Evaluation of Physicochemical, Nutritional and Sensory Properties of the Wet Tarhana

The wet tarhana is a fermented product that prepared with wheat flour, yogurt, tarhana herb (Echiophora sibthorpiana)  and some chopped vegetables and spices. The basic difference of wet tarhana from other tarhana types is that it is prepared without a drying step. During its spontaneous fermentation process about 10 days, yogurt bacteria (Streptococcus thermophilus and Lactobacillus bulgaricus) produce several organic acids such as lactic acid and some other organic compounds. The ingredients and long fermentation process gain characteristic flavor and unique taste to the tarhana. Tarhana is similar to sourdough due to its' long spontaneous fermentation time. The aim of the study was to investigate physicochemical, nutritional and microbiological properties of wet tarhana, and to evaluate the relationships between them. For this purpose, wet tarhana samples were collected from different districts, and some physicochemical properties (pH, total acidity, dry matter, fat, and soluble ash content), antioxidant activity, phytic acid content, bioavailability, viscosity and counts of microbiota were performed. The results showed that the level of mineral digestibility was ranged from 67.22% to 88.88%, and a negative correlation was determined between mineral bioavailability and phytic acid content. The vitality of the microbiota especially lactic acid bacteria maintained during the storage period. Moreover, tarhana soups were prepared with the samples and their viscosity and sensory assessment were performed. Although the wet tarhana and soup samples had different viscosities initially, all the samples indicated pseudoplastic flow behavior. Furthermore, it was determined that the physicochemical properties of the samples affected the preference of the panelists in terms of sensorial assessment. Keywords: tarhana, fermented products, bioavailability, viscosity DOI: 10.7176/FSQM/83-0

Characterızatıon Of Mıcrobıota Isolated From Whıte Cheese And Mılk Processıng Facılıty

In this study, it was aimed to determine the microbiota of industrially produced white cheese, dairy products that occur during production and equipment using in production by culturomics based on Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) and shotgun metagenomic sequencing methods and evaluate the results in terms of lactic acid bacteria. In this line, dairy samples from raw milk to final product (raw milk, starter culture added milk, clot, curd, white cheese) and equipment surface samples using in production (raw milk truck, cheese vessel, stirrer, cutting wire, cheesecloth) are collected from a small-scale dairy plant. 109 isolates identified at species level belonging to Lactococcus lactis, Lactobacillus delbrueckii, Lactobacillus crispatus, Lactobacillus fermentum, Lactobacillus paracasei, Lactobacillus brevis, Streptococcus thermophilus, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans and Pediococcus pentosaceus and 9 isolates identified as Enterococcus at genus level by MALDI-TOF MS. 4 of the isolates couldn’t be identified by MALDI-TOF MS and resulted Enterococcus faecium, Lactococcus lactis, Enterococcus gallinarum ve Enterococcus gallinarum/Enterococcus casseliflavus as “The closest strain found by database if there is no identification”. These isolates have the potential to be new species. Microbial profile of dairy samples and equipment surface samples determined by shotgun metagenomic sequencing differed. Firmicutes was found as the dominant phylum (ranging from 63% to 70%) in the dairy samples while Proteobacteria was found as the dominant phylum (ranging from 84% to 89%) in the equipment surface samples. Firmicutes was found in the equipment surface samples by 5-14%. Lactococcus was the most abundant lactic acid bacteria genus for all samples. Among all bacterial species, the dominant species in dairy samples was Stapylococcus aureus (ranging from 21% to 37%). This followed by Streptococcus, Enterococcus, Leuconostoc, Weisella, Lactobacillus and Pediococcus genera respectively. Lactococcus lactis was the dominant species. The biodiversity obtained by metagenomics was much higher than the biodiversity obtained by culturomics. 11 species of Lactococcus genus, 46 species of Enterococcus genus, 54 species of Lactobacillus genus, 64 species of Streptococcus genus and 2 species of Pediococcus genus were determined by metagenomics while 1 species of Lactococcus genus, 3 species of Enterococcus genus, 6 species of Lactobacillus genus, 1 species of Streptococcus genus and 1 species of Pediococcus genus were determined by MALDI-TOF MS. In the continuation of this study, it is planned to examine the potential of bacteria isolated from samples to be starter culture and obtain a white cheese starter culture. In addition, the potential of being a new lactic acid bacteria species will be examined with whole genome sequencing analyzes of 4 isolates that couldn’t be identified by MALDI-TOF MS.Bu çalışmada, endüstriyel olarak üretilen beyaz peynirin, üretim süresince meydana gelen süt ürünlerinin ve üretimde kullanılan işletme ekipmanının mikrobiyotasının Matriks Destekli Lazer Desorpsiyon İyonizasyon- Uçuş Zamanı Kütle Spektrometrisi (MALDI-TOF MS, Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry) analizine dayalı kültüromik ve shotgun metagenomik dizileme yöntemleriyle belirlenmesi ve sonuçların laktik asit bakterileri açısından değerlendirilmesi amaçlanmıştır. Bu doğrultuda, küçük ölçekli bir süt işletmesinde gerçekleşen beyaz peynir üretimi süresince çiğ sütten itibaren son ürüne kadar çeşitli aşamalarda süt ürünü örnekleri (çiğ süt, starter kültür eklendikten sonra süt, pıhtı, teleme ve beyaz peynir) alınmıştır. Bunun yanında üretimde kullanılan ekipman yüzeylerinden (tanker, tekne, karıştırıcı, kesme teli, cendere bezi) örnekler alınmıştır. Örneklerden elde edilen izolatlardan MALDI-TOF MS analizi ile Lactococcus lactis, Lactobacillus delbrueckii, Lactobacillus crispatus, Lactobacillus fermentum, Lactobacillus paracasei, Lactobacillus brevis, Streptococcus thermophilus, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans ve Pediococcus pentosaceus türlerine ait 109 adet laktik asit bakterisi tür düzeyinde tanımlanmıştır. İzolatlardan 9 adedi cins düzeyinde tanımlanmış olup Enterococcus olarak belirlenmiştir. İzolatlardan 4 adedi MALDI-TOF MS ile tanımlanamamış olup “Tanımlama olmadığında veri tabanına göre bulunan en yakın suş” tanımı ile Enterococcus faecium, Lactococcus lactis, Enterococcus gallinarum ve Enterococcus gallinarum/Enterococcus casseliflavus olarak sonuçlanmıştır. Shotgun metagenomik dizileme ile belirlenen süt ürünü ve ekipman yüzey örneklerinin mikrobiyel profilleri farklılık göstermiştir. Süt ürünü örneklerinde en yoğun bulunan filum Firmicutes (%63-70 arasında değişen oranlarda) iken, ekipman yüzey örneklerinde Proteobacteria (%84-89 arasında değişen oranlarda) en yoğun bulunan filum olmuştur. Ekipman yüzey örneklerinde Firmicutes filumu %5-14 oranında tespit edilmiştir. Örneklerde laktik asit bakterileri içinde en yoğun bulunan cins Lactococcus olmuştur. Bunu Streptococcus, Enterococcus, Leuconostoc, Weisella, Lactobacillus ve Pediococcus takip etmektedir. En yoğun bulunan laktik asit bakterisi türü ise Lactococcus lactis’tir. Tüm bakteri türleri arasında süt ürünü örneklerinde baskın tür Stapylococcus aureus (%21-37 arasında değişen oranlarda) olmuştur. İki yöntem birbiriyle karşılaştırıldığında, metagenomik analizlerle elde edilen biyoçeşitlilik kültüromik ile elde edilen biyoçeşitlilikten çok daha yüksektir. Metagenomik yöntemler ile örneklerde Lactococcus cinsine ait 11 tür, Streptococcus cinsine ait 64 tür Enterococcus cinsine ait 46 tür, Lactobacillus cinsine ait 54 tür ve Pediococcus cinsine ait 2 tür tanımlanmıştır. MALDI-TOF MS ile ise Lactococcus cinsine ait 1 tür, Enterococcus cinsine ait 4 tür, Lactobacillus cinsine ait 5 tür, Streptococcus cinsine ait 1 tür ve Pediococcus cinsine ait 1 tür tanımlanmıştır. Bu çalışmanın devamında örneklerden izole edilip tanımlanan bakterilerin starter kültür olma potansiyelleri incelenerek bir beyaz peynir starter kültürü elde edilmesi planlanmaktadır. Ayrıca MALDI-TOF MS ile tanımlanamayan 4 izolatın tüm genom dizileme analizleri ile yeni laktik asit bakterisi türü olma potansiyelleri incelenecektir