Mineral And Phytochemical Content In Leaves Of Talinum Triagulare (Water Leaf) Subjected To Different Processing Methods

摘要

The mineral and phytochemical content of vegetables cannot be overemphasized. The effect of processing methods on the mineral and phytochemical contact in leaves of Talinum triagulare was studies to determine which of the methods will minimize nutrient loss. Talinum triagulare was researched using different methods; sun drying, steam blanching and combination of these methods for its mineral and phytochemical content. The mineral analyzed were magnesium, potassium, sodium, calcium and iron while the phytochemicals were saponin, oxalate, alkaloid, tannin and phytate. The results showed that sundried sample produces more value of the mineral content over steam blanched and the combined methods sample which means that sundrying method was the best. The phytochemical analysis showed that in sun dried samples, saponin was 2.200 (mg/g), phytate has 0.434 (mg/g) while in steam blanched sample alkaloid has the highest value of 5.200 (mg/g) oxalate has 3.600 (mg/g). The combined sample has the highest value of alkaloid 5.120 (mg/g). The three processing methods showed varied values which could not ascertain one method as been better or good in retaining the phytochemical content of the vegetables Introduction Fresh vegetables are important sources of nourishment and a vital ingredient in healthy and balanced diets. Fresh vegetables are highly recommended in any diet virtually without quantitative restriction and the roles of vegetables in maintenance of good health are well known (Osuagwe, 2008). Green leafy vegetables form an indispensable constituent of diet in Africa generally and west Africa in particular. Generally they are consumed as cooked compliments to the major stables like cassava, cocoyam, guinea corn, maize, millet, rice and plantain (Oguntona, 1998) they are noted to occupy an important place among the food crops as they provide adequate amount of vitamins and minerals for human. Vegetable are important as food both from economic and nutritional stand point. Their nutritive significance is their richness in minerals and vitamins which is essential is the maintenance of human health (Bolaji et al; 2008). The importance and awareness of nutrition is public health issues has resulted in the increase demand of knowledge of the biochemical nutrients of foods. They are good sources of carotene, ascorbic acid, riboflavin, folic acid and minerals like calcium, iron, and phosphorous (Fasuyi, 2006). Vegetables also contain phytochemical which are nutritionally and medicinally useful but atimes reduce the bioavailability of nutrients in human system (Fasuyi , 2006)Vegetable are eaten raw or processed. Any methods selected for processing vegetables should be such that does not adversely affect the colour, texture, flavour, and nutritional values especially the vitamins and minerals (Edeoga et al; 2006) The processing method used for vegetables therefore depends on the end product desired and storage facilities available (Cruess, 1985).Water leaf (Talinum triagulare) is a highly perishable vegetable. It needs special processing methods to prevent decomposition. These processing methods either change the nature and constituents of the vegetable positively or negatively. This work is aimed to evaluate the minerals and phytochemicals in water leaf (Talinum triagulare) as affected by commonly practiced food processing methods of sun drying steam blanching and combination of the two methods. Materials And Methods Collection of plant materials: Fresh leaves of water leaf (Talium triagulare) were harvested from a nearly farm within the Rufus Giwa Polytechnic, Owo, Ondo State.Preparation of plant materials: The fresh leaves of water leaf (Talinum triagulare) were thoroughly cleansed. 50g of the fresh leaves of the vegetable was weighted in three places. The first part was sun dried for five days, the second part was steam blanched while the third part was steam blanched and sun dried for 3 days.Determination of minerals and phytochemicals: T