Studies On The Physiology And Biochemistry Characteristics And Fresh Keeping Technology Of Post-Harvest In Pleurotus Eryngii

Pleurotus eryngii is a new successfully developed and cultivated edible fungi in recent years, which has edible Medicinal and dietotherapy effects. However, the fruiting bodies are prone to lose water, soften, brown and so on, and have lower eating quality and value. So we have to develop more effective preservation methods for Pleurotus eryngii. In this article, we used electron beam irridiation and preservative film together with lower temperature storage to study the sensorial, physio-chemical, carbon metabolism and nitrogen metabolism of Pleurotus eryngii, in order to find the appropriate fresh-keeping method in the storage of post-harvest Pleurotus eryngii.1. The fruit bodies were kept at 4℃and RH 85%～95% after electron beam irradiation of 0.8,1.2,1.6 and 2.0 kGy, the effects of different doses irradiation on physical and physiological biochemical parameters were studied. The results show that electron beam irradiation could perfectly delay the onset of aerial hypha. Though been conserved for 21 days, the fruit bodies exposed to 0.8 kGy irradiation have no aerial hypha and abvious browning phenomenon. Moreover, compared with other irradiated simples they have higher CAT activity, lower weight-loss and less membrane damage. Altogether, electron beam irradiation of 0.8 kGy is the best fresh-keeping irradiation dose for Pleurotus eryngii.2. Packaged with LDPE, PVC, BOPP and CPP, the fruit bodies were kept at 4℃and RH 85%～95% in order to study the effects of different preservative film on sensorial, physical and physiological biochemical parameters. The results show that without preservative film, CK is likely to loss water, shrink, brown and lignify; Though the samples packaged with LDPE and PVC are preserved by film, the samples browned, lignified, became crisp, emerged unpleasant smell and so on, because the permeability of those two films is very high; The samples packaged with BOPP and CPP, which were stored for 20 days, still had features of fresh mushrooms obviously not so as to the samples packaged with LDPE and PVC. So we think BOPP and CPP are of better effects for storing of Pleurotus eryngii. 3. We determined the content of free soluble sugars in the samples packaged by preservative films with ion chromatograph, in order to study the effects of preservative films treatment to carbon metabolism in the fruiting bodies with total soluble sugar content. The results show that, during the storage, variation of free sugars (trehalose, mannitol, mannitose and glucose) and total soluble sugars content in the fruiting body packaged with BOPP and CPP is similar, while that with LDPE and PVC is similar. We find that packaging fruiting bodies of Pleurotus eryngii with BOPP and CPP are more conductive to keep stable osmotic pressure, reduce the impact of micro-organisms and inhibit the effect of after-ripening by comparing the free sugars and total soluble sugars content in them, and are more conductive to the preservation.4. We determined the content of free amino acids in the samples packaged by four preservative films with automatic amino acid analyzer, in order to study the effects of preservative films treatment to nitrogen metabolism and taste of the fruiting bodies of Pleurotus eryngii with soluble protein content. The results show that CPP packaging could create an environment with higher CO2 content and lower O2 content through modified-atmosphere, consequently could inhibit respiration, afterripening and microbial growth of fruiting bodies. Moreover, CPP packaging could make free amino acids content in fruiting bodies change less, so is good for keeping taste.