Health-promoting effects of Thai curry pastes and rice dishes following simulated gastrointestinal digestion: insights into antioxidants, tyrosinase enzyme inhibition and anti-inflammatory properties

Abstract This study investigated the bioactivity of Southern Thai curry pastes and ready-to-eat dishes after simulated gastrointestinal digestion. Antioxidant activity, anti-inflammatory effects, cytokine production, tyrosinase inhibition, and phenolic profiles were evaluated in nine samples: red curry paste (RCP), sour curry paste (SCP), kua kling curry paste (KCP), red curry (RC), sour curry (SC), kua kling curry (KC), and rice-based dishes (RRC, RSC, RKC). Total phenolic content (TPC) was highest in RCP, KC, and RKC, while total flavonoid content (TFC) peaked in SCP, RC, and RSC (p<0.05), consistent with DPPH and ABTS results. KCP exhibited the strongest tyrosinase inhibition (64.57±1.88%), whereas rice-based samples showed the lowest activity. All samples were non-cytotoxic, maintaining cell viability above 80%. RCP and KCP showed the strongest nitric oxide inhibitory effects. ELISA analysis demonstrated significant inhibition of TNF-α, particularly in RC and KC, while rice-based dishes were less effective. RCP also showed the greatest inhibition of IL-1β. Pyrogallol was most abundant in RCP, RC, and RRC. LC-QTOF-MS/MS identified key bioactive compounds, including quercitrin, capsaicin, ferulic acid, and linoleic acid. These findings suggest that digested Southern Thai dishes possess promising antioxidant and anti-inflammatory properties; however, in vivo studies are needed for confirmation.