghee's fat into water-soluble fatty acids and glycerol, resulting in a uniform ghee tea. The high content of tea polysaccharides in Tibetan tea contributes to its distinctive sweetness and viscosity. Furthermore, functional components such as tea pigments, cellulose, and minerals not only provide a rich taste and nutritional value, but also enhance health benefits.

[0004] In modern food processing and preservation technologies, extending the shelf life of meat products and improving their taste and nutritional value are key research areas. Meat products, rich in fat and protein, are susceptible to enzyme and microbial degradation, leading to protein breakdown, fat oxidation, and discoloration, which in turn reduces their nutritional value, taste, and flavor. To address this issue, researchers have explored various natural antioxidants and preservatives. Tea polyphenols, among them, have been widely used in meat preservation due to their excellent antioxidant and antibacterial properties. Studies have shown that tea polyphenols can inhibit spoilage, improve color, and slow oxidation by inhibiting bacterial growth, thereby extending shelf life. Furthermore, tea polyphenols can form an impermeable, hard film with proteins on the surface of meat products, further enhancing their antioxidant and preservative properties. Tea polysaccharides can improve the sensory qualities of meat, including color, texture, and taste. Studies have shown that tea polyphenols can significantly increase the redness of meat and reduce drip loss, thereby improving its appearance and taste. In addition, tea polysaccharides can improve the water retention of meat, reduce juice loss, and thus improve the quality of meat.

[0005] Currently, the best-selling crispy pork on the market are all pre-made crispy pork, which needs to be re-fried after purchase by customers before it can be eaten. The flavors are mostly pepper and sesame crispy pork, original crispy pork, sour soup crispy pork, sweet and sour crispy pork, etc. However, there is no instant tea-flavored crispy pork that combines Tibetan tea with crispy pork on the market. Summary of the Invention

[0006] Technical problems to be solved: The instant crispy pork on the market currently has a poor taste and a single category. How to maintain the taste and quality of the crispy pork is a technical problem. In addition, chemical flavorings, preservatives, etc. are added to foods to extend the shelf life. These substances may also have a negative impact on health. The present invention extends the shelf life of the product by adding natural antioxidants and antibacterial agents in the form of an emulsion and nitrogen-filled packaging. The emulsion uses avocado ingredients as an emulsifier and adds Tibetan tea to improve the permeability of effective substances such as polyphenols and polysaccharides, forming a network coverage with good water retention. Combined with the fragrance of Tibetan tea, the taste is rich. A multi-layer coating method is adopted. Each layer of coating is compounded, and a dense and stable coating layer can be formed during the frying process, which increases the crispness of the crispy pork, improves the taste and flavor of the crispy pork, and increases consumer acceptance.

[0007] Technical solution: A method for preparing instant Tibetan tea flavored crispy pork, comprising the following steps: S1. Marinate the meat: Cut the pork belly into strips, add seasonings, mix well, and refrigerate to marinate; S2. Emulsion preparation: tea polyphenols and tea polysaccharides were added to the Tibetan tea water, cooking oil and avocado puree were mixed and stirred, and then the Tibetan tea water was added, and then high-speed homogenization was performed, and finally insoluble matter was removed by centrifugation to obtain an emulsion; S3. Meat processing: soak the marinated pork belly in the emulsion and perform ultrasonic treatment; S4. Preparation of the first layer of batter: modified starch, egg white powder, flour and Tibetan tea powder were mixed with water and stirred to form a batter A; S5. Preparation of the second layer of batter: pregelatinized starch, wheat protein, calcium carbonate, and water were mixed, and then flour and salt were added to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately, drain the oil, wrap with batter B, put into oil, and fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil, drain the oil, cool, fill with nitrogen, and package to obtain ready-to-eat Tibetan tea flavored crispy pork.

[0008] Furthermore, the seasoning in step S1 is prepared from the following raw materials in the following weight ratio: 15-25 parts of green onion, 15-25 parts of ginger, 1-1.5 parts of cinnamon, 2-3 parts of star anise, 0.5-2 parts of peppercorns, 0.2-0.4 parts of five-spice powder, 2-4 parts of salt, 0.5-1 parts of soy sauce, 0.5-1 parts of vinegar, and 1-2 parts of cooking wine; the mass ratio of pork belly to seasoning is 10:(1-3), the refrigeration temperature is 4-8°C, and the marinating time is 30-60 minutes.

[0009] Furthermore, in step S2, the content of tea polyphenols added to the Tibetan tea water is 0.01-0.1wt.%, and the content of tea polysaccharides is 0.02-0.05wt.%; the mass ratio of edible oil, avocado puree and Tibetan tea water is 10:(2-5):(50-80); the mixing speed is 700-1000 rpm, the high-speed homogenization speed is 5000-10000 rpm, and the high-speed homogenization time is 1-3 min; the centrifugal speed is 3000-5000 rpm, and the centrifugation time is 2-5 min.

[0010] Furthermore, the ultrasonic treatment in step S3 is performed at a power of 300-800 W and for a time of 15-30 min.

[0011] Furthermore, the batter A in step S4 is prepared from the following raw materials in the following weight ratio: 2-3 parts of modified starch, 1-2 parts of egg white powder, 2-4 parts of flour, 0.3-0.8 parts of Tibetan tea powder, and 12-15 parts of water.

[0012] Furthermore, in step S4, the modified starch is cassava hydroxypropyl distarch phosphate, and the stirring speed is 500-800 rpm.

[0013] Furthermore, the batter B in step S5 is prepared from the following raw materials in the following weight ratio: 2-3 parts of pregelatinized starch, 1-2 parts of wheat protein, 8-10 parts of flour, 25-30 parts of water, 0.05-0.1 parts of salt, and 0.05-0.1 parts of calcium carbonate.

[0014] Furthermore, the pregelatinized starch in step S5 is pregelatinized hydroxypropyl starch, the mixing and stirring speed is 300-500 rpm, and the stirring speed is 500-800 rpm.

[0015] Furthermore, in step S6, the oil temperature in the oil pan is 140-180° C., and 5-10% edible ethanol solution is sprayed during the cooling process or before packaging.

[0016] The above-mentioned preparation method obtains instant Tibetan tea flavored crispy pork. Beneficial effects

[0017] The invention combines the crispness of processed pork with the fragrance of Tibetan tea, resulting in a rich taste and endless aftertaste. Tibetan tea has the effects of lowering blood lipids and losing weight, which makes up for the greasy feeling of traditional crispy pork. At the same time, it is rich in nutrition and conforms to the trend of healthy diet of modern consumers. Moreover, the product can be eaten immediately without processing, which is more convenient and quick.

[0018] The present invention soaks pork in a functional and flavorful emulsion. Compared to aqueous solutions, the emulsion can encapsulate tea polyphenols, improving the stability of the functional ingredients. It also has a certain sustained-release function, enhancing antioxidant and antibacterial properties. Furthermore, the emulsion has a higher viscosity, making it easier to adhere to the surface of the pork. It also improves permeability, promoting the absorption of the functional ingredients, and retaining a longer-lasting and richer Tibetan tea flavor.

[0019] The raw materials used in the present invention are all natural antioxidants and preservatives, and the product is greener and healthier; the added tea polyphenols can effectively inhibit the fat oxidation and protein oxidation in meat, thereby maintaining the sensory quality and physical and chemical properties of the meat product, and has a significant inhibitory effect on a variety of pathogenic bacteria, thereby extending the shelf life of the meat product; the tea polyphenols and tea polysaccharides can also improve the tenderness, water retention and flavor of the meat product, and the synergistic effect of the two, coupled with the fact that Tibetan tea contains, in addition to tea polyphenols and tea polysaccharides, a variety of functional substances that work together can significantly enhance the product flavor and improve the product quality.

[0020] The present invention adopts a multi-layer coating preparation method. The first layer adopts a combination of high-viscosity modified starch and egg white powder to enhance the adhesion and stability of the coating, and tea powder is added. The fiber inside reduces the water penetration rate and further enhances the Tibetan tea flavor. The second layer is a combination of pregelatinized starch and wheat protein to enhance the crispness of the coating and reduce the oil absorption rate, and calcium ions are added for cross-linking to enhance the brittle network structure.

[0021] The multi-layered coating structure of the present invention has a first layer of coating that helps to form a certain protective layer during the frying process, preventing internal moisture loss and keeping the meat tender and smooth; while the formula of the second layer of coating controls the moisture content and oil distribution, making the outer layer after frying more crispy while reducing the overall oil content; this layered structure design enables the coating to form a dense and stable coating layer during the frying process, thereby increasing the crispness of the crispy meat and improving the taste and appearance of the food. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 TBARs values ​​of Examples 1-5 and Comparative Examples 1-5 are shown in FIG. Figure 2 Graph showing changes in TVB-N values ​​during storage at 15° C. for Example 3 and Comparative Examples 1-5; Figure 3 Graph showing changes in TVB-N values ​​during storage at 25°C for Example 3 and Comparative Examples 1-5. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. The following embodiments are intended to explain the present invention, but the present invention is not limited to the following embodiments: Example 1

[0024] A method for preparing instant Tibetan tea flavored crispy pork comprises the following steps: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.01wt.% tea polyphenols and 0.02wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Example 2

[0025] A method for preparing instant Tibetan tea flavored crispy pork comprises the following steps: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 2 parts of avocado puree, then add 50 parts of Tibetan tea water, then homogenize at 5000 rpm for 3 minutes, and finally centrifuge at 3000 rpm for 5 minutes to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Example 3

[0026] A method for preparing instant Tibetan tea flavored crispy pork comprises the following steps: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Example 4

[0027] A method for preparing instant Tibetan tea flavored crispy pork comprises the following steps: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.8 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Example 5

[0028] A method for preparing instant Tibetan tea flavored crispy pork comprises the following steps: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 30 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Comparative Example 1

[0029] The difference between this comparative example and Example 3 is that no avocado and edible oil are added, and no emulsion is prepared. The details are as follows: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2 Tibetan tea preparation: Take an appropriate amount of Tibetan tea, brew with boiling water and let cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides, mix and stir; S3. Meat processing: Soak the marinated pork belly completely in Tibetan tea water and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Comparative Example 2

[0030] The difference between this comparative example and Example 3 is that no tea polysaccharide is added, specifically as follows: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew with boiling water and let cool, add 0.1wt.% tea polyphenols to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of cassava hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Comparative Example 3

[0031] The difference between this comparative example and Example 3 is that the first layer of powder coating is not used, specifically as follows: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form a batter; S5. Frying of crispy pork: Wrap the processed pork belly with batter, put it into the oil pan at an oil temperature of about 160℃, and fry it slowly over medium-low heat until the surface is golden and crispy. Remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution and fill it with nitrogen to obtain ready-to-eat Tibetan tea flavored crispy pork. Comparative Example 4

[0032] The difference between this comparative example and Example 3 is that modified starch and pregelatinized starch are not used in the coating, specifically as follows: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts corn starch, 1 part egg white powder, 2 parts flour and 0.3 parts of Tibetan tea powder were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts corn starch, 1 part wheat protein, 0.05 parts calcium carbonate plus 25 parts of water, 500rpm mixing, then add 8 parts of flour and 0.1 parts of salt 800 rpm stirring to make batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Comparative Example 5

[0033] The difference between this comparative example and Example 3 is that no tea powder is added to the first layer of batter, specifically as follows: S1. Marinate the meat: Cut 300 parts pork belly into strips, add 15 parts scallion, 15 parts ginger, 1 part cinnamon, 2 parts star anise, 0.5 parts Sichuan peppercorns, 0.2 parts five-spice powder, 2 parts salt, 0.5 parts soy sauce, 0.5 parts vinegar, and 1 part cooking wine, mix well, and marinate at 4°C for 30 minutes. S2. Emulsion preparation: Take an appropriate amount of Tibetan tea, brew it with boiling water and let it cool, add 0.1wt.% tea polyphenols and 0.05wt.% tea polysaccharides to the Tibetan tea water, mix 10 parts of cooking oil and 5 parts of avocado puree, then add 80 parts of Tibetan tea water, then homogenize at 5000 rpm for 3min, and finally centrifuge at 3000 rpm for 5min to remove insoluble matter to obtain an emulsion; S3. Meat processing: Immerse the marinated pork belly completely in the emulsion and ultrasonically treat at 500W for 15 minutes. S4. Preparation of the first layer of batter: 2 parts of tapioca hydroxypropyl distarch phosphate, 1 part of egg white powder, 2 parts of flour were mixed, 15 parts of water were added, and the batter was stirred at 800 rpm to form a batter A; S5. Preparation of the second layer of batter: 2 parts of pregelatinized hydroxypropyl starch, 1 part of wheat protein, 0.05 parts of calcium carbonate plus 25 parts of water, mixed at 500 rpm, then 8 parts of flour and 0.1 parts of salt were added and stirred at 800 rpm to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately after draining the oil, wrap with batter B, put into the oil at about 160℃, fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil and drain the oil. After cooling, spray 5% edible ethanol solution on it, fill it with nitrogen and package it to obtain ready-to-eat Tibetan tea flavored crispy pork. Performance Testing

[0034] Sensory evaluation A 10-person evaluation panel was formed. After evaluating each sample, they rinsed their mouths with water and waited 2 minutes before evaluating the next sample. The sensory scoring criteria and details for crispy pork are shown in Table 1.

[0035] Table 1 Sensory scoring standards and rules for crispy pork

[0036] The sensory evaluation results are shown in Table 2. The scores of the examples are in the range of 92-96 points, and all examples have similar scores, but Example 3 is the best (96 points). Examples 1 and 2 scored lower (92 points) due to the reduction of tea polysaccharides and tea polyphenols. The scores of the comparative examples are in the range of 83-88 points, and the scores of the comparative examples are significantly lower than those of the examples, mainly due to the lack or simplification of key steps. Comparative Example 1 scored the lowest because the meat was not soaked in emulsion, the permeability was reduced, and the lack of oil and avocado puree resulted in a dry and hard texture and insufficient flavor. Comparative Example 2 lacked tea polysaccharides, and Comparative Example 5 did not add tea powder, so the smell and color of the crispy meat were greatly affected, and the tea flavor was incomplete. Comparative Examples 3 and 4 had poor appearance and taste. This is because only a single layer of powder was used, or ordinary starch was used, and the powder coating effect was poor, which affected the crispiness.

[0037] Table 2 Sensory evaluation scores of crispy pork

[0038] Antioxidant evaluation Thiobarbituric acid reactants (TBARs) were determined by spectrophotometry according to the national standard GB 5009.181-2016 “Determination of malondialdehyde in food”. Each group was measured three times in parallel and the average value was taken.

[0039] The results are as follows Figure 1As shown, the TBARs value reflects the content of malondialdehyde generated by the oxidation of fatty acids. The TBARs values ​​of the examples are between 0.13-0.18 mg / kg. Among them, Example 4 has a lower TBARs value because of the addition of more Tibetan tea powder, which enhances the antioxidant capacity. Example 1 has a weakened antioxidant capacity due to the reduced concentration of tea polyphenols. The TBARs values ​​of the comparative examples are higher than all the examples. Comparative Example 1 has the weakest antioxidant system due to the lack of emulsion soaking, which makes it difficult for functional substances to penetrate. Although the value of Comparative Example 2 is relatively the lowest, it is still higher than the examples. Figure 1 The results show that the use of emulsion (containing tea polyphenols, tea polysaccharides, avocado puree and edible oil) and double-layer powder coating (especially containing modified starch and Tibetan tea powder) in the examples are the key to reducing TBARs value and improving antioxidant properties. The simplification of related processes or the lack of elements in the comparative examples will increase the degree of oxidation.

[0040] Storage experiment The packaged crispy pork was placed in a thermostat at 15°C and 25°C respectively. Every 3 days, the TVB-N value of the crispy pork in the 15°C and 25°C thermostats was measured, and the pH value of the crispy pork in the 15°C thermostat was measured.

[0041] The pH of the samples was measured according to the method in GB5009.237-2016, "National Food Safety Standard - Determination of pH Value of Foods." The volatile basic nitrogen content (TVB-N value) was measured according to Method 2 (Automated Kjeldahl Nitrogen Analyzer) in GB5009.228-2016, "National Food Safety Standard - Determination of Volatile Basic Nitrogen in Foods." The results are expressed in mg / 100g.

[0042] According to GB5009.228-2016 "National Food Safety Standard for Determination of Volatile Basic Nitrogen in Food", the TVB-N value of 15 mg / 100 g was selected as the upper limit to determine the shelf life of crispy pork. 10 The model predicts shelf life, the shelf life ratio Q at two temperatures 10 The calculation formula is shown in formula (1), and the predicted shelf life of the sample crispy pork stored at 4℃ can be obtained by formula (2).

[0043]

[0044] Where: F T F is the shelf life in days at T ℃; T+10 F is the shelf life in days at (T+10)℃; b T b Shelf life days at ℃; F a T a The shelf life is in days at ℃; Δt is T aWith T b The difference.

[0045] Table 3 shows the pH changes of the samples during storage at 15°C. pH changes during food storage can, to a certain extent, reflect microbial growth and metabolic activity. The pH of Example 3 decreased the slowest, while that of Comparative Example 1 decreased the most significantly. Tea polysaccharides and tea polyphenols were not prepared as an emulsion, resulting in poor stability and inability to sustain release, leading to poor antibacterial efficacy. Comparative Example 3 lacked a coating layer, weakening the physical barrier and causing a significant pH drop.

[0046] Table 3 pH changes of crispy pork during storage at 15℃ Figure 2 and Figure 3 The TVB-N value changes during sample storage at 15°C and 25°C are shown. If the TVB-N value exceeds the safe range, the sample is considered to be spoiled, which can be used to predict the shelf life of the sample at 4°C. The higher the TVB-N value, the more serious the spoilage. The TVB-N growth rate of the comparative example is higher than that of Example 3, and the TVB-N of Comparative Example 1 increases the fastest, indicating that emulsion immersion has a significant effect on extending the shelf life. 10 The model predicted the shelf life of the crispy pork, and the results are shown in Table 4. Example 3 had the longest shelf life, at 18 days, followed by Comparative Example 5, which did not add tea powder. This indicates that tea powder has a minimal effect on extending shelf life. Comparative Example 3 and Comparative Example 1 had the greatest impact, indicating that the emulsion pretreatment and the double-layer powder coating structure play an important role in extending the shelf life of the crispy pork.

[0047] Table 4. Q 10 Model-predicted shelf life

[0048] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. 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 content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing instant Tibetan tea flavored crispy pork, characterized in that: The following steps are involved: S1. Marinate the meat: Cut the pork belly into strips, add seasonings, mix well, and refrigerate to marinate; S2. Emulsion preparation: tea polyphenols and tea polysaccharides were added to the Tibetan tea water, cooking oil and avocado puree were mixed and stirred, and then the Tibetan tea water was added, and then high-speed homogenization was performed, and finally insoluble matter was removed by centrifugation to obtain an emulsion; S3. Meat processing: soak the marinated pork belly in the emulsion and perform ultrasonic treatment; S4. Preparation of the first layer of batter: modified starch, egg white powder, flour and Tibetan tea powder were mixed with water and stirred to form a batter A; S5. Preparation of the second layer of batter: pregelatinized starch, wheat protein, calcium carbonate, and water were mixed, and then flour and salt were added to form batter B; S6. Frying of crispy pork: Wrap the processed pork belly with batter A, fry in oil until it is set, remove immediately, drain the oil, wrap with batter B, put into oil, and fry slowly over medium-low heat until the surface is golden and crispy, remove from the oil, drain the oil, cool, fill with nitrogen, and package to obtain ready-to-eat Tibetan tea flavored crispy pork.

2. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, characterized in that: The seasoning in step S1 is prepared from the following raw materials in the following weight ratio: 15-25 parts of green onion, 15-25 parts of ginger, 1-1.5 parts of cinnamon, 2-3 parts of star anise, 0.5-2 parts of peppercorns, 0.2-0.4 parts of five-spice powder, 2-4 parts of salt, 0.5-1 part of soy sauce, 0.5-1 part of vinegar, and 1-2 parts of cooking wine; the mass ratio of pork belly to seasoning is 10:(1-3), the refrigeration temperature is 4-8°C, and the marinating time is 30-60 minutes.

3. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, wherein: In step S2, the content of tea polyphenols added to the Tibetan tea water is 0.01-0.1wt.%, and the content of tea polysaccharides is 0.02-0.05wt.%; the mass ratio of edible oil, avocado puree and Tibetan tea water is 10:(2-5):(50-80); the mixing speed is 700-1000 rpm, the high-speed homogenization speed is 5000-10000 rpm, and the high-speed homogenization time is 1-3 minutes; the centrifugal speed is 3000-5000 rpm, and the centrifugation time is 2-5 minutes.

4. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, wherein: The ultrasonic treatment in step S3 has a power of 300-800 W and a duration of 15-30 min.

5. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, characterized in that: The batter A in step S4 is prepared from the following raw materials in the following weight ratio: 2-3 parts of modified starch, 1-2 parts of egg white powder, 2-4 parts of flour, 0.3-0.8 parts of Tibetan tea powder, and 12-15 parts of water.

6. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, characterized in that: In step S4, the modified starch is cassava hydroxypropyl distarch phosphate, and the stirring speed is 500-800 rpm.

7. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, characterized in that: The batter B in step S5 is prepared from the following raw materials in the following weight ratio: 2-3 parts of pregelatinized starch, 1-2 parts of wheat protein, 8-10 parts of flour, 25-30 parts of water, 0.05-0.1 parts of salt, and 0.05-0.1 parts of calcium carbonate.

8. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, characterized in that: The pregelatinized starch in step S5 is pregelatinized hydroxypropyl starch, the mixing and stirring speed is 300-500 rpm, and the stirring speed is 500-800 rpm.

9. The method for preparing instant Tibetan tea flavored crispy pork according to claim 1, characterized in that: In step S6, the oil temperature in the oil pan is 140-180° C., and 5-10% edible ethanol solution is sprayed during the cooling process or before packaging.

10. An instant Tibetan tea flavored crispy pork obtained by the preparation method according to any one of claims 1 to 9.

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