Quality indices of ice cream produced from dairy milk partially substituted with Bambara groundnut (Vigna subterranean (L)Verdc.) beverage

Abstract

The most important ingredient in ice cream production is milk. However, keeping the body, structure, and texture of ice cream requires maintaining the right balance of various constituent ingredients. Recently, a number of plant-based milk alternatives have emerged with reduced particle size distribution. Although Bambara groundnut milk (BGNM) beverage appears increasingly applicable in yoghurt production, there is paucity of relevant literature reporting its application in ice cream production. In order to supplement the existing information, this work investigated the quality indices of ice cream from dairy milk partially substituted with Bambara groundnut beverage. Different proportions of dairy milk and BGNM blended to produce ice cream involved seven formulations (100:0, 0:100, 90:10, 80:20, 70:30, 60:40 and 50:50, all v/v %). Quality indices measured included the antinutrients (phytic acid and tannins), physicochemical, microbial and sensory aspects. The obtained results showed that fat and ash content decreased with increased substitution of dairy milk, whereas the protein, carbohydrate, calcium, iron, potassium and magnesium contents increased with addition of Bambara groundnut. In addition to statistical differences that occurred across the samples (p<0.05) in most cases, with varying ranges from pH (5.20-6.61), overrun (11.00-73.50%), total solids (10.98-12.35%), viscosity (1.00-2.25 Pa.s), to total titratable acidity (0.05-0.11 g/100 mL). Besides the increased meltdown values, and the somewhat varying anti-nutrients (tannin = 0.32-2.64 mg/100 g; phytic acid = 2.97-63.85 mg/100 g), the total viable count ranged from 1.2 x 103 to 8.7 x 102 CFU/mL, while sensory characteristics had quite a number of resemblances (p>0.05) between some samples. This current work has demonstrated a desirable ice cream can be produced by partially substituting dairy milk with up to 30% Bambara groundnut extract.