Foodinfo Online FSTA Reports -->8 October 2004
Effect of packaging materials and dissolved oxygen on the survival of probiotic bacteria in yoghurt.
Talwalkar, A.; Miller, C. W.; Kailasapathy, K.; Nguyen, M. H.
Correspondence (Reprint) address, K. Kailasapathy, Cent. for Advanced Food Res., UWS, Locked Bag 1797, NSW 1797, Australia.
International Journal of Food Science & Technology 39 (6) 605–611
Oxygen toxicity has been suggested to be a significant factor influencing the viability of probiotic bacteria, such as Lactobacillus acidophilus and Bifidobacterium spp., in yoghurts. Along with manufacturing steps (particularly agitation and mixing), which incorporate high amounts of oxygen into the yoghurt, the packaging materials used may also affect the level of oxygen diffusing into the product. This study investigated the effects of packaging materials having different oxygen permeabilities on the levels of dissolved oxygen and survival of the probiotic bacteria in yoghurt. Oxygen adapted and non-oxygen adapted strains of L. acidophilus and Bifidobacterium spp. were incorporated in yoghurts, which were packaged in oxygen permeable high-impact polystyrene (HIPS), oxygen-barrier material (NupakTM) and NupakTM with an oxygen scavenging film (Zero2TM). Results showed that, during storage, the level of dissolved oxygen increased steadily in HIPS packaged yoghurt, but remained low in yoghurts packaged in NupakTM and Zero2TM. In all yoghurts, no significant decreases were observed in the viability of either oxygen adapted or non-oxygen adapted cells of L. acidophilus and Bifidobacterium spp. It is suggested that, although the level of dissolved oxygen in yoghurt can be influenced by the type of packaging material, it may not affect the survival of probiotic bacteria in yoghurts.
Milk and dairy products
BIFIDOBACTERIUM; INHIBITION; LACTOBACILLUS; LACTOBACILLUS ACIDOPHILUS; MICROORGANISMS; OXYGEN; PACKAGING MATERIALS; PERMEABILITY; PROBIOTIC BACTERIA; YOGHURT