(17Z)-icosenoic acid

Abstract

Țaga cheese is a traditional Romanian smear-ripened cheese made from bovine milk and identified with the name of the village and caves where it is produced. As no previously reported microbiological and chemical studies have been undertaken on this product, this research aimed to investigate the microbiological and biochemical characteristics which ensure the uniqueness of Țaga cheese during the ripening process, to inform producers as to key quality determinants. Cheese samples, consisting of retail blocks, were collected on days 2, 5, 12, 18, and 25 of the ripening process. The evolution of lactic microbiota during the production and maturation of traditional cheeses involves isolating lactic acid microorganisms present in cheese. Cheese samples were analyzed for pH, fat, NaCl, fatty acids, and volatile compounds. The microbial ecosystem naturally changes during the maturation process, leading to variation in the microorganisms involved during ripening. Our results show that specific bacteria were identified in high levels during the entire ripening process and may be responsible for milk fat lipolysis contributing directly to cheese flavor by imparting detailed fatty acid flavor notes, or indirectly as precursors formation of other flavor compounds.

Introduction

Țaga cheese, also known as Năsal cheese, is a raw milk cheese named after one of the villages in the Transilvania region of Romania. It is an acid-curd cheese with a creamy texture, exhibiting a very strong pungent flavor with a slightly spicy taste []. Currently, it is produced from cow's milk by the Someș Arieș Agricultural Cooperative and it is certified as a traditional Romanian product. Approximately 51100 kg of Țaga cheese is produced annually. Locally, this cheese is considered unique because its maturation takes place in a special microbiological environment from the natural cave from Țaga. The caves' conditions are typical temperatures of 14–15°C and an air relative humidity of 90–95%, mostly constant throughout the year. These conditions could potentially favor the development of a specific selection of bacteria, such as Brevibacterium linens during the ripening process which may be responsible for the transformation of the cheese into a highly appreciated specialty by the costumers.

Introduction

Maturation takes 25–30 days, and during this period, the cheeses are turned over daily during the first week, and subsequently every 2–3 days. The cheeses are washed with brine at these times, with a concentration of 10% (w/v). During this time, the surface coloration develops with characteristic surface bacteria. Once the maturation process is completed, the cheeses are again washed, then left to dry. Then the cheese surface is dusted with starch powder, and it is packed in parchment paper. The amount of Țaga cheese that is produced daily is approximatively 140 kg.

Sampling

For this study, Țaga cheese samples were collected directly from the manufacturer, Someș Arieș Agricultural Co-operative, andsampling was undertaken 2, 5, 12, 18, and 25 days after cheese production initiation. Each sample set consisted of three 'bricks' of cheese (each approximately 300 g) taken from one day's cheese production, i.e., from a single batch of milk and the same vat. The three samples were collected in individual sterile plastic bags, deposited in the laboratory's refrigerator at 4°C and collected on the same day for shipment to the analytical laboratory under chilled conditions. Analyses were initiated on the day of sampling. Each set of three samples were subjected to all analyses; hence they were all undertaken in triplicate.