Effects of Konjac Glucomannan Coating on the Freshness of Fresh Grapes after Vibration

In order to study the effect of Konjac Glucomannan(KGM)on the freshness of fresh grapes after vibrating stress,three different concentrations of konjac glucomannan(1,2,3 g/L)were used to coat the grapes after vibration(vibration intensity 5 Hz,maximum amplitude 5 cm,vibration time 12 h). The freshness of the fresh grapes with distilled water and the freshness of the fresh grapes treated with different concentrations of Konjac Glucomannan in the storage period(10 days)at room temperature(25±1)℃ was compared,mainly determined by measuring the quality index(weight loss rate,decay rate,hardness,soluble solids),respiration intensity,V_C content and total phenol content. The results showed that different concentrations of Konjac Glucomannan coating could improve the freshness of fresh grapes in different degrees,mainly in reducing the loss of water and reducing the weight loss rate(compared with the control group,the maximum can reduce 35.19%),slowing the storage process of softening and decay(highest decay rate decreased 29.78%),reducing the respiratory strength,reducing the consumption of V_C and total phenol(the highest was reduced 53.02% and 68.97% separately). At the same time,it was found that 2 g/L concentration of Konjac Glucomannan has the best freshness effect,after 10 days,the weight loss rate,decay rate and hardness were 21.44%,49.35%,323.53 kg/cm² respectively,V_C content and total phenol content reduced 23.45% and 17% respectively. This provides the theoretical basis for the freshness of fresh grapes in the future.