Kecepatan Pertumbuhan Spesifik Bakteri Asam Laktat dengan Ekstrak Kacang Merah (Phaseolus vulgaris L.) sebagai Studi Awal Produksi Flavored Yogurt

Abstract

ABSTRACT. Bakteri asam laktat merupakan bakteri yang memfermentasi bahan pangan melalui fermentasi karbohidrat menghasilkan sejumlah besar asam laktat. Penelitian ini bertujuan untuk mengetahui kecepatan pertumbuhan spesifik dari bakteri asam laktat (Streptococcus thermophilus FNCC 0040 (ST), Lactobacillus bulgaricus FNCC 0041 (LB), Lactobacillus acidophilus FNCC 0051 (LA), Lactobacillus casei ALG.2.12 (LC ALG 2.12), Bifidobacterium ATCC 12746 (BF) sebagai studi awal pembuatan flavored yogurt. Dari hasil pengujian, diperoleh penambahan ekstrak kacang merah meningkatkan kecepatan pertumbuhan spesifik isolat bakteri asam laktat dan menurunkan pH medium sehingga, penggunaan ekstrak kacang merah dapat digunakan sebagai prebiotik yang dapat meningkatkan pertumbuhan bakteri asam laktat. Kecepatan pertumbuhan spesifik paling tinggi adalah isolat Bifidobacterium dalam medium MRS Broth dengan ekstrak kacang merah.  (Specific growth rate of lactic acid bacteria with red bean extract (Phaseolus vulgaris L.) as a preliminary study of flavored yogurt production) ABSTRAK. Lactic acid bacteria are group of bacteria which ferment food carbohydrates and produce lactic acid as the main product of fermentation. This study aimed to determine the specific growth rate of lactic acid bacteria (Streptococcus thermophilus FNCC 0040 (ST), Lactobacillus bulgaricus FNCC 0041 (LB), Lactobacillus acidophilus FNCC 0051 (LA), Lactobacillus casei ALG.2.12 (LC ALG 2.12), Bifidobacterium ATCC 12746 (BF) as a preliminary study for the production of flavored yogurt. In this study, lactic acid bacteria was culture in two different medium, deMan Rogosa Sharpe (MRS) Broth and deMan Rogosa Sharpe (MRS) Broth with red bean extract. Optical density, lactic acid biomass and pH was measured during fermentation processed. The results showed that the addition of red bean extract increased the specific growth rate of lactic acid bacterial isolates and lowering the pH of the medium so that the use of red bean extract can be used as a prebiotic which can increase the growth of lactic acid bacteria. The highest specific growth rate was Bifidobacterium in MRS Broth medium with red bean extract.