Calcium enriched guava crisps: effect of material and process parameters

Guava ranks among top five economically important crops of India. However, it records highest postharvest loss and needs to be processed for higher shelf life and utility. This study entails evaluation and process standardisation for development of guava crisps through atmospheric frying. Three maturity stages based on firmness affected the composition of guava and thereby the quality of crisps. ANOVA, PCA and correlation analysis indicated significant effect of fruit maturity (starch, pectin, solids, sugars, ascorbic acid) and process parameters. 84% variation in data could be explained by the first four PCs together. Colour, browning, fracturability and crispness of crisps were significantly affected by fruit maturity, freezing pre-treatment, and calcium impregnation. Freezing pre-treatment enhanced the texture, decreased toughness and gave superior crisps with crunchy mouthfeel. More than 15-fold increase in the calcium content of crisps (524.76 mg/ 100 g) was realised on calcium infusion. Highest ascorbic acid retention (56.7%) and overall acceptability of crisps (7.5) were recorded for crisps from ripe stage of guava fruits given freezing and calcium infusion pre-treatments. The shelf life of guava crisps was 90 days with free fatty acids value < 2%. Thus, nutrient rich guava fruit could be a good candidate for conversion to shelf stable and attractive snacks.