不同成熟度杏果实采后细胞壁物质代谢规律的研究

Studies of the Patterns of Cell Wall Material Metabolism in Postharvest Apricot Fruits at Different Degrees of Maturity

为探究不同成熟度杏果实采后细胞壁物质代谢的变化。以新疆"赛买提"杏为试材,根据转黄率将果实分为成熟度Ⅰ(着色面积<50%)、成熟度Ⅱ(着色面积50%~80%)和成熟度Ⅲ(着色面积>80%),置于4℃、90%~95%RH贮藏,每7 d测定相关指标的变化。试验结果表明,成熟度Ⅰ、Ⅱ和Ⅲ杏果实可溶性果胶(WSF)、CDTA溶解性果胶(CSF)、纤维素含量逐渐上升,Na_2CO_3溶解性果胶(NSF1)和NaOH溶解性果胶(NSF2)含量逐渐下降,木质素含量、多聚半乳糖醛酸酶(Polygalacturonase,PG)、果胶甲酯酶(Pectinmethylesterase,PME)、β-葡萄糖苷酶(β-glucosidase,β-G)、纤维素酶(Cellulase,Cx)酶活性呈先上升后下降趋势。贮藏结束时,成熟度Ⅱ杏果实纤维素含量、PG、PME活性低于成熟度Ⅰ和Ⅲ果实(p<0.05),木质素含量高于成熟度Ⅰ和Ⅲ果实(p<0.01),硬度、Cx活性高于成熟度Ⅰ和Ⅲ杏果实(p<0.05)。说明采后贮藏杏果实可选择成熟度Ⅱ作为适宜采收成熟度。

In order to explore the changes in the metabolism of cell wall materials in postharvest apricot fruits with different degrees of maturity, Xinjiang ＂Saimaiti＂ apricot fruits were analyzed in this study. According to the yellowing rate, the fiuits were classified into three different stages of maturity： I （colored area：〈50%）, II （colored area： 50-80%）, and III （colored area： 〉80%）. These fruits were stored at 4~C with 90-95% relative humidity （RH） and several related physiological indices were determined every seven days. The results showed that the content of water-soluble fraction （WSF） of pectin and cyclohexane diaminotetmacetic acid （CDTA）-soluble fractions （CSF） of pectin and cellulose were in the order of maturity stage I 〈 maturity stage II 〈 maturity stage III, while the content of sodium bicarbonate-soluble and sodium hydroxide-soluble fractions of pectin were in an order of maturity stage I 〉 maturity stage II 〉 maturity stage III. From maturity stage I to stage II1, the lignin content and the activities ofpolygalacturonase （PG）, pectin methylesterase （PME）, β-glucosidase （B-G）, and cellulase （Cx） showed a downward trend after the initial increase. However, at the end of storage, the cellulose content and the PG and PME activities of the apricot fiaxits at maturity stage II were lower than those at stages I and III（p 〈 0.05）, and the lignin content at stage II was higher than that at stages I and III （p〈0.05）. The fruit firmness and Cx activity of apricot fruits at maturity stage II were significantly higher than those of the fruits at maturity stages I and III. These results suggested that maturity stage II could be selected as a suitable maturity stage for postharvest storage of apricot fruits.