Evaluation of Bioactive Compounds, Antioxidant, Anti-Diabetic, and Anti Inflammatory Properties of Pasteurized Juice from the Noni Fruits (Morinda citrifolia L.) Growing in Sri Lanka

Abstract

Noni (Morinda citrifolia L.) fruit, locally known as ‘Ahu’, is a traditional medicinal plant in Sri Lanka, but not commonly consumed or processed. However, noni juice has gained global popularity as a wellness drink. In this study, we evaluated the bioactive components and antioxidant, anti-diabetic, and anti-inflammatory activities of pasteurized noni juice, expressed per 1 g (FW) of the fruit pulp. The results showed that the total phenolic content was (165.85 ± 0.84) μmol gallic acid equivalent, total flavonoids were (6.36 ± 0.22) μmol rutin equivalent, ascorbic acid content was (24.68 ± 0.89) μg, monomeric anthocyanin content was (8.91 ± 0.96) μg, β-carotene content was (0.15 ± 0.02) μg, and lycopene content was (0.14 ± 0.01) μg. The juice exhibited antioxidant activities as observed with phosphomolybdenum reduction (14.04 ± 0.05) mg ascorbic acid equivalent), ABTS radicals scavenging (723.98 ± 2.67) mg Trolox equivalent, DPPH radicals scavenging (645.98 ± 2.45), lipid peroxidation inhibition (589.98 ± 2.56) mg ascorbic acid equivalent), nitric oxide inhibition (157.08 ± 1.45) mg ascorbic acid equivalent, and singlet O2 inhibition (87.02 ± 2.78) mg gallic acid equivalent. The juice also exhibited anti-diabetic activities with (11.10 ± 0.07) % and (16.10 ± 0.03) % of α-amylase and α-glucosidase inhibitory activities, respectively, at 2 μg/mL. Additionally, the juice showed anti-inflammatory activities such as heatinduced hemolysis inhibition (30.43 ± 0.39) %, protein denaturation inhibition (33.33 ± 0.34) %, and proteinase inhibition (2.25 ± 0.54) %, respectively, at 2 μg/mL. These findings suggest that pasteurized noni juice from Sri Lanka contains significant amounts of bioactive compounds and exhibits antioxidant, anti-diabetic, and anti-inflammatory activities, which could potentially contribute to its health benefits.