Yusuf Tunçtürk

The effect of storage temperatures and packaging methods on properties of Motal cheese

The effects of storage temperature (+4 degrees C and -18 degrees C) and packaging method (nonvacuum and vacuum) on biogenic amines in Motal cheese during storage periods were investigated. In addition, dry matter, titratable acidity, total nitrogen, water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen, free amino group (proteolysis), electrophoretic patterns of casein, and amounts of lactic acid bacteria and coliforms were determined. Storage period had a significant effect on all of the biogenic amines. When compared with vacuum packaging, normal packaging had higher amounts of putrescine, cadaverine, histamine, and tyramine. Coliforms were not found at detectable levels (<100cfu/g) in all cheese samples. Results of urea-PAGE analysis of cheese samples were in good agreement with biogenic amine results and other proteolysis parameters.

The effect of different packaging methods on the formation of biogenic amines and organic acids in Kashar cheese.

The effects of packaging methods (nonvacuum and vacuum) on biogenic amines (cadaverine, putrescine, tyramine, tryptamine, phenylethylamine, and histamine) and organic acids (citric, lactic, formic, acetic, propionic, and butyric) during storage for 180 d at 4°C were investigated in Kashar cheese. Dry matter, titratable acidity, total nitrogen, water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen, free amino group (proteolysis), pH, fat, and acid degree value were also determined. Storage period had a significant effect on all of the biogenic amines. When compared with vacuum packaging, nonvacuum packaging resulted in no large differences among the amounts of biogenic amines. Vacuum-packaged cheeses had more lactic, formic, acetic, and butyric acids than did cheeses packaged without vacuum. Water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen, proteolysis, pH, and acid degree values of the cheese samples increased continuously until the end of the ripening in all the samples. No significant change was observed in total nitrogen, dry matter, or fat content within the ripening period, whereas titratable acidity values changed significantly in vacuum-packaged cheese and decreased slightly in the non-vacuum-packaged cheeses. The results of this study showed that storage period and packaging method had significant effects on the quality of Kashar cheese.

Effects of frozen storage and vacuum packaging on free fatty acid and volatile composition of Turkish Motal cheese

Effects of vacuum packaging and frozen storage were studied on the formation of free fatty acids (FFAs), volatile compounds and microbial counts of Motal cheese samples stored for a period of 180 days. The FFA concentration of Motal cheese samples increased throughout the storage period of 180 days. However, the FFA contents of samples stored at —18 °C showed considerably lower values than those of the samples stored at 4 °C. Palmitic (C16:0) and oleic (C18:1) acids were the most abundant FFAs in all the treatments. The volatile compounds detected by headspace solid-phase microextraction (HS-SPME) profile of Motal cheese consisted of 16 esters, 10 acids, 6 ketones, 4 alcohols, 3 aldehydes, styrene, p-cresol and m-cresol. Results showed that storage at —18 °C can limit the excessive volatile compound formation. Samples stored at 4°C with vacuum packaging showed comparatively high concentration of esters, ketones and alcohols. Samples stored without vacuum packaging at 4°C showed 2-nonanone as the most abundant volatile compound toward the end of storage period. Storage at 4°C under vacuum packaging decreased the mold—yeast counts of samples. Frozen storage could be a suitable method for storing the Motal cheese.

Changes in Volatile Compounds of Cheese

Abstract The volatile profile is quite important for the organoleptic quality of dairy products. The volatile composition of cheeses varies during ripening. The ripening process is carried out by the microflora and enzymes from different sources. There are numerous volatile flavor compounds involved in cheese aroma, which are derived mainly from four metabolic pathways: lactose, lipid, protein, and citrate metabolisms. The development of unique and well-appreciated flavor characteristics of each type of cheese is the result of these complex reactions. Various groups of volatiles have been identified as being important for the final taste and aroma of cheese. Such groups are fatty acids, esters, aldehydes, alcohols, ketones, hydrocarbons, and sulfur compounds. In this review, the factors affecting volatile formation and composition in cheese are discussed based on the information available in the literature.

Farklı Tür Sütlerinden Üretilen Van Otlu Peynirlerinde Olgunlaşma Boyunca Meydana Gelen Değişiklikler: II. Mikrobiyolojik Değişiklikler, Lipoliz ve Serbest Yağ Asitleri

Bu calismada, koyun, inek ve keci sutunun farkli oranlardaki karisimlarindan geleneksel ve endustriyel yontemlerle uretilen Otlu peynirlerin olgunlasma suresince mikrobiyolojik ozellikleri, lipoliz ve serbest yag asitlerindeki degisimleri arastirilmistir. Calismada, %100 koyun sutu (A), %50 koyun+%50 inek sutu (B) ve %50 koyun+ % 25 inek+% 25 keci sutu (C) karisimlarindan iki farkli yontemle Otlu peynir uretilmistir. Birinci yontemde, geleneksel uretim teknigine gore kultur katmadan, cig sut kullanilarak Otlu peynir uretilmistir. Ikinci yontemde ise (endustriyel), hem sut hem de kullanilan otlar pastorize edilip (65°C’de 30 dk.), starter kultur kullanilmistir. Uretilen peynirlerden depolamanin 2., 30., 60., 90. ve 180. gunlerinde ornek alinarak mikrobiyolojik, lipoliz ve serbest yag asitleri analizleri yapilmistir. Sonuclar, pastorize sut ile uretilen peynirlerin cig sutten uretilenlerden daha dusuk serbest yag asitleri icerigine sahip oldugunu gostermistir. Asetik, miristik, palmitik ve oleik asidin taze ve olgunlasmis orneklerde en cok bulunan organik asit ve serbest yag asitleri olduklari tespit edilmistir.