| The anti-drought, good product foreground, and eminent nutrition values of apricot, makes it to be the pioneer in hungriness control and ecological economy construct in the three-north of our country. The apricot product is also the traditionl predominant commodity for the export of our country. In 2000, the concentrate apricot juice in Tunhe group, Xinjiang, accounts for 20% of trade quantity in occident country. The study and building of evaluation items of juicing is the important process of breeding juicing apricot and evaluating its quality. The distribution characteristics of many items related to adaptability of juicing and the evaluation standard were studied. In this study, the juicing characteristics such as juicing ratio, soluble sugar content , tannin content , Vc content ect were studied. And several factors in relation with enzymatic browning, such as browning degree, total phenolics, PPO activity, phenolic composition etc were studied. The evaluation standard for juicing apricot is advanced , it gives foundations for breeding the juicing cultivars and the product quality evaluation. The results are as follows:1. Fruits of 111 F1 progenies from Katy×Xinshiji, Badan×Katy, and of 9 apricot cultivars including Katy, Jintaiyang, Shannongkaixin1 etc were chosen as materials during commercial ripe stage in this study. The juicing ratio varied with different fruit weight in one cultivar (strain); In this study, the frequency of distribution was nearly normal distribution for per weight. The distribution frequency of per weight which was lower than 30g accounted for 4.9%, and distrition frequency ranging from 30g to 50g , from 50 g to 70g , from 70g to 90g and more than 90g was 33.33%, 36.27%, 18.63%, 6.86%, respectively.2. It was skew distribution for juicing ratio in this study, the juicing ratio fewer than 59.4%, between 59.5% and 62%, between 62% and 64.5%, between 64.5% and 67%, and more than 20% was 4%, 16%, 22%, 38%, 20%, respectively.3. In the materials chosen for this study, it was discrete distribution for soluble solids content(SSC).The frequency of distribution was nearly normal distribution for Vc content, and the peak was 9～12mg/100g.4. According to the distribution characteristics of juicing apricot, the primary evaluation standard was made. It was listed as follows, average fruit weight≥50g, juice ratio≥64.5%, SSC≥12%, tannin < 90.69mg/100g, Vc≥9mg/100g; The ratio of soluble sugar content to titrable acid content ranged from 3.33 to 3.98; and soluble sugar content was between 7.09% and 7.88 %. The excellent item was considered as average fruit weight≥70g, juice ratio≥67%, SSC≥15%, tannin<90.69mg/100g, Vc≥12mg/100g; The ratio of soluble sugar content to titrable acid content ranged from 4.15 to 4.80, and soluble sugar content was between 8.12% and 11.11 %.5. The analysis of phenolic compositions by HPLC revealed that (-)-epicatechin, chlorogenic acid and (+)-catechin were the major phenolic compounds in apricot fruits during tree ripe stage, and the content of (-)-epicatechin was the highest in all three cultivars.6. The main factors related to enzymatic browning in apricot fruits varied in different cultivars. The browning degree of Hongyu was the highest, because of the highest PPO activity and chlorogenic acid content. Besides, total phenolics and PPO activity were positively related with browning degree in it (r=0.938, 0.9944 respectively); Except for ferulic acid, the total phenolics and phenolic compounds in Shannongkaixin2 were the lowest, and these factors led to the lowest browning degree.
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