Optimization of Processing Parameters in the Production of Mango Flakes

Abstract

Mango fruit (Mangifera indica. L) is a common fruit seasonally produced in large volumes in Kenya. However, post-harvest losses which can be attributed to a lack of enough modern processing technology have been a bottleneck in the maximization of the fruit’s economic and nutritional potential. Mango flakes are one of the products that can be produced from mango fruits. Further enrichment of mango flakes with locally produced green grams has been viewed to have the potential to enhance their nutrition profile. The study was designed to optimize the processing parameters in the production of mungbean-enriched mango flakes. A randomized block design was used to determine the consumer acceptability of drum-dried mango flakes. A total of 15 treatments were obtained using sugar variations of 0%, 2%, and 4%, and starch at 0%, 10%, and 20%. 30% of cooked mungbean paste was incorporated into the formulations. 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. Response Surface Methodology (RSM) of Design Expert 13 software, was used to optimize mango flakes production procedures by adjusting factorial variables. Moreover, bacteriological status analysis for yeasts and molds was determined using dextrose potato agar. A completely randomized design was used to compare means between variables and test for significance. A total of 16 samples were taken through microbial analyses with respect to the type of packaging material, storage temperature, and mango varieties. Physicochemical and nutritional analysis was done using predetermined AOAC procedures. Results indicated that formulations that were incorporated with 20% starch, and 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 sensory score of 5.79. Homogeneity of variances was observed between different formulations for overall acceptability (P=0.192). The average yeast and mold counts were 2.8 log10cfu/g within the eight-month storage duration, with 98.4% of the samples compliant with Kenya Bureau Standards (KEBS), and East African Standards for dried mango products. Packaging material and storage temperatures did not play a role in influencing the rate of microbial growth with one-way ANOVA analysis indicating P-values of 0.064 and 0.851 respectively for statistical differences. Mungbean-enriched mango flakes showed average ash, beta carotene, vitamin C, crude fiber, protein, and moisture content of 0.21±1.50 g/100 g, 0.21±1.50 g/100 g, 15.75±13.22 μg/100 g, 22.17±5.81 mg/100 g, 0.63±0.17 g/100 g and 15.57±1.50 g/100 g respectively. Magnesium was the predominant mineral with an average of 44.16±2.52 mg/100g. Significant differences were noted in ash, and fiber composition in mango flakes processed from different mango varieties as well as those drum ...