Rancid oil

The reaction of neomycin with many compounds has been described in Section 3, hence numerous reports of neomycin incompatibility may be expected. Dale and Rundman have extensively reviewed the compatibility of neomycin with substances that may be encountered by the formulation pharmacist. Kudalker et al 03 have described the incompatibility of the antibiotic with rancid oils, and the incompatibility with bentonite, a montomorill-onite clay, has been reported by Danti and Guth306. The incompatibility with lactose, causing a discoloration of the mixture has been studied by Hammouda and Salakawy- 0 . The amount of browning produced was shown to be dependant on the initial pH of the solution. The rate of discoloration of the lactose/neomycin powder was directly related to the temperature of storage and the relative humidity of the atmosphere. Discoloration was overcome by addition of sodium bisulphite. 

Vinyl guaiacol Musty, rancid oil, old fruit, rotten flavour [69, 74] 75 [74]... 

Azelaic acid Nonanedioic acid H02C(CH2)7C02H Rancid oils... 

The alkylhydroperoxides are also interesting because of their formation in natural products. Unsaturated fatty acids and their esters (plant oils) are oxidized in air to peroxides (auto-oxidation). This leads to a stepwise breaking of the double bonds leading to the formation of aldehydes, ketones and fatty acids, all of which make their presence known through their strong odor intensities (e.g. rancid oil). 

As illustrated by a number of recent reports, peroxidizing lipid affects protein in a variety of ways. For example. Jacks et al. (18) observed that rancid oil (P.V. = 144) had no effect on the storage protein of peanut. Other studies with lysozyme (19, 20), y-globulins and albumin (21) demonstrated considerable damage to protein. Lysozyme exposed to either peroxidizing linoleic acid or methyl linoleate resulted in mainly the formation of lysozyme dimers and trimers (19, 20),... 

Watts, B. M., Cunha, T. J., and Major, R. 1946. Effect of feeding and injecting hogs with tocopherols on the susceptibility of pork fat to rancidity. Oil Soap 83, 254. Watts, B. M., and Faulkner, M. 1953. Unpublished data. Florida State University, Tallahassee. 

Kajimoto, G. and Mukai, M. (1970) Toxicity of rancid oil. IX. Digestibility of polymerized fatty acids in thermally oxidized soybean oil. Yukagaku (J. Jpn. Oil Chem. Soc.) 19, 66-71. 

The amount of vitamin E required by the body depends upon its size and the amount of polyunsaturated fats in the diet, as vitamin E is needed to protect these fats from oxidation. The requirement for vitamin E depends upon intake of refined oils, fried foods, or rancid oils. Supplemental estrogen or estrogen imbalance in women increases the need for vitamin E, as does air pollution. The recommended dietary allowance (RDA) for vitamin E is really quite low, many people do not consume this in their diet alone. Table 19.1 lists the RDAs and tolerable upper intake levels (ULs) for vitamin E. The new recommendations for vitamin E are expressed as milligrams of RRR-a-tocopherol equivalents. Dietary supplements of vitamin E are labeled in terms of international units (lU). 1 mg of synthetic vitamin E (a//-rac-a-tocopheryl acetate is equivalent to 1 lU vitamin E, but only 0.45 mg RRR-a-tocopherol. 1 mg of natural vitamin E (RRR-a-tocopherol) provides 1.5 lU. For the LIE, the Food and Nutrition Board recommended 1000 mg of any a-tocopherol form, which is equivalent to 1500 lU RRR- or 100 lEI all-rac-a-tocopherol (Food and Nutrition Board, 2000 Hathcock et al., 2005 Combs, 2008). 

An equally undesired effect is the creation of odors in some plastics. Among the materials affected are mainly polyethylene, PVC (odor of rancid oil), and polyurethane. If the reason for the formation of the substances responsible for the odors is... 

The aroma substances that comprise flavors are found in nature as complex mixtures of volatile compounds. A vast majority of volatile chemicals that have been isolated from natural flavor extracts do not provide aroma contributions that are reminiscent of the flavor substance. For instance, n-hexanal is a component of natural apple flavor (1) however, when smelled in isolation, its odor is reminiscent of green, painty, rancid oil. Similarly, ethyl butyrate has a nondescript fruity aroma although it is found in strawberries, raspberries, and pears, it does not uniquely describe the aroma quality of any of these individual fruits. It has long been the goal of flavor chemists to elucidate the identity of pure aroma chemicals that have the distinct character impact of the natural fruit, vegetable, meat, cheese, or spice that they were derived from. Often, these are referred to as character impact compounds (2). 

In certain brilliantine compositions, vegetable and animal oils are used as substitutes for mineral oil. In these systems, because of their potential for rancidity, antioxidants must be included. Other alternatives to mineral oils that have found utiHty in brilliantines are the polyethylene glycols which come in a variety of solubiHties and spreading properties. Use of these materials offers the advantage of chemical stabiHty to rancidity. Other additives found in brilliantines to improve their aesthetics include colorants, fragrance, medicated additives, lanolin, and fatty acid esters. 

Antioxidants are used to retard the reaction of organic materials with atmospheric oxygen. Such reaction can cause degradation of the mechanical, aesthetic, and electrical properties of polymers loss of flavor and development of rancidity ia foods and an iacrease ia the viscosity, acidity, and formation of iasolubles ia lubricants. The need for antioxidants depends upon the chemical composition of the substrate and the conditions of exposure. Relatively high concentrations of antioxidants are used to stabilize polymers such as natural mbber and polyunsaturated oils. Saturated polymers have greater oxidative stabiUty and require relatively low concentrations of stabilizers. Specialized antioxidants which have been commercialized meet the needs of the iadustry by extending the useflil Hves of the many substrates produced under anticipated conditions of exposure. The sales of antioxidants ia the United States were approximately 730 million ia 1990 (1,2). 

The effectiveness of antioxidants as preservatives for fats and oils is evaluated by determining the rate of peroxide development using the Active Oxygen Method (AOM) (29). The development of a rancid odor is used to evaluate the stabiUty of food items (Schaal Oven StabiUty test) (30). 

Butter is used in some, usually more expensive, bakery foods, and is prized for its flavor contribution. Fats are used in some products such as pie cmst, croissants, or puff pastry, up to 60%, based on flour. StabiHty of fats and oils in perishable items such as breads, cakes, or pastries is of no consequence because shelf life is so limited that rancidity does not occur. In cookies and crackers, however, stable fats must be used in the formula since prolonged shelf life could lead to product deterioration with fats that develop rancidity. 

In a study of the effect of nutrition on reproduction in the rat in the 1920s, Herbert Evans and Katherine Bishop found that rats failed to reproduce on a diet of rancid lard, unless lettuce or whole wheat was added to the diet. The essential factor was traced to a vitamin in the wheat germ oil. Named vitamin E by Evans (using the next available letter following on the discovery of vita-... 

Nitrobenzene, CgH5N02, also known as oil of mirbane, is an artificially prepared benzene derivative, having a coarse, but powerful odour resembling that of oil of almonds. Its coarse odour renders it quite unsuitable for fine perfumery, but it finds considerable employment in the manufacture of cheap soaps, polishes, and other articles where more or less rancid fats are used, as it covers the bad odour of the fat and gives the product a coarse almond perfume. 

Propionic acid,. COOH, has been found in lavender and a few other oils in traces. It is a liquid of rancid odour having the following characters —... 

Butyric acid, CgHy. COOH, is an oily liquid ha-ving an odour of rancid butter. It has been found in the oils of Eucalyptus globulus, Heracleum giganteum, and in nutmeg, niaouli, and other essential oils. It has the following characters —... 

Tourill, m, bombonne, tourie (Woolfe bottle used in distilling acids), — pi. TouriUs. Tournantbl, n. rank (rancid) olive oil, Tournesol, m. litmus. 

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