The Research On Quality Evaluation Of Fresh Apples

In this dissertation instrumental analysis and sensory analysis of161apple varieties were carriedout to study the distribution, variance and correlation of quality indexes. A comprehensive instrumentalevaluation method was established by screening core instrumental quality indexes and ensuring theweight of each quality index. Comprehensive sensory analysis of161apple varieties was carried out toselect apple varieties with excellent sensory quality. The work is aiming to provide theory basis forselecting apple varieties with good quality and provide methodological guidance for comprehensiveevaluation.Through the instrumental analysis and sensory analysis of161apple varieties, analyzed the qualitydistribution, correlation, comprehensive evaluation, the conclusions can be summarized as follows:1. Instrumental analysis of161apple varieties showed that24quality indexes have differentcoefficient of variation, and the range of C.V. was from-1683.80%to68.03%, the histogram of mostquality indexes present normal distribution. The correlation analysis of24quality indexes showed that46correlation coefficient had significant correlation at α=0.05level and35correlation coefficient hadsignificant correlation at α=0.01level among276correlation coefficient, most quality indexes have nosignificant correlation.2.8core instrumental quality indexes were screened from24instrumental quality indexes forcomprehensive evaluation, including soluble solid content (SSC), malic acid content (MAC),“a” valuefor skin color (SC“a”), flesh hardness (FH), fruit weight (FW), flesh browning degree (FBD), vitamin Ccontent (VCC) and magnesium content (MC). Weight of each index was ensured as SSC of0.26, MACof0.26, SC“a” of0.14, FH of0.14, FW of0.08, FBD of0.05, VCC of0.04, MC of0.03. Thecomprehensive instrumental evaluation scores of161apple varieties were from0.310to0.881, with amean value of0.530. The coefficient of variation is19.25%, and more apple varieties had a scorebetween0.4and0.6. Fuji, shanxia and new world of apple varieties were selected to be of excellentfresh quality.3. Sensory analysis of161apple varieties showed that the distribution of6sensory quality indexeshave different forms. The scores of comprehensive sensory evaluation (Z) include six sensory qualityindexes of fruit size, fruit surface color, fruit texture, flavor, juice and aroma. The distribution ofcomprehensive sensory evaluation exist a peak and relatively advantage on the left. The scores ofcomprehensive sensory evaluation were divided into5levels, which are grade one (the score greaterthan13), grade two (the score between11and12.5), grade three (the score between9and10.5), gradefour (the score between7and8.5), grade five (the score less than6.5), and most apple varieties were ingrade two and grade three. The value of fruit size and surface color had high correlation coefficient withinstrumental anayisis quality indexes, and other sensory qualities (fruit texture, flavor, juice and aroma)had small correlation coefficient with instrumental analysis quality indexes.