title: Enhanced Microbial, Functional and Sensory Properties of Herbal Yogurt Fermented with Korean Traditional Plant Extracts.
abstract: This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt.
authors: R&D Center, Seoul Dairy Cooperative, Ansan 15407, Korea.
authors: Jae Yeon
authors: JY
authors: Joung
authors: R&D Center, Seoul Dairy Cooperative, Ansan 15407, Korea.
authors: Ji Young
authors: JY
authors: Lee
authors: R&D Center, Seoul Dairy Cooperative, Ansan 15407, Korea.
authors: Young Sik
authors: YS
authors: Ha
authors: R&D Center, Seoul Dairy Cooperative, Ansan 15407, Korea.
authors: Yong Kook
authors: YK
authors: Shin
authors: Department of Animal Science and Institute of Rare Earth for Biological Application, Chonbuk National University, Jeonju 54896, Korea.
authors: Younghoon
authors: Y
authors: Kim
authors: Division of Food Bioscience and Technology, College of Life Science & Biotechnology, Korea University, Seoul 02841, Korea.
authors: Sae Hun
authors: SH
authors: Kim
authors: R&D Center, Seoul Dairy Cooperative, Ansan 15407, Korea.
authors: Nam Su
authors: NS
authors: Oh
keywords: antioxidant activity; fermentation; herbal yogurt; sensory evaluation; volatile compound