Identification Of Advantage Post-Harvest Pathogens And Shelflife Pridiction Of Red Globe Grape

Red globe grape from Huailai,Hengshui and Jinzhou of Hebei province, Jixian of Tianjin province, Jinzhou of Liaoning province as material, studied on the relativity between the disease incidence rate and the carrier rate of flesh, peduncle and pedicel, the water content of peduncle in 0℃±0.5℃,RH90%～95%, isolated, purified and identificated the main pathogens of postharvest decay of the red globe of grape, the content of titratable acid, the phenolic substance content and the activity of PPO,POD,PAL were measured during cold storage. To determine the relativity between main indexes and the disease incidence rate and the predictive indicator for storage effect of red globe grape. Red globe grape from Jixian of Tianjin province as material, applied the mechanism of Q₁₀ and the 3T model to predicting the remain shelflife of the grape. Red globe grape from Huailai of Hebei province as material, at 20°C RH90%～95% following inoculation with a spore suspension of Botrytis cinerea, the production of volatil profiles by ripening Red Globe grapes from Tianjin Jixian were measured, to find the relativity between the volatil profile and the development of decay. The results showed as following:1. Some pathogens were isolated from the internal pulp, pedicel and peduncle, it indicated that the pathogen infection was started in the field, therefore measures should be taken in the flowering stage to prevent grapes from rotting. The descent rate of the water content of peduncle was fast in the first 30 days of storage, the water content of peduncle was negative correlation with the carrier rate of grape peduncle and the disease incidence rate of grape.2. The isolation and identification result indicated that main pathogens of postharvest decay of the red globe grape were Botrytis cinerea, Alternaria SPP., Penicillium, Rhizopus nigricans and Aspergillus niger, among them Botrytis cinerea and Alternaria SPP. were the advantage pathogens during the cold storage.3. The relativity with the disease incidence rate was not at the same level in different quality indexes, the correlation coefficient between the SSC and the disease incidence during the cold storage were above 0.90, The SSC could well monitor the disease incidence rate during the cold storage.4 The correlation coefficient between the initial phenolic substance content of flesh and the disease incidence rate after 80d'storage was above 0.89, therefore the initial phenolic substance content could be a reliable indicator to predicting the batch quality of red globe grape.5.The shelflife of the red globe grepe was caculated by the form Qs ( T )=29×1.897 ^(10-T)/10from 0℃to 10℃; and Qs(T)=17×1.706 ^(20-T)/10 from 10℃to 20℃.6.Only ethylene could be detected more than 24 h before the first decay symptom was visible, therefore Ethylene might be used as an early marker for infection in harvested flesh produce.