Effect Of Cooking And Storage On Effective Nutritional And Functional Values Of Fruits And Vegetables

Fruits and vegetables are important sources of vitamin, non-vitamin phytochemicals andantioxidant activity. They are useful for maintaining people’s health and also are importantminerals provider. Consuming enough fruits and vegetables can prevent many human diseases.However, compared with fresh fruits and vegetables, cooking and storage methods can lead tovarious degree of loss on the nutrients, functional components and antioxidant propertiesdepending on the different cooking methods and dietary habits. Microwaving and boiling aretwo common cooking methods in China and abroad while chilling at4°C and freezing at-18°C are common approaches for food preservation, These processing methods have greatinfluences on the food nutritional and functional values. In the current study, candidate fruitsand vegetables were preprocessed under different cooking and storages conditions. Effects ofprocessing were studied in the aspect of nutrients and functional ingredients. Data from thestudy will be helpful to predict the loss of nutrition and function characteristics in fruits andvegetables during cooking and storage, and to provide dietary guidelines recommendation forthe consumers.To understand the effects of microwaving and boiling heating on nutrients and functionalproperties in fruits and vegetables, changes of nutrients and functional properties weremonitored, which were compared between fresh and processed with relationship between theproperties analyzed. The results showed that microwaving caused a great loss of nutrition andfunction values for pepper and tomato (reduction of23.68%and17.54%respectively), whilefor carrots nutrition and function values increased1.74%. Boiling led to a reduction in alleffective nutritional and functional properties for all the fruits and vegetables tested includingpepper, carrot, tomato, apple, orange and kiwi fruits with a reduction of37.51%、26.80%、21.06%、21.28%、17.92%and17.09%compared to the fresh one, respectively.A group of fruits and vegetables were also storaged at4°C and-18°C respectively, forunderstanding the changes of nutrients and functional properties during storage. When storedat4°C for7d, the loss of vitamin C in carrot, apple, orange and kiwi fruit was more than20%compared to fresh ones. After14d storage at4°C, the loss of vitamin C was38.74%and 25.01%respectively for pepper and carrot. However, folate content in apple increased21.01%.The retention rate of folate content in pepper, carrot, tomato, orange and kiwi fruit were42.42%,70.49%,78.56%,89.94%and93.53%, respectively. Moreover, total phenols contentin pepper declined during storage while for all other fruits and vegetables it increased. Totalflavonoids content in all fruits and vegetables declined. Interestingly, lycopene didn’t changesignificantly in pepper, apple, orange and kiwi fruit during processing and the antioxidantactivity of kiwi fruit remained stable during storage. When stored at-18°C, the vitamin Ccontent of all tested fruits and vegetables declined at14d of storage. In addition, thecarotenoid content in pepper and tomato decreased gradually during storage and the folatecontent declined in all fruits and vegetables at14d of storage. The total phenols andflavonoids content of fruits and vegetables presented an overall downward trend while thelycopene content of carrot and tomato were increased compared with fresh ones.