Influence of different heating media on thermal resistance of Neosartorya fischeri isolated from papaya fruit.
Rajashekhara E., Suresh E. R., Ethiraj S.
Author Affiliation: Division of Post Harvest Technology, Microbiology Laboratory, Indian Institute of Horticultural Research, Hessaraghatta Lake (Post), Bangalore 560 089, India.
Journal of Applied Bacteriology 81 : 337-340
Abstract : A heat-resistant mould identified as a strain of Neosartorya fischeri was isolated from microbiologically spoiled papaya fruits [pawpaw] (Carica papaya. The optimum heat activation temperature and time for the ascospores of the test mould was found to be 80 °C for 15-30 min. The decimal reduction times (D-values) at 85 °, 87 ° and 89 °C in phosphate buffer (pH 7.0) as heating medium were 35.25, 11.1 and 3.90 min., resp., and hence the calculated z-value was 4.0 °C. In grape and mango (Mangifera indica) juices as heating media, the D80°C and the D85°C values were increased as the °Brix level raised from 10 to 45. In commercial fruit juices of mango, orange, pineapple (Ananas comosus) and mango-pineapple blend as heating media D85°C values were greater than those observed for phosphate buffer.