title: Antioxidant effects of pH-regulating agents on the thermal deterioration of vegetable oils.
abstract: pH-Regulating agents, such as sodium tartrate, disodium succinate, and trisodium citrate, were investigated for their antioxidant activities during the thermal deterioration of vegetable oils. Refined rapeseed and rice bran oils, supplemented with pH-regulating agents and α-tocopherol (0.1%) were heated at 180℃. After heating, acid values (AVs), carbonyl values (CVs), polar material contents, and color (absorbance at 420 nm) of each sample were measured. All pH-regulating agents gave rise to reduced AVs, CVs, and polar material contents of vegetable oils during heating relative to samples not containing a pHregulating agent. Rapeseed and rice bran oils supplemented with sodium tartrate showed the lowest AVs, CVs, polar material contents and absorbances at 420 nm after heating. Sodium tartrate not only retarded the hydrolysis, thermal oxidation, polymerization, and coloration of both oils while heating at high temperatures, but it also showed antioxidant activity at the supplementation level of 0.01%. The antioxidant activity of sodium tartrate was higher than that of α-tocopherol during the deterioration of vegetable oils. Sodium tartrate was particularly effective retarding hydrolysis while heating at high temperatures, resulting in increase of AVs of vegetable oils. Sodium tartrate is therefore expected to be an effective antioxidant for the thermal deterioration of fats and oils during deep-fat frying.
authors.affiliation: School of Bioscience and Biotechnology, Tokyo University of Technology.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Endo
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamadera
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tsukui
mesh_terms: D000975:Antioxidants; D002951:Citrates / Q000494:pharmacology*; D003116:Color; D003296:Cooking; D005229:Fatty Acids, Monounsaturated; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects*; D010084:Oxidation-Reduction / Q000187:drug effects*; D010938:Plant Oils / Q000737:chemistry*; D058105:Polymerization / Q000187:drug effects*; D000074262:Rapeseed Oil; D000073879:Rice Bran Oil; D013386:Succinates / Q000494:pharmacology*; D013644:Tartrates / Q000494:pharmacology*; D024502:alpha-Tocopherol / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D002951:Citrates; D005229:Fatty Acids, Monounsaturated; D010938:Plant Oils; D000074262:Rapeseed Oil; D013386:Succinates; D013644:Tartrates; C514290:trisodium citrate; D024502:alpha-Tocopherol; D000073879:Rice Bran Oil; C029768:tartaric acid