1. Comparative Physicochemical, Microbiological, Antioxidant, and Sensory properties of pre- and post-fermented yoghurt enriched with olive leaf and its extract.
- Author
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Pourghorban S, Yadegarian L, Jalili M, and Rashidi L
- Abstract
This study investigated the comparative effect of yoghurt samples enriched with different concentrations of olive leaf powder (OLP) (0.1, 0.5, 1, and 1.5 mg/ml) and its extract (OLE) (0.5, 1, 3, and 5 mg/ml) on the microbiological, sensory, physicochemical, and antioxidant properties of pre- and post-fermented samples during 21 days of storage. Sensory evaluation showed that concentrations lower than 1.5 and 5 mg/ml of OLP and OLE, respectively, were acceptable. Adding OLP or OLE did not have an influence on yoghurt starter culture bacteria ( p > .05). All enriched samples significantly showed higher acidity and lower pH compared with control samples ( p < .05). The most important polyphenols were oleuropein (from 0.132 to 0.224 and 0.373 to 0.413 mg/g for 0.5 and 3 mg/ml of OLE, from 0.194 to 0.321 mg/g and 0.413 to 1.280 mg/g for 0.5 and 1 mg/ml of OLP, respectively) and catechin (from 0.369 to 0.382 and 0.461 to 0.477 mg/g for 0.5 and 3 mg/ml of OLE, from 0.386 to 0.405 mg/g and 0.310 to 0.710 mg/g for 0.5 and 1 mg/ml of OLP, respectively) in enriched yoghurts. Adding OLP or OLE increased shelf life, antioxidant activity percentage (AA%), and total phenol content (TPC) of enriched samples ( p < .05). During 21 days of storage of all samples, TPC, AA%, and pH decreased and TTA increased., Competing Interests: There is no conflict of interest regarding the publication of this manuscript., (© 2022 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)
- Published
- 2022
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