Deciphering the Microbiota and Volatile Profiles of Algerian Smen, a Traditional Fermented Butter

Abstract

In Algeria, Smen is a fermented butter produced in households using empirical methods. Smen fermentation is driven by autochthonous microorganisms; it improves butter shelf-life and yields highly fragrant products used as ingredients in traditional dishes as well as in traditional medicine. The present study is aimed at investigating microbial diversity and dynamics during Algerian Smen fermentation using both culture-dependent and culture-independent approaches, as well as by monitoring volatile organic compound production. To reach this goal, fifteen Smen samples (final products) produced in households from different regions in Algeria were collected and analyzed. In addition, microbial and volatile compound dynamics at the different stages of Smen manufacturing were investigated for one Smen preparation. The results showed that Smen is a microbiologically safe product, as all hygiene and safety criteria were respected. The dominant microorganisms identified by both techniques were LAB and yeasts. Lactococcus spp. and Streptococcus thermophilus were the main bacterial species involved in spontaneous raw milk fermentation preceding butter-making, while lactobacilli and enterococci were the only bacteria found to be viable during Smen maturation. Regarding fungal diversity, yeast species were only recovered from two mature Smen samples by culturing, while different species (e.g., Geotrichum candidum, Moniliella sp.) were identified in all samples by the culture-independent approach. Using microbial analysis of a single batch, many of these were found viable during manufacturing. Concerning the volatile profiles, they were highly diverse and characterized by a high prevalence of short chain fatty acids, methylketones, and esters. Correlation analysis between microbial diversity and volatile profiles showed that several yeast (Moniliella sp., K. marxianus) and LAB (e.g., Lactococcus spp., S. thermophilus) species were strongly correlated with one or more volatile organic compound families, including several ethyl esters and methyl ketones that can be linked to pleasant, sweetly floral, fruity, buttery, and creamy odors. This study clearly identified key microorganisms involved in Smen fermentation and maturation that could be used in the future for better fermentation control and improvement of quality attributes.

Traditional Fermented Dairy Products in Southern Mediterranean Countries: From Tradition to Innovation

“…Lactococcus, Lactobacillus, and Leuconostoc are the main microflora involved in ghee fermentation [64]. There are two variants of ghee: rancid butter and butter oil [65,66]. Rancid butter is obtained through the maturation (1-12 months) of raw salted butter (8-10%) made from spontaneously fermented milk [67,68].…”

Leuconostoc mesenteroides and Liquorilactobacillus mali strains, isolated from Algerian food products, are producers of the postbiotic compounds dextran, oligosaccharides and mannitol

“…(Benheddi and Hellal 2019 ). This type of milk, along with cow’s milk, often forms the basis for traditional butter, and its artisanal production method strengthens the connection between tradition and local practices (Boussekine et al 2022 ). Also, barley and the sap of the date palm, known as Lagmi , are also fundamental and highly nutritious ingredients in many regions of Algeria, particularly in the south (Ben Thabet et al 2009 ).…”