Effect of Ripening and Extraction Method on the Physicochemical Properties of Pectin Extracted from Peels of Apem and Apantu Plantain Cultivars in Ghana

Abstract

Fruit waste has emerged as a significant environmental issue in recent years, adding to the global burden. In Ghana, the extensive use of plantains at various stages of ripeness results in substantial waste during each processing stage, leading to disposal challenges. Interestingly, these wastes often hold considerable economic value and can be repurposed as a source of valuable raw materials or products. Given the broad range of uses for plantains and the significant pollution problems associated with their processing, finding new uses for this organic waste has become a pressing necessity. This study investigated the impact of the method of extraction and ripening stages on the physicochemical characteristics of pectin obtained from two different cultivars of plantains, namely, Apem (M) and Apantu (T), which are indigenous to Ghana. Pectin samples were extracted from different stages of ripening (matured-green (G), half-ripe (H), and full-ripe (R)) by the utilization of acidic (D) and alkaline (L) extraction methods. The analyses conducted on the extracted pectin included proximate composition and moisture content determination, assessment of mineral/elemental composition, and solubility testing. Phytochemical investigations were performed to determine the phytoconstituents present in these pectin extracts. The pectin samples were characterized by determining their equivalent weight, methoxyl and anhydrouronic acid content, and the degree of esterification. The pectin yields obtained from the samples ranged from 10.01% to 46.55%. The moisture levels of all the pectins were below 20%. All pectin samples had swelling indexes between 37.5 ± 0.01% and 185.71 ± 0.02%. The equivalent weight (EW) of the pectin samples ranged from 1351.00 ± 0.6 g/mol to 10000.00 ± 0.07 g/mol. The methoxyl content (MeO) fell within the range of 6.2 ± 0.07% to 14.88 ± 0.14%, while the anhydrouronic acid content (AUA) varied between 38.72 ± 0.28% and 86.59 ± 0.21%. The degree of esterification (DE) ranged from 81.22 ± 0.21% to 97.56 ± 0.14%. Furthermore, the result of the micronutrient and mineral analysis indicated compliance with nutritional requirements. The levels of heavy metals were also within acceptable thresholds, thereby adhering to existing regulatory requirements. These findings highlight the significance of both the extraction technique and the ripening stage on the physicochemical properties of the extracted pectins. Generally, the extracted pectins possess excellent nutritional quality and physicochemical properties, rendering them a very valuable resource that holds promising potential for use in the food and pharmaceutical sectors.