Bacteriological and nutritional assessment of tiger nut milk (kunun-aya) consumed by students of Nasarawa State University, Keffi Nigeria

Tiger nut milk is a locally prepared indigenous non-alcoholic beverage that is widely produced and consumed in Nigeria most especially in the Northern part of Nigeria where it is referred to as kunu-aya. Twenty five (25) kunun-aya samples were obtained as freshly formulated beverages from five (5) different locations within Nasarawa State University, Keffi, Nigeria. The samples were separately subjected to nutritional assessment (proximate analysis, minerals analysis and determination of vitamins content) and bacteriological assessment. The bacteria loads were determined in terms of total bacteria counts using standard methods involving pour plates. The antibiotic susceptibility pattern of the bacteria isolates was determined using the Kirby-Bauer disc diffusion method. The bacteria counts of the samples from all the locations revealed the total viable counts which ranged from 1.2 – 12.0 × 104cfu\ml, total coliform (0.8-6.6×104cfu\ml), total feacal count (1.0-11.0 x 104 cfu/ml) and total staphylococcus count [1.2-7.0x104 cfu/ml) Five species of bacteria were isolated and identified by standard microbiological methods and these were Escherichia coli, Staphylococcus aureus, Salmonella spp., Klebsiella spp and Proteus spp.   Result of the proximate composition showed that moisture content ranged from 79.50-81.30%, crude protein( 6.84-7.1%), ash (1.87-2.01%),crude fat( 4.66-5.62%), Crude fiber( 0.70-1.24%) Carbohydrate (2.0-4.50%). Energy values ranged from 77-97(cal). The mineral [mg/l] analysis was done using atomic absorption spectrophotometric method and the result revealed Ca (5.13-8.7), K (0.42-0.53), Na (0.23-0.64), Mg [1.14-2.6], Fe (0.61-0.86). These results provided information about the nutritional value and confirm that tiger milk is an interesting healthy beverage but its contamination with potentially pathogenic bacteria poses a great threat to the consumer.