Mechanism Of Controlling Fresh-Cut Pumpkin With Salicylic Acid And Hydrogen Sulfide

Fresh-cut fruits and vegetables is that after the initial treatment, ready to eat fresh fruit or vegetables. With the continuous progress of society, consumers more in favor of fresh-cut fruits and vegetables.Pumpkin is a common vegetable in daily life, its nutrient rich, and has the effect of lowering blood sugar, blood pressure and so on. Due to the large size of a single pumpkin, the former processing more difficult, so the distribution of the pumpkin in the market has been a lot of restrictions. Fresh-cut pumpkin solves its large size, the difficult of market to deal with the problem before. But after the processing of fresh-cut pumpkin tissue integrity is destroyed, will induce a series of physiological and biochemical reactions. Along with loss of processing juice, fresh-cut processing not only influence the fruit freshness, quality and nutritional characteristics, but also to stimulate the enzymatic browning reaction occurred, resulting in appearance and quality of fruit and vegetable products, while the decline in the fresh-cut processing destroyed the original fruit and vegetable protection system, to microbial infection reduced ability to resist. And the characteristics of acid leakage is caused by processing and fruit and vegetable juice nutrition, also provide favorable conditions for the growth and reproduction of microorganisms. Therefore, it plays an important role in regulation of the fresh keeping of fresh-cut and signal molecular mechanism of pumpkin.In this paper, the effects of salicylic acid(SA) and sodium hydrogen sulfide(Na HS) deal with fresh-cut pumpkin. To study the effects of SA and H2 S on the fresh-cut pumpkin preservation and the molecular mechanism of the signal. The basic quality indexes, active oxygen metabolism and benzene propane metabolism of fresh cut pumpkin were measured and analysed.1、The results of this experiment showed that compared with the control group, 0.5mmol/L SA and 0.5mmol/L Na HS treatments can effectively enhance the antioxidant activity of fresh-cut pumpkin. In the active oxygen free radicals, SA treatment can effectively reduce the content of H2O2 than Na HS, H2 S can effectively reduce the O2- production rate of more than SA; In the antioxidant enzyme, SA was more effective than H2 S in improving the activity of CAT, and H2 S was more effective than SA in improving the activity of SOD, APX and GR.2、With 0.1, 0.5, 1.0, 1.5, 2.0, 2.5mmol/l Na HS and 0.1, 0.25, 0. 5, 1.0, 1.5 mmol / L SA deal with fresh-cut pumpkin, determination of hardness, color and total number of bacteria, the total number of fungal that 0.5 mmol/L SA, 0.5mmol/l Na HS can significantly inhibit the fresh-cut pumpkin hardness is reduced, and the cut surface whitening, while suppressing increase in the total number of bacteria and total number of molds. Weight loss rate: SA 0.5mmol/L treatment group is better than Na HS 0.5mmol/L treatment group, soluble solids, electrical conductivity, yellow element: Na HS 0.5mmol/L treatment group is better than the SA 0.5mmol/L treatment group.3、SA, H2 S improved the plant phenylpropanoid metabolism of pod and PAL activity in fresh cut pumpkin, reduced the activity of PPO and secondary metabolites such as the content of total phenolics, flavonoids and lignin also have varying degrees of increase.Effect of H2 S on fresh cut pumpkin Phenylpropanes metabolism is better than that of SA. The effect of H2 S on fresh cut pumpkin phenylpropanoid metabolism results: decrease 10.3% PPO activity, POD activity increased 22.8%, improve the activity of PAL 30.6%, with a 17 percent increase in total phenolic content, flavonoid content increased 18.9%, lignin content increased by 18.2%.