Quality characteristic and antioxidant activity of yogurt containing olive leaf hot water extract

• Published in: CYTA: journal of food Vol. 18; no. 1; pp. 43 - 50
• Main Authors: Cho, Won-Young, Kim, Da-Hee, Lee, Ha-Jung, Yeon, Su-Jung, Lee, Chi-Ho
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01.01.2020; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: actividad antioxidante; antioxidant activity; Antioxidants; Bacteria; evaluación sensorial; High-performance liquid chromatography; hoja de olivo; Hot water; HPLC; Lactic acid; Lactic acid bacteria; Leaves; Liquid chromatography; Oleuropein; olive leaf; Phenolic compounds; Phenols; Plant extracts; Scavenging; sensory evaluation; Sensory properties; Storage; yogur; Yogurt
• ISSN: 1947-6337; 1947-6345
• DOI: 10.1080/19476337.2019.1640797

The objective of this study was to determine the antioxidant and quality characteristics of yogurt containing olive leaf hot water extract (CON: 0, OLY1: 0.1, OLY2: 0.2, and OLY4: 0.4% (w/v)) stored at 4°С for 15 days. After storage, the lactic acid bacteria count showed no significant difference between yogurt samples either in the presence or absence of olive leaf extract (p > 0.05). The total phenolic content, DPPH radical scavenging activity, and reducing power increased upon increasing the content of the olive leaf hot water extract. Oleuropein was found to be the most abundant phenolic compounds present in olive leaf, and the oleuropein content in OLY4, as measured by HPLC, decreased gradually to 1.09, 1.00, and 0.96 g/L upon increasing the storage time; however, this reduction was not significant (p > 0.05). In sensory evaluations, OLY1 gave the highest score among the experimental groups. The results of this study thereby demonstrate that olive leaf hot water extract can be used to improve the antioxidant capacity and sensory characteristics of yogurt.