Effects of Heat and Fermentation on the Anti-inflammatory and Antioxidant Activities of Ricinus communis (Castor) Seeds

Abstract

This study investigated the effects of heat and fermentation on anti-inflammatory and antioxidant properties of R. communis seeds; determined the total protein and sugar contents of onionroots grown in seed extracts; and profiled constituents using Fourier transform infrared (FTIR) spectroscopy. De-hulled air-driedsamples were grouped into five. Group 1: control (NC) was incubated at 37oC for 72 h. Groups 2-5 were cooked for 30, 60, 90 and 120 mins respectively and incubated at 37oC for 72 h. Fermented seeds were homogenized and used for membrane stabilizing (MS), anti-denaturant, anti-haemolytic, total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), nitric oxide (NO), 1,1-diphenyl-2-picryl hydrazyl (DPPH), H2O2 radicals scavenging, total protein and sugar contents assays. Functional groups were profiled via FTIR. Results showed that the percentage MS of NC (26.62±0.0%) was significantly (p < 0.0001) lower than group 4 (71.79±0.02%). The percentage of anti-denaturant activity of NC (60.85±0.01%) was significantly lower than in cooked-fermented groups. The Percentage of anti-hemolytic activity in groups 4 and 5 was significantly higher than in NC.  Group 2 had the highest TAC (276.43±0.00 µg AAE/g); cooked groups showed significantly high FRAP values. Group 4 had the highest NO scavenging activity (99.79±0.01%). Group 3(IC50 131.36±0.04) scavenged DPPH as standard. No significant difference was observed in H2O2 activity. Total sugar and protein contents of NC were significantly lower than cooked-fermented groups. FTIR identified halo, alkenes, alkanes, 1,3-disubstituted, alcohols, ether, sulfonamides, ketenimines, carboxylic acids, isothiocyanate, nitro, fluoro and aromatic compounds. The study concluded that cooking R. communis seeds for 90-120 mins before fermentation produced robust antioxidant, anti-inflammatory and metabolic effects.