Dönmez Özge, Mogol Burçe Ataç, Gökmen Vural
Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe Campus, Ankara, Turkey.
Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe Campus, Ankara, Turkey.
J Dairy Sci. 2017 Feb;100(2):901-907. doi: 10.3168/jds.2016-11262. Epub 2016 Dec 21.
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.
本研究旨在探讨添加绿咖啡粉（GCP）和绿茶粉（GTP）对凝固型酸奶脱水收缩行为和稠度的影响。添加1%或2%的GCP可降低脱水收缩率。GTP对脱水收缩率的影响取决于浓度。与对照组相比，添加0.02%的GTP可降低脱水收缩率，但添加2%时则会导致脱水收缩率增加。分别在储存14天和7天时，添加1%和0.01%的GTP时，脱水收缩率无显著差异。赫谢尔-布尔克利模型参数表明，在14天内，对照组的稠度明显低于添加GCP的酸奶，而在储存结束时则更高。GTP酸奶的结果表明，在储存14天之前，GTP酸奶的稠度系数与对照样品不同。总之，GTP和GCP在凝固型酸奶的酸化凝胶网络中的行为不同，因其多酚的含量和浓度不同，从而改变了酸奶的流变学行为。
