| Apple (Malus domestica Borkh) is an important source of nutritive and bioactive compounds, including the carbohydrates, organic acids and phenolic compounds, which are the main nutritive and bioactive compounds. Apple ployphenols are very important contributors for antioxidants, which can protect the human body against cellular oxidation reactions and are helpful to decrease the concentration of free radicals to higher the resistance to some diseases, including cancer, atherosclerosis, neurodegenerative diseases, inflammatory, and so on. The physicochemical properties and antioxidant activities of thirteen cultivars of apples were studied and the apples were collected from Shannxi Province. The contents of ascorbic acid, soluble sugar, titrable acid and total phenols and pH values of thirteen cultivars of apples were measured and their antioxidant activities were investigated in present study, and cluster analysis based on chemical compositions and comprehensive antioxidant value was implemented. Moreover, the study on processing technology of cookies with apple flavor was performed. The main results are as follows:1. The contents of ascorbic acid, titrable acid, soluble sugar, soluble solid and total phenols, and pH values were measured by the corresponding methods (2, 6-Dichcloroindopenol Sodium Salt Hydrate titration method, acid-base titration, anthrone colorimetry, Abbe refractometer, pH meter and Folin-Ciocalteu), and the one-way analysis of variance was made. The results showed that there is a significant difference in chemical compositions; The L* and b* values (70.46 and 39.05) of Yanguan apple peel are greatest, and the a* value of Fujimaki No.1 (38.27) is biggest; Pacific Rose has the highest content of ascorbic acid and soluble sugar (5.72 mg/100g·FW and 14.49 g/100g·FW); The apples with the highest content of soluble solid are Pacific Rose and Red Fuji (14.70 oΒrix and 14.04 oΒrix); Pink Lady is richer in titrable acid than the others (0.48 g/100g·FW); Jonagold is with the lowest pH value (3.47); the total phenols in Red Fuji are the most abundant (112.92 mgGAE/100g·FW).2. The antioxidant activities of thirteen cultivars of apples were investigated by four methods (FRAP reducing power, scavenging of 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH·) and hydroxyl radical (·OH), and inhibition of lipid peroxidation), one-way analysis of variance was done and the weighted values of antioxidant activities of the results from the four methods were calculated and compared. The results showed that there is a significant difference in antioxidant activities and a significant correlation between antioxidant activities and total phenols is observed and both of them are affected by genotypes; the comprehensive antioxidant activity of selected apples are: Yanguang > Starkrimson > Fujimaki No.1 > Golden Delicious > Red Fuji > Hokuto > Matsumotokin > Pacific Rose > Gala > U.S. Pat > Jonagold > Pink Lady > Qinguan.3. Factor analysis based on chemical compositions (ascorbic acid, soluble sugar, soluble solid, titrable acid, pH value, total phenols) and comprehensive antioxidant activity was made, the results of factor analysis showed that the order for quality of selected apples is: Red Fuji > Starkrimson > Yanguang > Qinguan > Fujimaki No.1 > Pacific Rose > Matsumotokin > Jonagold > U.S. Pat > Gala > Golden Delicious > Pink Lady > Hokuto.4. Cluster analysis was made based on ascorbic acid, soluable sugar, titrible acid, total phenols and comprehensive antioxidant activity score, the results showed that U.S. Pat and Pacific Rose was a category with the higher content of L-ascorbic acid, Jonagold, Pacific Rose, Pink Lady, Qinguan and Red Fuji had the higher content of soluable sugar, while Pink Lady was rich in titrable acid and Qinguan and Red Fuji with the highest sugar acid ratio, respectively. Simultaneously the phenols in Rattan No. 1, Yanguang, Starkrimson and Jonagold were the most abundant.5. Optimization of technology for cookie-process with the Red Fuji apple was added in by response surface methodology. The results showed that the optimal parameters are: flour: apple is 59:41; 44.2% shortening, 20.1% sugar, 1.1% sodium bicarbonate, 8.0% full-cream milk powder, 5.0% egg, 0.5% salt and 0.8% Soybean Lecithin based on the total dose of flour and apple. The contents of water and fat, acid value, basicity and peroxide value in apple cookies made by the optimum ingredient measure up the QB, and the sensory is fine. The dietary fiber (2.72 g/100g) and polyphenols (11.02 mgGAE/100 g) are found in apple cookies. |
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