Characteristics of okara color change during convective drying process

[摘要] Okara is a byproduct of the tofu factory that is perishable in nature and requires an immediate handling and treatment to preserve it. Drying has been a preferred method since it can increase the product compactness. However, the majority of okara drying studies done in the past are disregarding the influences of process condition on color change characteristic. Hence, this work aimed to investigate the characteristic of okara color changes during convective drying at temperatures of 85, 100, and 115°C. The okara color was expressed in terms of L a b values and its derivative attributes, i.e. whiteness, hue angle, chroma and the total color difference. The results showed that an increase in drying time and temperatures decreased the lightness, yellowness and the total color difference, but conversely increased the redness of okara. Fitting of two exponential models to the experimental data revealed that the Page's equation was better in predicting the okara color degradation than Newton's model.

[发布机构] Department of Agricultural Engineering, Faculty of Agricultural Technology, University of Jember, Jember, Indonesia^1

[效力级别] 生物科学

[关键词] Color changes;Color degradation;Convective drying;Drying time;Exponential models;Page's equations;Process condition;Total color difference