Impact of an Omega-3-Enriched Sheep Diet on the Microbiota and Chemical Composition of Kefalograviera Cheese

Abstract

Kefalograviera is a well-known hard Greek cheese. The aim of this study was to determine how milk produced from ewes fed omega-3-enriched diets could influence the microbiota as well as the chemical composition of Kefalograviera cheese. At the start of the trial, 30 dairy ewes (Lesvos and Chios crossbreed) were selected and fed a conventional diet, based on alfalfa hay, straw and concentrate feed that contained soybean meal for a period of thirty days. Then, for a period of sixty days the same ewes were fed an omega-3-enriched concentrate feed with a lower level of soybean meal that contained 10% flaxseed and 10% lupins. Milk yield was collected individually on Days 30, 60 and 90 and used to produce three different batches of Kefalograviera cheeses, at the same cheese factory, by using a traditional recipe and identical preparation conditions (pasteurization of milk, salt, rennet and culture). Sample analysis was done after six months of Kefalograviera cheese ripening. MALDI-TOF-MS (matrix-assisted laser desorption/ionization time of flight mass spectrometry) identification was performed by contrasting the samples’ mass spectra with the corresponding reference database. The correlation between the different Kefalograviera cheeses revealed the predominant species being Lactococcus lactis, Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus paracasei, Enterococcus faecium and Enterococcus faecalis, with significant quantitative differences between the experimental groups and the controls. Pediococcus spp. was isolated only from the experimental groups’ cheeses and Staphylococcus spp. only from the controls’ cheese, suggesting—among other differences—a bacterial microbiota distinction between the groups. Moreover, increased levels of alpha-linolenic acid and total polyunsaturated omega-3 fatty acids were noted in the enriched Kefalograviera cheeses. These promising findings suggest that enriched Kefalograviera cheese could be manufactured via enriching the ewes’ diets, with potential benefits for the consumers’ health.

Quality indicators of traditional Bulgarian artisanal sheep’s cheese

“…Some of them have identified representatives of Enterococcus, Lactobacillus, Streptococcus, Lactococcus, and Pediococcus. The present study found no pathogenic microorganisms, which confirmed the fondings reported by some authors [2,4,5,21,22]. Other authors [5] report on artisanal cheeses in which molds and yeasts have a higher availability in the ripening process due to the penetrating air in the vessel (Tulum).…”

“…The short-chain fatty acids (C4:0 -C14:0) and those with C16:0 were synthesized due to fermentation processes in the rumen of animals [22]. At the same time, long-chain fatty acids (C18:0 -C22:0) were mainly synthesized from lipids, which were absorbed into the bloodstream through the small intestine.…”

The “Crosstalk” between Microbiota and Metabolomic Profile of Kefalograviera Cheese after the Innovative Feeding Strategy of Dairy Sheep by Omega-3 Fatty Acids

“…bulgaricus ( p -value = 0.0198) with 100% similarity identified by EzBioCloud’s 16 S rRNA gene-based ID and OTU_21: Lactobacillus helveticus / crispatus / gallinarum ( p -value = 0.0202) with 99.1% similarity identified by EzBioCloud’s 16 S rRNA gene-based ID that decreased and increased in the experimental cheese samples, respectively ( Figure 5 ). In our previous study, the omega-3-enriched diet of dairy ewes influenced the lactobacilli population of the produced Kefalograviera [ 22 ]; however, different Lactobacillus species were affected, namely, Lb. rhamnosus , Lb.…”

“…In a previous study, an omega-3 enriched diet in dairy ewes led to compositional differences in the microbiota determined by conventional microbiological methods and an increase in the omega-3 polyunsaturated fatty acids in the produced Kefalograviera [ 22 ]. However, culture-independent methods can provide a more in-depth understanding of the composition and the diet-induced changes in the Kefalograviera microbiota, while metabolomic analysis can provide information on the microbial metabolites.…”

Effects of Dietary Omega-3 Enrichment on the Chemical Composition and the Pathogenic Microbiota of Ovine Milk

“…The bacterial isolates’ identification was performed with the Bruker Microflex™ LT MALDI-TOF MS system (Bruker Daltonik GmbH, Bremen, Germany) according to the ethanol-formic acid extraction procedure, as previously described [ 38 , 39 ]. Acquisition and mass spectra analyses were performed by the MALDI Biotyper software package (MBT Compass version 4.1) and the reference database version (BDAL Rev.…”