Micronutrient and antinutrient content of semi-processed fruit peels: Towards boosting immunity

Fruits are excellent sources of micronutrients; hence, their consumption is highly recommended. However, fruit peels, often discarded, despite some being edible have been reported to contain essential nutrients and antioxidants, which contribute to disease prevention and well-being.

This study sought to evaluate the micronutrient and antinutrient content of 10 edible fruit peels namely, orange, mango, pineapple, banana, lemon, mandarin, red apple, cucumber, guava and pawpaw peels.

Laboratory analyses of the fruit peels were conducted at the University of Calabar, in a well-ventilated and temperature controlled environment to ensure accurate results.

The research design was quantitative and experimental; laboratory analyses were carried out to determine the minerals, vitamins and antinutrients in fruit peels using AOAC standard methods. Data were analysed using ANOVA on SPSS version 20.0.

Calcium was the most predominant of the minerals analysed, with values ranging from 33.12 ± 0.05 mg/100 g (cucumber peels) to 72.04 ± 0.08 mg/100 g (mango peels); calcium was followed by magnesium. Mandarin, banana and pineapple peels had statistically similar (p > 0.05) content of zinc (about 1.2 mg/100g), which was significantly (p < 0.05) higher than others. Mandarin peels had significantly higher content (100.48 ± 2.03 mg/100 g) of vitamin C, while cucumber peels recorded the lowest (27.50 ± 0.01 mg/100 g). The results show significant concentrations of micronutrients such as iron, selenium and vitamin K; among the antinutrients, hydrogen cyanide had the highest concentrations, followed by phytate. The values were within safe limits.

Therefore, the processing of fruit peels, for use as dietary additives to enrich foods and boost immunity, should be promoted.

The study shows the potential of fruit peels as food additives.