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KINETIC STUDIES ON COOKING OF RICE
Author(s) -
SUZUKI UANICHI,
KUBOTA KIYOSHI,
OMICHI MANABU,
HOSAKA HIDEAKI
Publication year - 1976
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.1365-2621.1976.tb14412.x
Subject(s) - reaction rate constant , activation energy , diffusion , arrhenius equation , chemistry , degree (music) , arrhenius plot , materials science , thermodynamics , analytical chemistry (journal) , kinetics , organic chemistry , physics , quantum mechanics , acoustics
The mechanism of cooking rice was investigated in this study. The rheological method using the parallel plate plastometer was adopted for measurement of the degree of cooking. The range of temperatures measured ran from 75–150°C. Experimental results showed that cooking rate followed the equation of a first order chemical reaction. We designated the proportional constant as the cooking rate constant, but the slope of Arrhenius plots of the cooking rate constants changed around 110°C. The activation energy of cooking at temperatures below 110°C and above 110°C was about 19,000 and 8,800 cal/mol respectively. The influences of water soaking time before cooking were also studied. We concluded that the cooking process comprises two mechanisms; at temperatures below 110°C the cooking rate is limited by the reaction rate of rice components with water; and at temperatures above 110°C it is limited by the rate of diffusion of water through the cooked layer toward the interface of uncooked core where the reaction occurs. The reaction rate constant and the diffusion coefficient of water were calculated by assuming the core model or shell‐type model.