Novel frozen yogurt production fortified with sea buckthorn berries and probiotics

The objective of the present study was to produce a novel frozen yogurt fortified with sea buckthorn berries supported probiotic cells. Berries originated from Hippophae rhantnoides L. were used as immobilization carrier of the probiotic strain Lactobacillus casei ATCC393. A commercial yogurt culture was used as starter culture while free and immobilized probiotic cells were added as adjuncts for frozen yogurt production. The viability of the immobilized probiotic cells was maintained in high levels during 90 storage days (-18 degrees C), while the viability of free probiotic cells decreased (similar to 10%). L. bulgaricus counts reduced by approximately 3 log cycles and no counts of S. thermophilus were detected by the end of freezing storage. Gastrointestinal simulation showed that cell immobilization offer protection to probiotic cells against the harsh environmental conditions of the gastrointestinal tract and help in maintaining the minimum viable cell counts required to offer health benefits to the consumers (> 10(7) CFU g(-1)). Finally, frozen yogurt with the immobilized biocatalyst showed superior properties, exceptional appearance and an enhanced citrus aroma as described by the assessors.