Optimization of Foam Mat Drying Conditions of Black Plum (Vitex Doniana) for Improved Amino Acid Composition.

Abstract

Black plum (Vitex doniana) is a sweet, edible perennial shrub widely distributed in tropical West Africa and are nutritional rich. Foam mat drying is a technique whereby foam is incorporated into food material by addition of a foaming agent before subjecting it to drying. Optimization of foam mat drying of black plum pulp to powder using response surface methodology for amino acid determination was studied. The fruits were processed to powder through foam mat drying using glycerol monostearate (5 to 15%) as foaming agents, carboxymethyl cellulose (3 to 5%) as foam stabilizer at temperature of 50oC to 70oC and 90oC for non-foam dried sample till moisture content of less than 10% was achieved. The samples were analyzed for and amino acid composition using standard analytical methods. The values recorded for the essential amino acid was in the range of, threonine, 0.19 mg/100 to 0.35 mg/100g, histidine, 0.11 mg/100g to 0.23 mg/100g, 0.16 mg/100g to 0.27 mg/100g, isoleucine, 0.09 mg/100g to 01.8 mg/100g, tryptophan, 0.20 mg/100g to 0.34 mg/100g, methionine, 0.12 mg/100g to 0.24 mg/100g, valine, 0.11 mg/100g to 0.23 mg/100g, lysine, 0.05 mg/100g to 0.15, mg/100g, phenylalanine 0.12 mg/100g to 0.21 mg/100g. Amino acids varied significantly (P≤0.05). Foam mat dried samples and samples with higher concentration of foaming agent recorded the highest values. The study shows that foam mat drying minimize the loss of amino acid composition and thus, improvement in the nutritional quality of the fruit powder