复合保鲜剂对无核白葡萄保鲜效果研究

Fresh-Keeping Effect of Compound Preservative on Seedless White Grapes

以新疆无核白葡萄(Vitis vinifera L.cv.Thompson seedless)为试材,蔗糖、柠檬酸、Vc、亚硫酸氢钠为果柄保鲜剂成分,探究果柄保鲜剂对葡萄果梗褐变的影响。通过预实验筛选出15 g/L蔗糖+2 g/L Vc+2 g/L亚硫酸氢钠(Vc复配)和15 g/L蔗糖+0.30 g/L柠檬酸+2 g/L亚硫酸氢钠(柠檬酸复配)2种较优果柄保鲜剂。分别采用2种果柄保鲜剂对葡萄果梗进行处理,在10℃条件下贮藏10 d,测定失重率、好果率、褐变指数、含水量、色差、相对电导率、叶绿素含量、多酚氧化酶(Polyphenol oxidase,PPO)、过氧化物酶(Peroxidase,POD)等指标。结果表明:贮藏第4天,柠檬酸复配与无处理相比,褐变指数和POD活性分别降低了29.10%和0.06 U/min·g;Vc复配与无处理相比,分别降低了20.77%、0.07 U/min·g。贮藏第8天,柠檬酸复配保水效果最好,含水量与初始相比只损失了9.81%。2种果柄保鲜剂均有效延缓了葡萄果梗色差、PPO活性和失重率的升高,明显提高了好果率及叶绿素相对含量。果柄保鲜剂不仅能够延缓葡萄果梗褐变,对果梗有较好的护绿效果,还提高了葡萄的感官品质和商品价值。该研究为葡萄果柄保鲜技术在电商物流方面的应用提供了新的研究思路。

Xinjiang Thompson seedless(Vitis vinifera L.cv.Thompson seedless)was used as experimental material,sucrose,citric acid,Vc and sodium bisulfite were used as the components of fruit stalk preservative,and the effect of fruit-stalk preservative on delaying browning of grape fruit stem was studied.Through a large number of preliminary experiments,two kinds of better fruit-stalk preservatives have been screened out,they are:15 g/L sucrose+2 g/L Vc+2 g/L sodium bisulfite(Vc compound)and 15 g/L sucrose+0.30 g/L citric acid+2 g/L sodium bisulfite(citric acid compound).Grape stems were treated with two kinds of fruit-stalk preservatives,stored at 10℃for 10 days.The weight loss rate,good fruit rate,browning index,water content,color difference,relative conductivity,chlorophyll content,polyphenol oxidase(PPO)and peroxidase(POD)were measured.Compared with no treatment,the citric acid compounded preservative reduced the browning index and POD activity by 29.10%and 0.06 U/min·g,respectively,and Vc compounded preservatives decreased the browning index and POD activity by 20.77%and 0.07 U/min·g at the 4th day of storage,respectively.At the 8th day of storage,citric acid compound preservative had the best effect on water retention,and compared with the initial amount,water content was only lost by 9.81%.The two kinds of fruit stalk preservative delayed the increase of color difference,PPO activity and weight loss rate of grape stem,and increased the rate of good fruit and the relative content of chlorophyll.The fruit stalk preservative can delay the browning of grape fruit stalk,keep the green appearance of fruit stem,and improve the sensory quality and commercial value of grape.This study provides new research ideas for the application of grape fruit stalk preservation technology in e-commerce logistics.