Prodromos Prodromidis, a PhD Candidate, from the Aristotle University of Thessaloniki and a member of Food Innovation RI research team awarded the 2nd place in in Poster and Short Orals Competition of ISEKI Food Association e-conference for his work “Use of phenol-rich red onion skin waste extracts as natural colorants in yoghurt-like products” (please find the abstract below). We wish the best to this new scientist of our research group.
Abstract.
The aim of this study was to investigate the stability of colorants occurring naturally in red onion wastes (skins) and to explore their use as natural and sustainable alternatives for some of the colorants currently used in food industry. A drawback of most natural colorants is their instability at various pH values and after heat treatment. Thus, the stability of onion skin waste (OSW) colorants with respect to heat treatment (60-90°C), pH, UV irradiation and long term storage of colorants was examined by using macroscopic assessment, UV-Vis and FT-IR spectroscopy. Additionally, the efficiency of using cyclodextrins (CDs) to aid the extraction of OSW colorants was examined. It was found that the presence of CDs at the extraction stage of the onion colorants not only improved the extraction efficiency, but also protected the colorants from degradation. OSW colorants showed good thermal, long term storage and UV-light stability in a broad pH range. Especially at pH values close to neutral an enhanced color intensity was observed. Subsequently, OSW colorants were successfully employed for the production of a stable red colored, fermented yoghurt-type product. Finally, it may be concluded, that the wide availability and the excellent stability of onion skin waste colorants have the potential to replace synthetic colorants in food and cosmetic products.
