Processing Characteristics And Construction Of Evaluation Index System Of Different Nectarine Varieties

Nectarine with diverse species is one of the most important commodity fruit all over the world, and processing it increase the value of nectarine, so the classification processing of different varieties of nectarine has increasingly become a research focus ponit for citrus.In this paper, the key processing technology for producing the nectarine canned, juice and vinegar was studied and suitable parameters were suggested.10 varieties of nectarines Jinchun, Wangchun, Hongshanhu, Jinmeixia, Meiqiu, Jingheyou 1, Qiannianhong, Zhongyou 11, Ruiguang 18 and Ruiguang 19 were processed into canned, juice and vinegar. Using principal component analysis (PCA), physicochemical and sensory indicators were analyzed to construct the nectarine index evaluation system, and determine the appropriate processing of nectarine varieties. Through the studies above, conclusions were made as follows:1. Optimization of process parameters on the nectarine juiceSingle factor tests showed that the rate of juice extraction changed by controlling different pectinesterase concentration, cellulase concentration, temperature. The results of orthogonal test showed that various factors affected the order of the rate of juice extraction as follows:temperature>pectinesterase concentration>the concentration of cellulose> enzymatic hydrolysis time.The best conditions of orthogonal test were as follows:0.06% pectinex,0.04% celluclast and enzymolysising 2 h under 55℃.Single factor tests showed that the light transmittance changed by controlling different chitosan concentration, temperature, time. The results of orthogonal test showed that various factors affected the juice transmittance as follows:chitosan concentration> temperature>time.The best conditions of orthogonal test were as follows: 0.4g/L chitosan, reaction 2 h under 50℃The results of orthogonal test showed that various factors affected the taste and flavor of juice as follows:the ratio of sugar to acid> sugar degree> the content of raw juice>CMC-Na concentration. The best formula was that the content of raw juice of 35%and the ratio of sugar to acid of 35:1 and the concentration of CMC-Na of 0.08% with 7.0% of the sugar.2. Optimization of process parameters on the nectarine vinegarSingle factor tests showed that the alcohol content changed by controlling different Brix, fermentation temperature, inoculation volume. The results of orthogonal test showed that various factors affected the order of the alcohol content as follows: Brix>pectinesterase concentration>inoculation volume>fermentation temperature.The best conditions of orthogonal test were as follows:yeast inoculums 10%,12.0% of the sugar at 30℃.Single factor tests showed that the acidity changed by controlling different sugar degree, inoculation volume, pH, alcohol content, stirring speed. The results of orthogonal test showed that various factors affected the acidity as follows:alcohol content>pH>inoculation volume>sugar degree.The optimal acetic fermentation was set with 15% inoculums amount,7% alcohol degree,3.0% of the sugar, and pH 4.0 through the orthogonal experiment.The results of orthogonal test showed that various factors affected taste and flavor of vinegar as follows:nectarine vinegar>sugar degree>honey concentration>nectarine fruit juice. The best formula was that 15% nectarine vinegar,30% nectarine fruit juice, 5% honey and 3.0% of the sugar.3. Comprehensive evaluation of the quality of processed products of different varieties of nectarinesAccording to certain principles, there were nine indicators by analysising main processing issues of nectarine canned, such as the flesh firmness, soluble solids content (TSS), Vc concentration, total acidity, light transmittance, moisture content of fruit, chroma b, sensory evaluation scores, clingstone classification evaluation scores. The raw data of the eight indicators of the 10 varieties of nectarine canned were standardized by PCA. The eigenvalues and the variance contribution rate were calculated by PCA. The cumulative variance contribution rate of the first four principal components was 86.41%. Using function expression of the main ingredients to calculate the principal component scores and composite score of 10 varieties of nectarines, the result was that Qiannianhong and Jinmeixia were suitable for processing into nectarine canned, the next was Jinchun, Ruiguang 18, Meiqiu, Zhongyou 11, and Hongshanhu, Jingheyou 1, Ruiguang 19, Wangchun were not suitable for processing. The main factors affecting the quality of nectarines canned were the flesh firmness, light transmittance, clingstone classification evaluation scores, chroma b and moisture content of fruit.According to certain principles, there were eight indicators by analysising main processing issues of nectarine juice, such as the flesh firmness, soluble solids content (TSS), Vc concentration, total acidity, light transmittance, moisture content of fruit, reducing sugar concentration, sensory evaluation scores. The raw data of the eight indicators of the 10 varieties of nectarine juice were standardized by PCA. The eigenvalues and the variance contribution rate were calculated by PCA. The cumulative variance contribution rate of the first four principal components was 85.47%. Using function expression of the main ingredients to calculate the principal component scores and composite score of 10 varieties of nectarines, the result was that Jinchun, Ruiguang 18 and Ruiguang 19 were suitable for processing into nectarine juice, the next was Jingheyou 1, and Wangchun, Jinmeixia, Meiqiu, Hongshanhu, Qiannianhong and Zhongyou 11 were not suitable for processing. The main factors affecting the quality of nectarines canned were reducing sugar concentration, light transmittance, the flesh firmness, Vc concentration, and moisture content of fruit.According to certain principles, there were eight indicators by analysising main processing issues of nectarine vinegar, such as the flesh firmness, soluble solids content (TSS), Vc concentration, total acidity, light transmittance, moisture content of fruit, reducing sugar concentration, sensory evaluation scores. The raw data of the eight indicators of the 10 varieties of nectarine vinegar were standardized by PCA. The eigenvalues and the variance contribution rate were calculated by PCA. The cumulative variance contribution rate of the first four principal components was 94.46%. Using function expression of the main ingredients to calculate the principal component scores and composite score of 10 varieties of nectarines, the result was that Jinchun, Jinmeixia Meiqiu and Ruiguang 18 were suitable for processing into nectarine vinegar, the next was Wangchun, Jingheyou 1, and Ruiguang 19, Hongshanhu, Qiannianhong, Zhongyou 11 were not suitable for processing. The main factors affecting the quality of nectarines canned were reducing sugar concentration, soluble solids content (TSS), total acidity, light transmittance and moisture content of fruit.