Plant-based functional colored potato milk and preparation method thereof

Abstract

The invention relates to the field of food, in particular to plant-based functional colored potato milk and a preparation method thereof.The plant-based functional colored potato milk is prepared from colored potatoes as a main raw material and compounded vegetable oil, trehalose, dipotassium phosphate, anthocyanin-nanocellulose composite modified chitosan and salt as additive components through pretreatment, pulping, enzymolysis, enzyme deactivation and blending and shearing and emulsifying. And filling, sterilizing and the like. The functional colored potato milk does not contain animal milk, the content of antioxidant substances, namely anthocyanin and vitamin C, in the colored potato milk is reserved and increased to the maximum extent, the functional colored potato milk has a very strong antioxidant function, meanwhile, the fat intake can be reduced, the weight losing effect is achieved, and the cancer risk of eaters can also be prevented.

Description

Technical Field

[0001] The invention relates to the field of food, and in particular to a plant-based functional colored potato milk and a preparation method thereof. Background Art

[0002] Milk, known as "white blood", is a nutritious natural drink. It is rich in protein, calcium, phosphorus, vitamin B group and various trace elements, and plays an important role in promoting bone health and enhancing immunity. The popularity of milk is due to its easy access and processing, as well as its nutritional value for people of different ages. However, the lactose component in milk has become an obstacle for some people to enjoy this natural nutrient source.

[0003] Lactose intolerance is caused by the lack of sufficient lactase in the body, which cannot break down the lactose in milk, leading to symptoms of indigestion, such as bloating, abdominal pain, diarrhea, etc. According to statistics, the incidence of lactose intolerance varies significantly worldwide, and the incidence is particularly prominent in Asian populations. In China, according to research, the proportion of people with lactose intolerance is as high as 75%-100%, and this proportion is even as high as 87% among children aged 3-13. Lactose intolerance not only affects the nutritional intake of this group of people, but also limits their choice of milk and dairy products. Faced with the challenge of lactose intolerance, the milk industry and consumers are seeking solutions. On the one hand, dairy companies meet the needs of specific groups by developing low-lactose or lactose-free products; on the other hand, consumers are also adapting to their own nutritional needs by changing their eating habits or choosing substitutes.

[0004] Plant milk, with its healthy and environmentally friendly image, has gradually won the favor of consumers around the world. They are usually made from plant ingredients such as soybeans, oats, and almonds. They not only provide alternatives for people with lactose intolerance, but also add new choices for people who pursue a healthy diet. With the advancement of technology and the diversification of consumer demand, the plant milk market has ushered in explosive growth, and many innovative products such as oat milk, almond milk, and pistachio milk have emerged.

[0005] Potatoes are the fourth largest food crop in China and an important food crop in the world. They are rich in starch, edible fiber, vitamins, and minerals such as calcium, phosphorus, and iron. They are recognized as complete nutritional foods worldwide. Their protein has high nutritional value, high digestible content, and is easily absorbed by the human body. Studies have found that eating potatoes and whole milk can provide all the nutrients needed by the human body. In particular, the quality of potato protein is similar to that of animal protein. It contains 18 kinds of amino acids, including 8 essential amino acids that cannot be synthesized by the human body but are not found in cereals. It is known as the "super vegetable", "underground apple" and "second bread".

[0006] Colored potatoes are a new variety of special potatoes that have been cultivated in recent years and are edible, nutritious, health-promoting and ornamental. In addition to all the nutritional values ​​of ordinary potatoes, colored potatoes are also rich in important antioxidant functional active ingredients - polyphenols, anthocyanins, dietary fiber and multiple vitamins, especially carotenoids and vitamin C. They have strong antioxidant, anti-tumor, anti-viral, cardiovascular disease prevention and blood sugar regulation functions. International research in recent years has found that colored potatoes, with their unique high antioxidant content and starch characteristics, have great potential and broad application prospects in the food market that provides functional health care and beauty and anti-aging as a popular food.

[0007] Plant-based functional colored potato milk made from colored potatoes has begun to enter people's field of vision with its unique nutritional value and health benefits. Compared with traditional plant milks derived from grains and nuts, colored potato milk provides a new nutritional option. Colored potato milk does not contain more than a dozen common food allergens, and can reduce the risk of allergies to a greater extent than other plant milks and nut milks. In addition, the antioxidants contained in colored potatoes help to resist the invasion of free radicals and maintain physical health. Dietary fiber helps to promote intestinal health and prevent constipation. Moreover, colored potato milk usually contains lower saturated fat, which is a healthier choice for consumers who need to control fat intake. At present, there are few studies on potato dairy products. For example, CN109479973A discloses "a formula for nutritious potato dairy products" made from potato flour and raw milk, and the protein comes from animal raw materials. The potato dairy product has both taste and health and nutritional effects. For another example, CN112167568B discloses “a buckwheat-flavored potato custard filling and a preparation method thereof” which is made from baked potato mash, dry buckwheat flakes, whole egg liquid, light cream, sweetener, whole milk powder, custard powder and water. The potato dairy product content is even lower, and only a certain chewing sensation and buckwheat flavor are provided.

[0008] However, all of the above patents contain animal milk ingredients, which are not friendly to people with lactose intolerance. It also shows that it is not easy to prepare pure potato dairy products in actual production, especially pure plant-based colored potato milk rich in dietary fiber, vitamin C, phosphorus and other mineral elements. Therefore, it is urgent to develop a plant-based functional colored potato milk that does not contain animal milk, has good antioxidant properties, high vitamin C content, and can reduce fat intake and achieve weight loss. Summary of the invention

[0009] The main purpose of the present invention is to provide a plant-based functional colored potato milk and a preparation method thereof. The colored potato milk does not contain animal milk, has good antioxidant properties, is high in vitamin C content, can reduce fat intake and have a slimming effect, and can also prevent the risk of cancer in consumers.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] On the one hand, the present invention provides a method for preparing plant-based functional colored potato milk, comprising the following steps:

[0012] (1) washing, peeling, and slicing colored potatoes, adding a color preservative and soaking them for 15 to 20 minutes, taking them out and placing them in hot water at 90 to 100° C. for blanching for 1 to 3 minutes, then placing them in salt water for soaking for 5 to 10 minutes, taking them out and draining them, thereby obtaining pretreated colored potato slices;

[0013] (2) mixing the pretreated colored potato slices in step (1) with deionized water and beating for 3 to 4 minutes, then filtering, adding α-amylase to the filtrate, and performing enzymolysis at 45 to 55° C. for 45 to 55 minutes to obtain a colored potato enzymatic hydrolyzed slurry;

[0014] (3) placing the colored potato enzymatic hydrolyzed slurry in step (2) in an environment of 85 to 95° C. for 2 to 5 minutes, then centrifuging at a speed of 4000 to 6500 r / min for 15 to 30 minutes, and collecting the supernatant to obtain colored potato juice;

[0015] (4) 10 to 15 parts by weight of the colored potato juice in step (3) is mixed with 1 to 3 times the weight of deionized water of the colored potato juice, and the mixture is heated to 45 to 60° C., and 1 to 3 parts by weight of vegetable oil, 0 to 5 parts by weight of trehalose, 0.05 to 0.3 parts by weight of potassium dihydrogen phosphate, 0.1 to 0.3 parts by weight of anthocyanin-nanocellulose composite modified chitosan, and 0 to 0.1 parts by weight of edible salt are added thereto at a constant temperature, and then deionized water at 68 to 72° C. is added, and the mixture is heated to 68 to 72° C. and stirred at a constant temperature for 15 to 25 minutes to obtain a prepared solution, and the prepared solution is subjected to high-speed shear emulsification at a homogenization temperature of 65 to 75° C., a pressure of 20 to 25 MPa, and a time of 2 to 3 minutes, and then filtered for sterilization, cooled, bottled, and packaged, and sterilized by ultraviolet light to obtain plant-based functional colored potato milk.

[0016] It is understood that there are few types of potato food processing at present, plant-based potato milk beverages are lacking, and pure plant-based functional colored potato milk is still blank. The heat processing method will destroy the nutrients in potatoes, and the existing processing methods have technical problems such as browning, loss of nutrients, liquid stratification, severe precipitation, and rough taste in the beverage development process. Therefore, it is necessary to develop a product with high nutritional value and the ability to increase the added value of colored potato milk.

[0017] The plant-based functional colored potato milk of the present invention does not add any animal milk ingredients, and is more friendly to lactose-intolerant groups. In addition, the functional colored potato milk can achieve the effect of both medicine and food, reduce the risk of cancer in consumers, supplement vitamin C, and also have the effect of body shaping and weight loss. At the same time, the functional colored potato milk preparation method of the present application can avoid the problem of lack of nutrients in potatoes caused by thermal processing methods. The reason may be that the functional colored potato milk preparation method of the present application uses anthocyanin-nanocellulose composite modified chitosan as a supplementary ingredient to achieve the above effects.

[0018] In some embodiments, in step (1), the color protecting agent is one or more of citric acid, ascorbic acid and L-cysteine, and must contain citric acid.

[0019] In some embodiments, the concentration of the citric acid is 0.1-0.3 wt %.

[0020] In some embodiments, in step (1), the volume of the color protecting agent is 4 to 6 times the mass of the colored potatoes.

[0021] Preferably, in step (1), the volume of the color protecting agent is 5 times the mass of the colored potatoes.

[0022] In some embodiments, in step (2), the mass ratio of the pretreated colored potato slices to α-amylase is 1:(0.0005-0.0008).

[0023] Preferably, in step (2), the mass ratio of the pretreated colored potato slices to α-amylase is 1:0.0007.

[0024] The present application can partially decompose the starch in the pretreated colored potato slices into small-molecule sugars by regulating the mass ratio of the pretreated colored potato slices and α-amylase, thereby improving the nutritional value and absorption and digestibility of the dairy product, and can also prevent the subsequent enzyme inactivation time from being long or incomplete, which may lead to a change in the flavor of the dairy product.

[0025] In some embodiments, in step (4), the total weight of the colored potato juice, vegetable oil, trehalose, potassium dihydrogen phosphate, anthocyanin-nanocellulose composite modified chitosan, edible salt and deionized water is 100 parts.

[0026] In some embodiments, the method for preparing anthocyanin-nanocellulose composite modified chitosan comprises the following steps:

[0027] S1, adding chitosan to acetic acid solution and stirring to dissolve, to obtain chitosan dispersion;

[0028] S2, mixing the carboxymethyl cellulose and the chitosan dispersion in step S1, heating to 40-50° C., stirring at a constant temperature for 3-5 hours, concentrating under reduced pressure and drying to obtain carboxymethyl cellulose modified chitosan;

[0029] S3, anthocyanin and the carboxymethyl cellulose modified chitosan in step S2 are mixed and added into a solvent, a catalyst is added thereto, the pH value of the system is adjusted to 4-5 with a phosphate buffer solution, the temperature is raised to 40-50° C. and stirred at a constant temperature for 4-5 hours to obtain anthocyanin-nanocellulose composite modified chitosan.

[0030] Colored potatoes contain a large amount of anthocyanins and vitamin C. Colored potato dairy products are often sterilized and steamed at high temperatures during the preparation process. Anthocyanins and other ingredients in them will be partially degraded at high temperatures, thereby reducing the anthocyanin content in the colored potato milk and weakening the efficacy. However, some common methods of stabilizing anthocyanins are mainly to add stabilizers and other additives. This method may reduce the biocompatibility of colored potato milk and cause discomfort, which is especially unfriendly to young children and people with weak immunity.

[0031] The anthocyanin-nanocellulose composite modified chitosan of the present application can not only improve the high temperature degradation resistance of anthocyanin, but also reduce the body's absorption of fat, reduce obesity, and reduce the risk of cancer. The reasons may be that, on the one hand, anthocyanin can react and graft with carboxymethyl cellulose modified chitosan under catalyst conditions, and the increase in molecular weight and the interaction between molecules enhance the high temperature stability of anthocyanin-nanocellulose composite modified chitosan and prevent anthocyanin from decomposing; on the other hand, nanocellulose can cross-link with chitosan to form a cross-linked structure that increases the anthocyanin-nanocellulose composite modified chitosan. The specific surface area of ​​polysaccharides can better form complexes with bile salts, reducing the amount of bile salts on the surface of fat droplets, thereby weakening their ability to emulsify fat and weakening the absorption of fat digestion products by the small intestine. In addition, fat droplets can be loaded in the anthocyanin-nanocellulose composite modified chitosan structure to form larger fat droplets, reducing their specific surface area, thereby reducing the ability of lipase to bind to them, thereby reducing the rate of fat hydrolysis and reducing fat digestibility; thirdly, nanocellulose can cross-link with chitosan, and the formed three-dimensional network structure can better chelate heavy metals in the body and excrete them out of the body, thereby reducing the risk of cancer in consumers.

[0032] In some embodiments, the concentration of the acetic acid solution is 1-2 wt %.

[0033] Preferably, the concentration of the acetic acid solution is 1 wt %.

[0034] In some embodiments, the volume ratio of the chitosan mass to the acetic acid solution is 1:(20-25).

[0035] Preferably, the volume ratio of the mass of the chitosan to the acetic acid solution is 1:23.

[0036] In some embodiments, the mass ratio of the carboxymethyl cellulose in step S2 to the chitosan in step S1 is (0.1-0.3):1.

[0037] Preferably, the mass ratio of the carboxymethyl cellulose in step S2 to the chitosan in step S1 is 0.2:1.

[0038] The present application can prevent the system from being too viscous due to excessive crosslinking density and causing the taste of dairy products to deteriorate by regulating the mass ratio of carboxymethyl cellulose to chitosan. In addition, it can also prevent the intestinal fat absorption efficiency from increasing due to the change in ratio, making it difficult to lose weight.

[0039] In some embodiments, in step S3, the mass ratio of anthocyanin to carboxymethyl cellulose modified chitosan is (0.2-0.3):1.

[0040] Preferably, in step S3, the mass ratio of anthocyanin to carboxymethyl cellulose modified chitosan is 0.25:1.

[0041] In some embodiments, the catalyst is laccase.

[0042] The anthocyanin-nanocellulose composite modified chitosan of the present invention is prepared by using natural catalysts and natural extracts as raw materials, thereby improving biocompatibility and reducing the generation of side effects.

[0043] In some embodiments, the mass ratio of the catalyst to the chitosan in step S1 is (0.005-0.009).

[0044] Another aspect of the present invention provides a plant-based functional colored potato milk prepared by the above scheme.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The plant-based functional colored potato milk of the present invention uses colored potatoes as the main raw materials, and compound vegetable oil, trehalose, dipotassium hydrogen phosphate, anthocyanin-nanocellulose composite modified chitosan and salt as added ingredients. It is prepared by pretreatment, beating, enzymolysis, enzyme inactivation, high-speed shear emulsification, filling and sterilization, etc., and retains the nutritional components of colored potatoes to the greatest extent. The functional colored potato milk prepared at the same time has a unique flavor, strong antioxidant function, and is easy to carry and drink, which conforms to the current healthy, simple, nutritious, delicious, and fast life concepts and consumption trends of people, and has a wide range of applications. The functional colored potato milk prepared by this method does not contain animal milk, has good antioxidant properties, and has a high vitamin C content. At the same time, it can reduce fat intake and achieve a weight loss effect. In addition, it can also prevent the risk of cancer in consumers.

[0047] (2) The anthocyanin-nanocellulose composite modified chitosan of the present invention, on the one hand, anthocyanin can react and graft with carboxymethyl cellulose modified chitosan under catalyst conditions, and the increase in molecular weight and the interaction force between molecules enhance the high temperature stability of anthocyanin-nanocellulose composite modified chitosan and prevent the decomposition of anthocyanin; on the second hand, nanocellulose can be cross-linked with chitosan, and the formed cross-linked structure increases the specific surface area of ​​anthocyanin-nanocellulose composite modified chitosan, thereby better forming a complex with bile salts, reducing the amount of bile salts on the surface of fat droplets, thereby weakening its ability to emulsify fat and weakening the absorption of fat digestion products by the small intestine. At the same time, fat droplets can be loaded in the anthocyanin-nanocellulose composite modified chitosan structure to form larger fat droplets, reducing its specific surface area, thereby reducing the binding ability of lipase to it, thereby reducing the fat hydrolysis rate and reducing the fat digestibility; on the third hand, nanocellulose can be cross-linked with chitosan, and the formed three-dimensional network structure can better chelate heavy metals in the body and excrete them out of the body, thereby reducing the risk of cancer in consumers. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the following preparation examples, embodiments and comparative examples, chitosan was purchased from Hebei Baipin Biotechnology Co., Ltd.; carboxymethyl cellulose was purchased from Anhui Zhonghong Bioengineering Co., Ltd.; anthocyanins were purchased from Lanzhou Waters Biotechnology Co., Ltd.; yellow and purple potatoes were purchased from Inner Mongolia Woheni Agricultural Technology Co., Ltd.; and vegetable oil was purchased from Guangxi Xilin County Qingzhong Agriculture Co., Ltd.

[0050] Preparation Example 1

[0051] The preparation method of anthocyanin-nanocellulose composite modified chitosan comprises the following steps:

[0052] S1. Add 10 g of chitosan into 230 mL of 1 wt% acetic acid solution and stir to dissolve to obtain a chitosan dispersion;

[0053] S2, mixing 2 g of carboxymethyl cellulose with the chitosan dispersion in step S1, heating to 45° C. and stirring at a constant temperature for 4 h, and concentrating and drying under reduced pressure to obtain carboxymethyl cellulose-modified chitosan;

[0054] S3, 2.5g anthocyanin and 10g carboxymethyl cellulose modified chitosan in step S2 were mixed and added into 200mL ethanol, 0.02g laccase was added thereto, pH of the system was adjusted to 4 with phosphate buffer solution, the temperature was raised to 45°C and stirred at a constant temperature for 4h to obtain anthocyanin-nanocellulose composite modified chitosan.

[0055] Preparation Example 2

[0056] The preparation method of anthocyanin-nanocellulose composite modified chitosan is the same as that of Preparation Example 1, except that the added amount of carboxymethyl cellulose is 4 g.

[0057] Preparation Example 3

[0058] The preparation method of anthocyanin-nanocellulose composite modified chitosan is the same as that of Preparation Example 1, except that the added amount of carboxymethyl cellulose is 0.5 g.

[0059] Preparation Example 4

[0060] The preparation method of anthocyanin-nanocellulose composite modified chitosan, the specific implementation method is the same as that of Preparation Example 1, except that the added amount of anthocyanin is 4g.

[0061] Preparation Example 5

[0062] The preparation method of anthocyanin-nanocellulose composite modified chitosan, the specific implementation method is the same as that of Preparation Example 1, except that the added amount of anthocyanin is 1 g.

[0063] Example 1

[0064] A method for preparing plant-based functional colored potato milk comprises the following steps:

[0065] (1) 200 g of yellow potatoes were washed, peeled, and sliced, and 1 L of color preservative was added and soaked for 17 min. After being taken out, the potatoes were blanched in 95° C. hot water for 2 min, and then soaked in 1 L of 1 wt % salt water for 7 min. After being taken out, the potatoes were drained to obtain pretreated colored potato slices;

[0066] (2) 180 g of the pretreated colored potato slices prepared in step (1) and 540 g of deionized water were mixed and slurried for 3 min, followed by filtering, and 0.13 g of α-amylase was added to the filtrate, and enzymatic hydrolysis was performed at 55° C. for 50 min to obtain a colored potato enzymatic hydrolyzed slurry;

[0067] (3) heating 600 g of the colored potato enzymatic hydrolyzed slurry in step (2) at 95° C. for 2 min, then centrifuging at 5000 r / min for 17 min, and collecting the supernatant to obtain colored potato juice;

[0068] (4) 500 g of the colored potato juice in step (3) was mixed with 1 L of deionized water, heated to 55° C., 82 g of vegetable oil, 123 g of trehalose, 7 g of potassium dihydrogen phosphate, 8 g of anthocyanin-nanocellulose composite modified chitosan and 2 g of edible salt were added thereto at a constant temperature, and then 2.4 L of deionized water at 70° C. was added, and the mixture was heated to 70° C. and stirred at a constant temperature for 20 min to obtain a prepared solution, and the prepared solution was subjected to high-speed shear emulsification at a homogenization temperature of 70° C., a pressure of 23 MPa, and a time of 2 min, followed by filtration sterilization, cooling, bottling, and ultraviolet sterilization to obtain functional colored potato milk.

[0069] The color preservative is citric acid with a mass concentration of 0.2 wt %, and the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 1.

[0070] Example 2

[0071] The preparation method of plant-based functional colored potato milk comprises the following steps:

[0072] (1) 200 g of yellow potatoes were washed, peeled, and sliced, and then 900 mL of a color preservative was added and soaked for 15 min. After being taken out, the potatoes were blanched in 90° C. hot water for 3 min, and then soaked in 900 mL of 0.9 wt % salt water for 10 min. After being taken out, the potatoes were drained to obtain pretreated colored potato slices;

[0073] (2) 180 g of the pretreated colored potato slices prepared in step (1) and 360 g of deionized water were mixed and slurried for 3 min, followed by filtration, and 0.09 g of α-amylase was added to the filtrate, and enzymatic hydrolysis was performed at 45° C. for 55 min to obtain a colored potato enzymatic hydrolyzed slurry;

[0074] (3) placing 600 g of the colored potato enzymatic hydrolyzed slurry in step (2) in an environment of 85° C. for 5 min, then centrifuging at 4000 r / min for 30 min, and collecting the supernatant to obtain colored potato juice;

[0075] (4) 410 g of the colored potato juice in step (3) was mixed with 500 mL of deionized water, heated to 45° C., 41 g of vegetable oil, 2 g of potassium dihydrogen phosphate, and 4.1 g of anthocyanin-nanocellulose composite modified chitosan were added thereto at a constant temperature, and then 3.1 L of deionized water at 68° C. was added, and the mixture was heated to 68° C. and stirred at a constant temperature for 25 min to obtain a prepared solution, and the prepared solution was subjected to high-speed shear emulsification at a homogenization temperature of 68° C., a pressure of 25 MPa, and a time of 3 min, followed by filtration sterilization, cooling, bottling, and ultraviolet sterilization to obtain functional colored potato milk.

[0076] The color preservative is citric acid with a mass concentration of 0.1 wt %, and the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 1.

[0077] Example 3

[0078] The preparation method of plant-based functional colored potato milk comprises the following steps:

[0079] (1) 200 g of yellow potatoes were washed, peeled, and sliced, and then 1.1 L of color preservative was added and soaked for 20 min. After being taken out, the potatoes were blanched in 90° C. hot water for 1 min, and then soaked in 1.1 L of 1.1 wt % salt water for 5 min. After being taken out, the potatoes were drained to obtain pretreated colored potato slices;

[0080] (2) 180 g of the pretreated colored potato slices prepared in step (1) and 720 g of deionized water were mixed and slurried for 4 min, followed by filtering, and 0.14 g of α-amylase was added to the filtrate, and enzymatic hydrolysis was performed at 55° C. for 45 min to obtain a colored potato enzymatic hydrolyzed slurry;

[0081] (3) heating 600 g of the colored potato enzymatic hydrolyzed slurry in step (2) at 90° C. for 3 min, then centrifuging at 6500 r / min for 15 min, and collecting the supernatant to obtain colored potato juice;

[0082] (4) 450 g of the colored potato juice in step (3) was mixed with 1.3 L of deionized water, heated to 55° C., 90 g of vegetable oil, 150 g of trehalose, 9 g of potassium dihydrogen phosphate, 9 g of anthocyanin-nanocellulose composite modified chitosan and 3 g of edible salt were added thereto at a constant temperature, and then 940 mL of deionized water at 72° C. was added, and the mixture was heated to 72° C. and stirred at a constant temperature for 15 min to obtain a prepared solution, and the prepared solution was subjected to high-speed shear emulsification at a homogenization temperature of 75° C., a pressure of 20 MPa, and a time of 2 min, followed by filtration sterilization, cooling, bottling, and ultraviolet sterilization to obtain functional colored potato milk.

[0083] The color preservative is citric acid with a mass concentration of 0.3 wt %, and the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 1.

[0084] Example 4

[0085] A method for preparing plant-based functional colored potato milk comprises the following steps:

[0086] (1) 200 g of purple potatoes were washed, peeled, and sliced, and 1 L of color preservative was added and soaked for 17 min. After being taken out, the potatoes were blanched in 95° C. hot water for 2 min, and then soaked in 1 L of 1 wt % salt water for 7 min. After being taken out, the potatoes were drained to obtain pretreated colored potato slices;

[0087] (2) 180 g of the pretreated colored potato slices prepared in step (1) and 540 g of deionized water were mixed and slurried for 3 min, followed by filtering, and 0.13 g of α-amylase was added to the filtrate, and enzymatic hydrolysis was performed at 55° C. for 50 min to obtain a colored potato enzymatic hydrolyzed slurry;

[0088] (3) heating 600 g of the colored potato enzymatic hydrolyzed slurry in step (2) at 95° C. for 2 min, then centrifuging at 5000 r / min for 17 min, and collecting the supernatant to obtain colored potato juice;

[0089] (4) 500 g of the colored potato juice in step (3) was mixed with 1 L of deionized water, heated to 55° C., 82 g of vegetable oil, 123 g of trehalose, 7 g of potassium dihydrogen phosphate, 8 g of anthocyanin-nanocellulose composite modified chitosan and 2 g of edible salt were added thereto at a constant temperature, and then 2.4 L of deionized water at 70° C. was added, and the mixture was heated to 70° C. and stirred at a constant temperature for 20 min to obtain a prepared solution, and the prepared solution was subjected to high-speed shear emulsification at a homogenization temperature of 70° C., a pressure of 23 MPa, and a time of 2 min, followed by filtration sterilization, cooling, bottling, and ultraviolet sterilization to obtain functional colored potato milk.

[0090] The color preservative is citric acid with a mass concentration of 0.2 wt %, and the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 1.

[0091] Example 5

[0092] The preparation method of plant-based functional colored potato milk has the same specific implementation as Example 1, except that the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 2.

[0093] Example 6

[0094] The preparation method of plant-based functional colored potato milk has the same specific implementation method as Example 1, except that the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 3.

[0095] Example 7

[0096] The preparation method of plant-based functional colored potato milk has the same specific implementation as Example 1, except that the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 4.

[0097] Example 8

[0098] The preparation method of plant-based functional colored potato milk has the same specific implementation mode as Example 1, except that the anthocyanin-nanocellulose composite modified chitosan is prepared by Preparation Example 5.

[0099] Comparative Example 1

[0100] The preparation method of plant-based functional colored potato milk has the same specific implementation as Example 1, except that an equal mass of chitosan is used instead of anthocyanin-nanocellulose composite modified chitosan.

[0101] Performance Testing:

[0102] (1) DPPH scavenging rate: Weigh 2 g of colored potato milk, add 40 mL of 60 wt% ethanol solution, ultrasonically oscillate for 1 h, centrifuge at 4000 r / min for 30 min, take 1 mL of the supernatant, add 2 mL of 0.40 mmol / L DPPH free radical solution, mix well and place in dark for 30 min, measure the absorbance at a wavelength of 517 nm, and calculate the DPPH free radical scavenging rate according to the following formula:

[0103]

[0104] Among them, A 1 is the sample absorbance, A 2 is the absorbance of ethanol instead of DPPH, A0 is the absorbance of blank control;

[0105] (2) ABTS scavenging rate: Weigh 2.0 g of colored potato milk, add 40 mL of 60 wt% ethanol solution, ultrasonically oscillate for 1 h, centrifuge at 4000 r / min for 30 min, take 0.4 mL of the supernatant, add 3 mL of ABTS cation free radical stock solution, shake well and let stand for 30 min, measure the absorbance at a wavelength of 734 nm, and calculate the ABTS cation free radical scavenging rate according to the following formula:

[0106]

[0107] Among them, B 1 is the sample absorbance, B 2 The absorbance of ABTS is replaced by ethanol, B 0 is the absorbance of blank control;

[0108] (3) Small Intestinal Fat Absorption Test: The FFA reduction rate was tested by referring to the method provided in the journal ACS Nano, “Reducing Intestinal Digestion and Absorption of Fat Using a Nature-Derived Biopolymer: Interference of Triglyceride Hydrolysis by Nanocellulose.” The nanocellulose was replaced with colored potato milk with the same content of anthocyanin-nanocellulose composite modified chitosan.

[0109] The functional colored potato milk of each embodiment and comparative example was tested according to the above method. The test results are shown in Table 1.

[0110] Table 1

[0111]

[0112]

[0113] According to the data analysis in Table 1, the plant-based functional colored potato milk prepared in Examples 1 to 4 has good antioxidant properties and can also reduce the absorption of fat in the small intestine, thereby achieving a slimming effect; in Example 5, due to the change in the mass ratio of carboxymethyl cellulose and chitosan, although the FFA reduction rate is increased, the viscosity of the potato milk is too high and it is unpalatable; in Example 6, due to the change in the mass ratio of carboxymethyl cellulose and chitosan, the cross-linking density of anthocyanin-nanocellulose composite modified chitosan is reduced, resulting in a decrease in the FFA reduction rate, which is not conducive to the body shaping effect; in Example 7, due to the change in the mass ratio of carboxymethyl cellulose and chitosan, the cross-linking density of anthocyanin-nanocellulose composite modified chitosan is reduced, resulting in a decrease in the FFA reduction rate, which is not conducive to the body shaping effect. Due to the change in the mass ratio of anthocyanin to carboxymethyl cellulose modified chitosan, the content of anthocyanin inserted into anthocyanin-nanocellulose composite modified chitosan increased, which was not conducive to the formation of fat droplets. Although the antioxidant effect was improved, the FFA reduction rate decreased; Example 8 changed the mass ratio of anthocyanin to chitosan. In contrast to Example 6, the FFA reduction rate was improved, but the antioxidant effect was weakened; Comparative Example 1 used an equal mass of chitosan instead of anthocyanin-nanocellulose composite modified chitosan, resulting in weakened antioxidant effect and anti-fat absorption effect of the colored potato milk.

[0114] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing plant-based functional colored potato milk, characterized in that: The steps include: (1) washing, peeling, and slicing colored potatoes, adding a color preservative and soaking them for 15 to 20 minutes, taking them out and placing them in hot water at 90 to 100° C. for blanching for 1 to 3 minutes, then placing them in salt water for soaking for 5 to 10 minutes, taking them out and draining them, thereby obtaining pretreated colored potato slices; (2) mixing the pretreated colored potato slices in step (1) with deionized water and beating for 3 to 4 minutes, then filtering, adding α-amylase to the filtrate, and performing enzymolysis at 45 to 55° C. for 45 to 55 minutes to obtain a colored potato enzymatic hydrolyzed slurry; (3) placing the colored potato enzymatic hydrolyzed slurry in step (2) in an environment of 85 to 95° C. for 2 to 5 minutes, then centrifuging at a speed of 4000 to 6500 r / min for 15 to 30 minutes, and collecting the supernatant to obtain colored potato juice; (4) 10 to 15 parts by weight of the colored potato juice in step (3) is mixed with 1 to 3 times the weight of deionized water of the colored potato juice, heated to 45 to 60° C., 1 to 3 parts by weight of vegetable oil, 0 to 5 parts by weight of trehalose, 0.05 to 0.3 parts by weight of potassium dihydrogen phosphate, 0.1 to 0.3 parts by weight of anthocyanin-nanocellulose composite modified chitosan and 0 to 0.1 parts by weight of edible salt are added thereto at a constant temperature, deionized water at 68 to 72° C. is then added, the mixture is heated to 68 to 72° C. and stirred at a constant temperature for 15 to 25 minutes to obtain a prepared solution, the prepared solution is subjected to high-speed shear emulsification at a homogenization temperature of 65 to 75° C., a pressure of 20 to 25 MPa, and a time of 2 to 3 minutes, and then filtered for sterilization, cooled, bottled, and packaged, and sterilized by ultraviolet light to obtain plant-based functional colored potato milk.

2. The method for preparing plant-based functional colored potato milk according to claim 1, characterized in that: In step (1), the color protecting agent is one or more of citric acid, ascorbic acid and L-cysteine, and must contain citric acid.

3. The method for preparing the plant-based functional colored potato milk according to claim 2, characterized in that: The concentration of the citric acid is 0.1-0.3 wt %.

4. The method for preparing plant-based functional colored potato milk according to claim 1, characterized in that: In step (1), the volume of the color protecting agent is 4 to 6 times the mass of the colored potatoes.

5. The method for preparing plant-based functional colored potato milk according to claim 1, characterized in that: In step (2), the mass ratio of the pretreated colored potato slices to α-amylase is 1:(0.0005-0.0008).

6. The method for preparing plant-based functional colored potato milk according to claim 1, characterized in that: The preparation method of anthocyanin-nanocellulose composite modified chitosan comprises the following steps: S1, adding chitosan to acetic acid solution and stirring to dissolve to obtain chitosan dispersion; S2, mixing the carboxymethyl cellulose and the chitosan dispersion in step S1, heating to 40-50° C., stirring at a constant temperature for 3-5 hours, concentrating under reduced pressure and drying to obtain carboxymethyl cellulose modified chitosan; S3, anthocyanin and the carboxymethyl cellulose modified chitosan in step S2 are mixed and added into a solvent, a catalyst is added thereto, the pH value of the system is adjusted to 4-5 with a phosphate buffer solution, the temperature is raised to 40-50° C. and stirred at a constant temperature for 4-5 hours to obtain anthocyanin-nanocellulose composite modified chitosan.

7. The method for preparing plant-based functional colored potato milk according to claim 6, characterized in that: The mass ratio of the carboxymethyl cellulose in step S2 to the chitosan in step S1 is (0.1-0.3):

1.

8. The method for preparing plant-based functional colored potato milk according to claim 6, characterized in that: In step S3, the mass ratio of anthocyanin to carboxymethyl cellulose modified chitosan is (0.2-0.3):

1.

9. The method for preparing plant-based functional colored potato milk according to claim 6, characterized in that: The catalyst is laccase.

10. Plant-based functional colored potato milk prepared by the preparation method according to any one of claims 1 to 9.

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