Title: Optimization of oven drying conditions of banana (musa spp., aaa group, cv ‘luvhele’ and ‘mabonde’) using response surface methodology

Biography:

Adewale Omolola is a postdoctoral research fellow in the Department of Agricultural and Rural Engineering, University of Venda. He specializes in modeling and optimization of food processing operations.

Abstract

Statement of the Problem: Luvhele and Mabonde banana varieties are bananas grown in Limpopo province of South Africa. They are rich in nutriments and antioxidants. Color is a main quality characteristic of food products that are affected by the drying conditions while texture changes in solid foods during processing by drying are an important cause of quality deterioration. Methodology & Theoretical Orientation: Optimization of oven drying conditions of Luvhele and Mabonde banana varieties were studied using response surface methodology. The drying was performed according to a central composite rotatable design to explore two sets of variables: oven temperatures (40, 50 and, 60oC) and drying time (1260, 1080, and 900 min) for Luvhele; (40, 50 and, 60oC) and (1260, 900, and 600 min) for Mabonde. The color and texture (hardness) data were analyzed using ANOVA and regression analysis. Findings: Results indicated that L*, a*, b*, hue angle and hardness varied with drying conditions for the two banana varieties. Values to the hue angle ranged between 63.38 – 74.70 and 60.14 - 72.80 to dried slices of the banana varieties Luvhele and Mabonde. The hardness of dried slices of the banana varieties, Luvhele and Mabonde ranged between 1.15 - 14.62 N and 1.28 - 14.29 N, respectively. Oven temperature and drying time had significant (p < 0.05) effects on the overall color (hue) and hardness of Luvhele and Mabonde banana varieties. Models obtained for the prediction of overall color (hue) and hardness of dried slices of both banana varieties as a function of the process variables drying temperature and time had no significant (p > 0.05) lack of fit test, adequate and acceptable regression values: adjusted R2 between 078 and 0.80 coefficient of variance (CV) < 10%; hence the models obtained for the responses were adequate and acceptable. The drying conditions of 47.56oC drying temperature and 944.87 min of drying time were found optimum to obtain a quality at desirability of 0.97 to the Luvhele variety; whereas 40oC drying temperature and 646.17 min of drying duration with a desirability of 0.83 was predicted as optimum drying for Mabonde. Conclusion: The result of this study could be used as a standard for oven drying of Luvhele and Mabonde banana varieties.