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An investigation into the influence of UV irradiation on keratin hydrolysates was carried out using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. It was found that the absorption of keratin hydrolysates in solution increased during irradiation of the sample, most notably between 250-280 and 320-410 nm. The increase in absorbance in the region 320-410 was because of the new photoproducts formed during UV irradiation of keratin hydrolysates. The fluorescence of keratin hydrolysates was observed at 328 nm after excitation at 270 nm. UV irradiation caused fluorescence fading at 328 nm, and after 60 min of irradiation, a new broad weak band of fluorescence, attributable to new photoproducts, emerged in the UV wavelength region with emission maximum between 400 and 500 nm. FTIR spectroscopy results showed degradation of keratin under UV irradiation. A slight increase in oxidized sulphur species was also observed. The results obtained suggest that UV irradiation can be used as modifying agent for preparation of keratin hydrolysates for cosmetic applications.

Phenolic acids and derivatives of quercetin in Indian (amla) and European gooseberry were determined by high-performance liquid chromatography with diode array detector. The calibration curves were constructed using phenolic compounds standards (the coefficient of determination (R 2) was 0.9990–0.9997 for phenolic acids and 0.9989–0.9994 for flavonols, respectively). The lowest detection limit was 0.28 mg L−1 and 0.35 mg L−1 for hyperoside and gallic acid, respectively, whereas the highest was 1.80 mg L−1 and 7.98 mg L−1 for quercetin and chlorogenic acid, respectively. The quantification limits calculated were 0.85–24.04 mg L−1 for hyperoside and chlorogenic acid, respectively. The predominant phenolic acid in amla and gooseberry is gallic acid: (5.37 ± 0.04) mg per 100 g of dry mass (d.m.) and (3.21 ± 0.03) mg per 100 g of d.m., respectively. The next one was caffeic acid, 0.65–1.22 mg per 100 g of d.m., followed by p-coumaric acid, 0.84–1.17 mg per 100 g of d.m. Out of the flavonols, rutin is predominant: (3.11 ± 0.13) mg per 100 g of d.m. and (2.12 ± 0.03) mg per 100 g of d.m., respectively. Anti-oxidant activity was also determined.

Hydrophobic polymeric membranes (PP, PTFE, and PVDF) were efficiently applied in juice concentration by osmotic membrane distillation process at room temperature. The properties of applied membranes were characterized by the value of static contact angle, hysteresis of contact angle, surface free energy, roughness, mean flow pore size, maximum pore size or bubble point, and the pore size distribution before and after their utilization in osmotic membrane distillation (OMD). Furthermore, the mechanical strength of the membranes was evaluated using the Mullen burst technique and characterization of fouling behavior was done. The impact of stripping solutions, characterized by different water activities (NaCl and CaCl 2 ), type of membrane materials, and membrane morphology, on the transport properties in a dehydration process was evaluated. Apple and beet juices with a high level of antioxidants were chosen. The quality of juices has been assessed by determination of total polyphenols and antioxidant activity. In the dehydration process, the most efficient were 0.45-μm PTFE and 0.45-μm PVDF membranes (24 % improvement). No loss of polyphenol content or reduction of antioxidant activity was observed after the juice dehydration.