title: Antioxidant activities of purple rice bran extract and its effect on the quality of low-NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat.
abstract: Purple rice bran contains high amounts of natural antioxidants that consist of water- and lipid-soluble compounds. Hexane-insoluble and hexane-soluble fractions were separated from 100% methanolic extract from purple rice bran (RBE-HI and RBE-HS, respectively). Total anthocyanin, tannin, flavonoid, and phenolics contents were determined in those fractions, and their antioxidant capacities were evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capability, oxygen radical absorbance capacity (ORAC), and iron chelating capability (ICC). RBE-HI and RBE-HS were also added to restructured patties made from minced channel catfish (Ictalurus punctatus) belly flap meat. Lipid oxidation, color, and/or textural properties were determined for raw and cooked patties during a 12-d storage at 4 degrees C. All antioxidant indices, except for ICC, of RBE-HI were significantly higher than those of RBE-HS due probably to its higher anthocyanin content (P < 0.05). RBE-HS showed higher ICC (P < 0.05). However, both fractions showed similar antioxidant activity in raw and cooked patties during storage, resulting from the complexity of antioxidant action in food systems. Textural properties (hardness, cohesiveness, chewiness, and springiness) in cooked patties with RBE-HS and RBE-HI were well maintained during storage, but changed significantly in the control (P < 0.05). Only RBE-HS limited microbial growth in raw patties during storage (P < 0.05), but its inhibitory effect was marginal because of low-dose and physical interactions with the matrix. L* (lightness) and a* (redness) of raw and cooked patties decreased significantly by both fractions, whereas b* (yellowness) was significantly decreased by RBE-HI and increased by RBE-HS (P < 0.05). In conclusion, we suggest that purple rice bran extract is applicable to meat products as a natural preservative, but color change in the products may limit its application.
authors.affiliation: US Department of Agriculture, Agricultural Research Service, Rice Research Unit, 1509 Aggie Dr., Beaumont, TX 77713, USA.
authors.forename: B
authors.initials: B
authors.lastname: Min
authors.forename: M-H
authors.initials: MH
authors.lastname: Chen
authors.forename: B W
authors.initials: BW
authors.lastname: Green
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000032:analysis; D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D003080:Cold Temperature; D005396:Fish Products / Q000032:analysis* / Q000382:microbiology; D005419:Flavonoids / Q000032:analysis; D005511:Food Handling / Q000379:methods; D005519:Food Preservation / Q000379:methods; D007059:Ictaluridae; D007502:Iron Chelating Agents / Q000032:analysis; D015227:Lipid Peroxidation / Q000187:drug effects; D012275:Oryza / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry; D012639:Seeds / Q000737:chemistry*; D012965:Sodium Chloride / Q000032:analysis; D013634:Tannins / Q000032:analysis
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D005419:Flavonoids; D007502:Iron Chelating Agents; D010636:Phenols; D010710:Phosphates; D010936:Plant Extracts; D013634:Tannins; D012965:Sodium Chloride