灵武长枣贮藏过程中细胞壁成分及其相关酶活性的变化

Changes in cell wall components and its related enzyme activities during the storage of Lingwu long jujube

为了解析贮藏过程中鲜食灵武长枣硬度变化的微观机理,该文利用原子力显微镜对长枣细胞壁多糖纳米结构的降解规律进行了研究,并对其降解酶活性、水分含量与果实硬度进行了相关分析。结果表明,前8 d为果实快速软化期,液泡水水分含量A_(23)与硬度同步降低(P<0.05)。多聚半乳糖醛酸酶、果胶甲酯酶、β-半乳糖苷酶(β-galactosidase,β-Gal)、纤维素酶等细胞壁降解酶均参与了长枣果实软化过程。其中β-Gal对果实硬度下降起促进作用,贡献率为0.2729。随着贮藏时间的延长,螯合性果胶中的长链结构和聚集体逐渐降解,短链(15.625、19.531、23.438、31.252 nm)出现的次数及频率均有所增加,其对硬度的贡献率为0.4780。该研究为灵武长枣贮藏保鲜技术的开发提供了理论支持。

To explore the micromechanism of hardness changes of fresh Lingwu long jujube during storage,the degradation law of polysaccharide nanostructure in the cell wall of long jujube was analyzed by atomic force microscopy,and the correlation analysis between the activity of degrading enzyme,water content and fruit hardness was also carried out.The results showed that the first 8 days were the rapid softening period of fruit,and the A_(23) of free water decreased simultaneously with the hardness(P<0.05).Polygalacturonase(PG),pectin methylesterase(PME),β-galactosidase(β-Gal),cellulase(CE)and other cell wall degrading enzymes were involved in the fruit softening process.β-Gal promoted the decrease of fruit hardness,and the contribution rate was 0.2729.With the prolonging of storage time,the long chain structure and aggregates in the chelating pectin CSP gradually degraded,and the occurrence and frequency of short chains(15.625,19.531,23.438,31.252 nm)increased,and their contribution rate to the hardness was 0.4780.This study provids theoretical support for the development of storage and preservation technology of Lingwu long jujube.