Jessica I. Igwebuike¹, Lucretia I. Barber¹, Patience C. Obinna-Echem^1,

Physicochemical and sensory properties of partially hydrolysed tigernut milk and beetroot beverage fermented with probiotic Lactobacillus acidophilus was evaluated. Ability of the blended beverage (hydrolysed tigernut and beetroot juice) to support the growth of L. acidophilus was also determined. Partially hydrolysed tigernut milk produced using alpha amylase and amyloglucosidase was blended with 10, 20, and 30% beetroot juice designated as HTNB₁₀, HTNB₂₀ and HTNB₃₀ respectively while sample without beetroot juice (HTN₁₀₀) served as control. Analysis were carried out using standard analytical methods. Hydrolysis of the tigernut milk resulted in significant (P<0.05) decrease in starch from 29.70 - 17.14% and increase in sugar from 9.08 - 20.23 ⁰Brix. pH significantly (P<0.05) decreased with time irrespective of the concentration of beetroot juice. Decrease was from 6.54 – 5.05, 6.52 – 5.38, 6.52 – 5.46 and 6.46 – 5.66 for the control (HTN₁₀₀), HTNB₁₀, HTNB₂₀ and HTNB₃₀ respectively. Titratable acidity (TTA) as % lactic acid increased respectively, from 0.19 - 0.67, 0.30 – 0.66, 0.31 – 0.69 and 0.31 – 0.42 for HTN₁₀₀, HTNB₁₀, HTNB₂₀ and HTNB₃₀. All the samples supported L. acidophilus growth with significant (P<0.05) increase from <2.00 - 6.22, 2.81 - 6.37, 2.30 - 6.94 and 2.45 - 6.29 log₁₀ CFU/ml respectively, for HTN₁₀₀, HTNB₁₀, HTNB₂₀ and HTNB₃₀. Assessors’ degree of likeness for the sensory attributes varied respectively, from 4.3 - 5.45, 4.8 - 5.2, 4.85 - 5.56, 5.8 - 7.0 and 5.11 - 5.74 for colour, aroma, mouthfeel, taste and general acceptability. The partially hydrolysed tigernut and beetroot beverages supported the growth of the L. acidophilus (6 Log₁₀ CFU/ml). The physicochemical properties of beverage were of satisfactory levels and could be recommended as a potential probiotic product. The addition of 20% of beetroot juice will be recommended based on the assessors’ degree of likeness.

Tigernut, partial hydrolysis, beetroot, Lactobacillus acidophilus, beverage, physicochemical and sensory properties