Abstract

COMPARATIVE EVALUATION OF NUTRIENTS AND ANTINUTRIENTS CONTENTS OF THREE VARIETIES OF HIBISCUS SABDARIFFA LINN CALYCES

Garba Abdullahi*, Yakubu Yahaya, Hannatu Abubakar Sani, Ibrahim Kalle Kwaifa, Hasana Sani Ibrahim and Sani Garba

Abstract

The nutrients and anti-nutrients contents of H. sabdariffa linn (roselle) calyces of dark red, red and green varieties sourced from Zuru, Kebbi State, Nigeria, were sun-dried and grounded into powder form and then analysed in triplicate. Nutrients contents were assessed by proximate analyses, minerals by atomic absorption spectrophotometer, flame photometer and spectrophotometer. Vitamin C was analysed spectrophotometry while anti-nutrients (phytic acid, oxalate and nitrate) by titrimetric, saponin by gravimetric and cyanogenic glycoside by spectrophotometry. Dark red calyx was rich in carbohydrates (37.67%) and had the highest crude lipid content (2.36%). The highest levels of ash, moisture, fibre and proteins were observed in the green calyx (9.50%), green calyx (8.83%), red calyx (11.00%) and dark red calyx (9.86%) respectively. Calorific values for all calyces were between 142.48 and 211.12 kcal. The mean minerals values in most abundant were Calcium, magnesium and potassium with levels ranging from 91.04 to 208.46 mg /100g. The highest levels of Calcium, magnesium and potassium were observed in the red calyx (208.46 mg/100g and 203.68 mg/100g) and dark red calyx (133.33 mg/100g) respectively. Sodium, manganese, phosphorus, iron, zinc and copper were present in small amounts. Vitamin C levels ranged from 77.13 to 108.66 mg/100 g, with the highest level in the green calyx (108.66 mg/100g). Oxalate, cyanogenic glycoside and nitrate were present at appreciable levels than phytate and saponin, in green calyx (405.00 mg/100g), dark red calyx (355.88 mg/100g and 51.00 mg/100g) respectively. In conclusion, the results indicated that these calyces are good sources of valuable nutrients with lower anti-nutrients, which is processed and consumed could contribute towards meeting the human nutritional requirement.

Keywords: Nutrients, anti-nutrients, three varieties, roselle, calyces.