Research On The Changes Of Functional Components And Activities Of Fifteen Kinds Of Special Foods During Storage

Health foods,foods for special medical purposes and infant formula foods are referred to as special foods.Special food industry started late in our country,and the expression of product label was vague about the storage temperature,lacking specific storage recommendations for different products.Due to the complex nutritional composition and refined content requirements of special foods,some slight adjustment may cause its quality changes,especially vulnerable to the impact of environmental temperature,resulting in the decline of nutritional value and functional activity of products.Therefore,whether the functional ingredients and activities of special foods are attenuated during long-term storage and whether they can protect the body effectively becomes a matter of great concern to consumers.Fifteen kinds of commercial special foods were investigated as the research objects and simulated the changes of their main functional components in the real storage environment（room temperature and 4°C）after consumers purchase them.The changes of immune activity and antioxidant activity were evaluated by two cell models in vitro.This paper provides references for the study of long-term stability and the establishment of the principle of stability evaluation during the shelf life of special foods.The main research results were as follows:1.The content changes of main functional components in fifteen special foods under different storage conditions were determined.The results showed that the storage stability of functional components from low to high were lycopene,coenzyme Q10,vitamin C,chrysophanol,triterpenes,protein and crude polysaccharide.The storage stability of fatty acids in linseed oil was weaker than that in walnut oil.In summer,room temperature accelerated the decay of lycopene,coenzyme Q10,vitamin C,chrysophanol,triterpenes and unsaturated fatty acids,while protein and polysaccharide remained stable.2.Based on macrophage RAW 264.7 model,the changes of immune activity of five special foods with improved immunity under different storage conditions were investigated.The results showed that five special foods could significantly promote the proliferation of macrophages and improve the secretion of NO,TNF-α,and IL-6（P<0.05）.During storage,the immune activity of five special foods decreased in a time-dependent manner,and there was a dose-effect relationship between the attenuation rate and the content decline of main functional components.Coenzyme Q10 vitamin C granules,Ganoderma lucidum spore Lycium chinense Hericium erinaceus capsules and G.lucidum spore oil lycopene capsules were susceptible to high temperature in summer,and their immune activity decreased significantly compared with that stored at 4°C（P<0.05）.Health foods with lycopene,coenzyme Q10,vitamin C,chrysophanol and triterpenes as functional factors should be stored at 4°C as far as possible.Protein powder granules and G.lucidum L.chinense grape seed capsules showed relatively strong stability of immune activity,so the health foods with protein and polysaccharide as functional factors could be stored at room temperature.3.The model of oxidative damage was established to explore the protective effect of ten kinds of special foods with antioxidant on H₂O₂-induced oxidative stress injury of PC12 cells under different storage temperatures.The results showed that special foods could reduce the contents of ROS,NO and MDA in cells significantly and increase the activity of SOD significantly,but with the extension of storage time,the protective effect of special foods on PC12 decreased.It was recommended that calcium iron zinc rice flour,infant molar rods,infant cooking oil and health foods with chrysophanol as the main functional factor should be stored in 4°C refrigerator.Infant formula and milk powder for special medical purposes had strong stability and could be stored at room temperature in four seasons.