Fermented foods, which are widely consumed around the world, are of great importance for human health. Standard production should be carried out in order to extend the shelf life of fermented products and increase their positive effects on human health. Therefore, there is a need for starter cultures that can be used in the production of fermented products. In this study, antifungal activity on 9 yeast isolates, antibiotic resistance, growth at different temperatures, pH and salt concentrations, arginine hydrolysis and gas production from glucose of 5 lactic acid bacteria (Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus paracasei, Pediococcus parvulus, Leuconostoc holzapfel) were investigated. The lactic acid bacteria have antifungal effects on all yeasts except Hanseniaspora opuntiae, Kazachstania exigua and Pichia fermentans, and they grow at 10 and 25 o C, 3.9 and 5 pH and 4% salt concentration. In addition, all of the isolates showed resistance to vancomycin. The results indicated that L. brevis, L. plantarum, L. paracasei strains can be used as starter cultures in term of standart pickle production and antifungal effect.

Fermented products such as yoghurt, pickles, and kefir are considered as sources of probiotic microorganism. However, it is known that bacteria specific to yoghurt are weak in terms of probiotic properties. For this reason, it is important to develop probiotic starter cultures that can be used in yoghurt production. In this study, genotypic identification and probiotic and technological properties of 198 isolates from 50 yoghurt samples were investigated. It was determined that 104 isolates were Lactobacillus delbrueckii subsp. bulgaricus and 94 were Streptococcus thermophilus. It was found that 20 of the 198 isolates were probiotic candidate. It was determined that none of the candidate probiotic isolates hydrolyzed arginine except L29 and produced gas from glucose. Nine of these had the exopolysaccharide production gene. It was determined that the highest acid‐producing isolates were S58 and L11. In addition, it was determined that all isolates grew at 45°C and 5.0 pH. Novelty impact statement Yoghurt is one of the most important fermented products, which is a cultural heritage. For this reason, it is vital to determine the starter and probiotic properties of isolates from yoghurt and bring them into production. This study is one of the comprehensive studies that includes isolation from yoghurt and examining the technological and probiotic properties of isolated bacteria. It is important to reveal these characteristics of isolates in terms of technology and public health.

Beslenme ile sağlıklı yaşam arasındaki ilişki çok uzun zamandır bilinmektedir. Bu ilişkinin temelini oluşturan beslenme genomiği alanı son yıllarda oldukça fazla dikkat çekmektedir. Genomik, proteomik, transkriptomik, metabolomik, epigenomik gibi “omik” teknolojileri ile yakından ilişkili olan beslenme genomiği, gıda bileşenlerinin gen ekspresyonunda oluşturabilecekleri değişiklikleri ve insan vücudunun bu gıda bileşenlerine verebileceği yanıtları incelemektedir. Gıdalar, özellikle DNA metilasyonu, histon modifikasyonları ve kodlamayan RNA gibi mekanizmalarla doğrudan genomun işleyişini etkilemektedirler. Bunların yanında, çölyak, nörodejeneratif rahatsızlıklar, obezite, diyabet, laktoz intolerans, fenilketonüri ve kanser gibi hastalıklar da dolaylı olarak beslenme ile yakından ilişkilidir. Beslenme genomiği alanı gelişim aşamasında olduğundan dolayı, beslenme-sağlık mekanizmasının tam olarak ortaya konulabilmesi için daha fazla çalışmaya ihtiyaç duyulmaktadır.

In the study, some physicochemical, viscosity, rheological properties, benzoic and sorbic acid contents of a total of 96 yoghurt samples (consisting of homemade, local and national) collected from different provinces of Turkey were investigated. It was determined that national yoghurt samples had the highest average dry matter (13.8%) and the lowest syneresis values (35.8%). Homemade yoghurts had the lowest average viscosity (at 20 rpm, 4079 cP; 50 rpm, 2142 cP), consistency coefficient values (44.4). It was determined that the flow behavior index values of all yoghurt samples were between 0 and 1 and showed pseudoplastic behavior. It was found that the national commercial yoghurt samples were higher than the homemade and regional samples in terms of dry matter, syneresis, viscosity and consistency coefficient. Although the mean benzoic acid values were detected between 5.43 and 31.9 mg kg−1, sorbic acid was found in only one sample (local brand yoghurt sample).

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