Identification of Volatile Flavor Compounds of Fresh, Frozen Beef Stew and a Comparison of These with Those of Canned Beef Stew

The volatile flavor compounds of fresh, frozen beef stew were isolated, fractionated and identified by standard methodology. A total of 132 compounds was either positively or tentatively identified. A comparison of the volatile compounds and their relative amounts in the fresh, frozen stew with those previously identified in canned stew demonstrated both qualitative and quantitative differences between the volatiles of the two stews. This difference was due mostly to the greater number and amounts of the oxygen-containing compounds such as alcohols, 2-alkenals, esters, lactones, and ionones found in the fresh, frozen stew as compared with the greater number and amounts of hydrocarbons and nitrogen and/or sulfur-containing heterocycles found in the canned stew.     

Identification of 2-Pentyl Furan in Fats and Oils and Its Relationship to the Reversion Flavor of Soybean Oil

SUMMARY— 2-Pentyl furan is identified as a component of the volatile decomposition products of slightly autoxidized soybean and cottonseed oils and those of thermal oxidation of corn oil and hydrogenated cottonseed oil. The flavor threshold of this compound in oil at room temperature is 1 ppm. At concentrations of 1-10 ppm, it imparts to the oil a characteristic beany odor and flavor reminiscent of those of a reverted soybean oil. Expert organoleptic panels consistently identified a deodorized cottonseed oil containing 5 ppm of 2.pentyl furan as a reverted soybean oil. It is proposed that this compound is formed by autoxidation of linoleic acid.     

CHANGES IN LEAD CONCENTRATION OF FOODS STORED IN THEIR OPENED CANS

A study was made of the effect on the concentration of lead in canned fruits and juices when these food products are stored in their original containers after opening. Samples stored in a refrigerator were analyzed for lead upon initial opening, 2 days after opening, and 5 days after opening. Products in nonlacquered cans showed significant increases in lead concentration with time. The increase of lead in the food product could have an effect on estimates of average dietary intakes of lead if this practice is found to be widespread.     

EFFECT OF RAPID COOLING OF SHELL EGGS ON MICROCRACK DEVELOPMENT, PENETRATION OF SALMONELLA ENTERITIDIS, AND EGGSHELL STRENGTH

Eggs were subjected to cryogenic cooling treatments using liquid CO₂ or liquid N_2. In order to minimize the thermal stress in eggshells due to rapid cooling, a two-stage air-cooling method was also evaluated in this study. Eggs were cooled from an initial temperature of 25C to approximately 7C. It was found that cooling produced microcracks on eggshells. However, rapid cooling did not increase the penetration of Salmonella enterica serovar Enteritidis (Salmonella enteritidis) into egg contents. When egg contents alone were sampled for Salmonella enteritidis, extending the immersion time from 24 to 48 h significantly (P < 0.01) increased the penetration of Salmonella enteritidis from 5.0 to 25.0%. When egg contents together with eggshells were sampled, Salmonella enteritidis was detected in 100% of the egg samples at the above two time intervals. There were no significant differences (P > 0.05) in the eggshell strength between control (no cooling) and cooling treatments, indicating that cooling did not weaken eggshell strength.     

Modelling Musical Perception: A Critical View

This is a study of two attempts to develop quantitative models of timing in music performance, one based on connectionism and the other involving the autocorrelation function. The former is concerned with the ‘quantization problem’ of interpreting durations of time from a musical performance as note shapes which represent duration in music notation. The latter is an attempt to represent what makes such performances ‘‘expressive ’. These models were derived by Peter Desain, but there is a paucity of validating data in the published literature. Attempts to collect additional data have revealed significant shortcomings in both models, as well as methodological flaws. The most important problem is that the attempt to solve the quantization problem lacks any representation of high-level structure. As a result, if the music itself tends to be based on relatively irregular rhythmic patterns, the connectionist model can distort even a metronome-perfect performance, rather than recognizing the correct temporal patterns. Attempts are made to explain how these shortcomings may have arisen.     

Stability of Mackerel Surimi Prepared under Lipid-Stabilizing Processing Conditions

Surimi from mackerel whole and light muscle was prepared under conditions designed to minimize oxidation and development of rancidity. The lipid-stabilizing procedure included early addition of both lipid-and water-soluble antioxidants, avoidance of added sodium chloride, and exclusion of oxygen. Surimi prepared from light muscle was stable to rancid odor development in both the raw and cooked form; gel strength was reasonably stable during frozen storage, although the color was somewhat dark. Surimi prepared from mackerel whole muscle was darker, its odor quality lower and less consistent, and its gel strength lessened more rapidly during frozen storage than surimi prepared from light muscle.     

In-line viscometry in the dairy processing industry

The viscosity of a fluid, or fluid like material, is a measure of its resistance to flow. Many foods are fluid in nature, as final products and/or during production. The viscosity of the final product is an indicator of product consistency and can determine consumer preferences. During production a suitable and reliable in-line viscometer can help monitor the process, optimize yield, increase efficiency, reduce costs, enable a degree of automated control and improve final product consistency and quality. Whether such goals can be achieved in practice depends on many factors. This paper gives an overview of these factors.     

MULTIELEMENT ANALYSIS OF FOODS STORED IN THEIR OPENED CANS1

A multielement analysis of canned foods was performed on foods stored in their opened containers. Canned fruits and fruit juices were sampled upon initial opening as well as two and five days after opening. After mineralization, the samples were analyzed for 25 elements using an inductively coupled argon plasma. The following elements were quantitated: Al, Ca, Cu, Fe, Mg, Mn, Ni, P, Sn, Ti, and Zn. The concentration of Fe and Sn increased between successive sampling days. These increases did not exceed permissible limits of Sn in canned foods and the Fe concentrations may be of nutritional interest. A decrease in the concentration of P between successive sampling days was associated with insoluble material formation. Scanning electron microscope micrographs coupled with X-ray fluorescence analysis of the can interior surfaces were used to characterize the corrosion of the interior surface of the cans.     

Interaction of ultraviolet light, chemicals and cultured mammalian cells: photobiological reactions of halogenated antiseptics, drugs and dyes

We have successfully demonstrated that cells in culture are sensitive to damage produced by a variety of phototoxic agents. Differences in the apparent sensitivity of the three cell systems employed (photohaemolysis, phototoxicity to macrophages and to Chinese hamster CHV79 cells) have been exploited to reflect the mechanism of action of the phototoxic materials. Overall four distinct patterns of phototoxic response were observed which indicate specific sites of action of the phototoxic materials within the cell. Of the two halogenated antiseptics tested 3,3',4',5-tetrachlorosalicylanilide (T₄CS) was phototoxic and 3,4,4'-trichlorocarbanilide (TCC) was not; of the drugs both 8-methoxypsoralen (8-MOP) and chlorpromazine (CP) were phototoxic; and of the three dyes rose bengal (RB) and Blankophor (FB) were phototoxic and Tinapol (EMS) was not. Phototoxic cellular damage produced by CP, RB and FB could be totally prevented by continuous gassing with O₂-free, 5% CO₂ in N₂. T₄CS and 8-MOP phototoxic cellular damage was found to proceed independently of the presence or absence of O₂.