E. Zubaidah et al./Agroindustrial Journal Vol. 3 Issue 1 (2014) 107-111 107 Comparative Study Production of Exopolysaccharide (EPS) by Lactic Acid Bacteria (L. casei and L. plantarum) in Different Media (Dates and Mulberry juice) Elok Zubaidah *,1 , Yusry Muqit Suryawira 2 and Ella Saparianti 1 1 Staff of Department of Food Science and Technology, Agricultural Technology Faculty 2 Alumni of Department of Food Science and Technology, Agricultural Technology Faculty Brawijaya University, Malang Indonesia. Email : elzoeba@yahoo.com * Abstract Exopolysaccharides (EPS) are polysaccharides that are secreted by some strains of bacteria. E PS contribute in health improvement where it has prebiotic properties, immunostimulatory, anti- tumoral, and hypocholesterolemic effects. A number of Lactic Acid Bacteria (LAB) has ability t o synthesise Exopolysaccharides (EPS). This study aimed to determine the ability LAB (L. casei and L. plantarum B2) to produce EPS in different media (dates and mulberry juice). L. casei sh owed higher EPS production (3413.33 mg/L) than L. plantarum (3316.67 mg / L) were grown in medium dates juices. Based on the type of media, EPS production in dates juice medium higher t han mulberry juice as medium, and there are differences production of EPS by both types of isol ates (L. casei and L. plantarum) in both media. The growth rate of LAB does not always show a positive correlation with EPS formation. Keywords: Dates juice, exopolysaccharide, LAB, mulberry juice 1. INTRODUCTION Exopolysaccharide (EPS) is a sugar or a polysaccharide polymer that is secreted by the microbes out of the cell. EPS produced by lactic acid bacteria (LAB) have generated increasing attention among researchers for the last few years (Pham et al., 2000). LAB is food-grade organisms, and the EPS that they produce contribute to the specific rheology and texture of fermented milk products. EPS have health effects as immunostimulant activity, antitumor, activation of macrophages and lymphocytes to increase their endurance, and as prebiotics (Tallon et al., 200 6). The amount of EPS produced by microbes influenced by several factors such as the composition of the medium (source of carbon and nitrogen) and incubation conditions (temperature, time and pH) (Tallon et al., 2006). EPS production produced depends on the species of the microorganism used. Many strains of Lactobacillus, including L. casei, has the ability to produce EPS, that are secreted into the environment (Lam and Lee, 2006). According to Tallon et al., (2006), L. plantarum is capable of producing EPS ranged from 126- 800 mg / L in milk medium. Mulberry juice as medium for L. plantarum B2 produce EPS higher than skim milk medium (Zubaidah and Maulida, 2007). Dates fruit contain compounds of high nutritional value, such as glucose and fructose 20-70% (dry weight), sucrose in the range 0-40%, as well as several other compounds such as niacin (2 mg), thiamin (Vitamin B1) (93 mg ), folic acid (5.4 mg), riboflavin (Vitamin B2) (144 mg). This study aimed to determine the ability of LAB (L. casei and L. plantarum B2) to produce EPS in different media (dates and mulberry juice ). 2. MATERIALS AND METHODS 2.1 Materials Semi-dry kind of dates (Egypt) obtained