Physical, antioxidant and antibacterial properties of rice (Oryza sativa L.) and glutinous rice (Oryza sativa var. glutinosa) from local cultivators and markets of Peninsular, Malaysia

Rice (Oryza sativa L.) is an important grain and basic food for a large population in the world, especially in Malaysia. It has been reported to contain highest antioxidative and antibacterial properties against pathogenic bacteria such as Bacillus cereus that may cause diarrhoea and vomiting in human bodies. Therefore, ten rice (Oryza sativa L.) (four of pigmented and six of non-pigmented) and four glutinous rice (Oryza sativa var. glutinosa) varieties (two of pigmented and two of non-pigmented) from local cultivators and markets of Peninsular, Malaysia were studied for their colour parameters, antioxidant and antibacterial properties. The pigmented rice samples showed the highest antioxidative properties such as total phenolic content (TPC) (11.12 +/- 2.49 - 104.87 +/- 3.65 mg GAE/100 mg FW), ferric reducing antioxidant power (FRAP) (11.87 +/- 3.49 - 72.47 +/- 3.07 mg TE/10g FW) and radical-scavenging activity (DPPH) (11.87 +/- 0.20 - 104.93 +/- 2.77 mg TE/100mg FW) compared with non-pigmented rice samples (3.76 +/- 0.88 - 11.24 +/- 1.39 mg GAE/100mg FW, 6.43 +/- 0.34 - 20.24 +/- 0.32 mg TE/10g and 2.76 +/- 0.44 - 14.76 +/- 1.00 mg TE/100mg respectively). The higher antioxidative properties were determined in darker pigmented rice such as black, red and brown rice samples compared to the non-pigmented rice samples. Pigmented rice samples also had the lowest minimum inhibitory concentrations (MX) and minimum bacterial concentrations (MBC), where it demonstrated the higher antibacterial properties to reduce the growth of Bacillus cereus (ATCC (R) 11778 (TM)) compared to non-pigmented rice samples especially FPH (Black Floral glutinous) and THA (Thai Red). This study demonstrated that the darker pigmented rice and glutinous rice had the higher antioxidative and antibacterial activities. (C) All Rights Reserved