Physical Properties of Ripening by Lactococcus lactis inoculation and microstructural features with scanning electron microscope

ABSTRACT

Ratmawati Malaka, Fatma Maruddin, Syahriana Sabil Laboratory of Biotechnology of processing, Faculty of animal science, Hasanuddin University e-mail: [email protected]

Physical properties of dangke cheese can be improved by ripening process by 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 complete randomized design (RAL) 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. Microstrucure were observed by scanning electron microscope. The treatments were replicated three times each. The data were processed statistically with analysis of variance followed by the least significant difference test. The research 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 to perform 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 provides 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 molecules with other casein molecules and spread evenly in the three-dimensional network of molecules (casein micelles, fat and lactose).

Keywords: Carbohydrates; dangke; Lactococcus lactis; pH; protein; total lactic acid