Showing papers in "Critical Reviews in Food Science and Nutrition in 1973"

Pyrazines in foods

Abstract: Because of their unique organoleptic properties, pyrazine compounds have recently been receiving increased attention in food related areas. Numerous compounds have been detected in foods, and others have been synthesized and promoted as flavoring agents. This review provides the reader with a composite appreciation of pyrazines in foods. A total of ten areas is discussed. The introduction section assesses the increasing role of pyrazines in food flavor. This is followed by a detailed discussion of the food systems and types of pyrazines found to date. Pyrazine isolation, concentration, and fractionation techniques are discussed. The flavor properties including odor descriptions and thresholds are reported. Various pyrazine formation pathways in food systems are also reviewed. The role of pyrazines in flavor applications, including pertinent patents, are also discussed. This is followed by a detailed section on pyrazine synthesis techniques. The last section deals specifically with identification technique...

Recent research and development in the field of low‐moisture and intermediate‐moisture foods

Abstract: The article reviews current state of knowledge and the most recent research and development in the following areas: the state of water in foods and its effect on food properties; recent developments in dehydration process other than freeze drying, with an emphasis on research on the role of physical properties of foods and how they affect the dehydration processes Recent developments in freeze dehydration Research progress in mechanisms of flavor retention in dehydrated foods Recent developments in intermediate moisture foods

Eggs as a source of protein

Abstract: With the advent of formulated and fabricated new products in the food industry and the shift from the art of “mixology” to the science of “functionality” it has become important to maximize the functional properties of various proteins on a unit basis. This review will attempt to interrelate the biochemical properties of egg proteins including the albumen and yolk with their functional properties. The foaming (whipping), binding and emulsifying properties of egg proteins will be discussed. The uniqueness of the gel structure of the fresh egg white, its deterioration on aging, and the interaction of the complex system of proteins will be reviewed. Emphasis will be placed on the effect of processing on the biochemical and functional changes of egg proteins. The chemical and enzymatic modification of the egg white and egg yolk proteins will be discussed.

Fresh meat color

Abstract: This review presents a critical evaluation of the recent developments in the study of fresh meat color. Importance of color as a primary quality attribute deciding the consumer acceptance of fresh meats, is pointed out. The stability of myoglobin pigment, essential for the maintenance of fresh meat color, is examined in the light of 3‐dimensional structure of the molecule. The dynamic and reversible nature of color cycle involving constant oxygenation, oxidation, and reduction is emphasized. Oxygenation and oxidation are discussed on the basis of thermodynamic principles. The factors affecting fresh meat color are examined. The enzymic and nonenzymic metmyoglobin reducing systems are discussed in relation to fresh meat color. A full discussion on the inter‐relationship between lipid and pigment oxidation is presented. Recent developments on the methodology of color measurement are traced, pointing out the advantages and limitations of various methods.

Assessment of nutritive value, quality, and stability of cruciferous vegetables during storage and subsequent to processing

Abstract: Today the world is confronted with the need for additional food sources which should be easily available, cheap in cost, and high in nutritive value. This article is focused on these interests and critically reviews literature relating to cruciferous vegetables which are able to fulfill the needs. Among the horticultural considerations, the effects of variables such as cultivars, light intensity, growing season, climate and locations, soil fertility, and irrigation, on the nutritive value of these crops are examined. Statistical data from governmental and institutional studies are collected and analyzed to consider the production and performance aspects. Concerning the toxicological considerations, roles that the progoitrogenic thioglucosides play inside the body and the possible correlation between flavor and toxic components are elucidated. Emphasis has been placed on the effects of various handling, processing and storage processes on the nutritional retention of the product. Different processing metho...

Salmonella and the food industry ‐ methods for isolation, identification and enumeration

Abstract: The presence of Salmonella in foods is a continuing problem for the food industry. These organisms are frequently found in food products of animal origin. In particular, turkeys and chickens were implicated in 36% of the food‐borne outbreaks reported in 1971. This review discusses the various procedures that can be used for isolating, identifying, and enumerating Salmonella in foods and the advantages and limitations of these procedures. Some of the methods for rapid detection of salmonellae such as enrichment serology and fluorescent antibody procedures are considered. It is pointed out that at the present state of development, none of the rapid methods can be substituted completely for conventional cultural methods in isolating and identifying salmonellae in foods.

The role of enzymes in food flavors part I: Dairy products

Abstract: The role of enzymes in the development of dairy flavors is critically reviewed. The chemistry and mechanisms of flavor development are discussed in detail. An attempt has been made to provide an objective approach to both desirable and undesirable flavor problems associated with the action of milk and microbial enzymes on various milk constituents.

Developments in technology and nutritive value of dehydrated fruits, vegetables, and their products

Abstract: Remarkable developments in technology of dehydrated fruits, vegetables, and their products have been made during the past several decades. Many dehydration techniques that have shown to be applicable for drying fruits and vegetables are widely adapted by the industry for commercial'scale production while constantly undergoing improvement. At the same time, various new techniques are also being developed and introduced to the public. A compilation of information along with assessing the merit on current technology of dehydration of fruits, vegetables, and their products would benefit not only those who are engaged in this rapidly growing industry but also those who are interested in developing a better way to preserve the highly nutritious fruits and vegetables. For each of the currently known dehydration techniques, a condensed description of the principle, operation, advantages, and limitations will be presented with the kind of fruits and vegetables being dehydrated. Next, the storage stability of dehyd...

Chemistry and biological function of α‐lactalbumin

Abstract: α‐Lactalbumins, a family of low molecular weight single‐chain globular proteins, are synthesized under hormonal control by the mammary glands of all mammals capable of lactose synthesis shortly before and after parturition and make up to 0.12% (w/v) of the final secretory product, i.e., the milk. The most intensively characterized of all are the bovine α‐lactalbumins from various species in terms of the molecular size, amino acid composition and sequence, immunological cross‐reactivity, and even their capacity to modify the rate of galactosyltransferase activity. ?‐Lactalbumins and lysozymes exhibit considerable degree of amino acid sequence (primarily structure) homology and similarity in their covalent structures. The up‐to‐date theoretical and experimental reports on the similarity of molecular conformations and three‐dimensional structures of the two families of proteins, presumably of common ancestry, are more transgressive than confirmatory at the present time. The preceding facts, along with the re...

Microwave heating of foods ‐ use and safety considerations

Abstract: The current status of microwave ovens and the practice of heating foods with microwaves are reviewed. Particular attention is paid to biological and health considerations, with the objective not to hinder the growth of microwave technology, but to illuminate its public health aspects to allow future growth and acceptance through proper research and design.

Recent research on Olfactton

Abstract: The marked interest demonstrated for the last decades in research on olfaction has not yet abated. However, after the publication of an extremely large number of theories tending to explain such and such a point in the mechanism of olfaction, it appears necessary to stop and consider in what fashion the accepted theories have undergone confrontation with more extensive experimentation. One should also verify whether the objections that have caused rejection of certain theories are still to be considered in the same light (since new facts may cause review of a lawsuit). The application of electrophysiological methods to olfactic research constitutes the outstanding novel fact of the century in this field. However, a finer understanding and the accumulation of experimental data make it more difficult to interpret the results obtained by such techniques. A number of physiologists whose works are authoritative in the field of olfaction, Moulton and Beidler, Doving, Ottoson and Shepard, and Dravnieks, felt tha...