Antioxidant, mineral and hydrophobicity properties of value added yoghurt made from tropical fruits

Abstract

In recent times, interests have been generated globally in the use of plant derived natural enhancers in the food industries due to their acceptability, palatability and minimal side effects on consumers’ health. This study examined the antioxidant, mineral and hydrophobicity qualities of yoghurts made from raw cow’s milk enhanced with tropical fruits and synthetic pineapple flavourants at 1, 7 and 14 days of storage. The antioxidant capacity showed that DPPH was highest (26.95 ± 4.56 % ) in orange flavoured yoghurt, while the FRAP value was superior (13.72 mg/ ml) in grape yoghurt. All samples showed low (0.01 mmol/ g) scavenging activity with ABTS. Storage effect indicated that antioxidants capacity assay was highest at day 1 with values 0.02 mmol/ g ABTS, 38.53 ± 1.00 % DDPH and 15 mg/ ml FRAP. Interaction effect revealed that grape yoghurt at day 1 had a stronger FRAP activity of 18.08 ± 0.04 mg/ ml, while the DPPH activity was superior (43.51 ± 0.29 % ) in pawpaw yoghurt at 14 day storage. Lemon yoghurt recorded the highest potassium and zinc concentrations (1164.14 ± 46.54, 50.08 ± 3.88 mg/ L respectively). Calcium concentration was highest in orange yoghurt (1629.83 ± 7.94 mg/ L). Pawpaw flavoured yoghurt showed superiority in sodium and iron contents (32.96 ± 2.01 mg/ L and 12.25 ± 0.23 mg/ L respectively), while synthetic pineapple yoghurt had the highest phosphorus (439.40 ± 8.93 mg/ L) concentration. L. delbrueckii subsp. bulgaricus had the strongest hydrophobicity. Conclusively, indigenous fruits could enhance the nutritional value of yoghurt and also replace synthetic flavourants in yoghurt production.