短时减压处理对双孢蘑菇采后品质调控机制的研究

Hypobaric storage is a safety storage method developed on the basis of refrigerated storage and controlled atmosphere storage. It has been known for a long time that hypobaric storage technique, characterized by reduced oxygen level, lowered pressure and quickened heat removal, has been shown to significantly inhibit ripening and senescence, and extend shelf-life in various fruits and vegetables. "High cost tank container and large compressive strength ", "high weight loss and the flavor fades away," and " the high cost" have hindered the promotion and application of hypobaric storage. The time of short time hypobaric treatment is always less in 24h. It can reduce the cost of hypobaric storage and the loss of weight and flavor. Our previous studies have shown that short time hypobaric treatment could maintain quality, delay senescence, reduce the decay rate and extend the shelf life of Agaricus bisporus. Several studies have demonstrated that physical treatments elicit resistance responses in harvested commodities, increasing enzymatic activity (e.g. phenylalanine ammonia lyase, and peroxidase) related to the host's resistance against the pathogens. Currently, there is little in the literature about the mechanism of short time hypobaric treatments on the quality of the Agaricus bisporus. This project intends to investigate the mechanism of short hypobaric treatment for physiological metabolism, the change of the host's own resistance and antioxidant enzymes, controlling the postharvest decay.

减压贮藏是在冷藏和气调贮藏的基础上发展起来的一种气调贮藏方法。"罐体容器造价高与耐压强度大"、"易造成果蔬失水、风味变淡" 和"贮藏费用高"等问题阻碍了减压保鲜技术的推广应用。短时减压处理是果蔬采收后在合适的贮藏阶段进行一定时间的减压贮藏，以达到延缓衰老，保持品质，延长保质期的目的。短时减压的处理时间通常在24h以内，而一般减压贮藏都是从采摘后到出库为止。因此短时减压处理既可以避免减压贮藏造成的果蔬严重失水与风味变淡，还由于处于减压阶段贮藏时间短，有效减少了贮藏费用。我们的前期研究表明，短时减压处理可较好的延缓双孢蘑菇的采后衰老，降低腐烂率的发生。目前，关于短时减压处理延缓果蔬衰老的机制研究还较少，有必要对此进行深入研究。本项目拟通过减压短时处理对双孢蘑菇生理代谢机制的影响，对其自身抗性物质代谢和相关酶活性的影响，对其易腐微生物的抑制机制的研究，探讨短时减压延缓果蔬衰老的生物学机制。

减压贮藏是在冷藏和气调贮藏的基础上发展起来的一种气调贮藏方法，它被认为是果蔬保鲜技术的第三次飞跃，被国际上称为 21 世纪的保鲜技术。随着消费者对食品安全性的关注，减压贮藏作为一种安全的物理贮藏方法，越来越受到从事采后物流与质量控制的企业和研究人员的重视。短时减压处理是果蔬采收后在合适的贮藏阶段进行一定时间的减压贮藏，以达到延缓衰老，保持品质，延长保质期的目的。本项目通过对双孢蘑菇短时减压处理过程中环境压力对生理代谢机制的影响，对自身抗性物质代谢和相关酶活性的影响，对易腐微生物的代谢的影响进行研究，从而明确短时减压处理延缓衰老的生物学机制，为双孢蘑菇的采后物流贮藏和运输研究提供理论科学指导。本研究表明短时减压处理能够抑制双胞蘑菇的呼吸强度和乙烯生成速率，使其呼吸代谢处于一个较低的程度，进而使双孢蘑菇的营养物质损耗减少，保持较好的贮藏品质。而且，短时减压处理抑制了双孢蘑菇在采后的贮藏过程中膜透性、MDA含量、超氧阴离子生成速率、H2O2的含量的上升，可以诱导双孢蘑菇中CAT活性的上升，保持了相对较高的SOD活性，提高双孢蘑菇的抗氧化能力提高。同时，短时减压处理可作为一种逆境胁迫，诱导了抗病性相关的GHT和GLU的活性，并使其酶活保持在相对较高的水平上，提高了双孢蘑菇自身的抗性，从而在贮藏前期较好的抑制了疣孢霉菌丝的生长速率。因此，短时减压贮藏可有效延缓贮藏期双胞蘑菇品质的下降。对大力促进我国相关产业的健康和持续发展，增加农民收入具有十分重要的理论意义和实用价值。