Product and process development of mango flakes using response surface methodology

Abstract

Mango fruit (Mangifera indica L.) is one of the tropical fruits which are produced in large volumes in Kenya. Transformation of the perishable fruit into shelf-stable nutritious products is one of the interventions that can be used to reduce losses while accruing better returns for farmers. The objective of this study was to determine the optimum processing parameters in the production of consumer-acceptable mango flakes. Fifteen treatments were obtained using sugar variations of 0%, 2%, and 4%, and starch at 0%, 10%, and 20%. Process variables were determined by varying pressure of steam (0.8 BAR, and 1.6 BAR) and speed of drum drying (2.2 rpm and 7.6 rpm). Sensory analysis was done using a 7-pointer hedonic scale while physicochemical, and proximate lab analysis was done using predetermined AOAC procedures. Response Surface Methodology (RSM) of Design Expert 13 software, was used to optimize mango flakes production procedures by adjusting settings of factorial variables. Results indicated that formulations that were incorporated with 20% starch, 0% sugar, and dried at 7.57 rpm for 5 minutes and 2 seconds at a constant gauge pressure of 0.8 BAR were the most preferred with a mean overall score of 5.79. Homogeneity of variances was observed between different formulations for overall acceptability (P=0.192). The predictive model of the Central Composite Design stipulated that an increase in sugar concentration reduces the sensory quality of drum-dried mango flakes. Nutritional profile of the most acceptable mango flakes was a composite of 1.9g/100g, 2.8g/100g, 0.9g/100g, and 0.5g/100g for carbohydrates, vitamin C, crude protein, and crude fat, respectively. A significant difference was observed between values for protein and vitamin C (P=0.002). In conclusion, the organoleptic acceptability and nutritional profiles of drum-dried mango flakes were affected by the time: pressure exposure of the puree as well as the product ratios of ingredients.