Physicochemical and antioxidant properties, total phenolic and nutritional contents of noni (Morinda citrifolia) seed and its oil cultivated in Sabah, Malaysia

Abstract

Noni (Morinda citrifolia) is a climatic small evergreen plant that belongs to the Rubiaceae or coffee family, available throughout the year. This study aimed to identify the nutritional contents, extraction of noni seed oil (NSO) and their physicochemical properties, antioxidants, specifically total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) assay of noni seed (NS) and NSO cultivated in Sabah, Malaysia. The results showed 8.37 g/100 g moisture, 10.55 g/100 g crude oil, 7.1 g/100 g protein, 1.29 g/100 g ash, and 25.20 g/100 g carbohydrates indicating NS has considerable biomolecules that can be utilized as excellent resources of biomolecules. NSO showed a high iodine value of 125.90 g I2/100 g, peroxide value of 10.60 mEq/g, and free fatty acid (FFA) of 1.07%. The fatty acids composition revealed that NSO dominated by linoleic acid (omega-6) (71.74%) which makes it beneficial for human health. The TPCs for NS powder and NSO were 22.65 mg GAE/g and 48.85 mg GAE/g, respectively. Moreover, NS powder's FRAP was 73.15 mM/100 g. These results suggest that NS and NSO have the potency to be a healthier source of edible functional food, cosmetic and pharmaceutical products, and vegetable oil due to considerably high omega-6 fatty acid, carbohydrates, low FFA, and antioxidant activities.