Effect of Using Cactus Pear Pulp on The Properties of Goats’ Milk Bio- Yoghurt Drinks

Document Type : Original Article


GOATS’ MILK bio-yoghurt drinks were made using different levels (5, 10 and 15 %w/w) of cactus pear fruits’ (Opuntia dillenii) pulp (CPFP) and fermented with Yo-Fast1 (containing of Lactobacillus delbrueckii ssp. bulgaricus & Streptococcus thermophilus) as commercial yoghurt starter and ABT-5 (containing of Lactobacillus acidophilus, Streptococcus thermophilus & bifidobacteria) starter culture with potential probiotic properties. All treatments differed significantly (p ≤ 0.05) in their properties; depending on the percent of CPFP added, starter culture used and storage period (9days at 60.5°±C). Fresh yoghurt drinks made with CPFP displayed (p≤0.05) higher rheological parameters than that of the control except for flow behaviour index values. The viscosity of all yoghurt drinks increased while the whey separation decreased with the increase of added CPFP till the end of the storage period. Furthermore, with increasing the percentage of CPFP used, there were slight and gradual decreases (p≤0.05) in the pH values of all treatments as compared with control. Also, the colour parameters for all yoghurt drinks changed slightly during storage and the rate of pigments degradation depending on the percentage of CPFP used. Results exhibited new bio- yoghurt drinks rich in the total phenolic compounds and high in antioxidant activity, which are increased significantly (p ≤ 0.05) with rising CPFP levels added. Also, the counts of viable cells in all treatments were maintained at an acceptable level (>106cfu/ml) to be considered as functional foods until the end of storage period. Sensory evaluation showed that all CPFP yoghurt drinks treatments were more accepted by the panelists, rated above average, particularly when fermented with a probiotic starter culture. The addition of CPFP significantly improved the quality attributes of goats’ milk yoghurt drinks and could be considered as new goats’ milk products with probiotic properties and health benefits.