DBPapers
DOI: 10.5593/sgem2017/61/S25.098

INFLUENCE OF MILK HEAT TREATMENT AND SALTING METHODS ON COMPOSITION, PROTEOLYSIS AND VOLATILE PROFILE OF NASAL CHEESE

F. Radu, I. Popescu, D.G. Dumbrava, C. Moldovan, L. Rotariu
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 753-760 pp, DOI: 10.5593/sgem2017/61/S25.098

ABSTRACT

Nasal cheese is a smear ripened traditional Romanian cheese produced in a natural cave near Taga commune, Cluj County. The effect of varying heat treatments (65 or 80 °C for 20 and 5 minutes respectively) and salting methods (dry or brine salting) on bacterial viability and biochemical properties in Nasal cheese were investigated. Brevibacterium linens, a corynebacterium produce a characteristic "sulphur" aroma associated with such cheese. Therefore, this study also investigated the profile of volatile compounds, especially sulfur-containing ones, by B. linens, which are thought to be the main cause in respect to the flavor fingerprint of smear surface-ripened Nasal cheese. Physicochemical properties, proteolysis, and volatile profile data were obtained from 20 cheese samples (ripened for 30 days), made throughout May-June period of 2016 and provided by the cheese maker. A milk pasteurization temperature of 80°C resulted in reduced primary proteolysis and increased pH in comparison with that in cheese samples obtained from bovine milk pasteurized at 65°C for 20 minute. Samples were characterized by pH values varied between 5.23 to 5.51, moisture content (51.5 to 53.8%), and protein from (19.3 to 22.5%). Dry salting resulted in decreased of lactic acid bacteria, increased in free amino acids level compared with brine salted cheese samples. The main chemical groups of volatile profile were alcohols, organosulfur compounds (methanethiol, dimethyldisulfide, and 2, 3, 4 - trithiapentane) and thioesters (S-methylthioacetate) whereas aldehydes and ketones were found in trace amounts.

Keywords: Nasal cheese, biochemical properties, Brevibacterium linens, sulphur aroma