STUDY OF CHEMICAL, MICROBIAL AND SENSORY EVALUATION OF LOCAL AND LABORATORY PESTA(AUSHARY) CHEESE

Abstract

The objective of this study to manufacture a developed and healthy laboratory Pesta cheese through different treatments which include the integration of the following common types of probiotic starters: Lactobacilus acidophilus , Leuconostic dextranicum and Bifidobacterium animalis sub.sp.Lacti (probio-Tec Bb-12) , in addition to starter from the local tradition Pesta cheese in Kurdistan regional, which is prepared in the laboratory .Also to know the best type or mixture of the types of the above starters through the study of the chemical, microbiological and organoleptic characteristics of the cheeses that made by such starters through different periods of ripening up to 16 weeks .The starters percentages were added by 2% of the milk. The treatments were include : the control treatment which is represent the local tradition Pesta cheese ,and six other treatments which include, different mixture of the three types of starter and the starter of local tradition pest cheese . The chemical, microbiological tests and the organoleptic characteristics were determined through the ripening period (1, 8, 16 weeks). The study also, covered the effects of different percentages of the emulsifier compounds (Tri sodium citrate). The results showed that there are significant differences (0.01 P) in the chemical characteristics of the laboratory and local tradition Pesta cheese between the starter types and the ripening period's treatments. The results showed also, there were significant differences at (0.01) P for the organoleptic tests between the traditional local Pesta cheese and other cheese treatments. As well as ,there were significant differences at (0.01 ) P for the correlation between bacterial starter type and the period of ripening on the the organoleptic characteristics of the Pesta cheese .The fifth treatment (T5), showed the highest degree of acceptance ( 82.67 %) and the Sixth treatment (T6) have the lowest degree of acceptance ( 26.33 %) at the end of the ripening period (16 weeks ). The microbiological results showed that numbers of L.acidophilus were decreased in the (T1 & T5 )treatments ,but the numbers of the (T3) treatments dose not affected that much, and the number of the three treatments are(21105 X ,8106 X, 68104 X ) Cfu/ g respectively after 16 weeks, the numbers of the Bif.lactis also have similar decrease after ripening ,and the numbers of the ( T2 ,T3 & T5 )treatments were(88 104X ,3106 X ,63104 X ) respectively. Leu. decxtranicum bacteria , have similar trend in their numbers, and have( 92104 X ,55 X 104 ,18104 X,98103 X) cfu/g for the Treatments of (T1 ,T2 ,T3 , & T5) respectively .The content of the traditional local Pesta and laboratory cheeses of Coliform bacteria and Staphylococcus aureus were less than 10 cfu/g for both bacteria which are with in the permissible numbers .However, the highest numbers of fungi were found for the treatments ( T4 and the control )( 53.0 x310 and 3.0 x310) respectively , and still under the permissible numbers

Keywords

Study, Chemical, Sensory