Preparation method of sweet potato and milk composite milk beverage

Abstract

The invention discloses a preparation method of a sweet potato and milk composite milk beverage, and belongs to the technical field of food processing. Sweet potatoes and UHT cow milk are used as raw materials, alpha-amylase, sodium citrate, carboxymethyl cellulose (CMC) and xanthan gum are added, and processing technologies of blending, enzymolysis, homogenization, sterilization, cooling and the like are performed to prepare the sweet potato milk. A single-factor experiment and a response surface optimization experiment are carried out by taking the centrifugal precipitation rate and sensory score of the sweet potato and milk composite dairy beverage as inspection indexes, and the optimal ratio of sweet potato pulp to cow milk and the optimal addition amounts of sodium citrate, carboxymethyl cellulose (CMC) and xanthan gum are determined. The sweet potato and milk composite milk beverage which is simple in process operation, low in cost, unique in taste, mellow in taste, uniform in tissue and good in stability is prepared.

Description

TECHNICAL FIELD

[0001] The present application relates to a sweet potato milk compound milk beverage and a preparation method thereof, and belongs to the technical field of food processing. BACKGROUND

[0002] Sweet potatoes have very high nutritional value, rich in dietary fiber, can stimulate the peristalsis of the gastrointestinal tract, and also have high medicinal value, can calm the mind, clear the mind, remove sores and swelling, treat night blindness, and tonify the spleen and stomach; modern research shows that sweet potatoes have the effects of preventing cancer, inhibiting alcohol in bile, reducing blood lipids, and improving immunity, etc. In addition, sweet potatoes can also scavenge active oxygen, inhibit the generation of melanin causing freckles and old spots, and play an anti-aging role. UHT milk is a kind of milk treated by ultra-high temperature sterilization technology, which can be sealed and stored for a long time at room temperature. Milk is a very important natural beverage, rich in protein, fat, and calcium, phosphorus, iron, zinc, copper, manganese and other minerals. In addition, milk protein also contains 8 kinds of amino acids required by the human body.

[0003] With the improvement of living standards and the increasing concern about food safety, people begin to doubt the nutrition of carbonated beverages and alcoholic beverages which have large demand in the market. At the same time, with the continuous change of Chinese dietary structure and living habits, the intake of vitamins, minerals, dietary fiber and other nutrients is insufficient and unbalanced, which is gradually common. These nutrients are essential for the normal growth and development of the body and the maintenance of life activities, and their lack will cause a series of diseases. The development of healthier drinks has become a new demand in the market. Cereal milk beverage enters the center of public vision with its natural, green and healthy characteristics.

[0004] The present application takes sweet potatoes and milk as main raw materials, and improves the bad taste and stability of the compound milk beverage through enzymolysis and food additives, etc. to avoid the precipitation, stratification and taste that consumers do not accept during the processing and storage of sweet potato pulp, and improve the flavor of UHT treated milk. A new type of sweet potato milk compound milk beverage with good stability, nutritional health, mellow taste and easy digestion and absorption is developed. SUMMARY

[0005] The purpose of the present application is to meet the needs of modern people, and to research and develop a new type of sweet potato milk compound beverage with sweet taste, smooth taste and best stability. The sweet potato and milk are used as main raw materials, and appropriate food additives are added, and through many processing technologies, the precipitation and stratification are reduced, the stability of the sweet potato milk beverage is improved, the product flavor and taste are improved, and a new type of sweet potato milk compound beverage with novel combination and natural health is prepared.

[0006] The purpose of the present application is realized by the following technical scheme:

[0007] A preparation method of sweet potato and milk compound beverage, the steps are as follows: sweet potato→cleaning→peeling→cutting→cleaning→steaming→adding water and squeezing juice→mixing (food additive) →enzymolysis→adding milk→homogenization→sterilization→finished product

[0008] The preparation method and the obtained product have the following advantages and beneficial effects:

[0009] (1) The color is attractive, the taste is sweet, and the milk and sweet potato have a fragrance.

[0010] (2) The protein content is rich, the nutritional value is high, has the effects of antioxidation, defecation, beauty, etc., and is suitable for old and young.

[0011] (3) The natural compound emulsifying stabilizer is adopted, the organization is uniform, and good stability is shown.

[0012] According to the principle of nutritional complementation, the cooking time of sweet potato, the addition amount of white granulated sugar and alpha-amylase are determined according to sensory score and centrifugal sedimentation rate indexes, and through single factor test, the formula is optimized by combining with a response surface method. Finally, the best formula of the sweet potato and milk compound milk beverage is obtained, and the flavor of the compound milk beverage is evaluated by using an electronic nose. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A preparation process flow of sweet potato and milk compound milk beverage

[0014] Figure 2 Effects of different sweet potato pulp and milk ratios on the compound milk beverage

[0015] Figure 3 Effects of sodium citrate addition amount on the compound milk beverage

[0016] Figure 4 Effects of CMC addition amount on the compound milk beverage

[0017] Figure 5 Effects of xanthan gum addition amount on the compound milk beverage DETAILED DESCRIPTION

[0018] The technical solutions of the present application are further described below in combination with the drawings, but are not limited thereto, and any modification or equivalent replacement to the technical solutions of the present application without departing from the spirit and scope of the present application shall be covered in the protection scope of the present application.

[0019] Experimental process

[0020] (1) Select sweet potatoes that are not rotten, have a complete appearance, and are firm in texture. After peeling the skin, cut the sweet potatoes into pieces of about 5g. Boil them in boiling water at 100℃ for 10 minutes, then cool them in cold water and drain them.

[0021] (2) Beat the sweet potato pieces pretreated in step 1, specifically: add pure water and pour into a beater and beat repeatedly for 2 minutes, with a material-liquid ratio of 1:2

[0022] (3) Add 4.5% white sugar at the same time and filter it with gauze for the first time

[0023] (4) Add 4% α-amylase at pH = 6.5 and 55°C for 40 minutes

[0024] (5) After enzyme decomposition, the sweet potato pulp is sterilized by heating and boiling, and filtered through gauze to obtain the sweet potato pulp.

[0025] (6) Compound the prepared sweet potato pulp with milk and add a composite emulsifier stabilizer, and stir evenly.

[0026] (7) The obtained liquid was homogenized in a homogenizer for 1 min at a speed of 8500 r / min, and then placed in a boiling water bath for 10-15 min for sterilization.

[0027] (8) Cooling the obtained sweet potato milk composite milk to obtain the finished product

[0028] Single factor experiment and response surface optimization experiment

[0029] Through preliminary experiments, the approximate addition ranges of each factor were determined. Subsequently, the volume ratios of sweet potato pulp to milk were set at 1:9, 2:8, 3:7, 4:6, and 5:5, respectively. The addition levels of sodium citrate were 0.06%, 0.08%, 0.10%, 0.12%, and 0.14%, respectively; the addition levels of carboxymethyl cellulose (CMC) were 0.05%, 0.10%, 0.15%, 0.20%, and 0.25%, respectively; and the addition levels of xanthan gum were 0.03%, 0.06%, 0.09%, 0.12%, and 0.15%, respectively. A single-factor experiment was conducted using the centrifugal sedimentation rate and sensory score of the sweet potato and milk composite dairy beverage as evaluation indicators.

[0030] Based on the results of single-factor experiments, the Box-Benhnken central composite experimental design was used to conduct a four-factor three-level experiment to study the effects of different ratios of sweet potato pulp to milk (A), the dosage of sodium citrate (B), the dosage of CMC (C), and the dosage of xanthan gum (D) on the stability of the mixed dairy products of sweet potato pulp and milk, thereby optimizing the formula of the sweet potato milk compound beverage.

[0031] ①The different sweet potato pulp and milk ratio (1:9, 2:8, 3:7, 4:6, 5:5) were analyzed, with the increasing of sweet potato pulp and milk ratio, the centrifugal precipitation rate and sensory evaluation of the beverage changed obviously, so the next step of response surface method was still needed to optimize, and the selected sweet potato pulp and milk ratio interval was 3:7-5:5

[0032] ②5 portions of the obtained sweet potato milk compound milk beverage semi-finished product, each 30 ml, were taken out and added with 0.06%, 0.08%, 0.10%, 0.12% and 0.14% of sodium citrate respectively, with the increasing of the sodium citrate addition amount, the sensory score continuously increased and the centrifugal precipitation rate continuously decreased, the sensory score was the highest when the sodium citrate addition amount was 0.10% of the sweet potato pulp, and the sensory score gradually decreased and the centrifugal precipitation rate had an upward trend when the ratio exceeded 0.10%. According to the centrifugal precipitation rate and sensory score, the sodium citrate addition amount still needed to be further optimized and determined, and the selected addition amount was 0.08%-0.12%.

[0033] ③5 portions of the obtained sweet potato milk compound milk beverage semi-finished product, each 30 ml, were taken out and added with 0.05%, 0.10%, 0.15%, 0.20% and 0.25% of carboxymethyl cellulose CMC respectively, with the increasing of the CMC addition amount, the sensory score continuously increased and the centrifugal precipitation rate continuously decreased, the sensory score was the highest when the CMC addition amount was 0.15% of the sweet potato pulp, and the sensory score gradually decreased and the centrifugal precipitation rate had an upward trend when the ratio exceeded 0.15%. The CMC addition amount had obvious influence on the smoothness, thickness and overall flavor fullness of the beverage, and the CMC addition amount still needed to be further optimized and determined, and the selected addition amount was 0.10%-0.20%.

[0034] ④5 portions of the obtained sweet potato milk compound milk beverage semi-finished product, each 30 ml, were taken out and added with 0.03%, 0.06%, 0.09%, 0.12% and 0.15% of xanthan gum respectively, with the increasing of the xanthan gum addition amount, the sensory score continuously increased and the centrifugal precipitation rate continuously decreased, the sensory score was the highest when the xanthan gum addition amount was 0.09% of the sweet potato pulp, and the sensory score gradually decreased and the centrifugal precipitation rate had an upward trend when the ratio exceeded 0.09%. According to the centrifugal precipitation rate and sensory score, the next step of optimization was needed to be carried out by response surface method, and the selected xanthan gum addition amount was 0.06%-0.12%.

[0035] The production process of sweet potato milk compound beverage was optimized by response surface analysis. The results showed that the sweet potato milk compound beverage had the best sensory evaluation when the sweet potato was cooked at 100 ℃ for 10 min, the water was added at the ratio of 1:2, the sweet potato was pulped for 2 min, and 4.5% white sugar was added. The sweet potato milk compound beverage was yellow, full and soft. The stability of sweet potato milk compound beverage was effectively improved by using the emulsifying stabilizer composed of 0.10% sodium citrate, 0.15% carboxymethyl cellulose (CMC) and 0.09% xanthan gum, and the sweet potato milk compound beverage had the best stability, with light yellow color, sweet taste and smooth taste.

Claims

1. A preparation method of sweet potato milk composite milk beverage, characterized by The method steps are as follows: Step one: raw material selection: select sweet potatoes without corruption, complete appearance, and solid texture. After cleaning, peeling, cutting (about 5g of block), washing, and other steps, use 100℃ boiling water to scald for a period of time, then put it into cold water to dry, take out and drain. Step two: beating: add pure water to the sweet potato pieces into the beating machine and beat repeatedly for 2min, the ratio of material to liquid is 1:

2. Use gauze to filter for the first time. Step three: enzyme hydrolysis: add α-amylase for enzyme hydrolysis. After enzyme decomposition, sterilize by heating and boiling to obtain sweet potato pulp. Step four: blending: blend the prepared sweet potato pulp with commercially available UHT milk and add a composite emulsifying stabilizer, stir evenly, and add 0.10% sodium citrate, 0.15% carboxymethyl cellulose (CMC), and 0.09% xanthan gum composite emulsifying stabilizer, and stir evenly. Step five: homogenization and sterilization: homogenize in a homogenizer for 1min (8500r / min), then put it into a boiling water bath for 10-15min for sterilization, and after cooling, it is the finished product.

2. The method of claim 1, wherein The boiling time in step one is 10min.

3. The method of claim 1, wherein In step two, add 4.5% white sugar before filtering with gauze.

4. The method of claim 1, wherein In step three, the amount of α-amylase added is 4%, and the enzyme hydrolysis conditions are pH=6.5, 55℃, and 40min.

5. The method of claim 1, wherein In step four, the ratio of sweet potato to milk is 4:6, and the composite emulsifying stabilizer is a composite of 0.10% sodium citrate, 0.15% carboxymethyl cellulose (CMC), and 0.09% xanthan gum.

6. The sweet potato and milk composite milk beverage prepared according to any one of claims 1-5.

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