| Red globe grape is an Eurasian species.It was cultivated by researchers from California State University in the 1970s and introduced into China in the late 1980s.It is the main grape variety in China.The planting area of Shaanxi Province is 13,340 hectares and the annual output is 240,000 tons.Red globe grape is rich in various nutrients and has high medicinal value and nutritional value.However,the red globe grape has strong respiration during storage,water transpiration is serious,microorganisms are easy to infect,highly perishable and deteriorated,and the storage period is short,which also greatly affects the edible quality and commercial value of red globe grape,and limits the long-term storage and long-distance sales of red globe grapes.1-MCP is a novel ethylene receptor inhibitor discovered in recent years.It can interfere with and block the binding of ethylene to receptors,effectively inhibiting the normal metabolism of endogenous ethylene in fruits and vegetables,thereby inhibiting A series of biochemical reactions of ripening and senescence of flesh cells have the advantages of non-toxicity and high efficiency,and have great development potential in the preservation and preservation of fruits and vegetables.Na2S2O5 slowly releases SO2 after water to inhibit microbial growth,destroys the activities of oxidase and hydrolase,and plays a role in quality preservation,color protection and anti-aging.It has been widely used in fruit storage and preservation.In this experiment,the effects of 1-MCP and Na2S2O5 combined treatment on postharvest physiology and storage quality of red globe grape were studied by using Shaanxi Heyang red globe grape.To explore the relationship between the quality change of red globe grape during storage and the preservation technology,and to find the best preservation method for red globe grape storage,in order to extend the storage period and improve the storage quality.The results are as follows:1.By measuring the respiratory intensity of red globe grape during storage,it was found that the different parts of red globe grape ears had different respiratory types.The cob has a significant respiratory peak,which is a typical climacteric type;the fruit's respiratory intensity changes smoothly,and it is judged to be a non-jumping type of breathing.By measuring the freezing point of red globe grape fruit,the freezing point temperature of the juice was-3.9?.2.Through the screening test of storage temperature of red globe grape,the storage temperature is preferably-2±0.5?,and no chilling damage occurs at the storage temperature.3.The preservative and dosage screening experiments of red globe grape were carried out,and the best preservative was 1-MCP combined with Na2S2O5.Each kilogram of red globe grape was compounded with 3 mg 1-MCP and 4 g Na2S2O5.4.The combined treatment of 1-MCP and Na2S2O5 could significantly delay the increase of cell membrane permeability,respiratory intensity,threshing rate and weight loss rate,slow down the decrease of fruit firmness and better maintain the contents of soluble solids,titratable acid,reducing sugar,vitamin C,flavonoids and anthocyanins.Stored for 180 days,the good fruit rate was 94.7%,and the sensory evaluation was 90.2 points.5.Treatment of red globe grape with 1-MCP and Na2S2O5 significantly reduced the activity of PME,PL,PG,Cx,and P-Glus slow down the original pectin,cellulose content is lower and the increase of the content of soluble pectin kept high fruit hardness.6.The combined treatment of 1-MCP and Na2S2O5 could effectively coordinate SOD,POD and CAT scavenging enzymes system and exert the ability of scavenging reactive oxygen species,maintain high content of endogenous antioxidants such as GSH,flavonoids,anthocyanins and vitamin C,and delay the production rate of O2-and the accumulation of MDA,a peroxidant of membrane lipids,and fruit fineness.The increase of relative permeability of cell membrane can alleviate the toxic effect of reactive oxygen species on fruit,maintain the integrity of cell membrane structure,and ultimately delay the senescence of red globe grape fruit.7.The combined treatment of 1-MCP and Na2S2O5 could effectively delay the increase of relative permeability of pericarp cell membrane,inhibit the increase of LOX and esterase activity,maintain low free proline content,reduce lipid peroxidation of pericarp cell membrane,maintain the stability and compartmentalization of pericarp cell membrane structure,and enhance the repair ability of cell membrane.The browning process of pericarp was slowed down and the storage quality and good fruit rate were improved. |
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