STUDIES ON NUTRIENT QUALITY, PHYTOCHEMICAL COMPONENTS AND ASSOCIATED MYCOBIOTA OF LETTUCE

Abstract

Studies on the nutrients and spoilage fungi of lettuce were carried out in the Department of Plant Science and Biotechnology, Rivers State University. Lettuce samples were subjected to proximate analysis and cultural isolation techniques  for  associated  fungi.  Proximate  assessment  revealed  the  presence  of  protein,  carbohydrate,  ash, moisture, fibre and lipid. The moisture and carbohydrate content recorded highest and lowest values (89.74±0.01%) and (0.43± 0.00%), respectively. Mineral investigation showed calcium, iron, phosphorus, potassium, magnesium and sodium to be present. Although, calcium had highest value of 19.75±0.05mg/100g while phosphorus recorded lowest value of 2.10±0.01mg/100g. Vitamin evaluation revealed vitamins C, A, thiamin and niacin. Highest vitamin (95.5±0.01mg/100g)   was   recorded   for   vitamin   C   and   lowest   vitamin   (0.73±0.00mg/100g)   for   thaimin. Phytochemical screening showed the availability of oxalate, saponin, phytate, polyphenol, flavonoid, tannin, lignate and carotenoid in appreciable concentrations. Aspergillus niger was the only fungal organism isolated from the spoilt lettuce leaf sample with an incident of 100%. Generally, lettuce is rich in vital nutrients just like other vegetables (fluted pumpkin, okazi, uziza and many more) and concerns should be targeted towards its safe handling to avoid contamination.