滇橄榄不同采摘期果实品质的变化规律

Dynamic Quality Changes of Phyllanthus emblica L. in Different Picking Periods

分析3个品种滇橄榄(‘翠珠’、‘盈玉’、野生)在不同采摘期的果实品质(物理指标及还原糖、蔗糖、总酸、VC、多酚、黄酮)变化规律,以确定不同滇橄榄品种的最佳采摘期。分析各品质指标的变化趋势并利用相关分析和判别分析对滇橄榄果实品质指标进行综合评价,分析得出物理指标呈现先上升后趋于稳定的变化规律;化学成分中总酸含量总体呈下降趋势后趋于稳定,除野生滇橄榄的蔗糖含量呈现先上升后下降趋势、‘翠珠’蔗糖含量呈下降后趋于稳定趋势外,3个品种的还原糖含量在整个采摘期都呈上升并趋于稳定的变化规律;活性成分中VC和黄酮含量呈现先上升后下降、多酚呈现先上升后趋于稳定趋势的变化规律。最终确定‘翠珠’的最佳采摘期在10月末~11月末,‘盈玉’和野生滇橄榄最佳采摘期在10月末~12月末。此阶段的滇橄榄果实外观大小、化学成分和活性成分均处于较优水平;各指标间相关性分析表明,3个品种滇橄榄各指标间的相关性强弱顺序为:野生>‘盈玉’>‘翠珠’;建立的3个品种滇橄榄的贝叶斯判别函数经交叉判别验证,正判率为100%,可以正确判别不同品种的滇橄榄。本文研究结果可为滇橄榄的采摘、增值加工以及商品分类提供理论依据。

The changes of fruit quality(physical indexes, reducing sugar, sucrose, total acid, VC, polyphenols and flavonoids) of three Phyllanthus emblica L. varieties(’Cuizhu’, ’Yingyu’ and wild) at different picking stages were analyzed to determine the best picking date of different Phyllanthus emblica L. varieties. The change trend of each quality index was analyzed, and the fruit quality index of Phyllanthus emblica L. was comprehensively evaluated by correlation analysis and discriminant analysis. The analysis showed that the physical index increased first and then tended to be stable. The total acid content in the chemical components generally showed a downward trend and then tended to be stable. Except that the sucrose content of wild Phyllanthus emblica L. increased first and then decreased, and the sucrose content of ’Cuizhu’decreased and then tended to be stable, the reducing sugar content of the three varieties increased and tended to be stable throughout the picking period. The contents of VC and flavonoids in active components increased first and then decreased,and polyphenols increased first and then tended to be stable. Finally, it was determined that the best picking period of’Cuizhu’ was from the end of October to the end of November, and the best picking period of ’Yingyu’ and wild was from the end of October to the end of December. The appearance, size, chemical components and active components of Phyllanthus emblica L. fruit at this stage were excellent. The correlation analysis among the indexes showed that the order of correlation among the indexes of the three varieties of Phyllanthus emblica L. was wild>’Yingyu’>’Cuizhu’. The Bayesian discriminant function of three varieties of Phyllanthus emblica L. was verified by cross discrimination, and the positive judgment rate was 100%, which could correctly distinguish different varieties of Phyllanthus emblica L. The results of this study would provide a theoretical basis for Phyllanthus emblica L. picking, value-added processing and commodity classification.