Effect of Non-Dairy Food Matrices on the Survival of Probiotic Bacteria during Storage

Abstract

The viability of probiotics in non-dairy food products during storage is required to meet content criteria for probiotic products. This study investigated whether non-dairy foods could be matrices for probiotics. Selected probiotic bacteria were coated on non-dairy foods under two storage conditions, and viabilities were assessed. The non-dairy foods were coated with 5-7 log cfu g^-1 of <i>Lactobacillus acidophilus</i> ATCC4356<i>^T</i>, <i>Lactobacillus plantarum</i> RC30, and <i>Bifidobacterium longum</i> ATCC15707<i>^T</i>. The coated non-dairy foods were stored at 20 °C and 20% relative humidity (RH) or 30 °C and 50% RH. Viability of probiotic bacteria was determined after 0, 2, and 4 weeks of storage. <i>B. longum</i> showed the highest survival at week 4 of 6.5-6.7 log cfu g^-1 on wheat bran and oat, compared with 3.7-3.9 log cfu g^-1 of <i>L. acidophilus</i> and 4.2-4.8 log cfu g^-1 of <i>L. plantarum</i> at 20 °C 20% RH. Under the storage conditions of 30 °C 50% RH, survival of 4.5 log cfu g^-1 of <i>B. longum</i> was also found on oat and peanut. This was two and four times higher than the population of <i>L. acidophilus</i> and <i>L. plantarum</i>, respectively. The results suggest that probiotics can survive on non-dairy foods under ambient storage conditions. However, the storage conditions, food matrices, and probiotic strains should be carefully chosen to maximize probiotic bacteria survival.