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Prediction of pH Change in Processed Acidified Turnips
Author(s) -
MOREIRA LÍLIA A.,
OLIVEIRA FERNANDA A. R.,
SILVA TERESA R.
Publication year - 1992
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.1365-2621.1992.tb14325.x
Subject(s) - chemistry , partition coefficient , thermal diffusivity , diffusion , arrhenius equation , diffusion process , thermodynamics , acetic acid , correlation coefficient , analytical chemistry (journal) , chromatography , mathematics , organic chemistry , activation energy , statistics , knowledge management , computer science , physics , innovation diffusion
The acetic acid uptake by turnips was studied during an acidification process in containers. The process was successfully described by a Fickian diffusion, using a correlation for the buffer effect. Diffusion coefficients (0.629 to 3.99 × 10 ‐9 m 2 /sec) and partition coefficients (0.8 to 1.1) were obtained by optimization of the fit between experimental and theoretical values, using the simplex method. The partition coefficient did not show an evident dependence on temperature, while diffusivity followed an Arrhenius type behavior. The relationship between acid concentration and pH was described using a cubic model with parameters independent of temperature. Results showed that the combination of these models describing the acid diffusion into the food and the buffering effects of the food allowed accurate prediction of pH evolution in the acidification process.