title: Phytosterols in onion contribute to a sensation of lingering of aroma, a koku attribute.
abstract: We aimed to examine the substance in a precipitate of heat-treated onion concentrate (HOC) that contributes to a sensation of lingering of aroma, a koku attribute induced by the sensing of richness and persistence in terms of taste, aroma and texture. Adding precipitate, separated from HOC, to consommé enhanced the lingering sensation of aroma in the consommé more than adding the supernatant from HOC. After the precipitate was washed with hot water and ethanol its enhancing effect disappeared. Analysis of the HOC precipitate showed that it contained phytosterols, such as beta-sitosterol and stigmasterol. Tests of binding to aroma compounds showed that both sterols, as well as the washed precipitate, were able to bind methyl propyl disulfide and N-hexanal. Thus phytosterols in the HOC precipitate seemed to bind and hold the aroma compounds and gradually release them, inducing a lingering sensation of aroma under the koku concept during consumption.
authors: Department of Food Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo 180-8602, Japan. Electronic address: toshixy@nvlu.ac.jp.
authors: Toshihide
authors: T
authors: Nishimura
authors: Department of Food Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo 180-8602, Japan.
authors: Ai Saiga
authors: AS
authors: Egusa
authors: Department of Food Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo 180-8602, Japan.
authors: Akira
authors: A
authors: Nagao
authors: Osaka Head Office, Kaneka Co., 2-3-8 Nakanoshima, Kita-ku, Osaka 530-8288, Japan.
authors: Tsutomu
authors: T
authors: Odahara
authors: Osaka Head Office, Kaneka Co., 2-3-8 Nakanoshima, Kita-ku, Osaka 530-8288, Japan.
authors: Takeshi
authors: T
authors: Sugise
authors: Osaka Head Office, Kaneka Co., 2-3-8 Nakanoshima, Kita-ku, Osaka 530-8288, Japan.
authors: Noriko
authors: N
authors: Mizoguchi
authors: Osaka Head Office, Kaneka Co., 2-3-8 Nakanoshima, Kita-ku, Osaka 530-8288, Japan.
authors: Yasuharu
authors: Y
authors: Nosho
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D009812:Odorants / Q000032:analysis*; D019697:Onions / Q000737:chemistry*; D010840:Phytosterols / Q000032:analysis*; D012855:Sitosterols / Q000032:analysis; D013261:Sterols / Q000737:chemistry; D013265:Stigmasterol / Q000032:analysis
chemical_list: D000447:Aldehydes; D010840:Phytosterols; D012855:Sitosterols; D013261:Sterols; D000431:Ethanol; C025473:gamma-sitosterol; D013265:Stigmasterol; C010463:n-hexanal
keywords: Aroma persistence; Koku attribute; Onion; Phytosterol