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
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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.
