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Effects of Different Gas Composition and Packaging Materials on Postharvest Quality and Active Oxygen Metabolism of Flammulina Velutipes

Author: BianXiaoLin
Tutor: XiaoHongMei
School: Nanjing Agricultural College
Course: Of Food Science
Keywords: Flammulina Velutipes gas composition nano-packaging material nutritional quality active oxygen metabolism
CLC: S646.15
Type: Master's thesis
Year: 2010
Downloads: 17
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Abstract

Flammulina velutipes is an important agricultural product and widely planted in China. Modified atmosphere storage is one of the most important methods in the storage of fruits and vegetables. This paper studied the effects of different oxygen and carbon dioxide concentration and package materials on postharvest F. velutipes storage quality and the influence of mushroom aging, to explore the appropriate gas composition. On the other hand, the effects on the preservation of F. velutipes by different packaging materials were observed and the mechanism of nano-packaging material was discussed.The contents and results are as follows:1. Effects of low O2 on quality and physiological characteristics of postharvest F. VelutipesThe experiment was carried out to evaluate the effects of gas composition on Flammulina velutipes. Postharvest F.velutipes was stored under the conditions of air temperature at (2±1)℃and relative humidity(RH) at 95% with the concentration of oxygen was 1%、2%、3%、5%, respectively. Respiration rate, browning degree, membrane penetrability, malondialdehyde (MDA) content, activities of peroxidase (POD) and superoxide dismutase (SOD) were investigated regularly. The experimental results showed that, compared to the control, modified atmosphere storage with 3% O2 could keep the fresh quality of F. Velutipes, restrain respiratory rate, membrane permeability and browning degree, control the increase of MDA, maintain the high activities of SOD, POD, reduce the losses of nutrition and prolong shelf-life.2. Effects of low O2 and high CO2 on preservation of F. VelutipesOn the basis of the last experiment, this test changed carbon dioxide concentration at 5%,10%,15%, then stored under the conditions of air temperature at (2±1)℃and RH at 95%, the results found that the appropriate improve of CO2 concentration could help lengthen mushroom storage period, but excessive CO2 decreased the preservation effect of F. Velutipes. By 3% O2 and 10% CO2 inhibited the respiration of postharvest F. Velutipes, delayed nutritional quality and declined color changes and browning degree, maintained high commodity value and high activity of antioxidant enzymes, which was beneficial to remove the excess accumulation of free radicals and protect the cell membrane system integrity, postpone the senescence of F. velutipes.3. Effects of different packaging materials on preservation quality of F. VelutipesPostharvested F. velutipes was packed with nano-packaging material or polyethylene (PE) material, and then stored at (2±1)℃. To explore the right atmosphere conditions of cold storage for F. velutipes, O2 and CO2 contents of different packages and active oxygen metabolism were detected, and the changes of the quality were observed. The results showed that nano package could maintain hypoxia and hypercapnia storage environment (CO2 11.5%, O2 1.6%), so as to keep the appearance of mushroom quality and the nutritional value, prolong the storage time from 12 to 20 days. Meanwhile, the microenvironment of nano package effectively inhibited the levels of superoxide anion and H2O2, and MDA content, while enhanced the activities of SOD, CAT, POD and APX. Which suggested the condition of CO2 11.5% and O2 1.6% is better than CO2 9.7% and O2 2.4% for F. velutipes cold storage.

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