Investigating viability of starter bacteria in yogurt enriched with oil and flavonoid extracted from orange peel

Nowadays, it has been excised lots of tendency among people for using functional foods. Functional foods are kind of foods which have at least one defined and proven health benefits in addition to basic nutritional value. This study aims at producing flavored functional yogurt enriched with flavonoid and oil extracted from orange peel and also, assessing the viability of yogurt starter culture during 15-days of storage. This study was carried out in two stages: in the first stage; flavonoid and oil were extracted from orange peel, and secondly, flavored functional yogurt enriched with different percentages of extracted flavonoid (7, 8 and 9%) and oil (0, 0.5, 1 and 1.5%) from orange peel, was produced. The results showed that increasing the orange peel oil had a negative effect on the growth of yogurt starter culture, Streptococcustermophilus and Lactobacillus bulgaricus.