RESUMEN
Antioxidant activity of dry ground rosemary [Rosmarinus officinalis L.] leaves of particle size = 70 micro m in purified corn and soybean oils triacylglycerols [CO TAG, SO TAG] was studied at 60 +/- 1 °C in dark. The systems were purified corn or purified soybean triacylglycerols without antioxidants [controls], with 100 micromole alpha tocopherol, 100 micromole butylated hydroxyanisol [BHA], 100 micromole butylated hydroxytoluene [BHT], 100 micromole tertbutyl hydroquinone [TBHQ], 100 micromole Trolox, 180 ppm carnosic acid and 0.2% ground rosemary leaves [filtered and non-filtered]. Oxidation was followed up by ferrous oxidation [Thiocyanate method] and hexanal determination. Diffusion of antioxidant constituents from rosemary into oil was monitored by radical scavenging method using alpha, alpha'-biphenyl-beta-picrylhydrazyl [DPPH]. Rosemary showed to be an effective antioxidant bearing plant especially with oils containing high percentage of polyunsaturated fatty acids. In CO TAG the order of decreasing hydroperoxide inhibition was Trolox >/= rosemary> TBHQ> carnosic> alpha-tocopherol> BHA. In SO TAG the inhibiton order was rosemary > Trolox> TBHQ>carnosic>alpha-tocopherol>BHA
Asunto(s)
Aceite de Soja , Aceite de Maíz , Antioxidantes , alfa-Tocoferol , Hojas de la Planta , Extractos Vegetales , Cromatografía Líquida de Alta Presión , TriglicéridosRESUMEN
Stripped soybean oil was used to investigate the effect of different packaging materials on photooxidation stability. Four packaging materials were used, two glass [clear and amber] and two plastic [low density polyethelene PE and polyethylene terephthalate PET]. Clear glass caused the highest hydroperoxide formation followed by PE and PET while amber glass caused the least one, since it excluded most of the incident light responsible for photoxidation, hence retarding it and decreasing off-flavour development. Also polyethylene terephthalate gave more inhibition of hydroperoxide than polyethylene. Polyethylene and polyethylene terephthalate packaging materials although they cause some of their constituents to migrate into edible oils, the over all amount migrated from them still below the international permitted level