Analysis of table olives microbiome using next-generation sequencing has enriched the available information about the microbial community composition of this popular fermented food. In this study, 16S and 18S rRNA sequencing was performed on table olives of five Greek popular cultivars, Halkidikis, Thassou, Kalamon, Amfissis, and Konservolia, fermented either by Greek style (in brine or salt-drying) or by Spanish style, in order to evaluate their microbial communities. Moreover, analytical methods were used to evaluate their biochemical properties. The prevailing bacterial species of all olives belonged to Lactobacillaceae, Leuconostocaceae, and Erwiniaceae families, while the most abundant yeasts were of the Pichiaceae family. Principal coordinates analysis showed a clustering of samples cured by salt-drying and of samples stored in brine, regardless of their cultivar. The biochemical evaluation of total phenol content, antioxidant activity, hydroxytyrosol, oleuropein, oleocanthal, and oleacein showed that salt-dried olives had low amounts of hydroxytyrosol, while Spanish-style green olives had the highest amounts of oleocanthal. All the other values exhibited various patterns, implying that more than one factor affects the biochemical identity of the final product. The protocols applied in this study can provide useful insights for the final product, both for the producers and the consumers.
Research has highlighted the nutritional benefits of ancient grains, especially emmer (Triticum turgidum ssp. dicoccum) and einkorn (Triticum monococcum), compared to modern varieties of common and durum wheat, focusing on their higher levels of antioxidants and phytochemicals. In this study, grains from old Greek landraces of einkorn, emmer, durum and common wheat were compared to modern wheat cultivars, as well as barley, oats and rye grains, to investigate their unique genetic profile and nutritional properties. Genotyping of Triticum species was performed using SSR markers, which allowed differentiation up to cultivar level. Nutritional factors like the total content of bound and free polyphenols, flavonoids, antioxidant activity and fatty acid profile were assessed. The results showed that emmer and einkorn had the highest total polyphenol, flavonoid and mono-unsaturated fatty acids content, as well as higher antioxidant activity than common and durum wheat. Local landraces of common and durum wheat also exhibited higher values than commercial cultivars. The results of this study demonstrate the high nutritional value of ancient wheat varieties. Many of these cultivars have been put aside by more productive, yet with lower qualitative characteristics, commercial cultivars, underlining the importance of maintaining sustainable agricultural practices to ensure their continued cultivation.