Rose hip (Rosa canina L.), gilaburu (Viburnum opulus L.), barberry (Berberis vulgaris L.) and black barberry (Berberis integerrima L.) are important endemic plants of Turkiye. This study determined the bioactive components, including total phenolic content, flavonoid compounds, and anthocyanin amounts. Antioxidant activity values of Rosa canina L., Viburnum opulus L., Berberis vulgaris L. and Berberis integerrima L. fruits grown in Türkiye were also evaluated after different extractions. According to the results, the highest total phenolic content was determined in the methanol extract of Berberis integerrima L.fruit as 3544.84 (mg GAE/100 g DM). The order of the total amount of phenolic substance for all three solvent extraction systems, from the highest to the lowest, was determined as: Berberis integerrima L.>Viburnum opulus L.>Berberis vulgaris L.>Rose canina L. In terms of total flavonoids, Berberis integerrima L. fruit extracted with methanol had the highest value of 2098.88 (mg CE/100 g). The order of total amount of flavonoid substance for all three solvent extraction systems, from the highest to the lowest, was determined as Berberis integerrima L. > Viburnum opulus L. > Berberis vulgaris L. > Rose canina was detected. The highest amount of Trolox equivalent (DPPH)(ABTS+) was determined as 2.95-3.30 (mM Trolox/100 g DM) in Berberis integerrima L. extracted with methanol. The highest total amount of anthocyanins found in the extracts was obtained for Berberis integerrima L. The highest amounts of vitamin C extracted with ethanol, methanol and water was determined for Berberis integerrima L.24.60; 33.22; 29.22 (mg/ 100 g), respectively. The highest value for CD, CI and T was obtained for Berberis integerrima L. extracted with methanol. The highest score for % R, %Y and % B was obtained for Berberis vulgaris L. exacted with water, for Berberis integerrima L. extracted with ethanol and Berberis integerrima L. extracted with water, respectively. The results demonstrated that the extraction solvent has a critical importance for the releasing of bioactive compounds for each used materials.

Safran Standardına göre (TS/ISO 3632, 2011) kalite açısından birinci derece bir safran baharatının, 13 farklı çözgen sistemi (saf su, metanol, etanol, asetonun farklı oranlarda karışımı) kullanılarak elde edilen ekstraktlarının toplam fenolik ve flavonoid madde miktarlarıyla antioksidan aktiviteleri üzerine etkileri incelenmiştir. Sonuçlar incelendiğinde en yüksek toplam fenolik madde miktarı 2265.00 mg GAE/100 g KM ile su/etanol/metanol (v/v/v, 30/30/40) ekstraktında saptanırken, en düşük toplam fenolik madde miktarı 40.00 mg GAE/100 g KM ile aseton ekstraktında saptanmıştır. Toplam flavonoid madde açısından en yüksek miktar 587.14 mg KE/100 g KM ile su/etanol/metanol (v/v/v, 30/30/40) ekstraktında tespit edilirken, aseton ekstraktında flavonoid bileşeni tespit edilememiştir. Antioksidan aktivite açısından DPPH ve ABTS+ analiz yöntemlerinde en yüksek değerler sırasıyla 1202.68 mg TE/100 g KM ve 1383.74 mg TE/100 g KM ile su/etanol/metanol (v/v/v, 30/30/40) ekstraktında saptanırken, en düşük miktar DPPH için 232.43 mg TE/100 g KM etanolde ve ABTS+ için 251.23 mg TE/100 g KM aseton ekstraktında saptanmıştır.

Background/Objectives: Commercial collagen peptide products may differ in their structural characteristics and in vitro biological properties depending on manufacturing processes and hydrolysis conditions. However, comparative studies integrating simulated gastrointestinal digestion with structural, physicochemical, and cell-based analyses remain limited. This study comparatively evaluated commercially available bovine collagen peptide products marketed in Türkiye before and after simulated gastrointestinal digestion. Methods: Collagen peptide samples were characterized before and after simulated gastrointestinal digestion by determining hydroxyproline content, degree of hydrolysis (DH), molecular weight (MW) distribution, antioxidant activity, and fibroblast responses to investigate digestion-induced structural and biological changes. Results: Significant differences were observed among the evaluated products in hydroxyproline content, degree of hydrolysis, molecular weight distribution, antioxidant activity, and fibroblast responses. Simulated gastrointestinal digestion further hydrolyzed all collagen peptide samples, although the extent of structural modification varied among products. Antioxidant responses also differed following digestion, with some products maintaining relatively stable radical scavenging activity, whereas others exhibited increased or decreased antioxidant responses. Cell viability assays demonstrated that all collagen peptide samples were non-cytotoxic toward L929 fibroblasts under the experimental conditions. Conclusions: The findings indicate that simulated gastrointestinal digestion influences the structural characteristics and in vitro biological responses of commercial collagen peptide products to different extents. The observed differences among products suggest differential in vitro bioactivity associated with their structural characteristics and digestion behavior. Nevertheless, these findings are limited to in vitro observations and require confirmation through peptide characterization, bioavailability studies, animal models, and well-designed clinical investigations before conclusions regarding physiological efficacy or potential health benefits can be drawn.