Pengaruh fermentasi dan pemanasan terhadap kemampuan pengikatan kolesterol bakteri asam laktat serta profil protein susu fermentasi

WIDJAJA, Andhi, Dr.Ir. Eni Harmayani, M.Sc

2005 | Tesis | S2 Ilmu dan Teknologi Pangan

Produk susu fermentasi berpotensi mempunyai beberapa efek positif terhadap kesehatan, antara lain menurunkan kolesterol dan tekanan darah. Efek tersebut diduga disebabkan oleh sel atau metabolit-metabolit hasil pemecahan protein susu akibat fermentasi. Penelitian ini bertujuan mempelajari karakteristik perubahan total BAL, pH, kemampuan pengikatan kolesterol, profil protein dan asam amino pada susu fermentasi dengan dan tanpa pemanasan. Dalam penelitian ini digunakan kultur bakteri Lactobacillus sp.Dad 13 (LD13), Lactobacillus bulgaricus FNCC 0041 (Lb) dan Streptococcus thermophillus FNCC 040 (St) sebagai starter untuk menghasilkan susu fermentasi. Fermentasi dilakukan selama 24 jam dengan suhu inkubasi 37 oC. Selama fermentasi dilakukan pengujian total bakteri asam laktat, pH, protein terlarut, kadar asam amino, kemampuan pengikatan kolesterol dan pengujian profil protein susu fermentasi pada jam ke- 0, 6, 12, 18 dan 24 dengan dan tanpa pemanasan (sterilisasi dan pasteurisasi). Hasil pengamatan menunjukkan jumlah bakteri meningkat selama fermentasi sebesar 2-4 siklus log dengan penurunan pH sebesar 2,9-3,13 dari ph awal susu 6,8 menjadi 3,73 tergantung jenis bakteri. Proses sterilisasi meningkatkan pengikatan kolesterol susu fermentasi secara in vitro. Asam amino ketogenik turun selama fermentasi dan setelah pemanasan. Fermentasi dan pemanasan meningkatkan jumlah fraksi protein sebesar 2-3 fraksi.

Fermented milk products have been studied and reported to have positive effects related to health such as reducing cholesterol level and blood pressure. These effects caused by viable cells, their metabolites or protein fraction resulted from milk fermentation. This research aimed to study the characteristic of fermented milk (total latic acid bacteria[LAB], pH, cholesterol binding, protein profiles and amino acids) during fermentation using latic acid bacteria before and after heating. In this research Lactobacillus sp.Dad 13 (LD13), Lactobacillus bulgaricus FNCC 0041 (Lb) and Streptococcus thermophillus FNCC 040 (St) were used as starters. Protein profiles during fermentation were analyzed at 0, 6, 12, 18 and 24 hour of incubation at 37°C. Analyses were conducted on heated (pasteurisation and sterilization) and unheated fermented milks. The result indicated that the total LAB of fermented milk increased 2-4 log cycle during fermentation LAB, pH value decreased (2,91-3,13) from 6,8 to 3,73 depend to bacterial strain. The highest capability on binding cholesterol occurred in sterilized milk using Lactobacillus bulgaricus. The ketogenic amino acids (leucine and lysine) decreased during fermentation and after heating. Fermentation and heating increased 2-3 protein fraction.

Kata Kunci : Pengolahan Pangan,Susu Fermentasi,Profil Protein,Kolesterol, protein profiles, fermentation, cholesterol