Effects of Bacillus coagulans and the biomass of Spirulina platensis on quality characteristics and probiotic viability of gluten free cupcakes

Abstract

In this study, gluten-free corn flour cupcakes were formulated with different levels of Spirulina platensis (0, 1, 2, and 3%) and the probiotic bacterium Bacillus coagulans (0 and 1%), and their physicochemical, microbial, textural, and sensory properties and probiotic survival were evaluated during 15 days of storage. The results showed that probiotic formulations containing increasing levels of Spirulina (particularly 3%) exhibited significantly lower total bacterial counts, reduced growth of spoilage and pathogenic microorganisms, and improved microbial stability compared with the probiotic-only treatment, which showed limited antimicrobial activity. Within the probiotic-containing formulations, increasing Spirulina levels were associated with enhanced microbial inhibition; however, because Spirulina was not evaluated as an independent treatment, its individual contribution could not be distinguished from its interaction with B. coagulans . Colour analysis showed that increasing Spirulina levels in probiotic cupcakes decreased lightness (L*) while increasing redness (a*) and yellowness (b*). Textural analysis indicated that higher Spirulina levels were associated with reduced hardness of probiotic cupcakes, which may be related to improved moisture retention during storage. Sensory evaluation demonstrated that although increasing Spirulina levels in formulations containing B. coagulans reduced participants’ satisfaction with sensory attributes related to aroma and flavour, formulations containing Spirulina , particularly in combination with B. coagulans , maintained higher scores for colour, texture, and overall acceptability compared with the control and probiotic-only treatments throughout the storage period. In addition, probiotic formulations containing Spirulina showed greater probiotic viability than the probiotic-only treatment. Overall, the results suggest that the combined incorporation of S. platensis and B. coagulans is a promising strategy for improving the microbial stability, textural properties, probiotic viability, and overall quality of gluten-free bakery products.