Dry bamboo leaves were extracted by subcritical water applying the following conditions: extraction temperature 130°C, extraction time 30 min, convection 500 rpm, nitrogen atmosphere 20 bars, sample-to-solvent ratio 20. Cosmetic products with bamboo extracts are popular, however in this research for the first time bamboo extracts for cosmetic applications were prepared with pure water in its subcritical state. Based on previous investigations, subcritical water extraction provides superior bioactivity in extracts and content of relevant compounds in comparison to other modern extraction techniques, such as microwave or ultrasound-assisted extraction. In addition, using pure water ensures safety and compatibility with cosmetic products. Prepared extracts were screened for phytochemicals presence, revealing tannins, gallic tannins, coumarins, alkaloids, Oand C-heterosides presence. Total phenols (117.10±2.37 mg/l) and flavonoids (52.68±0.83 mg/l) were quantified in extracts spectrophotometrically.
The extracts exhibited great antioxidant potential (712.5±24.75 mg AAE/l), important for cosmetic applications. Anti-wrinkle, hydrating facial serum for daily use, containing 0.3% of lyophilized bamboo leaves extract was formulated. The product was additionally enriched with two molecular weight hyaluronic acids, namely of 130 kDa and 3.2 kDa, and emollients. The serum provided long-lasting skin hydration and elasticity.

Jaroslava Švarc-Gajić*, Tanja Brezo-Borjan, Lana, Kisić, Kristina Čupić, Nina Kustudić, Milica Dostanić, Milana Maričić, Marina Čobanov, Ana-Marija Vujković-Bukvin ; Faculty of Technology, University of Novi Sad, 21 000 Novi Sad, Serbia