Impact of different starter cultures and Lactobacillus helveticus on volatile components, chemical and sensory properties of pasta filata cheese.

L.helveticus is known to follow mainly similar metabolic pathways to contribute to cheese flavor with S. thermophilus and L. delbrueckii subsp. bulgaricus. In this study, the flavor contributions of commercial S. thermophilus starter cultures of different brands and L. helveticus adjunct culture to pasta filata type fresh Kashar cheese were investigated. L. helveticus affected the buttery aroma components of fresh Kashar cheese and resulted in low diacetyl content. In addition, acetaldehyde and other aroma components of L. helveticus added cheese was found to be higher than control and modified control cheeses. On the other hand, the modified control sample containing S. thermophilus from Danisco instead of Chr-Hansen in the control was closer to the control sample in terms of volatile profile. As the shelf-life progressed, the contribution of alcohols and hydrocarbons to volatile components decreased, while the contribution of ketones, which was the dominant group, increased in all products. When the proteolysis and lipolysis levels were examined, the control sample differed from the other two cheese samples with its high proteolysis and lipolysis rate. In summary, the rates of increase in water-soluble nitrogen and free fatty acid contents in 8 weeks of storage (from 18 to 72 days) were determined as 61% and 47%, respectively, in the control Kashar cheese, while it was 39% and 27% in the L. helveticus added sample, and 37% and 28% in the modified control sample. Finally, the sensory scores revealed that cheese flavor and texture preferences could be increased with the addition of L. helveticus.