title: Syneresis and rheological behaviors of set yogurt containing green tea and green coffee powders.
abstract: This study aimed to investigate the effect of added green coffee powder (GCP) and green tea powder (GTP) on syneresis behavior and consistency of set yogurts. Adding GCP (1 or 2%) decreased syneresis rate. The effect of GTP on the syneresis rate was concentration dependent. In comparison to the control, GTP decreased syneresis rate when it was added at 0.02%, but it caused an increase when added at 2%. No significant difference was observed in the syneresis rates when GTP was added at 1 and 0.01%, until 14 and 7 d of storage, respectively. The Herschel-Bulkley model parameters indicated that the consistency of control was considerably lower than that of GCP yogurts during 14 d, whereas it was higher at the end of storage. The GTP yogurt results showed that the consistency coefficients of GTP yogurts were different from those of control samples until 14 d of storage. In conclusion, GTP and GCP behaved differently in acidified gel networks of set yogurt, modifying its rheological behavior, as they have different profiles and concentrations of polyphenols.
authors.affiliation: Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe Campus, Ankara, Turkey.
authors.forename: Özge
authors.initials: Ö
authors.lastname: Dönmez
authors.affiliation: Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe Campus, Ankara, Turkey.
authors.forename: Burçe Ataç
authors.initials: BA
authors.lastname: Mogol
authors.affiliation: Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe Campus, Ankara, Turkey. Electronic address: vgokmen@hacettepe.edu.tr.
authors.forename: Vural
authors.initials: V
authors.lastname: Gökmen
mesh_terms: D000818:Animals; D003069:Coffee; D005511:Food Handling; D008892:Milk; D011208:Powders; D012212:Rheology; D013662:Tea; D015014:Yogurt
chemical_list: D003069:Coffee; D011208:Powders; D013662:Tea
keywords: green coffee; green tea; protein-polyphenol interaction; set yogurt; syneresis rate