Photometric Analysis of Propolis from the Island of Samothraki, Greece. The Discovery of Red Propolis

Abstract

Propolis presents notable and variable antioxidant activity depending on the territory and the local flora. As a result, propolis collected from areas presenting botanical diversity can become an intriguing research field. In the present study, we examined propolis from different areas of Samothraki, a small Greek island in the north‐eastern Aegean Sea, considered a hot‐spot of plant biodiversity. The analysis of propolis samples presented huge variability in the antioxidant activity, the total polyphenol content and the total flavonoids content. Propolis from two areas presented high antioxidant activity with a maximum at 1741.48 μmol of Trolox equivalents per gram of dry propolis weight, very high polyphenol content, 378.73 mg of gallic acid equivalents per gram of dry propolis weight, and high flavonoid content with a maximum concentration of 70.31 mg of quercetin equivalents per gram of dry propolis weight. The samples that presented the best qualitative characteristics were all red propolis which is a type that has never been reported in any part of Europe.

Investigating Possible Synergism in the Antioxidant and Antibacterial Actions of Honey and Propolis from the Greek Island of Samothrace through Their Combined Application

“…Considering the net weight of the propolis tested in the assays (in g), the determined AA of its pure tincture (57.16 μmol TRE/mL) is equal to 922.3 μmol TRE/g, while its determined TPC (16.72 g GAE/L) is equal to 282 mg GAE/g. Results of the present study are thus in accordance with previous research, which revealed that Samothrace’s propolis presents a very high AA and is very rich in TPC [ 36 , 41 ]. Such functional properties are probably related to the island’s rich biodiversity [ 32 ].…”

“…Several previous studies on propolis and honey have also demonstrated a strong correlation between the AA and TPC of these products [ 46 , 48 , 53 ]. However, non-phenolic compounds such as diterpenes may also account for the AA of Samothrace’s red propolis [ 36 ].…”

“…Propolis samples were collected from hives of Apis mellifera macedonica in the north-western area of the same island. The specific type of propolis examined was “red propolis”, described as being highly antioxidant [ 36 ]. Crude propolis samples were frozen at −18 °C and ground to a fine powder of 50–60 μm in a chilled grinder (Kenwood, KMM060).…”

Evaluation of Yeast Strains for Pomegranate Alcoholic Beverage Production: Effect on Physicochemical Characteristics, Antioxidant Activity, and Aroma Compounds

“…Total flavonoid content (TFC) was determined by the flavonoid-aluminum chloride (AlCl 3 ) complexation spectrophotometric method [ 16 ], with some modifications. Specifically, in a 5-mL Eppendorf tube, 2 mL of sample (appropriately diluted with distilled water), 200 μL of AlCl 3 solution (20 g L −1 AlCl 3 in methanolic solution of 50 mL L −1 acetic acid), and 2.8 mL of 50 mL L −1 acetic acid in methanol were added, vortexed and allowed to stand at room temperature for 30 min.…”

Bioactives from Bee Products and Accompanying Extracellular Vesicles as Novel Bioactive Components for Wound Healing

“…The polyphenolic composition of propolis particularly determines its antioxidant activity, and even small changes in the final content can influence the pharmaceutical properties. For example, Papachristoforou et al (2019) analyzed propolis from different areas of a small Greek island Samothraki, known for its high plant biodiversity, and discovered a huge variability in the antioxidant activity depending on the territory and the local flora [ 24 ]. In particular, the sample with the lowest antioxidant activity had only 1.75 μmol of Trolox equivalents per gram of dry weight (TRE/g), while in the sample from the other area, a maximum value of 1813.2 μmol TRE/g was measured.…”