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Prediction of Vitamin C Retention of Potato Strips Blanched in Water

Author:
LUNA, JULIO A., GARROTE, RAUL L.
Source:
Journal of food science 1987 v.52 no.3 pp. 634-638
ISSN:
0022-1147
Subject:
ascorbic acid, blanching, diffusivity, equations, food science, heat transfer, models, potatoes, prediction, temperature, thermal degradation
Abstract:
A model based on the mathematics of diffusion was developed to predict the retention of vitamin C of potato strips blanched in water. The vitamin C loss mechanism is by diffusion in unsteady state, considering the losses caused by enzymatic action or thermal degradation to be negligible. The apparent diffusion coefficient of vitamin C in potato is supposed to be constant with the concentration, and variable with the temperature according to equation Dₐ= Dₐ₀exp (− Eₐ/RₐT), in which Da₀and Eₐare experimental values different in the 25–65°C and 65–100°C temperature ranges. The model determines adimensional average temperatures and vitamin C average concentration as a function of blanching time, at 66, 77 and 88°C, in straight cut potato strips of 9.5 × 9.5 × 96, 11 × 11 × 96 and 13 × 13 × 96 mm, with heat transfer coefficients ∞, 1000 and 300 W/m²⁰C, respectively. The model was verified using published data.
Agid:
1204001