The Effect of the Use of Berry Fruit Powder on the Sensory Characteristics and Antioxidant Activity under in vitro Gastrointestinal Digestion Conditions of Probiotic Yoghurt
Project no. 312 · Status: Kapanmış · 2015
Summary
The aim of this research was to evaluate the effect of the addition of different berry fruits (raspberry, cranberry and blueberry) at a ratio of 2% on chemical and sensory properties and phenolic content and antioxidant activity under in vitro gastrointestinal digestion of probiotic yoghurt containing Bifidobacterium animalis subsp. lactis. The highest pH values were detected in control yoghurt whereas the lowest values were determined in yoghurt added with cranberry powder throughout the storage period. There were no significant differences among the appearance and texture properties of probiotic yoghurts during the storage period. There were no significant differences among the total acceptability scores of the samples on the 1st and 14th days whereas the least preferred sample was the yoghurt with cranberry powder and the most preferred sample was the yoghurt added with raspberry powder on 28th day. The highest total phenolic content was determined in yoghurt with blueberry powder while the lowest values were detected in control yoghurt throughout the storage period. The total phenolic content significantly decreased under in vitro gastric phase conditions in the samples except the yoghurt added with blueberry powder. The related values of all yoghurts also significantly reduced through the intestinal phase. The phenolic contents of the yoghurts added with raspberry and blueberry powder in dialysed fraction were found to be lower than those of in duodenal fraction. The highest DPPH scavenging activity was determined in control sample whereas the lowest values were detected in blueberry powder added probiotic yoghurt during the storage period. The DPPH scavenging activities of all samples significantly decreased under gastric and intestinal phase conditions during 28 days of storage. The probiotic yoghurt added with blueberry powder showed the highest DPPH scavenging activity in the gastric phase. The highest DPPH scavenging activity in the dialysed fraction was observed in the yoghurt with blueberry powder at the end of the storage period.