Optimization of pre-treatment conditions for maximum pulp recovery with optimum quality from bael fruit (Aegle marmelos Correa.)

The effect of pH, heating temperature, heating time and crude mass to water ratio on yield, total soluble solids and ascorbic acid content of pulp were studied. A central composite design was used to optimize the conditions of pulp extraction from bael fruit to maximize pulp yield, total soluble solids and maximum retention of ascorbic acid in pulp. The regression model describing the changes of pulp yield, total soluble solids (TSS) and ascorbic acid of pulp with respect to pretreatment conditions were derived with the coefficient of determination (R2), 0.9883, 0.9814 and 0.9554, respectively. The models were found to be fit to predict the data under the different ranges of conditions. The pulp yield, TSS and ascorbic acid content of pulp obtained from bael fruit was 93.5 to 245.30%, 11-22°brix and 8.30-11.62 mg/100 g under the designed ranges, respectively. The optimized pretreatment conditions were pH; 3.3, heating time; 0.5 min, heating temperature; 70°C, and crude mass to water ratio; 1:0.8 and the pulp yield, TSS and ascorbic acid content under these conditions were 148.75%, 16.5°brix and 10.486 mg/100 g, respectively.   Key words: Yield, total soluble solids (TSS), ascorbic acid, pH, crude mass.