Kefir Enriched with Carob (Ceratonia siliqua L.) Leaves Extract as a New Ingredient during a Gluten-Free Bread-Making Process

This work is focused on the preparation of an innovative gluten-free (GF) bread with remarkable softness and antioxidant features over time. To overcome the technological inconveniences related to the removal of gluten from bread, the kefir beverage fortified with antioxidant vegetable extracts is employed as a functional ingredient in the bread-making process. In this context, carob (Ceratonia siliqua L.) leaves represent an outstanding source of active molecules and are proposed to enrich milk-based beverages. Different extraction strategies were evaluated, and the process was improved to select a solvent (water, ethanol, or hydroalcoholic solution) and methodology (Soxhlet or ultrasound-assisted extraction) able to guarantee the best performances in terms of yield and antioxidant capacity. For kefir addition, two varieties of carob leaves (Selvatica and Amele) are employed. Functional GF bread, obtained by partially replacing the water with the enriched kefir, is prepared, and the final product is characterized in terms of its antioxidant and rheological properties. The final product shows improved compositional and technological parameters over time.

Microbiological and chemical properties of wet tarhana produced by different dairy products

This study investigated the use of kefir, yogurt and their combination in the production of wet tarhana with an aim to increase the nutritional value of the end product. Along with microbiological and chemical properties, the volatile compound composition of wet tarhana was also evaluated. Wet tarhana revealed an increase in the lactic acid bacteria count (LAB) with the addition of kefir. After fermentation, counts of total yeast, LAB, and total mesophilic aerobic bacteria were 7.57, 8.26 and 7.64 log CFU/g, respectively. The values of pH and titratable acidity were measured as 4.78 and 4.68% in terms of lactic acid, respectively, at the end of fermentation. Lactic acid content increased from 3.31 to 10.82 g/kg throughout fermentation. A total of 72 volatile compounds were recorded during fermentation and 44 of these were identified by GC-MS. The most abundant compounds identified in the tarhana samples were hexadecanoic acid and 9,12-octadecadienoic acid. Moreover, ABTS antioxidant activity results of all formulations were measured in the range of 15.86 and 19.31 µmol TE/g at the end of fermentation and it was independent of the fermentation period.