Spraying Arginine at 5 Days before Harvest Delays Postharvest Broccoli Senescence via Nutrient Accumulation

采前5d喷施精氨酸通过营养积累延缓西兰花采后衰老

To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.

为明确采前喷施精氨酸对西兰花营养水平的影响及精氨酸提高西兰花贮藏品质的机制,在采前0、1、3、5 d喷施精氨酸(5 mmol/L),观测样品在贮藏0、2、4、6、8、10 d的外观,测定呼吸速率、质量损失率、电解质泄漏、硫代葡萄糖苷、抗坏血酸、总酚、总类黄酮、总糖和蔗糖含量及蔗糖磷酸合酶、转化酶、蔗糖合酶合成与裂解活性。结果表明:采前5 d喷施精氨酸有助于抑制西兰花在贮藏期间的呼吸作用,延缓电解质泄漏,较好地保持其原有色泽;在生长阶段,西兰花积累了更多总糖;此外,在贮藏期间,蔗糖合成加快,而蔗糖分解受到抑制,提高了西蓝花采后维持蔗糖含量的能力。总之,在采前5 d喷施精氨酸有助于西蓝花在生长阶段积累更多营养成分,并有效延缓贮藏期品质下降,进而延长货架期。本研究结果为采前处理改善西兰花采后贮藏特性提供了理论依据。