Traditional Amlou Spread as a Novel Shelf-Stable Carrier for Probiotics: Microbial Viability and Physicochemical Stability During Storage

The development of shelf-stable functional foods remains a key challenge in probiotic product formulation, particularly for non-dairy alternatives adapted to traditional diets. Amlou, a Moroccan low-moisture spread composed of argan oil, almonds, and sugar or honey, offers a promising matrix for probiotic delivery due to its nutrient-rich composition and cultural relevance. This study evaluated the potential of Amlou as a carrier for three probiotic strains: Lactobacillus gasseri (commercial), Latilactobacillus sakei AE126 (locally isolated from fermented fish), and Enterococcus durans Y17 (isolated from traditional Amlou). Each strain was inoculated separately into six Amlou formulations varying in argan oil (5% or 10%) and sugar (0%, 5%, or 10%) content, with an initial probiotic load of approximately 7 log CFU/g. The formulations were stored at ambient temperature (20–25 °C) for 45 days. Probiotic viability was assessed at regular intervals using selective media and standard plate counts. Physicochemical parameters, including pH and water activity (aw), were also measured throughout the storage period. The results showed that probiotic survival was significantly affected by formulation composition (ANOVA, p < 0.05). Overall, reductions in viability remained below 1 log CFU/g across all formulations. The best-performing formula for the commercial strain (L. gasseri) was Formulation 4 (10% argan oil, 0% sugar), which maintained the highest cell counts over time. For the locally isolated strains, Formulation 5 (10% argan oil, 5% sugar) provided the most favorable conditions for microbial stability. The pH values declined slightly during storage, while water activity decreased with increasing sugar concentration. These findings demonstrate the potential of Amlou as a shelf-stable, plant-based matrix for probiotic delivery, contributing to the diversification of functional foods rooted in North African culinary traditions.