Assessment of Some Health Beneficial Constituents of Edible Portions of Four Underutilised Fruits
Loading...
Date
2013-12-10
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The surge in chronic diseases has necessitated the global call for increased consumption of diverse fruits and vegetables resulting in the need to study the potential health beneficial constituents of the underutilised. This research was aimed at assessing the dietary fibre fractions, proximate composition, antioxidant activity and phytochemical constituents of edible portions of four underutilised fruits viz., African mango (seeds and pulp), breadfruit (pulp), soursop (pulp) and sweetsop (pulp). Their total phenolic and ascorbic acid (vitamin C) contents were also determined. Samples for all determinations except proximate analysis were freeze-dried and stored: Some under refrigeration conditions for dietary fibre analysis, and the rest at - 20 oC. Proximate and phytochemical analysis was done by standard methods. The antioxidant activity and phenolics were determined by spectroscopy using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging and the Folin-Ciocalteu protocol, respectively. The ascorbic acid content was determined by titrimetry and an enzymatic-gravimetric method employed for the dietary fibre determinations. Proximate values (% mean) ranged from 2.63±0.11 to 6.71±0.07; 2.44±0.07 to 4.00±0.03 and 2.60±0.41 to 13.90±0.58 for protein, ash and fat respectively. Generally, tannins, triterpenoids, saponins, sterols, cardiac glycosides, flavanoids and coumarins were detected. Antioxidant activity of the samples ranged from 63% (breadfruit) to 78% (African mango pulp) and the highest phenolic content was recorded in African mango seeds. Total dietary fibre contents ranged from 11.50 (soursop) to 22.70 (African mango pulp) g/100g while ascorbic acid contents of the fruit mesocarps ranged from 20.32 (sweetsop) to 62.52 (soursop) mg/100g. There were non-significant correlations (P < 0.05) between the phenolics, ascorbic acid contents and antioxidant activities. The study suggests significant composition of health beneficial constituents - dietary fibre, vitamin C and presence of an array of phytochemicals - as well as fairly high antioxidant activities of the stated fruits. Thus, the need to exploit them in seeking optimum health of the populace.
Description
A Thesis submitted to the Department of Food Science and Technology,
Kwame Nkrumah University of Science and Technology in partial fulfilment of the requirements for the degree of Master of Science.