Dha goat milk cheese sticks and methods of making the same

Abstract

The application discloses a DHA goat milk cheese stick and a preparation method thereof. The DHA goat milk cheese stick comprises the following components: 10 parts of goat milk powder, 5 parts of fruit pieces, 20 parts of cheese, 15 parts of light cream, 10 parts of white sugar, 5 parts of galacto-oligosaccharides, 2 parts of carrageenan, and 0.5 parts of tricalcium phosphate. The liquid milk and the natural cheese used in the application are goat milk products, so that most of the milk allergy can be solved, and consumers allergic to milk can achieve the purpose of supplementing related nutrients through the product.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and more particularly to a DHA goat milk cheese stick and a preparation method thereof. Background Art

[0002] Cheese sticks are a type of processed cheese, primarily made from cottage cheese with added ingredients like milk protein, pure cow's milk, and fruit juice. Their protein and calcium content is significantly higher than that of pure milk. Their soft, springy texture makes them ideal for children to chew, while their sweet taste, often featuring a variety of fruit flavors, makes them a popular choice. As a new type of children's food, cheese sticks are gaining increasing recognition and acceptance among parents. However, since most cheese sticks are based on milk protein, common proteins in milk, such as casein, α-s1 casein, and β-lactoglobulin, are significant potential allergens, especially for infants and young children. Studies have shown that milk allergy occurs in 2%-7.5% of young children, making it one of the most common food allergies. Therefore, the research and development of hypoallergenic cheese sticks is urgent.

[0003] Goat milk is rich in nutrients and easy to digest and absorb, earning it the nickname "King of Milk." It's recognized worldwide as the animal milk product closest to human milk. In particular, consumers allergic to cow's milk can supplement their nutrition with goat milk. Studies have shown that α-S1 casein accounts for 43% of total protein in cow's milk, while goat's milk only accounts for 1%-3%. Furthermore, goat's milk contains lower levels of β-lactoglobulin than cow's milk, and its amino acid sequence differs from cow's milk, making it easier to digest and absorb. Therefore, goat's milk can alleviate most cow's milk allergies. Furthermore, because infants and young children's intestines are immature and more susceptible to damage than adults, goat's milk is rich in epidermal growth factor (EGF), which promotes the proliferation and differentiation of gastrointestinal epithelial cells and is a regulator of intestinal balance. This helps repair and maintain the normal intestinal barrier function in infants and young children, helping to reduce the risk of allergies. In summary, goat's milk can be used as the milk base for hypoallergenic children's cheese sticks. In addition, goat milk contains immunoglobulins, which can enhance the body's resistance; the content of nucleotides and cephalin is also higher than that of cow's milk, which is very beneficial to the development of infants' nerves and brain functions.

[0004] DHA is an absolute essential nutrient for the development of sensory, perceptual, cognitive and motor nervous system during the high-speed development of the brain, and the differentiation and migration of nerve cells basically occur during the fetal period, so the impact on intelligence of infants starts from the fetus. Supplementing DHA can promote the functional development of the brain and vision of infants, and promote the development of growth and development, cognitive ability and learning and memory ability. As a new type of nutritional fortifier, DHA is added to the goat milk cheese stick, and the two synergistically enhance the intelligence effect, which can fill the market gap of intelligence goat milk cheese sticks.

[0005] At present, the main sources of DHA are deep sea fish oil and algae, but due to the fishy smell and water immiscibility, the DHA product has poor consumption degree. The existing DHA supplement products on the market mainly include algal oil soft capsules, algal oil drops, algal oil solid beverages and algal oil candies, which generally have the defects of low embedding amount and easy oxidation. How to optimize the carrying system of DHA algal oil is the key to solve its application in food matrix. Emulsion is a dispersion system in which one or more liquids are uniformly dispersed in the form of droplets in another liquid which is not soluble with it by mechanical stirring. Due to the characteristics of convenient application and excellent sensory properties, emulsion is widely used in various food systems such as milk, butter, fruit juice and infant food.

[0006] Children must supplement nutrients such as DHA to fully meet the needs of body development, and cheese stick is one of the good carriers. Direct addition of DHA algal oil into food matrix has the problems of easy oxidation and poor stability. At present, there are few cheese products combining goat milk and DHA algal oil on the market, which is difficult to meet the needs of nutritional fortification. The present application aims to explore and optimize the production process of DHA nutritional fortified goat milk cheese stick to meet the requirements of modern infant nutritional fortified food. SUMMARY

[0007] An object of the present application is to solve at least the above problems and to provide at least the advantages described later.

[0008] Another object of the present application is to provide a DHA goat milk cheese stick, which uses liquid milk and natural cheese made of goat milk products, which can relieve most of the milk allergy, and consumers allergic to milk can achieve the purpose of supplementing related nutrients through the product.

[0009] Still another object of the present application is to provide a preparation method of DHA goat milk cheese stick.

[0010] In order to achieve these objects and other advantages of the present application, a DHA goat milk cheese stick is provided, which comprises the following components:

[0011] 10 parts of goat milk powder, 5 parts of fruit chunks, 20 parts of cheese, 15 parts of light cream, 10 parts of white sugar, 5 parts of galacto-oligosaccharide, 2 parts of carrageenan, and 0.5 parts of tricalcium phosphate.

[0012] Preferably, the cheese is made from goat's milk.

[0013] Also provided is a method for preparing DHA goat milk cheese sticks, comprising the following steps:

[0014] Step 1: Dissolve goat milk powder in water to prepare goat milk, add 5-7% of green tea by weight to the goat milk, heat at 85-90° C. for 20 minutes, filter out the green tea residue to remove the smell of mutton, and obtain goat milk after removing the smell of mutton;

[0015] The weight ratio of the goat milk powder to water is 1:5-6;

[0016] Step 2: adding goat whey protein and DHA algae oil to the goat milk after removing the smell of mutton, stirring, and homogenizing to obtain DHA algae oil goat milk emulsion;

[0017] The amount of the goat whey protein is 0.8-1.2% (w / w) of the total weight of the goat milk, and the amount of the DHA algae oil is 4.5-5.5% (v / v) of the total weight of the goat milk;

[0018] Step 3: First, prepare the fruit pieces into juice, and then adjust the pH value to 4.7-4.9 to obtain acid-adjusted juice;

[0019] Step 4: Melt the cheese to obtain liquid cheese, and evenly mix the white sugar, galacto-oligosaccharide, and tricalcium phosphate to obtain a dry mixed powder;

[0020] Step 5: Add the dry mixed powder, acidified juice, liquid cheese, and light cream to the DHA algae oil goat milk emulsion, mix, and heat at 80-90° C. for 5 minutes to further emulsify to obtain a uniform emulsion; when the uniform emulsion is naturally cooled to 50-55° C., add the melted carrageenan and keep warm for 5 minutes to obtain a mixture;

[0021] Step 6: Fill the mixture into a mold and refrigerate to obtain DHA goat milk cheese sticks.

[0022] Preferably, the DHA goat milk cheese sticks are stored at 2-3°C.

[0023] Preferably, in step 2, after adding goat whey protein and DHA algae oil to the goat milk after removing the smell of mutton, a high-speed mechanical stirrer is used to stir the mixture at a speed of 8000 r / min for 1 minute to obtain colostrum, and the colostrum is homogenized using an ultrasonic cell disruptor for 2 minutes to obtain DHA algae oil goat milk emulsion.

[0024] Preferably, in step three, the fruit pieces are pulped and filtered through double-layered gauze to obtain fruit pulp, the fruit pulp is homogenized in an ultrasonic cell disrupter for 2 minutes to obtain fruit juice, and the pH value of the fruit juice is adjusted to 4.7-4.9 to obtain the fruit juice after acid adjustment.

[0025] Preferably, in step six, the refrigeration temperature is 4°C for 20 hours.

[0026] The present application at least includes the following beneficial effects:

[0027] First, most of the currently marketed cheese sticks are developed based on milk as the protein base, and for the main consumer group of cheese sticks, i.e. infants and young children, there is a potential allergen. The liquid milk and natural cheese used in the present product are both goat milk products, which can relieve most of the milk allergy, and consumers allergic to milk can achieve the purpose of supplementing related nutrients through the present product.

[0028] Second, the application of DHA nutritional fortifier in infant food is mainly in the form of microcapsule embedding in infant milk powder. Cheese sticks, as a new type of children's food, are widely loved by children and have been recognized and accepted by more and more parents. The present product perfectly combines DHA algal oil with goat milk and applies it to cheese sticks, which are a highly accepted food carrier, thereby not only strengthening the intelligence effect of goat milk, but also making the present product have a young market of infants, adolescents, etc.

[0029] Third, the present product applies DHA algal oil to goat milk cheese sticks by using the stable system of emulsion. The ultrasonic emulsification method used therein is a high-energy emulsification method for preparing nanoemulsion in the current food field, which has the advantages of clean and efficient, stable emulsion, flexible operation, high efficiency and energy saving, etc., and shows great potential in the preparation of nanoemulsion, which can not only prevent the premature oxidation of DHA and other unsaturated fatty acids, but also improve the bioavailability and environmental tolerance of DHA, thereby fully exerting the nutritional value.

[0030] Fourth, the prepared DHA goat milk cheese sticks use natural cheese without adding any preservatives, pigments, food modifiers and other synthetic substances, thereby ensuring the natural green safety of the product.

[0031] Other advantages, objects and features of the present application will be partly embodied by the following description, and partly understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 POV value of accelerated oxidation for 15 days for Comparative Example 1, Comparative Example 2 and Example 1;

[0033] Figure 2 TBARs value of accelerated oxidation for 15 days for Comparative Example 1, Comparative Example 2 and Example 1;

[0034] Figure 3 The changes in particle size during in vitro simulated gastrointestinal digestion (4 h) in Comparative Example 1, Comparative Example 2, and Example 1;

[0035] Figure 4 The changes in FFA release rate during in vitro simulated intestinal digestion (2 h) in Comparative Example 1, Comparative Example 2, and Example 1;

[0036] Among them, the particle size will change since the beginning of gastric digestion, so Figure 3 It is the change in particle size within 4 hours from the beginning of gastric digestion to the end of intestinal digestion; fatty acids can only be released after being digested by pancreatic enzymes in the intestine, so Figure 4 It is the release of fatty acids within 2 hours of intestinal digestion. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0038] <Example 1>

[0039] The fruit used is strawberry.

[0040] DHA goat milk cheese sticks, including the following ingredients:

[0041] 10 parts of goat milk powder, 5 parts of fruit chunks, 20 parts of cheese, 15 parts of light cream, 10 parts of white sugar, 5 parts of galacto-oligosaccharide, 2 parts of carrageenan, and 0.5 parts of tricalcium phosphate.

[0042] Cheese is made from goat's milk.

[0043] The preparation method of DHA goat milk cheese sticks comprises the following steps:

[0044] Step 1: Dissolve goat milk powder in water to prepare goat milk, add 5-7% of green tea by weight to the goat milk, heat at 85-90° C. for 20 minutes, filter out the green tea residue to remove the smell of mutton, and obtain goat milk after removing the smell of mutton;

[0045] The weight ratio of the goat milk powder to water is 1:5;

[0046] Step 2: adding goat whey protein and DHA algae oil to the goat milk after removing the smell of mutton, stirring, and homogenizing to obtain DHA algae oil goat milk emulsion;

[0047] The amount of the goat whey protein is 1% (w / w) of the total weight of the goat milk, and the amount of the DHA algae oil is 5% (v / v) of the total weight of the goat milk;

[0048] Step 3: First, prepare the fruit pieces into juice, and then adjust the pH value to 4.7-4.9 to obtain acid-adjusted juice;

[0049] Step 4: Melt the cheese to obtain liquid cheese (weigh 20 parts of cheese, heat it in a water bath at 40-50°C, and beat it until it is smooth to obtain liquid cheese), and evenly mix the white sugar, galacto-oligosaccharide, and tricalcium phosphate to obtain a dry mixed powder;

[0050] Step 5: Add the dry mixed powder, acidified fruit juice, liquid cheese, and light cream to the DHA algae oil goat milk emulsion, mix, and heat at 80-90° C. for 5 minutes to further emulsify to obtain a uniform emulsion; when the uniform emulsion is naturally cooled to 50-55° C., add melted carrageenan (melted carrageenan heated at 80-90° C.) and keep warm for 5 minutes to obtain a mixture;

[0051] Step 6: Fill the mixture into a 3×3×1.5 cm mold and refrigerate to obtain DHA goat milk cheese sticks.

[0052] DHA goat milk cheese sticks should be stored at 2-3°C.

[0053] In step 2, after adding goat whey protein and DHA algae oil to the goat milk after removing the smell of mutton, a high-speed mechanical stirrer was used to stir at a speed of 8000r / min for 1 minute to obtain colostrum, and the colostrum was homogenized using an ultrasonic cell disruptor (interval ratio 2s:2s, power 300W) for 2 minutes to obtain DHA algae oil goat milk emulsion.

[0054] In step 3, the fruit pieces are pulped and filtered through a double layer of gauze to obtain a pulp, and the pulp is homogenized in an ultrasonic cell disruptor (interval ratio 2s:2s, power 1000W) for 2 minutes to obtain juice, and the pH value of the juice is adjusted to 4.7-4.9 to obtain acidified juice.

[0055] In step six, the refrigeration temperature is 4°C for 20 hours.

[0056] Comparative Example 1

[0057] Step 3) of Example 1 was modified as follows: adding goat whey protein and DHA algae oil to the goat milk after removing the smell of mutton, and stirring and mixing for only 3 minutes using a high-speed blender; the rest was the same as in Example 1.

[0058] Comparative Example 2

[0059] The sheep whey protein used in step 3) of Example 1 was omitted, that is, the amount of sheep whey protein used was 0; the rest was the same as Example 1.

[0060] <Experimental Characterization>

[0061] Accelerated oxidation tests were used to evaluate the effects of ultrasonic emulsification and goat whey protein on the stability of DHA algae oil. The homogeneous emulsion prepared in Step 5 of Example 1 was incubated at 55°C for 15 days. The primary products of oil oxidation (peroxide value, POV) and secondary products (thiobarbituric acid reactants, TBARs) were measured every three days.

[0062] The bioavailability of DHA in the product was evaluated using an internationally standardized static in vitro digestion method. Simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were prepared according to Table 1, followed by in vitro simulated digestion.

[0063] Simulated gastric digestion: 10 mL of the homogeneous emulsion prepared in step 5) of Example 1 was mixed with 7.5 mL of SGF stock solution and 1.6 mL of enzyme with an activity of 25000 U mL -1 Mix 5 μL of porcine pepsin stock solution and 5 μL of CaCl₂ solution (0.075 mM) thoroughly. Adjust the pH to 3.0 with an appropriate amount of 1 M HCl solution, and then add a trace amount of pure water to 20 mL. Incubate the mixture in a shaker at 150 rpm and 37°C for 2 hours. Samples were taken every 30 minutes, and the particle size was measured using a Zetasizer Nano ZS90 particle size and potentiometric analyzer, as shown in Table 1.

[0064] Simulate intestinal digestion: 20 mL of gastric chyme was mixed with 11 mL of SIF stock solution and 5.0 mL of enzyme with an activity of 800 U mL -1 2.5 mL of porcine pancreatic enzyme solution, 2.5 mL of fresh porcine bile salt solution with a concentration of 160 mM, and 40 μL of CaCl2 solution (0.3 mM) were mixed, and the pH was adjusted to 7.0 with an appropriate amount of 1 M NaOH solution. Then, a trace amount of pure water was added to make up to 40 mL. The mixture was incubated in a shaker at 150 r / min and 37°C for 2 hours. Samples were taken every 30 minutes, and the particle size of the system was measured using a Zetasizer Nano ZS90 particle size and potential analyzer, as shown in Table 1. The pH change was monitored during the digestion process, and 0.5 mol / L NaOH was used every 30 minutes to neutralize the released free fatty acids (FFA) to maintain the pH of the system at 7.0. The consumption was recorded and the FFA release rate was calculated.

[0065]

[0066] Where C NaOH is the concentration of the standard NaOH solution used for titration (mol / L), V NaOH is the volume of NaOH solution consumed during the simulated intestinal digestion time (mL), Moil is the average relative molecular mass of DHA algae oil (g / mol), m oil is the weight of DHA algae oil (g).

[0067] Table 1 Formula of simulated digestive fluid stock solution

[0068]

[0069] SGF: simulated gastric fluid; SIF: simulated intestinal fluid

[0070] The comparative example was tested according to the method of Experiment 1, and the performance data obtained were compared with those of Example 1. Figures 1 to 4 As shown;

[0071] DHA algae oil is easily oxidized by nutrients such as air, water and light, which limits its application in the food industry. The O / W (oil-in-water) emulsion prepared by ultrasonic emulsification can effectively embed unsaturated fatty acids and other easily oxidized components through the emulsifier sheep whey protein particles, thereby improving the oxidative stability of DHA algae oil. Figures 1 and 2 It can be seen that the POV and TBARs values ​​of Comparative Examples 1 and 2 increased significantly during the accelerated oxidation process, indicating that significant lipid oxidation occurred. On the 15th day, the POV values ​​reached 72.14 and 74.36 meq / kg, respectively, and the TBARs reached 7.36 and 10.85 μM, respectively. In contrast, the primary and secondary oxidation products in Example 1 only increased slightly, and during the same storage time, they were significantly lower than those in Comparative Examples 1 and 2. This shows that the emulsion system of Example 1 can significantly improve the oxidative stability of DHA algae oil and effectively protect the biological activity of unsaturated fatty acids such as DHA in the algae oil.

[0072] Depend on Figure 3It can be seen that before the start of in vitro digestion, the emulsion particle size in Example 1 was only 22.18nm, which was reduced by 2 orders of magnitude compared to Comparative Examples 1 and 2, reaching the nanoemulsion level. And in the gastric digestion stage, the particle size of Example 1 did not change significantly, which shows that the structure of the emulsion was not destroyed, and the oil droplets of the emulsion could resist the low pH environment of the gastric digestive fluid. Entering the intestinal digestion stage, the emulsion particle size increased significantly, which shows that the emulsion was digested violently in the intestinal digestive fluid, and the emulsion droplets were quickly assembled into mixed micelles and vesicles with pancreatic enzymes, bile salts, etc., to release fatty acids. Studies have shown that the smaller the particle size of nanoemulsion, the larger the specific surface area, which can significantly improve digestibility, shorten the formation time of dissolved nutrient micelles, and enhance the release rate. The free fatty acid release situation in the intestinal digestion stage confirms the research of predecessors. Compared with Comparative Examples 1 and 2, the release rate of Example 1 is smooth and stable, and the release time is extended, achieving a long-term sustained release of fatty acids. The reason for this is that sheep whey protein forms a dense network structure or solid phase interface on the surface of DHA algae oil droplets, which hinders the contact of lipase with the oil phase to a certain extent. This not only isolates the oil phase from contact with the air, but also facilitates the slow release of active substances in the emulsion-encapsulated DHA algae oil, ensuring the stable and continuous release of DHA unsaturated fatty acids, thereby increasing its solubility in the mixed micelles, allowing it to diffuse faster in the mucus layer, increasing the permeability of small intestinal epithelial cells, and significantly improving bioavailability.

[0073] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. DHA goat milk cheese sticks, characterized in that, Includes the following components: 10 parts goat milk powder, 5 parts fruit chunks, 20 parts cheese, 15 parts light cream, 10 parts white sugar, 5 parts galacto-oligosaccharide, 2 parts carrageenan, 0.5 parts tricalcium phosphate; The preparation method of the DHA goat milk cheese sticks comprises the following steps: Step 1: Dissolve goat milk powder in water to prepare goat milk, add green tea in an amount of 5-7% by weight of the goat milk, heat at 85-90° C. for 20 minutes, filter out the green tea residue to remove the smell of mutton, and obtain goat milk after removing the smell of mutton; The weight ratio of the goat milk powder to water is 1:5-6; Step 2: After adding goat whey protein and DHA algae oil to the goat milk after removing the smell of mutton, a high-speed mechanical stirrer was used to stir the mixture at a speed of 8000 r / min for 1 minute to obtain colostrum, and the colostrum was homogenized using an ultrasonic cell disruptor for 2 minutes to obtain DHA algae oil goat milk emulsion; The amount of goat whey protein used is 0.8-1.2w / w% of the total weight of goat milk, and the amount of DHA algae oil used is 4.5-5.5v / v% of the total volume of goat milk; Step 3: First, prepare the fruit pieces into juice, and then adjust the pH value to 4.7-4.9 to obtain acid-adjusted juice; Step 4: Melt the cheese to obtain liquid cheese, and evenly mix the white sugar, galacto-oligosaccharide, and tricalcium phosphate to obtain a dry mixed powder; Step 5: Add the dry mixed powder, acidified juice, liquid cheese, and light cream to the DHA algae oil goat milk emulsion, mix, and heat at 80-90° C. for 5 minutes to further emulsify to obtain a uniform emulsion; when the uniform emulsion is naturally cooled to 50-55° C., add the melted carrageenan and keep warm for 5 minutes to obtain a mixture; Step 6: Fill the mixture into a mold and refrigerate to obtain DHA goat milk cheese sticks.

2. The DHA goat milk cheese stick according to claim 1, wherein Cheese is made from goat's milk.

3. The DHA goat milk cheese stick according to claim 1, wherein DHA goat milk cheese sticks should be stored at 2~3℃.

4. The DHA goat milk cheese stick according to claim 1, wherein In step 3, the fruit pieces are pulped and filtered through double-layer gauze to obtain pulp, and the pulp is homogenized in an ultrasonic cell disruptor for 2 minutes to obtain juice, and the pH value of the juice is adjusted to 4.7-4.9 to obtain acidified juice.

5. The DHA goat milk cheese stick according to claim 1, wherein In step six, the refrigeration temperature is 4°C for 20 hours.

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