Detail of "496-64-0"

Reference

Antioxidant effect of 3-hydroxy-2-pyrone on edible oils and fat

Antioxidant effect of 3-hydroxy-2-pyrone on edible oils and fat. Takizawa, Masaoki; Uematsu, Tsunemi; Sakurai, Hidetoshi; Ishii, Kenji (Coll. Agric. Vet. Med., Nihon Univ., Tokyo 154, Japan). Nihon Daigaku No-juigakubu Gakujutsu Kenkyu Hokoku, (41), 1-8 (English) 1984. CODEN: NIPDAD. ISSN: 0078-0839. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) 3-Hydroxy-2-pyrone (HP) [496-64-0] was evaluated as an antioxidant for peanut and soybean oils and lard by comparison with ascorbyl palmitate (AP), BHA, and tocopherol (I). HP at 0.04-0.08% was very active in lard compared with AP and d-I at 0.04% and BHA at 0.02%. AP at 0.04% was more effective than 0.04% HP and d-I in protecting crude peanut and soybean oils from autoxidn.; AP was apparently a synergist for natural I in these oils. In Florisil-treated peanut and soybean oils which contained no appreciable I, 0.08% HP was more effective than 0.02% BHA and d-I. HP and d-I added to peanut oil at 0.04% were susceptible to UV-catalyzed oxidn., whereas 0.04% BHA was very stable and had an antioxidant effect in peanut oil which was exposed to UV irradn. The antioxidant activity of HP is due to C(O)C:C in the pyrone ring structure.

Measurement of reaction rate of 3-hydroxy-2-pyrone with 2,6-dichlorophenolindophenol

Measurement of reaction rate of 3-hydroxy-2-pyrone with 2,6-dichlorophenolindophenol. Obata, Hitoshi; Fujiwara, Nobuki; Tanishita, Junichi; Tokuyama, Tai (Fac. Eng., Kansai Univ., Suita 564, Japan). Agric. Biol. Chem., 49(1), 195-6 (English) 1985. CODEN: ABCHA6. ISSN: 0002-1369. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) Kinetics of the reaction of the pseudoreductone 3-hydroxy-2-pyrone (I) [496-64-0], known to be a degrdn. product of ascorbic acid [50-81-7] and previously detected in orange juice, with 2,6-dichlorophenolindophenol (II) [956-48-9] were studied by following disappearance of the color at 524 nm as II was reduced. The reaction is expected to obey 2nd order kinetics. The half time of II redn. by I was 32.5 s for a I concn. of 2.0 mM at pH 7.0. The 2nd order rate const. (k) at pH 5.9 was ~26.6-fold larger than that at pH 8.7 and the k value of I was 1.0 x 10-4-fold that of L-ascorbic acid at pH 3.2, and ~2.5 ′ 10-2-fold greater at pH 7.0. A plot of the pH dependence of k shows a max at pH 5.0-7.0, this plot was different from that obtained for the reaction of ascorbic acid with II. Detn. of I by the kinetic method is discussed.