鲜切加工加速荸荠组织衰老与H2O2累积的关系

以荸荠为材料,研究了鲜切加工加速组织衰老与活性氧代谢的关系.结果表明:鲜切加工提高了荸荠切片抗氧化酶(超氧化物歧化酶、抗坏血酸-过氧化物酶和过氧化氢酶)的活性;但同时明显刺激了O2-产生,促进了H2O2累积,加速了抗坏血酸在贮藏后期的损失,加强了膜脂过氧化作用和增加了电解质渗出率.统计分析表明H2O2含量、丙二醛含量、电解质渗出率三者之间存在正相关性.H2O2组织定位结果也证实鲜切加速组织衰老与H2O2累积密切相关.完整荸荠组织O2-产生比较平稳,抗氧化酶活性维持稳定,H2O2未有明显累积.

Accelerated Senescence of Fresh-cut Chinese Water Chestnut Tissues in Relation to Hydrogen Peroxide Accumulation

Accelerated senescence of fresh-cut Chinese water chestnut (CWC) tissues in relation to active oxygen species (AOS) metabolism was investigated. Fresh-cut CWC (2 mm thick) and intact CWC were stored at 4 degrees C in trays wrapped with plastic films. Changes in superoxide anion production rate, activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were monitored, while contents of hydrogen peroxide, ascorbic acid, MDA as well as electrolyte leakage were measured. Fresh-cutting of CWC induced activities of SOD, CAT and APX to a certain extent (Fig. 2B and Fig. 3), but simultaneously stimulated superoxide anion production markedly (Fig. 2A), enhanced hydrogen peroxide accumulation and accelerated loss in ascorbic acid (Figs. 4 and 5), which resulted in increased lipid peroxidation indicated by malondialdehyde (MDA) content and electrolyte leakage (Fig. 1). Statistics analysis indicated that there was a significantly positive correlation among hydrogen peroxide accumulation, MDA content and electrolyte leakage (Table 1). Histochemical detection with 3, 3'-diaminobenzidine further demonstrated that hydrogen peroxide accumulation increased in fresh-cut CWC during storage (Fig. 5). AOS production rate and activities of SOD, CAT and APX changed little while no obvious hydrogen peroxide accumulation was observed, in intact CWC during storage.