Survivability of immobilized Lactobacillus plantarum cells within bacterial cellulose in mamao juice

This study was aimed to apply mature coconut water and mamao fruit residues as substrates for bacterial cellulose production via fermentation with Acetobacter xylinum TISTR 893. Selectedprobiotic strain identified as Lactobacillus plantarum was immobilized within suitable bacterial cellulose cubes. The survivals of free L. plantarum cells (control) and immobilized L. plantarumones within different bacterial cellulose cubes in mamao juice samples were determined on day 0, 4, 8, 12, 16, 20, 24 and 28 during storage at 4°C. It was found that mamao juice samples supplemented with free L. plantarum cells (control) had rapidly declined in numbers whereas the ones supplemented with immobilized L. plantarum cells had slowly declined during storage. Interestingly, it was found that after 28 days of storage, free L. plantarum cells in mamao juice samples were greatly decreased in numbers to 0.76 log CFU/ml while the immobilized L. plantarum ones within bacterial cellulose cubes from mature coconut water and mamao fruit residues were slowly decreased to 6.41 and 6.32 log CFU/ml respectively which were not significantly different (p>0.05). Moreover, total phenolic content, total anthocyanin content and antioxidant activity by DPPH assay of the mamao juice samples were significantly different between day 0 and 28 of storage period (p≤0.05). Sensory evaluation was eventuallyconducted by a panel of 30 untrained members on a 9 point hedonic scale. The results showed that all mamao juice samples were not significant different in appearance, odor, acidity and sweetness (p>0.05) whereas the one supplemented with immobilized L. plantarum cells within bacterial cellulose cubes from mamao fruit residues had the texture and overall liking scores higher than free L. plantarum cells treatment (p≤0.05) but it was not significantly different fromthe one supplemented with immobilized L. plantarum cells within bacterial cellulose cubes from mature coconut water (p>0.05).