摘要
Bignay pomace is a processing byproduct that can be a source of bioactive compounds. However, a suitable dehydrationmethod should be considered to efficiently valorize this waste material into high-value food ingredient andmaximize its health-promoting properties. Bignay pomace was subjected to convection oven-drying and freeze-dryingto investigate the effect of these pre-processing techniques on the physicochemical, bioactives, and antioxidantproperties of the samples. Both drying methods significantly (p<0.05) changed the total phenolic and anthocyanincontents of bignay pomace while flavonoids and tannins were not significantly affected. Freeze-drying of samplesresulted in higher phenolic content (1742 vs. 1273 mg gallic acid equivalent/100 g DW) and anthocyanin content(496 vs. 223 mg cyanidin-3-glucoside equivalent/100 g DW) than convection oven-drying. Freeze-drying also resultedin higher antioxidant properties based on DPPH, ABTS radical scavenging activity, and FRAP assays. Bignay pomaceextract was analyzed through HPLC (with photo-diode array detector) for its phenolic profile and nine compoundswere identified, with catechin and epicatechin as the dominant components. HPLC analysis also showed that whilethe drying process does not influence the phenolic profile of the samples, it significantly affected the concentrationof phenolic compounds present. The results of this study showed that freeze-drying is a more viable method to retainthe majority of bignay pomace’s functional properties compared to convection oven-drying.
基金
funded by the UP System Enhanced Creative Work and Research Grant(ECWRG-2020-2-22R).
