ABSTRACT
This paper evaluated methodologies for extracting phenolic compounds by DES (Deep eutectic solvents) associated with pectinlyase. Citrus pomace was characterized chemically, and seven DESs were formulated for extraction. Two groups of extractions were performed. Group 1 extractions were performed only with DESs, at 40 °C and 60 °C, with CPWP (Citrus pomace with pectin) and CPNP (Citrus pomace no pectin). In group 2, the DES was associated with pectinlyase and used only with CPWP at 60 °C in two ways of extraction: E1S (one-step extraction) and E2E (2-step extraction). The extracts were evaluated TPC (total phenolic compounds), individual phenolic compounds by HPLC, and antioxidant capacity by methodologies of DPPH and FRAP. The results of group 1 extractions for CPWP showed the highest phenolic compounds concentration (559.2 ± 2.79 mg/100 g DM) at 60 °C. Group 2 (E2S) showed high values of total phenolic compounds (615.63 ± 28.01 mg/100 g DM) and antioxidant activity (23,200 ± 721.69 µmol TE/g DM), with values higher than conventional extraction (545.96 ± 26.80 mg/100 g DM and 16,682.04 ± 2139 µmol TE/g DM). The study demonstrated the excellent extractive potential of DES for flavonoid extraction from citrus pomace. DES 1 and 5 by E2S showed the highest phenolic compounds and antioxidant capacity values, mainly when associated with pectinlyase.
ABSTRACT
Citrus by-products are inexpensive sources of polyphenols, important bioactive compounds with wide pharmaceutical and food applications. This study aimed to investigate the effect of enzymatic treatment of citrus by-products on the polyphenolic profile of extracts and assess the influence of extracts on the growth and adhesion of probiotics and foodborne pathogenic bacteria and on the inflammatory response of epithelial cells. Enzyme-assisted extraction altered the polyphenolic profile (as assessed by HPLC-DAD), increasing the content of aglycone flavanones (naringenin and hesperetin). Enzymatic extracts and aglycone flavanones exhibited higher antibacterial and prebiotic activities than non-enzymatic extracts and glycoside flavanones. However, a higher content of aglycones was not associated with higher anti-adhesion activity. Citrus extracts significantly (P ≤ 0.05) decreased the inflammatory response of Caco-2 cells to Salmonella Typhimurium adhesion. These results support the sustainable reuse of citrus agroindustrial wastes and indicate the potential of citrus extracts in preventing infection by foodborne pathogenic bacteria and inducing proliferation of probiotics in foods and the gut environment.
