Evaluating the behaviour of Lactobacillus plantarum 299v in non-dairy oat based yogurt using two different packaging materials

Abstract: There is an upsurge of consumer interest in functional foods, especially probiotics. Alongside there is a global rise in the ‘vegan’ market. However, there is insufficient research and development in the field of non-dairy probiotic food formulations. Development of probiotic oat-based yogurt, called oatgurt that is manufactured by Oatly AB, was studied by incorporating [i]Lactobacillus plantarum[/i] 299v strain, which maintains the products’ vegan label. The two important factors that could affect probiotic bacterial strain viability and oatgurt’s physicochemical properties include the step of strain incorporation and presence of oxygen. The probiotic strain was incorporated into two different food matrices; fresh oatgurt (incorporated before fermentation) and commercial oatgurt (incorporated after fermentation) maintained at 8°C in an incubator for 8 weeks. The effect of oxygen was evaluated by comparing polypropylene (PP) and glass as packaging materials for the two food matrices. In both food matrices, the viability of the strain in PP cups (~1 mm thickness), which has an oxygen transmission rate of 150-200 ml/m2.day.atm, was similar to the viability obtained in glass jars, which is impermeable to oxygen. The presence of probiotic strain in oatgurt resulted in a gradual reduction in pH over time in both packaging materials. Glass had comparatively superior effect on maintaining oatgurt colour stability than PP (p<0.05), which was perceptible only after close observation even at week 8. The overall comparative analysis showed that PP cups could be effectively used as packaging units for probiotic oatgurt. Sensory evaluation and pilot scale experimentation of the resulting probiotic oatgurt remains necessary to confirm commercial product stability.