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Microwave Heating of Grapeseed: Effect on Oil Quality

1998; American Chemical Society; Volume: 46; Issue: 10 Linguagem: Inglês

10.1021/jf980412f

1520-5118

B. Dave Oomah, Jun Liang, David V. Godfrey, Giuseppe Mazza,

Phytochemicals and Antioxidant Activities

The effects of microwave and air-drying of grapeseeds on the physical and chemical parameters of their oils were investigated. Microwave treatment improved oil yield and increased viscosity, conjugated dienes, and peroxide values while reducing pigment contents (K410 and K670 values) and p-anisidine and saponification values. Removal of tannin by washing grapeseed with alcohol resulted in oil with low pigment content (K410 and K670 values), peroxide value, and tocopherol contents and high diene, p-anisidine, and saponification values. γ-Tocotrienol, the major tocopherol of grapeseed oil, increased while δ-tocopherol concentrations decreased on heat treatment of grapeseed. The negative effect of tannin removal was confirmed by the low tocopherol contents of its oil. The results demonstrate the impact of using microwave heating in producing oil from grapeseed. Keywords: Microwave; heating effect; grapeseed oil; chemical and physical parameters; tocopherols; oil quality