Qualité microbiologique du lait caillé et du Wagashi Gassirè produits au Bénin : état des lieux et pistes d’amélioration
(2024)
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- Abstract
- Wagashi Gassirè cheese (WG) and spontaneously curdled milk (Fanirè or fermented milk) (LC) are among the most popular dairy products in Benin and beyond due to their nutritional value. However, their traditional production raises concerns about their sanitary safety. This study aims to evaluate the microbiological quality of these products available on the market and in camps, as well as those derived from improved processes, through various approaches. Initially, a preliminary study was conducted on WG cheeses (stained and unstained) from the markets of Cotonou and Abomey-Calavi. The results revealed that unstained WG were dominated by Lactobacillaceae (55%), mainly Lactobacillus delbrueckii, and Streptococcaceae (32%), while stained WG were primarily composed of Streptococcaceae (73%) with a low presence of Lactobacillaceae (2%). Although the overall bacterial diversity of both types of cheese did not show a significant difference, the low concentration of Lactobacillus in stained WG could be linked to their colouring process. A survey conducted among breeders, producers, traders, and consumers gathered information on the practices of transforming milk into WG and LC, as well as their preservation. Following this survey, the microbiological quality of raw milk, WG, and LC from production monitoring and those collected from the markets was evaluated. Out of 70 samples analyzed, Salmonella enterica and Bacillus cereus were isolated in 10 and 14% of the samples, respectively. Escherichia coli levels exceeded the standards of EC Regulation 2073/2005 in raw milk, curdled milk, and stained WG, while Staphylococcus aureus levels were acceptable in the majority of samples. To further this analysis, high-throughput sequencing of bacterial 16S rRNA gene amplicons was used on 114 dairy product samples. The dominant bacterial phyla were Firmicutes/Bacillota (64%) and Proteobacteria/Pseudomonadota (36%). Dairy products from the camps and markets of Nikki and Dassa-Zoumé mainly shared bacteria from the families Streptococcaceae (44%), Enterobacteriaceae (23%), Moraxellaceae (9%), Lactobacillaceae (7%), and Bacillaceae (5%). The dominant species were Lactococcus lactis (21%), Streptococcus sp. (18%), Lactobacillus delbrueckii (6%), Streptococcus thermophilus (3%), Weissella confusa (2%), Lactobacillus fermentum (1%), and Lactobacillus helveticus (1%). The dynamics of bacterial communities in red and white WG cheeses showed a significant difference during storage. The analysis also detected several potential pathogens, such as B. cereus, Clostridium perfringens, Klebsiella pneumoniae, and Streptococcus infantarius. These results highlight the importance of the diversity and dynamics of microbiomes in these traditional dairy products and help address associated safety and spoilage issues. To improve their sanitary quality, improvement proposals were formulated and tested in the laboratory, and the improved products were subjected to the same microbiological analyses. The Wagashi Gassirè samples were subjected to heat treatment at 100°C for 20 min, then packaged in two ways: simple packaging and vacuum packaging. Fanirè samples were subjected to fermentation with various starter cultures, including Lactococcus lactis alone and in combination with Leuconostoc mesenteroides, Lactobacillus plantarum, and L. fermentum. The controlled fermentation lasted 24 h at 30°C, followed by an evaluation 48 h after production. Wagashi Gassirè samples were monitored over three days, with analyses conducted on the first day and after three days of storage. The results showed that fermented milk produced with L. lactis alone had adequate microbiological quality, regardless of the analysis period. Products obtained through backslopping and combinations of lactic bacteria improved with storage. Double cooking of Wagashi Gassirè samples, with or without vacuum packaging, preserved the sanitary quality of the cheeses. To improve the safety of traditional dairy products, it is essential to implement strict protocols for microbiological quality control and to raise awareness among production chain actors about good hygiene practices. Awareness campaigns for consumers on risks and best consumption practices are also necessary. Exploring other beneficial bacteria present in these products and their potential role in inhibiting spoilage microorganisms and pathogens will help preserve and enhance the nutritional value of these studied products.
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Citations
Komagbé, G. (2024). Qualité microbiologique du lait caillé et du Wagashi Gassirè produits au Bénin : état des lieux et pistes d’amélioration.