Effects Of Different Treatments On The Antioxidant Activities And Components Of Apple

China is the largest producer and consumer of apple in the word.Apple is rich in polyphenols,flavonoids and other bioactive substances,which has many physiological functions,especially antioxidant function.Different consumers eat apples with different ways,such as the whole fruit with peel,peeled apple,freshly squeezed juice and sterilized juice from the supermarket,etc.Now it's still not clear that how to eat apples is most beneficial to people's health.There are many researches on the antioxidant activity of apple,while most of them are relatively scattered,which can't scientifically instruct consumers to eat apples.In addition,it's worth further study on how to store,the storage period after the purchase,and which cultivars are suitable for fresh food.Therefore,the effects of different dietary methods,storage temperatures,and cultivars on the antioxidant activity and related chemical components of apple were explored in this paper.At the same time,the correlation between these related chemical components and antioxidant activity was analyzed.It was expected to lay a theoretical foundation for further processing of apple,and play a guiding role for consumers to eat apples scientifically.The main results were as follows:1.Effects of different dietary methods on antioxidant activity and components of appleThe apple was peeled,squeezed,and sterilized respectively,then the contents of vitamin C,total phenol,total flavonoid,and antioxidant activity of each sample were determined,and the correlations among the indexes were analyzed.It was shown that the order of antioxidant activity in samples under different dietary methods were as follows:peel > whole fruit > pomace > pulp > juice> bactericidal juice;and the contents of vitamin C,total phenol,and total flavonoid in peel were respectively 6.93 mg/100 g,294.43 mg/100 g,and 207.77 mg/100 g,which were significantly higher than those in other samples(p<0.05).Vitamin C,total phenol,and total flavonoid had an important role in the antioxidant activity of apple.The phenolic components of apple were identified by high performance liquid chromatography.The results showed that phenolic compositions and contents in apples were different under different dietary methods.The contents of cianidanol,epicatechin,chlorogenic acid and phloridzin were relatively high in apple.The cianidanol,epicatechin,syringic acid,ferulic acid,quercitrin and quercetin had significant effects on the antioxidant activity of apple(p<0.05).Therefore,in order to have the maximum antioxidant activity,it was recommended that consumers eat apples with peel.And in order to reduce the waste of resources and environmental pollution,pomace should be fully reused.2.Effects of storage temperatures on antioxidant activity of appleApples were respectively stored at room temperature and low temperature.Then the physical and chemical indexes,vitamin C,total phenol,total flavonoid,and antioxidant activity of apples were determined every 7 days.At the same time,the correlations between components and antioxidant activity were analyzed.The results showed that the differences of p H,total soluble solids,titratable acid,colours and sugar/acid ratio of apples under different storage temperatures were obvious.Both the contents and the antioxidant activity of vitamin C,total phenol,and total flavonoid were decreased during the storage.Total phenol content,total flavonoid content,and antioxidant activity of apples stored at room temperature were higher than those stored at a low temperature when time was less than 14 days,but it reversed during14 to 35 days.The correlation results showed that vitamin C,total phenol and total flavonoid had different antioxidant contributions under different storage systems,but all of them had important effects on the antioxidant activity of apple.Compared with the condition of room temperature storage,vitamin C of apples stored at low temperature had no significant effects on ·OH scavenging ability.Therefore,considering sugar,acid and taste,it was recommended thatconsumers should store apples according to their own needs.However,in order to have the highest antioxidant function,it was recommended that apples should store at room temperature within 14 days.If it exceeded 14 days,it needed to be stored at a low temperature.3.Differences of antioxidant activity and components in different apple cultivarsFive apple cultivars such as Red Fuji were selected,which were represented by capital letters ABCDE respectively.Their physical and chemical indexes,vitamin C,total phenol,total flavonoid,antioxidant activity and related components were determined,and then the correlations among the indexes were analyzed.The results showed that some quality indexes had significant difference(p<0.05)among cultivars,including total soluble solids,titratable acid,p H,hardness,color and sugar/acid ratio,etc.The contents of vitamin C,total phenol,and total flavonoid in apples were respectively 1.90~3.61 mg/100 g,56.83~106.59 mg/100 g,and 56.57~97.66 mg/100 g.The contents of vitamin C and total phenol in D were the highest,and the total flavonoid content in C was the highest.And the order of antioxidant activity in apples was as follows: C>A>D>B>E.Compared with the concentration of 20 ?g/m L vitamin C and BHT,the antioxidant activity of apple was higher.The phenolic components of apple were mainly composed of cianidanol,epicatechin,chlorogenic acid and phloridzin,and compositions and contents of phenols were different in different apple cultivars.The correlation results showed that cianidanol,chlorogenic acid and phloridzin had important effects on the antioxidant activity of apple.Therefore,judging from sugar,acid and taste,consumers were advised to choose their favorite apple to eat;judging by the antioxidant function,consumers were advised to choose green apples for fresh food,such as C.