Effects of Methanol Extraction on Some Nutritional and Antinutrient Contents of Xylopia aethiopica Fruits from Enugu State, Nigeria

Abstract

Mineral contents and amino acid and fatty acid profiles of Xylopia aethiopica fruits from Enugu State, Nigeria were evaluated in this study. The amino acid and fatty acid profiles, phytochemical, proximate, mineral, anti-nutrient and vitamin contents of X. aethiopica fruits were determined using standard methods. The proximate, vitamins, phytochemical, anti-nutrient of both the crude and methanol extract were determined while the mineral and amino acid profile were determined in the crude fruit powder while fatty acid profile was determined in the oil extract of the fruits. Results show that the predominant amino acids present include proline, alanine, norleucine, isoleucine, glycine, threonine, cysteine, methionine, and tryptophan. Also, the most abundant fatty acids include arachidonic acid, dihomoÏ’-linolenic acid, palmitic acid, caproic acid, linoleic acid, palmitoleic acid, stearic acid and myristic acid. The mineral contents of X. aethiopica fruits detected in high amount were calcium, iron, potassium and magnesium. Sodium, zinc and manganese were detected in lower amounts. However, lead, silicon, nickel and chromium were not detected. The result of the proximate analysis shows moisture, total protein, crude ash, total fat, crude fibre, and carbohydrate contents. Anthraquinone was not detected in both crude and methanol extract of the fruit. The concentration of flavonoids, steroids, anthocyanin and terpenoids were significantly (p < 0.05) higher in crude sample when compared with methanol extract. The levels of carotenoid and glycosides were significantly (p < 0.05) higher in the methanol extract when compared with crude sample. Vitamins B1, B3, B6, B9, B12, C and E levels were significantly (p < 0.05) higher in crude extract when compared with methanol extract. However, vitamin A content was significantly (p < 0.05) higher in methanol extract when compared with crude extract. Results obtained showed that X. aethiopica fruits are rich in nutrients and that methanol extraction decreased the anti-nutrient contents of the fruits thereby increasing the bioavailability of the nutritive factors. However, the quantities of some of the nutritive factors were reduced after extraction