Valorization of cauliflower (Brassica oleracea L. var. botrytis) by-products as a source of antioxidant phenolics.
The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH(*) and ABTS(*)(+) radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.
Llorach
Rafael
R
Research Group on Quality, Safety and Bioactivity of Plan Foods, Department of Food Science and Technology, CEBAS-CSIC, P. O. Box 4195, Murcia 30080, Spain.
Espín
Juan Carlos
JC
Tomás-Barberán
Francisco A
FA
Ferreres
Federico
F
D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D001937:Brassica / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005290:Ferric Compounds / Q000737:chemistry; D016166:Free Radical Scavengers; D005612:Freeze Drying; D007501:Iron / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis* / Q000494:pharmacology; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry; D013861:Thiocyanates / Q000737:chemistry
D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D005290:Ferric Compounds; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D013451:Sulfonic Acids; D013861:Thiocyanates; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C103724:ferric thiocyanate; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron