Preparation Of Fruit And Vegetable Powder By Microwave Assisted Blanching Vacuum Freeze-drying And Its Application In Milk Slices

Milk tablets are rich in protein,carbohydrates and other nutrients,can use milk powder and some auxiliary ingredients to mix,compress,and packaged.As an auxiliary ingredient,fruits and vegetables are added to milk tablets to supplement the vitamin deficiency of milk tablets.In this experiment,vitamin C and carotenoid-rich fruit and vegetable milk tablets were prepared by freeze-drying and crushing of fruits and vegetables after microwave blanching and then added to milk powder and auxiliary materials.The quality,digestion and storage stability were studied to obtain the best preparation.Regulation of Vita and Carotenoid-rich Fruit and Vegetable Milk Tablets.The results of this study are as follows:1.Microwave-assisted blanching freeze-drying method for the preparation of fruit and vegetable powdersThe effects of microwave-assisted blanching and direct blanching on the content of vitamin C and carotenoids in fruit and vegetable powders prepared by freeze-drying were compared.Spectrophotometry was used to detect the peroxidase activity,Vc content and carotenoid content,and the results were screened out.The best blanching conditions.The results showed that the best blanching conditions were as follows: broccoli,carrot,and spinach were heated in a water bath at 30°C~40°C for 7~9 min,and microwave-assisted blanching was performed for 1 min.The highest reduction rate of enzyme activity was 93.50%.The highest preservation rate of Vc can reach 91.11%,and the preservation rate of carotenoids can reach 74.98%.Bananas and kiwifruits were heated in a water bath at 50°C for 7 min.Microwave-assisted hot blanching was performed for 0.5 min.The highest reduction rate of enzyme activity was 88.16%,and the highest Vc preservation rate was 89.57%.The preservation rate of carotenoids was up to 94.53%..2.Preparation and Quality Evaluation of Fruit and Vegetable Milk Flakes Containing Vc and CarotenoidsThe single factor and orthogonal test were used to screen out the ratio of the fruit and vegetable powder and the optimal conditions of the milk tablet molding process.The results showed that spinach: carrot: broccoli: kiwifruit: banana = 2:3:3:3:2,and the ratio of powdered milk and mixed fruit and vegetable powder was 10:1.In addition,when the mesh number is 200 mesh,the addition amount of magnesium stearate is 3%,and the addition amount of CMC-Na is 5%,the hardness of the milk tablet is large,and the moldability is better.The number of mesh has a greater effect on the hardness of the milk tablet,followed by the amount of CMC-Na added.The amount of oligoisomaltose is between 10% and 15%.When the temperature was 42? and the humidity was 42% under constant temperature and humidity conditions,the vitamin content in the fruit and vegetable milk tablets gradually decreased as the storage time increased,and the quality of the fruit and vegetable milk tablets gradually deteriorated.3.Effect of Milk and Vegetable Powders on the Digestion Stability of Vc and CarotenoidsThe effects of dietary fiber from different fruits and vegetables on the absorption of vitamins were studied by in vitro simulated digestion tests.The results showed that with the increase of the number of dietary fiber meshes,the smaller the particle size,the greater the surface area and porosity.The larger the diameter of the dietary fiber,the greater the effect on the absorption of vitamin C and carotenoids,and the more harmful the absorption of vitamins by the body.