Evaluation of the Suitability of Tigernut Milk and Tigernut-Cow Composite Milks for Yoghurt Production

Abstract

The cost of animal milk used in yoghurt production in Nigeria has continued to rise, making the price of yoghurt to become prohibitive. This study investigated the suitability of tiger nut milk for yoghurt production. Five milk formulations prepared from tiger nut milk and cow milk were used to produce yoghurts. pH and titratable acidity (TA) of the milks and yoghurts were determined. The yoghurts were assessed for total plate count (TPC), total fungal count (TFC), fat content and sensory properties. Sensory properties were evaluated by a 10-man taste-panel using a 5-point hedonic scale. pH values of the yoghurts ranged from 3.94 – 4.68. TA values ranged from 0.56 – 0.64. TPC of the yoghurts ranged from 1.0 x 102 – 1.3 x 103 cfu/ml while TFC ranged from 0.1 x 101 – 0.3 x 101. The microbial counts of the yoghurt samples were within acceptable safety limits. The yoghurts were generally acceptable to the panelists. There were significant (P < .05) differences in the sensory scores for appearance, taste, texture, and overall acceptability. Tiger nut-cow milk (75:25) yoghurt had the highest appearance and taste scores while tiger nut milk (100) yoghurt had the highest texture and overall acceptability scores. Tiger nut milk (100) yoghurt was the most preferred yoghurt with an overall acceptability score of 4.8±0.42 followed by tiger nut-cow milk (75:25) yoghurt. Yoghurts analysed had fairly high fat contents. The study showed that tiger nut milk and tiger nut-cow milk composites could be used as alternatives to cow milk for yoghurt production.

Quality evaluation and microbial enumeration of plant based probiotic yoghurt from powdered milk and tiger nut milk

“…The addition of tiger nut milk to the full cream yoghurt may not have a general effect on all the sensory properties assessed but a significant effect was noticed in some of the parameters. The result of the sensory characteristics in this current research is in discordance with the result obtained by Onyimba et al [19] where he reported that yoghurt produced from 100% tiger nut was generally acceptable while in the study of Ajibade et al [20], yoghurt produce from 50% tiger nut and cow milk was found to be generally acceptable. In this research as against the studies of the previous authors, addition of more than 30% tiger nut could affect the sensory characteristics of the yoghurt due the inability of the probiotics to ferment the sugar present in the tiger nut milk.…”

Appraisal of Proximate Composition in Tiger Nut Yogurts and Selected Commercially Available Yogurts in Enugu, Enugu State, Nigeria: A Comparative Study

“…Results of the previous studies indicates that pH values of 6.07 -6.67 [33]) and 4.7 [34] obtained from animal based yoghurt drink are higher than the results obtained in this study. Interestingly, pH values of 3.7±0.21 obtained from tiger nut yoghurt relatively agree with pH values of 3.9 reported by Onyimba et al [35] and finding of previous study done by Sanful [15]. The study confirmed that pure tiger nut yoghurt had higher pH values when compared with milk yoghurt obtained from animal based yoghurt.…”

“…Colony counts which reflect the presence of bacteria of the organisms plated out from the 10 -2 dilution factor showed heterotrophic counts of 8.0 x 10 2 CFU/ml, 7.8 x 10 3 CFU/ml and 1.3 x 10 3 CFU/ml for the yoghurts A, B and the tiger nut yoghurt respectively at day 0 of the microbial count. The microbial loads of TCC (1.3 x 10 3 cfu/ml) obtained in the recent study done by Onyimba et al [35] are similar to the result observed in the produced tiger nut yoghurt. The results of total bacterial counts which reflect the multiplicity of desired bacteria from the 10 -1 dilution factor showed heterotrophic counts of 6.8 x 10 6 CFU/ml, 5.33 x 10 5 CFU/ml and 5.6 x 10 4 CFU/ml for the yoghurts A, B and the tiger nut derived yoghurt respectively at day 0.…”

Utilization of Tigernut Milk in Yoghurt Production: Physicochemical Properties and Growth of Lactobacillus bulgaricus and Streptococcus thermophiles in Tigernut Yoghurt

“…There was significant (P<0.05) decrease in pH after 6 and 12 h of fermentation from 6.44 -3.57 and 3.52 for samples with sugar and from 6.46 -3.67 and 3.62 for samples with date. The initial pH of the samples before inoculation was in line with the report by Onyimba et al (2022) except for the cow milk which could be attributed to the type of milk used. The decrease in pH after fermentation for 6 and 12 h was similar to the report by Bristone et al (2015) for yoghurts produced from cow milk, tiger nut milk, soybean milk and their combinations but higher than 4.0 -4.5 reported by Makut et al (2018) for tigernut milk yoghurt and a commercially sold yoghurt.…”

“…A combination of other LAB such as Bifidobacterium animalis and Enterococus faecium has also been used (Crittenden et al 2003). Depending on the type of LAB, various short chain fatty acids and other metabolites are product from the metabolism of the milk sugar (lactose) (Onyimba et al, 2022).…”