Optimization of different processing variables to develop a fruit bar of guava (Psidium guajava L.) and Sapota (Achras zapota L.)

Abstract

A study was undertaken at the Post-Harvest Laboratory, Department of Horticulture, College of Agriculture, JNKVV Jabalpur (M.P.) in 2022. The objectives were to standardize the processing variables for the fruit bar, evaluate its physicochemical and organoleptic properties and assess its storage stability. The experiment utilized a Completely Randomized Design (CRD) with 15 treatment combinations involving different ratios of guava and sapota pulp (90:10, 80:20, 70:30, 60:40 and 50:50) and varying concentrations of potassium metabisulphite (KMS) (0.5%, 1.0% and 1.5%). Each combination was replicated three times. The fruit bars were stored at room temperature for 45 days and analyses were conducted at intervals of 0, 15, 30 and 45 days. Maximum TSS (76.73), ash content (1.71%) and moisture content (18.76%) were found in the 90% guava:10% sapota pulp + 0.5% KMS treatment. Highest acidity (1.38%), ascorbic acid content (193.81 mg/100g) and non- reducing sugar (64.68%) were reported with 90% guava:10% sapota pulp + 0.5% KMS and 1.0% KMS treatments. Highest total sugar (78.87%) and reducing sugar (15.48%) in the 50% guava:50% sapota pulp + 1.0% KMS treatment. The sensory evaluation, performed by a panel of judges using a 9-point hedonic scale, assessed color, appearance, taste, texture, flavor and overall acceptability. Statistical analyses were conducted at a 5% level of significance. The study observed a gradual decrease in acidity and ascorbic acid with an increase in total sugar and non-reducing sugar as the proportion of sapota pulp increased. The best organoleptic quality and storage stability were found in the 70% guava:30% sapota pulp + 1.0% KMS treatment, with no microbial growth detected over the 45-day storage period. In conclusion, the optimal treatment for preparing guava-sapota mixed fruit bars involved 90% guava:10% sapota pulp with 0.5% KMS, although the best sensory qualities were observed with 70% guava:30% sapota pulp and 1.0% KMS.