Chemical, microbiological and sensory characteristics of ‘Tsalafouti’ traditional Greek dairy product

Abstract

Tsalafouti is a traditional dairy product made from sheep’s milk at the end of the lactation period. It is mainly manufactured as a farmhouse product, in high altitude mountainous areas of Southern Pindos. It has a high moisture content, creamy texture and mildly sour flavour. Its production process included the addition of salt to the milk, heating of milk to 90oC with continuous stirring, cooling and transfer to containers placed in caves under running water (around 10oC) and daily stirring for 10 to 20 days until thickening of the milk without the aid of starter cultures (i.e., natural acidification) occurred. The present work presents the physicochemical, microbiological and sensorial characteristics throughout the ageing of artisanal Tsalafouti. The acid-curd product had a pH of about 4.3 and an approximate moisture content of 79%, fat 10%, fat in dry matter 45-48%, salt 0.4% and protein 7%. Proteolysis increased during ripening at 10oC for 20 days and storage at 4 oC for additional 70 days. Ethanol, 3-methyl-1-butanol, hexanal and heptanal were the most abundant volatile compounds. The indigenous microbiota was dominated by mesophilic lactic acid bacteria (LAB) whose numbers exceeded 8 Log CFU/g on day-10 of ripening. Enterococci also increased at an approximate level of 6.5 Log CFU/g, whereas thermophilic dairy lactobacilli were not found. Growth of aerobic spoilage yeasts and moulds was suppressed below 4.5 Log CFU/g for 45 to 60 days, but afterwards, yeasts and moulds outgrew on the product surface causing spoilage. Based on the microbiological results and primarily on sensory panel evaluations, Tsalafouti can have a shelf life of 45 days when stored aerobically under refrigeration.