原儿茶酸复合涂膜对辣椒采后保鲜的影响

摘要

采用原儿茶酸与乳化剂吐温-20制成复合保鲜剂,以浸泡时间、贮藏温度、原儿茶酸质量浓度和吐温-20体积分数为因素进行L9(34)正交试验设计,研究不同因素组合浸泡涂膜对湘研5号椒采后保鲜效果的影响.结果表明:浸泡2.5 min、贮藏温度10℃、125 mg/L原儿茶酸、体积分数0.02%吐温-20组合处理21 d后,优化处理组质量损失率与空白对照组(CK1组)和阳性对照组(CK2组,使用保鲜剂NW20)相比分别低了41.98%、15.74%,呈显著性差异(P<0.05);腐烂率与CK1组和CK2组相比分别降低了70.39%、20.09%,都存在显著性差异(P<0.05);原儿茶酸保鲜剂处理可以降低辣椒贮藏期间的呼吸强度,延缓VC和叶绿素含量的下降,有效抑制丙二醛含量、多酚氧化酶活力的上升,提高过氧化物酶、过氧化氢酶的活力.原儿茶酸保鲜剂处理后各项指标均显著优于CK1组(P<0.05),表明原儿茶酸保鲜剂处理可以延缓辣椒采后的衰老,有效延长辣椒的保藏期,对辣椒采后贮藏具有良好的保鲜效果.%In this study, a composite preservative consisting of protocatechuic acid and Tween-20 was used to evaluate the effect of soaking time, storage temperature, protocatechuic acid concentration and Tween-20 concentration on its efficacy in preserving the postharvest quality of Xiangyan No. 5 green hot peppers. The investigation was carried out using an L9 (34) orthogonal array design. The results showed that compared with the control (CK1) and positive control groups (CK2, using NW20 as preservative), 2.5 min soaking with 125 mg/L protocatechuic acid and 0.02% Tween-20 (V/V) significantly reduced water loss in green hot peppers by 41.98% and 15.74% (P < 0.05) and significantly decreased the incidence of decay by 70.39% and 20.09% after 21 days storage at 10 ℃, respectively. Meanwhile, this treatment could reduce respiration intensity, delay the decline in vitamin C and chlorophyll content, effectively restrain the accumulation of malondialdehyde and polyphenol oxidase, and improve peroxidase and catalase activity. The quality of this treatment was superior to that of CK1 (P < 0.05) with respect to all the above parameters. These data suggest that protocatechuic acid coating treatment (ZJZ) can delay the senescence of post-harvest peppers and extend the shelf life of pepper, so that it has a good efficacy in the postharvest preservation of green hot peppers.