SELECTION OF LEVELS OF INGREDIENTS OF WHITE SAPOTE FRUIT (CASIMIROA EDULIS) JELLY MANUFACTURING

Abstract

Thirty experiments were conducted to develop value added white sapote fruit jelly using constant level of white sapote fruit extract juice (500 mL) with various levels of four ingredients Viz., sugar (450, 500, 550, 600 and 650 gm), citric acid (5, 6, 7, 8 and 9 gm), pectin (4, 5, 6, 7 and 8 gm) and vanilla flavor (1, 1.5, 2, 2.5 and 3 ml) to enhance the economic value of the fruit. This study was carried out to investigate the effect of ingredients on the physicochemical properties like pH, moisture, ash, titratable acidity, total soluble solid, vitamin C, minerals and consumer acceptability of the product through sensory evaluation. The prepared white sapote fruit jelly filled in glass jars was labeled and stored at room temperature (21 – 28℃) up to 30 days to determine the Physico-chemical and sensory quality attributes at an interval of 15 days. The results revealed that processing of white sapote fruit extract juice in to jelly resulted in a significant (P < 0.05) increase in physicochemical properties like TSS and TA but a significant (p < 0.05) decrease in pH and calcium. Processing of white sapote pulp into jelly decreased the nutritional composition when compared with the pulp. Moisture, ash, crude fiber, crude protein, vitamin C decreased significantly (P < 0.05) except significant (p < 0.05) increase in the carbohydrate and thereby energy value. Central Composite Rotatable Design (CCRD) with five levels of each variable was used for experimental design. Response Surface Methodology (RSM) was used to analyze the effect of sugar, citric acid, pectin and vanilla flavor on the overall acceptability of the jelly. A uniform precision type central composite design consisting of four variables in a five level pattern with 30 runs (with six center point), was prepared. A four factor central composite design was employed to optimize the jelly in order to obtain a product with adequate sensory properties, especially, overall acceptability. All formulations were submitted to 40 semi-trained assessors using a 7- point hedonic scale. There were significant differences observed in physicochemical properties of all sample due to pectin and sugar concentration. Results showed that overall acceptability was affected mostly by change in sugar and pectin level (P < 0.05), while overall acceptability was not affected significantly (p>0.05) by change in citric acid and vanilla flavor levels. Among all samples constraint 1 (C1) scored highest for color (6.82), flavor (6.61), taste (6.4), texture (6.7) and overall acceptability (6.68) which shows the jelly with 500 gm sugar, 6 gm citric acid, 5 gm pectin, 1.5 ml vanilla flavor and 500 ml fruit extract juice is best jelly with highest sensory attributes. In general, there was decrease in most of physicochemical and sensory qualities during the storage.