The Research On Fat Oxidation Stability During Processing And Storage Of Formula Milk Powder For Infants And Young Children

The fat content of formula milk powder for infants and young children is in the range of 18～31g/100g milk powder. Fat provide energy to infants and young children for rapid growth, and it is also an important part of their body. Unsaturated fatty acids are rich in breast milk, which are necessary for the growth and development, and which have an important role in the formation of myelin sheath, brain and vision development of infants and young children. The formula milk powder for infants and young children is currently the closest nutritional alternatives to breast milk, which is rich in linoleic acid, linolenic acid, arachidonic acid (ARA), docosahexaenoic acid (DHA) and other polyunsaturated fatty acis.There are much vegetable oils and a centain amount of essential fatty acids such as polyunsaturated fatty acid in formula milk powder for infants and young children, because of which it is easily oxidized. Having long-term consumption of high levels of peroxide formula, infant may prompt the body cell mutation. Theoretical study clearly the fat oxidation stability variation of milk powder for formula infants and young children during processing and storage have a great significance in protection of milk safety and guidance of milk production.The main factors led to fatty acid oxidation, including temperature, time, homogeneous pressure, oxygen, iron, copper, manganese and other trace elements. Adding antioxidants, microencapsulated technology, nitrogen or CO2 packaging and other measures can be effective in improving fat oxidation stability.Firstly, we decide using polyunsaturated fatty acids content, peroxide value (POV), carbonyl value, acid value and flavor to evaluate fat oxidation stability of formula milk powder for infants and young children during processing and storage, and establishment the determination method of each index.This paper studies in detail the impact of antioxidants, milk powder production process, microencapsulated technology, the way of DHA vitamins, and minerals mixed, storage temperature and storage time on fat oxidation stability of formula milk powder for infants and young children.During processing technics of formula milk powder for infants and young children, the results show that fat oxidation stability in milk powder with DHA microcapsules mixed by dry process was higer than that of DHA oil mixed by wet process,and DHA microcapsules mixed by wet process sample was the lowest.ingredients mixed technology, UHT sterilization process and fluidized bed technology has litter effect on fat oxidation; homogeneous and concentration process has a certain influence on fat oxidation; yet the spray drying process significantly accelerated the fat oxidation. the fat oxidation stability of ascorbyl palmitate (AP) and vitamin E (VE) ratio of 2:3was higher than that ratio of 1:3. In the samples of adding 2.4,8,12,16 mg vitamin E per 100g milk powder, the DHA stability of sample with 8mg/100g vitamin E addition was the best, the fat oxidation of vitamins mixed by dry process was the sample mixed by wet process, but the fat oxidation of minerals mixed by dry process was much lower than the sample mixed by wet process.During storage, temperature effect on fat oxidation stability was obvious; Samples stored in incubator with 20,30,37℃separately for one months, the fat oxidation was enhanced with increasing temperature. Fat oxidation is slow in samples stored with temperature lower than 30℃,so we should control temperature in milk powder production.packaging,storage,tansportation and other sectors. In general, the POV value was under 10meq/kg in samples stored in 20℃temperature after 24 months. The milk quality can be maintained good.