ABSTRACT

Iru is a food flavouring condiment that is derived from fermentation of mung bean. These fermented food condiments are known to be a good source of diatery protein and vitamins. Most diets of Nigerians are lacking in fairly large amounts of protein due to the high cost of accessible protein. The high cost and inadequate supply of animal proteins and other nutrients have necessitated contemporary research, geared towards the utilization of protein from underutilized high protein legumes such as mung bean seeds. The processing steps includes, harvesting, sorting/cleaning, soaking, cooking, dehulling, with fermentation playing a significant role along the process through the activities of microorganism. The findings will be of great value to the masses by bringing to their awareness the nutritional value of iru from mung bean and soy bean. The pH, proximate, mineral, phytochemical, amino acid, volatile constituents and sensory quality of “iru” produced from dehulled and undehulled mung bean were comparatively evaluated using iru from soy bean as control. The pH showed an increase from initial 6.13 in unfermented mung bean to an alkaline pH of 7.24 and 7.67 at the end of 96 hours in iru from dehulled and undehulled mung bean. The moisture, protein, fat, flavonoid, alkaloid, tannin and phytate content of the iru samples ranged from 29.66 (dehulled mung bean) to 22.55% (control), 39.15 (control) to 25.84% (undehulled mung bean), 30.61 (control) to 14.92% (undehulled mung bean), 9.22 (undehulled mung bean) to 2.16 mg/100 g (control), 4.37(undehulled mung bean) to 1.06 mg/100 g (control), 2.13 (undehulled mung bean) to 1.05 mg/100 g (control), and 68.25 (undehulled mung bean) to 31.10 mg/100 g (control) respectively. Fifteen amino acids were detected comprising both the non-essential and the essential amino acids. Lysine, leucine, valine and phenylalanine generally had the highest amounts (5.25, 7.15, 4.18, and 5.14 g/100 g) in the iru samples as compared to other essential amino acids. Higher values were obtained for aspartic acid, arginine and glutamic acids.  Thirty two volatile compounds were detected in all the iru samples. Seventeen volatile compounds were identified in iru from dehulled and undehulled mung bean respectively, while fifteen was identified in iru from soy bean. There was no significant (P>0.05) differences in the amount of each volatile compound identified in dehulled and undehulled iru from mung bean, but significant (P<0.05) different existed between iru sample from soy bean. The sensory properties showed that iru from dehulled mung bean could compete favourably well with iru from dehulled soy bean (control) in terms of consumer acceptability, whereas iru produced undehulled mung bean were the least preferred by panelist. From the result obtained from the research, it can be conclude that iru should be produced from dehulled mung bean as this will reduce the over dependence on soy bean and enhance the utilization of mung bean.