Effects Of Drying Methods On Quality Of Ficus Carica L. Fruit And Preparation Of Fig Tea

Fig(Ficus carica L.),a deciduous tree belonging to the Moraceae family,is rich in sugars,proteins,crude fiber,fatty acids,polyphenols,vitamins,minerals and so on.The fig is a nutritive fruit and has medicinal properties such as antioxidant,anti-cancer and immune regulation.Fresh figs are easily infected by microorganism due to its thin skin,soft texture and high sugar content which made it difficult for storage and transportation while its economic and nutritional values was extensive affected.Drying is a common methods utilized to protect the fruit away from infection and inhabit its physiological activity.Different methods of drying have been developed for foods,and each methods has its own characteristics.Therefore,figs were used as raw materials to study the effects of different drying method on it's nutrition and aroma compounds.In the basis of this,the fig tea was prepared.The main results are as follows:1.The effects of natural drying,vacuum freeze drying,oven drying,far infrared drying and vacuum drying on the nutritional components of figs were assessed.The results indicated that there were significant differences in the values of soluble solids,total sugar,total acid,soluble protein,total phenol content as well as phenolics between the control sample and the treated figs by different drying methods(P < 0.05).In particular,the fig treated with vacuum freeze-dried method showed the highest values of soluble solids,total sugar and soluble protein among all of the drying methods.Additionally,the fig treated with vacuum drying method not only exhibited the highest values of total antioxidant,total phenols and phenolic substances,but also was of high quality studied by principal component analysis.However,vacuum freeze-dried method was the closest in the content of the nutritional components to fresh fruit.2.GC-MS was used to analyze and identify the volatile components of fresh fig and figs with and without treated by different drying methods suchas vacuum freeze drying,natural drying,oven drying,and far infrared drying.Subsequently,the principal component analysis was carried out.The results showed that a total of 117 compounds was identified,and 96 aroma compounds found in the fig samples treated with vacuum freeze drying method.Furthermore,the principal component analysis showed that different drying methods had impacts on the quantity,content and species of volatile compounds and vacuum freeze drying method was certainly preferred to fresh fig.3.On the basis of previous studies,the dried fig was used as the main raw material and dried jujubes,dried apple,dried apricot and roselle were used as auxiliary materials.Based on results of single factor,the preparation formulas of the fig tea were optimized by fuzzy comprehensive evaluation and orthogonal test and basic nutrients of the fig tea obtained were determined.The results showed that the optimum formulas could be concluded as: a fig dosage of 5.0 g,a dried jujube dosage of 2.0 g,a dried apples dosage of 0.8 g,a dried apricots dosage of 1.0 g,and a roselle dosage of 0.9 g.The resulting nutrients were determined as: 83.33% of soluble solids,37.81 g/100 g of total sugar,4.66 g/100 g of total acid,539.33 mg/100 g of total phenol,234.63 mg/100 g of protein.Moreover,the fruit tea was pale red,and the color of soup was clear and transparent after brewing.A harmonious blend of aromas within mixed fruit tea flavor and a harmonious taste.