Preparation of function-enhanced vegetable oils

Abstract

Background: Highly purified commercial vegetable oils, such as rape seed/canola oil, corn oil, safflower oil and soybean oil have virtually no antioxidant activity against lipid peroxyl radical scavenging activity (ROO.) (Figure 1), and peroxy nitrite (ONOO-). Methodology: Dried tomato-juice-waste-residues or dried wine-ferment-waste-residues were incubated with a highly purified oil obtained from the market, which is low-functional-grade oil (eg. canola oil), at room temperature for more than 2-3 weeks. Their antioxidant activities were then examined as described below Results: Antioxidant lipid soluble components such as lycopene/carotenoids, flavonoids, and chlorophylls, originally present in tomato-juice-waste-residue, wine-ferment-waste-residues and dried spinach leaf, etc,, were transferred to such pure yet low-functional-grade vegetable oils. Peroxide value, acid value, and TBARS (thiobarbituric acid reactive substances) measurement, as well as spectroscopic characterization, demonstrated that such treatment much improved the properties of the low-functional-grade oils; namely low-functional-grade oils became high-functional-grade oils. The absorption spectrum of dried waste of tomato-juice-waste-residue treated canola oil indeed became much improved against various oil-deteriorating effects. Conclusions: This method provides an easy procedure to convert low-functional-grade oils to high-functional-grade oils, using various vegetable-waste-residues.