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The development of warmed over flavor (WOF) in cooked chevon was monitored from its Tenax trapped volatiles by direct gas chromatography (GC). WOF markers, pentanal, hexanal, heptanal, 2,-3-octanedione and nonanal were identified from volatile profiles obtained with packed poly MPE coated Tenax-GC column. These volatile markers as well as the total volatiles increased over 6 days storage of cooked chevon at 4°C. Increase in hexanal was more rapid than the other WOF markers. Results suggest WOF development in cooked chevon is more rapid than reported rates for other cooked meats.

Samples of three commercial brands of peanut butter stored in the dark at about 25°C were evaluated periodically by direct gas chromatography and by their processors' taste panels. The areas of 9 peaks of each volatiles profile were computed and correlated with flavor scores. The natural logarithm of methyl-butanal peak area/hexanal peak area correlated with flavor score of peanut butter in earlier work, correlated well with flavor score for one brand of peanut butter, but other gas chromatographic peak ratios gave better correlations for the two other brands.

A simple, rapid, unconventional gas chromatographic procedure is described for objectively assessing the flavor (odor) quality of commercial egg products. The method requires no prior distillations or other means for the enrichment of volatiles. Samples can be analyzed with less than .5 g of product. The technique provides a tangible profile of volatiles that may be examined immediately or retained for future comparative use. The objectivity of instrumental assessment of volatiles precludes the subjective variations inherent in conventional organoleptic evaluations.

Profiles of volatiles of whole rice, brown rice, polished rice, rice bran, rice breakfast cereal, whole corn, and corn breakfast cereal were obtained by direct gas chromatography without prior enrichment of volatiles. Some of the volatiles were identified by combined gas chromatography-mass spectrometry. Methanol, acetaldehyde, ethanol, acetone, pentanal, hexanal, and hexanol were found in volatiles of whole rice, brown rice, polished rice, rice bran, and whole corn. In addition, 2-methylpropanal, 2methylpyrazine, furfural, 2,5-dimethylpyrazine, benzaldehyde, and 2,6-dibutyl-4-methylphenol were found in rice and corn breakfast cereals. This unconventional gas chromatographic technique in combination with mass spectrometry should provide a rapid means of analyzing volatiles that might impart desirable flavor or undesirable off-flavor in new cultivars and in raw and processed cereal products, before and after storage. Even at this early stage of development, the methodology is being used by industry to monitor raw materials.

Description d'une methode de recuperation et d'identification d'une cinquantaine de composes heteroatomiques, la plupart cycliques, dans de la viande de boeuf broyee ou deshydratee et dans un extrait de viande

Two methods were compared for quantitative determination of trace amounts of mesityl oxide and diacetone alcohol in acetone-extracted oilseed meals and flours. In the first, a simple, rapid and direct gas chromatographic procedure, a 0.04 g sample of oilseed meal or flour was placed between 2 small glass wool plugs in a liner of the injection port of a gas chromatograph. Water-saturated molecular sieve 5A (1.1 g) was added over the glass wool sandwich, and the liner was placed in the heated injection port and firmly secured. Mesityl oxide and diacetone alcohol, and other volatiles, were eluted rapidly from the sample onto the column by the combined action of heat, moisture, and carrier gas. The components then were resolved readily by temperature-programed gas chromatography on a 2 ft × 1/4 in. Porapak P column. The second method, which is time consuming and tedious, is a modification of the Todd azeotropic distillation procedure and was included, for comparison, as a conventional measure of the concentrations of mesityl oxide and diacetone alcohol. Samples of oilseed meals and flours were analyzed by both methods. The results are compared, and the relative merits of the two procedures are discussed.

A simple, efficient, external inlet assembly is described for analyzing volatile components in raw and processed foods by direct gas chromatography and mass spectrometry. The device comprises three sections: a sample inlet, a condenser, and a six-port rotary valve. The versatility and effectiveness of this assembly is demonstrated by the analysis and identification of volatiles from diverse food products as salad oils, vinegar, and corn-soy food blends. The procedure is rapid, efficient, and offers the following desirable features: it is compatible with all commonly used chromatographs and can accomodate samples of different size; sample volatiles are obtained without use of prior enrichment techniques, at ambient or elevated temperatures; uniform heating enhances volatiles elution, thereby improving sensitivity; moisture and air are removed to facilitate mass spectral analysis; the closed nature of the system minimizes loss of low molecular weight volatiles during elution, thus producing a highly reliable pro-file of volatiles.

The lathyrogenic entity of the Singletary pea is γ-glutamyl-β-aminopropionitrile. The toxicity resides in the β-aminopropionitrile portion of the molecule. A qualitative test was developed which showed the presence of γ-glutamyl-β-aminopro-pionitrile and the absence of free β-aminopropionitrile in the seed of Lathyrus odoratus and Lathyrus pusillus. This test was negative for both compounds when applied to seed of the reportedly more toxic L. latifolius.

Water-resistant, in tumescing fire-retardant paints have been formulated from different types of chemically modified oil-based vehicles, carbonific polyurethanes, spumific melamine phosphates, spumific organohalophosphorus compounds, additives, pigments, driers and solvent. The synthesis of their three major components—the vehicle itself, the spumific melamine phosphates and the carbonific polyurethanes—is described. As a result of evaluation in the standard fire-test cabinet and in the Underwriters' Laboratories' 25-ft tunnel furnace, the formulation whose vehicle has a higher content of tung oil and whose carbonific components are less thermoplastic appear to be most promising. However, these research results have again manifested the importance of the contribution ofeach component in achieving effective fire retardance.

Vinyl 12-ketostearate and vinyl 4-ketostearate were prepared by vinylating 12-ketostearic and 4-ketostearic acids, respectively, with vinyl acetate in the presence of a mercuric sulfate catalyst. The crude vinyl esters were purified by extracting the free fatty acids with dilute potassium carbonate, removing the mercury by distillation, and crystallizing successively from acetone and pertroleum ether.

Ricinoleic and acid oleic acid derivatives were screened for their antimicrobial activity, under optimum growing-conditions, against several species of bacteria, yeasts, and molds. Several ricinoleic acid derivatives and petroselinic (iso-oleic) acid exhibited considerable activity; in fact, their activity against some micro-organisms was comparable to sorbic and 10-undecenoic acid, known antimicrobial agents, as indicated by this test.

A simple, direct, gas chromatographic technique is described for the quantitative determination of residual hexane in extracted vegetable oils. The method if rapid and sensitive to one ppm hexane. The inlet liner of a gas chromatograph was packed with 1 1/2 in. glass wool, and 25 mg oil was added onto it. The sample was capped with a small plug of glass wool, and the liner was inserted in the heated inlet of the gas chromatograph. Residual hexane rapidly eluted onto the Poropak P column by heat, and carrier gas was resolved in 20 min by temperature programing between 70–180 C. The method appears useful for monitoring continuous solvent removal processes.

A simple and efficient procedure is described for the quantitative determination of ipomeamarone in sweet potato products. The method is rapid and sensitive to 1 ppm. Sweet potato shreds or mash are comminuted and extracted in a blender with a mixture of chloroform, methanol, and water. After filtering the homogenate, the chloroform layer is dried and evaporated under vacuum. The residual oily material is dissolved in a known volume of chloroform and analyzed quantitatively by gas chromatography. The method was applied to blemished and diseased sweet potatoes before and after processing. Although the method indicates that blemished and diseased sweet potatoes have a relatively high concentration of ipomeamarone, it also reveals that peeling and trimming raw, baked, or boiled sweet potatoes leaves healthy tissue with little or no detectable ipomeamarone. Neither baking nor boiling appears to promote diffusion of ipomeamarone into the healthy tissue; however, baking appears to reduce the concentration of this hepatotoxin. American and Japanese investigators have isolated several furanoterpenoid toxins from blemished and diseased sweet potatoes and have shown that ipomeamarone, the most common of these metabolites, produces liver necrosis in mice and other animals (Wilson and Hayes, 1973). Since most sweet potatoes are consumed as human food or animal feed, it is essential to determine the presence of this hepatotoxin in sweet potato products. Although several procedures are available for the determination of ipomeamarone (Boyd and Wilson, 1971; Wood and Huang, 1975; Coxon et al., 1975), we needed more practical methodology for our survey. A modified method of analysis was developed that permits rapid and efficient quantitative determination of ipomeamarone in sweet potato products. This procedure also indicates that ipomeamarone is concentrated primarily in the blemished and diseased tissue of the sweet potatoes. MATERIALS AND METHODS Sweet Potato Samples. Blemished and diseased sweet potatoes were selected either from discarded potatoes at the grading line of packing sheds or from washed potatoes that became blemished and diseased in storage.

Seafood products such as fish, crabs, shrimp and the aqueous solution from oysters, were analyzed for volatiles content by direct gas chromatography and mass spectrometry. Compounds were detected and identified which appear to be associated with freshness quality of the products. The data obtained suggests that the changing composition attending storage of seafood products can be effectively and rapidly analyzed by objective instrumental means.

The direct gas chromatographic procedure for analysis of the volatiles of peanut butter and other food products was applied to raw peanuts. A glass liner packed with ground, raw peanuts was placed in the heated inlet of a gas chromatograph and allowed to remain in place while the volatiles distilled out of the sample onto the head of a cool column. The liner was then removed and temperature programming was begun. Raw, Virginia type peanuts from the 1974 and 1975 harvests were analyzed, and some gas chromatographic data were correlated with flavor scores of the roasted peanuts. Ethanol was the predominant volatile component, and it tended to increase as flavor quality decreased. The correlation coefficients, significant at the 1% level, between the flavor scores and the ratios of ethanol-to-methanol and ethanol-to-total volatiles were −0.87 and −0.88, respectively.

A rapid and direct gas chromatographic procedure is described for the quantitative determination of residual hexane in finely ground oilseed meals and flours. A 0.04 g sample of meal or flour is added between two small plugs of glass wool in a liner of the injection port of a gas chromatograph. The liner with the sample is placed in the heated injection port and firmly secured, and 80 μl of water is immediately injected just above the glass wool which covers the sample. Volatiles which are rapidly eluted from the sample are then analyzed by temperature-programmed gas chromatography on a 2 ft × 1/4 in. Porapak P column. The results are comparable to the results obtained by the simple and efficient but more time consuming volatilization procedure. Since results are obtained within 20 min, this rapid procedure is very useful in monitoring desolventization processes.

Eight nitrogen-containing derivatives of ricinoleic acid, namely, 4-ricinoleoylmorpholine, 4-(12-hydroxystearoyl) morpholine, 4-(12-acetoxyoleoyl) morpholine, 4-(12-acetoxystearoyl) morpholine, 4-(12-β-cyanoethoxyoleoyl) morpholine, 4-(12-β-cyanoethoxystearoyl) morpholine, 1,12-bis(β-cyanoethoxy)-9-octadecene, and 1,12-bis(β-cyanoethoxy)octadecane were screened for their plasticizer characteristics. 1,12-Diacetoxy-9-octadecene and 1,12-diacetoxyoctadecane were also screened to compare cyanoethylated with acetylated derivatives.

A simple, rapid and direct gas chromatographic technique was developed for the examination of volatiles in salad oils and shortenings at the 10 ppb level without prior enrichment. The liner of the inlet of the gas chromatograph is carefully packed with volatile-free glass wool to allow slow diffusion of the sample on the glass wool, but to prevent seepage onto the gas chromatographic column. The liner with sample is inserted in the heated inlet, and the volatiles are eluted rapidly from the samples as the carrier gas flows through the linear and sweeps the volatiles onto the column, which is temperature-programed between 55 and 190C to resolve the volatiles. Numerous samples of salad oils and shortenings were examined, and the better quality oils had only small amounts of volatiles.

The oxidation of unsaturated fatty acids initially involves the formation of their hydroperoxides. Once these products are formed, they can be decomposed or further oxidized to secondary products such as alcohols, acids, ketones, and aldehydes that are capable of reacting with other constituents of food such as amino acids, proteins, enzymes, and vitamins. These reactions can have an adverse affect on the nutritive value and quality of their respective foods. Additionally, as witnessed in other chapters of this book, the free radicals generated by the oxidative mechanisms have been implicated in reactions that can lead to pathological changes in animal and human tissue.

Two simple but effective pilot-plant processes were developed to produce Halphen-negative cottonseed oil. Both involve treatment of the oil with cottonseed fatty acids in a conventional batch type of deodorizer in conjunction with deodorization. In one process, in which the acids were added to the oil, the cyclopropenoids were inactivated in as short a time as 5 min after the oil reached the maximum temperature of 450–455 F. In the other, in which the acids were generated in situ, the oil did not become Halphennegative until about an hour and 45 min after it reached maximum temperature. The excess acids produced by both methods were readily removed during conventional deodorization. In contrast, deodorization alone reduced the cyclopropenoid content of the oil to a low level (0.02%) but did not render it Halphen-negative even after 3 hr at maximum temperature.

A simple, rapid, efficient procedure for analyzing the volatile components in salad dressings is described. A unique inlet system, used in conjunction with gas chromatography and mass spectrometry, provides an objective, tangible profile of volatiles characteristic of the product. The individual components may be identified to qualify more effectively the odor and flavor quality of the specimen.

A procedure for the isolation from Singletary pea (Latbyrus pusillus) seed of a crystalline, nitrogen-containing organic compound is given. This material produces in albino rats the syndrome associated with the ingestion of large quantities of the seed. On the basis of certain differences in properties it is suggested that more than one toxic material will eventually be isolate from the members of the genus.

A simple volatilization procedure was developed for the determination of residual acetone in oilseed meals and flours. One gram of meal or flour and 0.2 g of water containing 0.4 mg of methanol are added into a 100 ml serum bottle, which is sealed and heated at 70 C for 5 hr in an oven. A 1 ml aliquot of the headspace gas is then analyzed by gas chromatography. The concentration of residual acetone is easily determined by comparing the ratio of the peak areas of acetone to methanol of the chromatogram with a calibration curve. Results are reproducible within ± 10%, and concentrations of a few ppm can be detected. This technique is much simpler and requires less operator time than other procedures available.

A simple and very sensitive technique was devised to analyze volatiles in vegetable oils by direct gas chromatography. A large sample of oil is diffused on glass wool in an injection port liner. After the liner is inserted in the injection port, the volatiles are rapidly swept into the column of the gas chromatograph for analysis.