Premium
Heat Sensitivity of Pectinesterase Activity in Papaya Purée and of Catalase‐Like Activity in Passion Fruit Juice
Author(s) -
AUNG THEIN,
ROSS EDWARD
Publication year - 1965
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1965.tb00278.x
Subject(s) - pectinesterase , chemistry , passion fruit , catalase , food science , water activity , chromatography , water content , enzyme , biochemistry , pectinase , geotechnical engineering , engineering
SUMMARY Passion fruit juice catalyzed hydrogen per‐oxide decomposition as a first‐order reaction with a rate constant equal to 0.009/min/ml of juice at 77°F. The activity was destroyed by mild heat and did not regenerate after storage. It was affected only slightly by increasing juice pH from 3.0 to 6.8, although the fresh juice inactivated commercial catalase. Pectinesterase (PE) activity in ripe papaya flesh averaged 0.013 meq/min/g at 86°F. Rate of destruction for PE in acidified purée was determined in the range 169–186°F, giving a z value of 11°F from the thermal inactivation curve and a D 180 = 10 min. Further experiments on heat‐processed acidified purée in No. 2 cans indicated a residual activity more heat resistant than that predicted by extrapolation of the thermal‐in‐activation curve.