Sustainable Solutions for the Development of Nutritional Fortified Cookies with Multi-Stage Dried Fruit Peels

Abstract

Fruit processing sector is the biggest contributor of environmental waste followed by household sewage. Banana peel and orange peel represents 35-50% and 50-65% of the total fruit weight respectively. These peels can be used in preparation of fortified cookies owing to presence of bioactive constituents. Transformation of waste residuals into value added ingredients for fortification requires the dehydration which affects the retrieval and accessibility of bioactive compounds from the fruit peels. A reasonable alternative to conventional drying is the integration of two stage drying. This study assessed and compared the effects of single-stage and two-stage drying on retention of different bioconstituents for incorporation in cookies. 10% of wheat flour was replaced by fruit peel powders in the cookie mixture which were baked at a high temperature of 170°C for 12 minutes. The results of the tests were analysed through one-way ANOVA and the Tukey’s test at a significance level of 95% (p < 0.05). The fiber was significantly increased from 0.61% in control cookies to 2.35% and 1.53% for banana and orange enriched cookies respectively. The scavenging activity was enhanced to 18.89% and 14.06% for orange and banana enriched cookies respectively. However phenolic compounds were retained significantly only in orange enriched cookies at 0.187 mg GAE/g. Multi stage drying significantly increased the phenolic compounds in orange and banana peels to 0.190 and 0.414 mg GAE/g respectively. The fiber content did not decrease significantly in two stage drying. However antioxidant activity was increased for banana peels to 22.75% and reduced for orange peels to 19.13% in two stage drying. The drying time was significantly xvi reduced by 2.87 and 4 hours for banana and orange peels respectively in multi-stage drying. In conclusion, the findings of this study support the use of orange and banana peels as a functional ingredient due to nutrient rich profile. Moreover it is suggestive of two stage drying as a potential alternative for enhancing the efficiency of the fortification process. Further research on conducting sensory evaluations would be crucial for assessing consumer acceptability for cookies.