铁棍山药黏液复合乳液保鲜鲜切马铃薯研究

为了降低鲜切马铃薯在贮藏过程中的酶促褐变程度、减缓营养流失,延长货架期,该文从铁棍山药中提取山药黏液,并与山梨醇以及V C复配,制备鲜切马铃薯保鲜乳液;通过色差、失重率、还原糖、抗氧化酶活性和抗氧化物质含量等指标的变化,探讨山药黏液复配乳液对鲜切马铃薯的保鲜效果。结果表明,1%山药黏液与0.5%的甘油、0.75%D-山梨醇以及0.02%V C(均为质量分数)的复配乳液涂膜的鲜切马铃薯,在室温下贮藏6 d,能够显著降低马铃薯的表面褐变程度、减少失重率和还原糖累积、显著抑制多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)和苯丙氨酸解氨酶(phenylalnine ammonialyase,PAL)的活力,降低总酚和丙二醛(malondialdehyde,MDA)含量;Zeta电位和粒径分析表明该乳液具有较好的稳定性和分散性。因此,铁棍山药黏液可作为天然的鲜切果蔬保鲜剂,具有应用潜力。

Preservation effects of composite emulsion from iron yam mucilage on fresh-cut potatoes

In order to reduce the enzymatic browning and the loss of nutrients,and to extend the shelf-life of fresh cut potatoes stored at room temperature,the mucilage extracted from iron yam was formulated with glycerol,sorbitol and V C for the preparation of fresh-keeping coating emulsion.The effects of the emulsion were evaluated using chromatic value,weight loss rate,reducing sugar content,the activity of antioxidant enzymes and the contents of antioxidants index.The results showed that the optimized emulsion recipes was 1%of the yam mucilage mixed with 0.5%glycerol,0.75%sorbitol and 0.02%V C.When the emulsion was applied for fresh-cut potatoes,the L value of the color difference increased,the weight loss rate and accumulation of reducing sugars reduced significantly compared with the control group after 6 days of storage at room temperature.The emulsion efficiently blocked enzymatic browning by inhibiting polyphenol oxidase(PPO),peroxidase(POD)and phenylalnine ammonialyase(PAL)activities,reducing the total phenol accumulation and malondialdehyde(MDA)content.The emulsion showed great dispersibility and stability in the analysis of particle size and zeta potential.The results show that the mucilage from iron stick yams could be a potential fresh-keeping agent for fresh-cut vegetables or fruits.