Effect of Lactococcus lactis inoculation on characteristics and microstructure of dangke cheese with different ripening temperature and incubation time

Abstract

Physical properties of Dangke cheese can be improved by the ripening process through starter culture inoculation. The purpose of this study was to analyze the characteristics of Dangke cheese with different temperature and incubation time of ripening as well as their interaction by Lactococcus lactis inoculation. The research method used was experimental using a completely randomized design (CRD) with 2 (two) factors. The first factor (A) is the ripening temperature (5, 15, and 25°C) and the second factor (B) is the Ripening time (6, 9, and 12 days). Dangke is made by adding a papaya sap solution as coagulation. Microstructure was observed by a scanning electron microscope. The treatments were replicated three times each process. The data were processed statistically with variance analysis, followed by the least significant difference test. The results indicated that the ripening temperature affected the activity of L. lactis in carbohydrate degradation to produce lactic acid so that it affected the hydrogen potential (pH) and the dangke protein content. Long time ripening provides an opportunity for L. lactis to continue performing activities resulting in a decrease in carbohydrate and pH levels, but there is an increase in total lactic acid and protein levels. The temperature and duration of ripening in dangke manufacture provide an interaction of carbohydrate and protein levels. The Ripening temperature used in the manufacture of Dangke cheese with the addition of L. lactis, preferably 5°C and the duration of 12 days of ripening. The microstructural features show that the duration of ripening causes the Dangke structure to be more compact, as indicated by the proximity of casein molecules with other casein molecules and fat spread evenly in the three-dimensional network of molecules.