Roasting temperatures

Sulfation Roasting. Acid roasting technology (Fig. 2) rehes on differences in the volatiUty of the tetravalent oxides of selenium and tellurium at roasting temperatures of 500—600°C to selectively volatilise selenium from slimes. Acid roasting uses sulfuric acid as the oxidant for the conversion of selenium/selenides and tellurium/teUurides to their respective tetravalent oxides. Typical oxidation reactions are as foUow ... 

Sweet chocolate can contain milk or milk soHds (up to 12% max), nuts, coffee, honey, malt, salt, vanillin, and other spices and flavors as well as a number of specified emulsifiers. Many different kiads of chocolate can be produced by careful selection of bean blends, controlled roasting temperatures, and varying amounts of ingredients and flavors (20). 

DUH p D, YEN G c, YEN w J and CHANG L w (2001) Antioxidant effect of water extracts from barley (Hordeum vulgare L.) prepared under different roasting temperatures , J Agric Food Chem, 49 (3) 1455-63. 

Deshpande, S. N., Aguilar, A. A., Effects of roasting temperatures and gamma-irradiation on the content of chlorogenic acid, caffeic acid and soluble carbohydrates of coffee, Int. J. Appl. Radiat. Isot., 26, 656, 1975. (CA84 57527r)... 

A Hunter Color and Color Difference Meter was used to evaluate flour color. The effect of roasting condition on Hunter L values of flours indicated that lightness values (L) decreased with increased roasting temperature and time with all navy bean cotyledonary fractions possessing a clear light appearance. 

Diethyl Ether. Drying with a zeolite. Put 500 ml of diethyl ether and 50-100 g of freshly roasted zeolite of Grade NaA or CaX into a one-litre flask provided with a stopper and a calcium chloride tube filled with roasted calcium chloride. The water capacity of the zeolite and its roasting temperature are indicated on the label. It is recommended to hold the ether over the zeolite about two days. 

Yoshida, H. and Takagi, S. 1997. Effects of seed roasting temperature and time on the quality characteristics of sesame (Sesamum indicum) oil. J. Sci. Food Agric. 75, 19-26. 

In this study the physical parameters involved in interaction of a major class of meat flavorants, methyl pyrazines, with soy proteins were determined at meat roasting temperatures. Beef diffusate, the water soluble, low molecular weight fraction that constitutes about IX of beef, was shown to contain the necessary precursors to obtain a desirable, thermally generated meat aroma (8). Diffusate was heated under controlled conditions and generated volatiles were transferred to a gas chromatograph for separation and quantitation. Methyl pyrazines, either from heated diffusate or from standard solutions, were measured in the presence of purified soy proteins and the thermodynamics of binding were determined. 

Effect of Roasting on Antioxidative Activity Roasted sesame oU was reported to be much more antioxidative than unroasted purified sesame oil (71). Yen and Shyu (67) found that roasted sesame oUs prepared from sesame seeds with different roasting temperatures (between 180°C and 210°C) exhibited... 

Glycolipids content of sesame seed, on the other hand, increased with roasting temperature and time (75, 78). When sesame seeds were roasted in an electric oven from 120°C to 250°C for 30 min, the glycolipids content was found to increase from 6.9-mg/lOOO-g seeds (0.5% of total lipids) to 262.9-mg/lOOO-g seeds (17.2%... 

Sulfuric Acid Roasting. In this method, the copper slimes are mixed with sulfuric acid and roasted at 500-600 °C to produce selenium dioxide, which volatilizes readily at the roasting temperature. The selenium dioxide is reduced to elemental selenium during the scrubbing process with sulfur dioxide and water. The resultant commercial grade selenium can be purified to 99.5-99.7% (Hoffmann and King 1997). 

Yen, G.C. and Shyu, S.L. (1989) Oxidative stability of sesame oil prepared from sesame seed with different roasting temperatures. Food Chem., 31, 215-224. 

Identified only tentatively by Tressl and Silwar (1981), but confirmed later. Silwar et al. (1986) (see 1.130) found 0.30-0.40 and 0.08-0.15 ppm respectively in two arabicas and two robustas, although Tressl (1989) reported lower values for arabicas than for robustas (respectively 0.5-0.8 and 0.6-1 ppm). Silwar and Liillmann (1993b) noted an increasing concentration with roasting temperature (after 5 min), from <0.001 to 0.10 and 0.20 ppm at 200, 230 and 260 °C respectively. 

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