Livanjski cheese belongs to the group of hard cheeses which is traditionally produced in Livno (Bosnia and Herzegovina). Proteolytic changes during the ripening of Livanjski cheese have not been investigated extensively. The aim of this paper was to determine its proteolytic changes during the different stages of ripening. Five Livanjski cheeses (from raw cow’s or a mixture of sheep’s and cow’s milk) were observed during the ripening to evaluate its typical proteolytic profile. An electophoretic profile of Livanjski cheese was determined by Urea-polyacrylamide gel electrophoresis (urea-PAGE) and a densitometric evaluation of the urea-PAGE gels was performed using a densitometer. The water-soluble nitrogen fraction in the total nitrogen (WSN %TN) and the 12%-TCA-soluble nitrogen fraction in the total nitrogen (TCA-SN %TN) of the cheese were determined using the Kjeldahl method. Degradation of αs1-casein by chymosin caused a significant decrease (P < 0.05) of relative content of this protein in Livanjski cheese at the sixth week point of ripening. Due to the activity of chymosin on αs1-casein, αs1-I-casein and αs1-II-casein developed, which caused a significant increase (P < 0.05) of Index alpha. The relative ratio of β-casein significantly decreased (P < 0.05) during ripening leading to a significant accumulation (P < 0.05) of degraded product (sum γ1-casein, γ2-casein and γ3-casein). These proteolytic changes caused a significant increase (P < 0.05) of Index betta. Accumulation of medium, small peptides and amino acids caused a significant (P < 0.05) increase of the relative content of WSN %TN and TCA-SN %TN. In general, proteolysis of Livanjski cheese during ripening was moderate probably due to the low moisture content and low water activity, although it was produced from raw milk. Taking into account that the ratio β-casein : αs1-casein at the end of ripening was 1.46, it could be concluded that degradation of αs1-casein could be the indicator of the maturity of Livanjski cheese. Due to that Livanjski cheese could be classified as “α-type of ripening” cheese.
The aim of this study was to investigate consumers’ preferences of Livanjski cheese depending on the type of milk (cow’s milk or a mixture of sheep’s and cow’s milk) and the originality of production (farm or industrially produced). Also correlations between sensorial scores and the composition of Livanjski cheese were determined. Sixty day old Livanjski cheese samples produced on four family farms and under industrial conditions produced cheese were used for sensory evaluation. During the cheese sampling every producer was visited regularly (every two weeks) to evaluate the ripening conditions of the cheeses (temperature, relative air humidity and ventilation). Sensory evaluation was performed by 160 consumers and 6 experts. Cheese from farm 1 received the highest scores (P<0.05) in general and for every single attribute as well. The production of Livanjski cheese on farm 1 was distinct due to mixing sheep’s and cow’s milk (70:30 %) and due to good controlled ripening conditions (15-18 °C, relative air humidity 80-90 %, regular air ventilation). Sheep’s milk was an important factor for the higher scoring of Livanjski cheese. In opposite to the consumers’ preference, experts evaluated industrially produced Livanjski cheese with the highest score. Significantly high and negative correlations (P<0.05) between total solids of cheese and scores for taste and odour judged by experts were obtained. Moreover, significantly higher and negative correlations (P<0.05) between the total solids of cheese and all sensorial attributes were obtained by consumers. On the contrary, preserving factors i.e. higher salt content and acidity positively influenced the sensory attributes of Livanjski cheese.
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