Résumé
This study aimed to improve the properties of white soft cheese made from goats' milk by adding spice essential oils at concentrations of 75 and 90 ppm cardamom, 50 and 75 ppm thyme and 40 and 60 ppm clove to goats' milk. All resultant cheeses were compared aganist that made from buffalos' milk [control I] and goats' milk [control II]. The quality of resultant cheeses was evaluated for their chemical composition, microbiological and organoleptic properties during storage at 6 +/- 1°C for 45 days. The results revealed that additives at two concentrations of essential oils insignificantly affected percentages of moisture, salt/ moisture and fat/dry matter. Moisture% significantly decreased [P = 0.05] while fat and protein% increased during storage period at 6 +/- 1°C. Values of titratable acidity [TA], water soluble nitrogen/total nitrogen [WSN/TN], non protein nitrogen/total nitrogen [NPN/TN] and total volatile fatty acids [TVFA] for all treated cheeses were significantly lower than control II during pickling period. Increasing the proportion of spice essential oils had a marked effect on the same properties. The TA, WSN/TN, NPN/TN and TVFA in cheese samples increased, while the pH values decreased continuously during storage period [P = 0.05]. The hysteresis area, expressed as alpha dpH values, of control II was lower than goats' cheese samples treated by cardamom, thyme and clove essential oils during the pickling period. The rate of decrease in the hysteresis area of control II was higher than that of control I. Statistically, there were significant differences due to treatments, pickling period and the interaction between treatments and pickling period [P = 0.05]. Addition of spice essential oils decreased clearly counts of different tested microbial groups [total viable count, psychrophilic bacteria, yeasts and moulds and coliforms] throughout storage period as compared to control II and control I. Spice essential oils added improved the flavour and quality of white soft cheese made from goats' milk. Therefore, white soft cheese could be successfully made from goats' milk with adding cardamom, thyme or clove essential oils, especially clove or cardamom at concentrations of 40 and 75 ppm, respectively and with storage at 6 +/- 1°C for 45 days
Sujets)
Animaux , Lait , Huile essentielle , Elettaria , Eugénol , Thymus (plante) , Capra , EugeniaRésumé
Edam-like cheese was made from pasteurized standardized cows', goats' milk and their mixture [1:1]. The resultant cheeses were ripened for 90 days at 12 +/- 2°C and 85-90% relative humidity. Samples of cheeses were periodically analyzed, for chemical composition, ripening indices, acid - base titration, total biogenic amines and organoleptic properties. Yield of cows 'milk Edam cheese was slightly higher than goats' milk cheese or their mixture [1:1] milk cheese. Moisture content, titratable acidity and area of hysteresis loop were higher in cows' milk-cheese than that of goats' milk or mixed milk-cheeses, whereas; fat; salt content; fatty acid composition; total soluble and non protein nitrogen and total biogenic amines were lower. Organoleptic taste panel evaluation was the highest for cows' milk Edam-like cheese and the lowest for goats' milk cheese. The mixing of cows' milk with goats' milk [at the ratio of 1:1] improved the quality of the resultant cheese. Statistically, in all treatments no significant differences between 60 and 90 days of ripening period were found in the organoleptic properties, so the 60 days age is economically preferred