The Effect Of Hot Water Immersion Treatment On Quality Of Raw Materials Of Mango Pulp

Because of limitations of product prices and raw material prices, at present, the disease of raw material was reported more frequently during processing in mango pulp industry in China, which leaded high loss rate of raw material before mango pulp processing. In this paper, raw meterial for mango pulp processing was used as experimental material to study on conditions of the thermal death of fungi which caused mango rotten during ripening, analyze conditions of the thermal death of fungi which caused mango to rot in ripening, determine extreme conditions of mango heat burns which maturity between 7 to 8, and compare the results of microbial indicators of mango skin, disease index, rot rate, maturity index, pulp quality indicators, and so on, that passed different hot water immersion treatment, attain the efficient and safe conditions of hot water immersion treatment for mango pulp processing enterprises. In the first part, Tainong No.1 mango was used to carry out the experimental study of hot water immersion treatment, the main results were made as follows:1. Hot water immersion treatment caused a significant inhibition on conidia and hyphae of fungi which caused mango rotten, when bacterial suspension dealed with a certain degree, there were lethal effect, thermal death conditions were listed in following table.2. Minor burns spot on part of Tainong No.1 mango of maturity 7 to 8 were caused by hot water immersion treatment of 55℃for 15min,60℃for 5min, 65℃for 1min, no damage on mango sarcocarp was abserved, and the ripening process was neihter affected; once hot water immersion treatment degree exceeded upward conditions, mango ripening process would be inhibited by obvious thermal damage.3. Hot water immersion treatment of 50℃for 10 to 30min,55℃for 5 to 15min,60℃for 3 to 5min could effectively reduce the microbial content of mango surface; inhibit the augment of lesion area and volume in the ripening process; reduce the rot rate, made the reduced rate of rotten fruit more than 70%.4. Comprehensive analysing the results of espiratory intensity, yellowing index, hardness, total soluble solids content, titratable acid content, color, malondialdehyde content, relative conductivity, we could draw a conclusion that, in the selected hot water immersion treatment conditions, mango ripening process was not effectivly inhibited, and no disadvantageous influences on pulp quality was generated.In the second part of this paper, based on the favourable experimental results, pilot scale test of hot water immersion treatment was carried out using Sannian mango cultivar. The result proved hot water immersion treatment of 55℃for 5min,60℃for 2min could effectively reduce the rot rate in the ripening process, made the reduced rate of rotten fruit more than 80%.