EFFECTS OF ARTICHOKE (CYNARA SCOLYMUS L.) EXTRACT ADDITION ON MICROBIOLOGICAL AND PHYSICO-CHEMICAL PROPERTIES OF PROBIOTIC YOGURT

摘要

In this study, the effects of addition of artichoke (Cynara scolymus L.) leaf extract into yogurt (0 or 0.5%) on biochemical parameters (pH, titrable acidity) and the viability of probiotic bacteria (Lactobacillus acidophilus LA-5, Bifidobacterium lactis BB-12) during fermentation and over 28 days of refrigerated storage (4°C) were investigated. Moreover, the amounts of syneresis, total phenolic content, antioxidant activity and sensory attributes of yogurts at the end of fermentation were assessed. Yogurts contained the two yogurt bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus: ABY) or only S. thermophilus (ABT) as adjunct culture to probiotics. Yogurts containing Cynara scolymus L. (ABT-C and ABY-C) had faster acidity increase, shorter incubation time and greater final titrable acidity than control yogurts (ABT and ABY). Also, yogurts containing Cynara scolymus L. had lower syneresis, higher total phenolic content and greater antioxidant activity. ABT-C yogurt had the ever greatest viability of probiotics. In case of samples sensory evaluation, generally, the highest total score was related to ABT yogurt whereas lowest total score belonged to ABT-C yogurt.