生物可降解聚乳酸薄膜对金针菇保鲜效果的研究

用聚乳酸(PLA)薄膜包装金针菇,置于20℃、相对湿度(RH)90%的环境贮藏,以聚乙烯(PE)薄膜包装,20℃、RH90%贮藏和无包装室温贮藏为对照组,研究PLA薄膜包装对金针菇保鲜的影响。定期评定金针菇感官,检测失重率、可溶性固形物和游离氨基酸保留量、褐变度等品质指标及包装袋内O2、CO2体积分数。结果表明,室温无包装、PE包装和PLA包装的金针菇的贮藏期分别为1、3、5d。3d后,PLA包装的金针菇较PE包装,无明显开伞、菌柄伸长、水渍状斑块及褐变现象,其褐变度为4.71,低于PE包装;可溶性固形物和游离氨基酸保留量分别为10.05%和55.66mg/100g,高于PE包装的8.30%和19.09mg/100g。气体含量测试发现,PLA包装内形成低O2,高CO2的环境,能有效抑制金针菇的衰老,从而延长金针菇的贮藏期。 

Study on biodegradable polylactic acid film on preservation of Flammulina Velutipes

Flammulina velutipes were packaged under air with polylactic acid (PLA) film and stored at 20℃, 90%relative humidity (RH) . Flammulina velutipes packaged with polyethylene (PE) film, stored under the same condition and without packaging, placed under room condition was used as control. The effect of PLA packaging on the preservation of Flammulina velutipes was evaluated by analyzing sensory quality and biochemical properties of Flammulina velutipes. The results indicated that the storage time of Flammulina velutipes packaged without film, with PLA film and PE film were 1, 3, 5d respectively. Compared with packaged with PE film, Flammulina velutipes with PLA packaging revealed a significant inhibition on mushroom parasol, stripe elongation, browning and physiological senescence after 3d. The browning degree of Flammulina velutipes with PLA-packing was 4.71, lower than that with PE packing which were 6.13. In addition, the content of soluble solids and free amino acid of Flammulina velutipes packaged with PLA film were 10.05% and55.66mg/100g respectively, which exhibited the enhancement to 8.30% and 19.09mg/100g of Flammulina velutipes packaged with PE film. Furthermore, the gas condition of high oxygen content and low carbon dioxide content was formed in PLA packaging, which showed more suitable to inhibit aging process and extend the storage time of Flammulina velutipes.