title: Physicochemical characteristics of rapidly dried onion powder and its anti-atherogenic effect on rats fed high-fat diet.
abstract: Rapidly dried onion (Allium cepa L. cv. Momiji No. 3) powder (OP) prepared from the outer layers (from second to fourth scale leaves from the surface) of onion bulbs was analysed for its quercetin and polyuronide contents, the effects of enzymatic treatment and the anti-atherogenic effect on rats fed a high-fat diet. Quercetin 4'-glucoside (50%), free quercetin (30%) and quercetin 3,4'-diglucoside (20%) were identified as quercetin derivatives, and boiling-water extraction was effective in extracting these compounds. OP contained 12.9% of polyuronides, the basic skeleton of pectin. Enzymatic degradation (cellulase and pectinase, 50°C for 12h, pH 6.0) of OP was effective in obtaining a slurry of smaller particle sizes. The free quercetin increased and the glucosides decreased with enzyme treatment. In Wistar rats fed an OP-added high-fat diet, the total cholesterol, HDL-cholesterol and triglyceride concentrations were not significantly different from the rats fed a high-fat diet without OP. However, the atherogenic index (AI) of Wistar rats fed an OP-added high-fat diet was lower (AI=3.3) than rats fed the diet without OP (AI=4.1). The incremental elastic modulus (IEM) of the aorta from rats fed the OP-added diet was also significantly lower than that of the rats fed the diet without OP. The AI and IEM values of the rats fed the OP-added diet were quite similar to the values of rats fed the diet without OP but were allowed spontaneous exercise. These results suggest that OP intake is effective for decreasing the risk of arteriosclerosis.
authors.affiliation: Graduate School of Agriculture, Shinshu University, 8304 Minamiminowa, Kamiina-Gun, Nagano 399-4598, Japan. Electronic address: hamauzu@shinshu-u.ac.jp.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Hamauzu
authors.affiliation: Nagano College of Nursing, 1694, Akaho, Komagane City, Nagano 399-4117, Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Nosaka
authors.affiliation: Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda City, Nagano 386-8567, Japan.
authors.forename: Fuyu
authors.initials: F
authors.lastname: Ito
authors.affiliation: Graduate School of Agriculture, Shinshu University, 8304 Minamiminowa, Kamiina-Gun, Nagano 399-4598, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda City, Nagano 386-8567, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Torisu
authors.affiliation: Novozymes Japan Ltd., Chiba 261-8501, Japan.
authors.forename: Miyoko
authors.initials: M
authors.lastname: Hashida
authors.affiliation: New Ton Club, Nagano 386-0012, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Fukuzawa
authors.affiliation: Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda City, Nagano 386-8567, Japan.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Ohguchi
authors.affiliation: Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda City, Nagano 386-8567, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yamanaka
keywords: Arteriosclerosis; Enzyme treatment; Onion skin; Polysaccharides; Quercetin derivatives; Rapidly dried powder; Rats