双孢蘑菇采后冷链流通过程品质劣变及活性氧代谢规律

The Quality Deterioration and Reactive Oxygen Metabolism of Agaricus bisporus during Cold Chain Circulation

探究双孢蘑菇采后冷链流通过程中子实体品质劣变及其活性氧代谢的变化规律。本试验对双孢蘑菇子实体在采后预冷、冷链运输过程及模拟低温货架期的感官品质、主要生理指标及活性氧代谢情况进行动态测定,并运用Pearson相关性分析软件探究品质劣变与生理指标及活性氧代谢之间的相关性。结果显示:冷链流通过程中,双孢蘑菇在预冷及冷链运输过程中品质变化不大,而在模拟超市低温货架期(12℃±1℃)贮藏期间出现品质逐渐劣变。在第3天出现呼吸高峰,之后其感官品质迅速下降,主要表现为萎蔫、褐变、开伞、质地软化等。同时,其生理指标也发生了显著变化,表现在可溶性固形物(SSC)含量、总抗氧化能力(T-AOC)下降,相对电导率(RC)、总酚(TP)、丙二醛(MDA)、O_(2)·^(-)和H_(2)O_(2)的含量及活性氧(ROS)代谢相关酶活性呈动态上升的趋势。通过Pearson相关性分析得出:双孢蘑菇采后褐变与多酚氧化酶(PPO)活性、总酚含量、丙二醛含量的变化存在显著相关性,且褐变受到多酚氧化酶、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性和酚类物质含量变化的影响。其中褐变与多酚氧化酶的相关性最高(R^(2)=0.95),失重率(WL)与丙二醛含量变化有很强的相关性(R^(2)=0.90)。随着贮藏时间的延长ROS不断积累,而抗氧化酶系中虽然PPO酶活性呈上升趋势,而总抗氧化能力呈下降趋势,导致其贮藏品质劣变加速。根据这些规律可更准确预测双孢蘑菇货架期,并为采后冷链流通与货架销售期间品质监测提供一定的理论指导。

To investigate the quality deterioration of mushrooms(Agaricus bisporus) and the law of their reactive oxygen metabolism during cold chain circulation.In this experiment,the sensory quality,main physiological indicators and reactive oxygen metabolism of A.bisporus fruiting bodies were dynamically measured during post-harvest pre-cooling,cold chain transportation and simulated low temperature shelf life,and the correlation between quality deterioration and physiological indicators and reactive oxygen metabolism was investigated by Pearson correlation analysis software.The results showed that the quality of A.bisporus did not change much during the period of pre-cooling and cold chain transportation during cold chain circulation,while gradual quality deterioration occurred during storage in simulated supermarket low temperature shelf life(12 ℃±1 ℃).The respiratory peak appeared at the 3rd day,and after the respiratory peak,its sensory quality decreased rapidly,mainly manifested as wilting,browning,opening,and texture softening,etc.At the same time,the physiological indexes also changed significantly,as shown by the decrease of soluble solid content(SSC),total antioxidant capacity(T-AOC),and the dynamic increase in relative conductivity(RC),the contents of total phenol(TP),malondialdehyde(MDA),O_2·~-,and H_2O_2,and the activities of enzymes related to active oxygen(ROS) metabolism.Pearson correlation analysis revealed that postharvest browning of mushrooms was significantly correlated with changes in polyphenol oxidase(PPO) activity,total phenol content,and malondialdehyde content,and browning was influenced by changes in PPO,peroxidase(POD),and superoxide dismutase activities(SOD) and phenolic content.The highest correlation was found between browning and PPO(R~2=0.95);there was a strong correlation between weight loss(WL) and changes in malondialdehyde content(R~2=0.90).The ROS contents accumulated with the extension of storage time,although the activities of PPO showed an increasing trend,but the total antioxidant capacity of the antioxidant enzyme system was decreasing,which led to the accelerated deterioration of storage quality.According to these laws,the shelf life of A.bisporus can be predicted more accurately and provide some theoretical guidance for mushroom post-harvest cold chain circulation and quality monitoring during shelf sales.