Abstract:
Probiotics and prebiotics are considered as health-promoting food ingredients. However, their potential sources are limited to some foods. Integration of edible film and coating and synbiotic technologies is an innovative approach that will enhance the incorporation of probiotics and prebiotics into more variety of food products and increase the accessibility for consumers. This research aimed to develop konjac glucomannan (KGM) film as a synbiotic carrier. To identify the potential synbiotic combination, three probiotic strains (Lactobacillus casei-01, Lactobacillus paracasei subsp. paracasei Lpc-37 and Bifidobacterium animalis subsp. lactis BB-12) were paired with commercial prebiotics (Orafti®P95, Orafti®GR, Orafti®HSI and Oligomate®55N) and KGM. The results revealed that L. casei-01 and Orafti®GR was the potential combination with the highest score (0.29±0.03). Furthermore, KGM which serve as a synbiotic carrier could promote the growth of all probiotic strains and resulted in the highest score when paired with L. paracasei. Thus, these two synbiotic combination were selected for developing films. After undergoing a film-forming process at 40 ºC for 16h, viable count in the film incorporated with L. casei-01 and Orafti®GR reduced approximately 2 log CFU/mL film-forming solution (FFS), allowing the survival of 78.75±0.56%. Taking both prebiotic activity score and the survival rate into account, this formulation was chosen for study on film properties and its application. Edible films from KGM incorporated with L. casei-01 and Orafti®GR was colorless, transparent, highly soluble in water (97.22 ± 0.66%), with good tensile strength (21.10 ± 3.97 MPa), % elongation at break (23.83 ± 5.77%) and water vapor permeability (0.0056 ± 0.0001g mm h-1 m-2 kPa-1 ). When stored the film at room temperature up to 8 days, 6 log CFU/g reduction in active cells in the film throughout the storage period was observed. After 4 days of storage, viability decreased to less than 6 log CFU/g film which was the lowest acceptance limit. Application of the film as an edible coating on surface of bread buns demonstrated a loss of L. casei-01 viability of 2 log CFU/portion during a storage period of 7 days, resulting in active cells of L. case-01 more than 6 log CFU/portion. The results from this research support the use of edible films from KGM formulated with L. casei-01 and Orafti®GR as an alternative approach to extend the application of probiotics and prebiotics in food products.