The exopolysaccharide obtained through water- based and MRS media- based fermentation was dried, weighed and stored at 4^oC for further analysis.

The results showed an exopolysaccharide content of 14.5, 13.5 and 4.5 g/L in water based fermented tamarind seed samples with Lactobacillus plantarum, Lactobacillus plantarum S1 and Lactobacillus helveticus respectively (Figure 2 and Table 1). Of the three strains used, highest exopolysaccharide content was found in Lactobacillus plantarum. Kumar et al., (2011) 7 reported that the polysaccharide from tamarind seeds were purified using water and precipitated with acetone. The percentage yield of polysaccharide was shown to be 78. The results of MRS media- based fermentation of Tamarindus indica seeds for exopolysaccharide production is shown in Figure 3 and Table 1. The results indicated an exopolysaccharide content of 4.5, 5.0 and 12.0 g/L in case of Lactobacillus plantarum, Lactobacillus plantarum S1 and Lactobacillus helveticus respectively where the highest EPS content was in Lactobacillus helveticus. Kim and Yun (2005) 8 reported a comparative study on the production of EPS by using two entomopathogenic fungal strains. The maximum concentration of EPS produced in optimal media (MY) was 20.94 g/l.

Figure 3

The results of water and MRS- based fermented defatted samples are shown in Table 2 & Figure 4. The result showed a highest exopolysaccharide content in Lactobacillus plantarum S1 (4.0 g/l). Followed by this, the other two strains showed same level of exopolysaccharide content (2.6 g/l). The lower level of exopolysaccharide in defatted samples may be due to the involvement of lipids in its synthesis. The exopolysaccharide content was significantly higher with defatted Tamarindus indica seed powder as substrate for fermentation using the three test organisms when compared to water- based medium. The results showed were 0.71 g/l in Lactobacillus plantarum and 0.68 g/l in both Lactobacillus plantarum S1 and Lactobacillus helveticus respectively. Balasubramanian et al., (2018) reported the optimization study to enhance the production of exopolysaccharide from Aspergillus sp., with central composite designs and showed a maximum yield of 22.2 mg/g.

Figure 4

An earlier study reported on the production of EPS by using Lactobacillus paracasei strain from kefir grains. The amount of EPS produced by strains of L. paracasei CIDCA 83124 was 1170, 527 and 373 µg with 1×10⁸ CFU at 20, 30, and 37°C respectively. Another strain, Lactobacillus paracasei CIDCA 83123, exhibited lower exopolysaccharide (EPS) production, showing similar behavior to CIDCA 83124. EPS yields of 390 µg, 309 µg, and 270 µg were observed at 20°C, 30°C, and 37°C, respectively, when cultured at a concentration of 1×10⁸ CFU/mL. This trend highlights a characteristic feature of mesophilic EPS-producing lactic acid bacteria (LAB), where EPS production tends to increase at lower temperatures 9, 10.

The results of EPS content in raw and defatted water based Tamarindus indica seeds fermented with and without inoculum is shown in Table 3. The results indicated that fermentation with inoculum had 10 and 3- fold higher yield of EPS when compared to fermentation without inoculum in defatted and raw tamarind seed sample. This shows the importance of using probiotic strains in the production of exopolysaccharides. The amount of EPS produced by Lactobacillus plantarum and Lactobacillus helveticus was 23 and 38% respectively, using both defatted and raw tamarind seed powder in Media based fermentation. Lactobacillus plantarum showed 34 and 39% more production of EPS in both tamarind seed powder through water based fermentation.