Nutrient and Antinutrient Determination of Some Agrowates in Port Harcourt, Rivers State

Abstract

Studies on the nutrient and antinutrient compositions of some agrowastes in Port Harcourt were carried out in the Department of Plant Science and Biotechnology, Rivers State University. Agrowastes such as sawdust, wood ash and rice bran were selected for this study. Sawdusts from Xylopia aethiopica and Mitragyna ciliata and Rhizophora racemose wood were obtained from Mile II Timber Market Diobu in Port Harcourt while the wood ash was sourced from burnt Rhizophora racemose wood after cooking. Rice bran was obtained from Dilomat Farms and Services Limited in Rivers State University. All selected agrowastes were brought to the Department for further studies. The atomic absorption spectrophotometer methods described by Association of Official Analytical Chemists (AOAC) were used for the determination of proximate, mineral, vitamin and antinutrient contents of these agrowastes. Proximate evaluation revealed rice bran to possess highest values for moisture (11.63±0.15), lipid (7.50±0.10) and carbohydrate (35.63±0.60). Highest values (9.56±0.03) for protein, 71.50±0.10 for fibre and 15.00±0.50 for ash were recorded for M. ciliata, X. aethiopica and R. racemose wood ash respectively. Mineral and vitamin assessment revealed wood ash to contain highest calcium, iron, magnesium, phosphorus, potassium and sodium while thiamine (0.23±0.01) was only recorded for rice bran. Antinutrient investigation showed the availability of oxalate, tannin, carotenoid, polyphenol, flavonoid and lignant in all tested agrowastes. However, X. aethiopica recorded highest antinutrient composition compared to other assessed agrowastes. Generally, these agrowastes still possess valuable nutrients and antinutrients that could support other production processes