Showing papers in "Critical Reviews in Food Science and Nutrition in 1983"

Glucosinolates and their breakdown products in food and food plants

Abstract: This review surveys the occurrence, analysis, and properties of glucosinolates and derived compounds in plants and products intended for humans and animal consumption. The paper, which includes references published in 1981, is also intended to compliment existing reviews on the chemistry of these sulfur‐containing natural products. Particular emphasis is placed upon members of the Brassica family because of their importance as vegetables, condiments, oilseeds, and animal feedingstuffs. Since much of the work considered here relates to glucosinolate decomposition products, biochemical information concerning the nature, occurrence, and properties of the glucosinolate‐degrading enzyme, myrosinase, is considered in Section III. The methods available for the chemical analysis of glucosinolates and their various breakdown products are discussed critically. Factors affecting the glucosinolate content of plants and plant products arc outlined in Section VII. Particular emphasis is placed upon the effect of proces...

Ginger--chemistry, technology, and quality evaluation: part 1.

Abstract: Ginger is used in more ways than any other spice. This monograph, published in two parts, comprehensively reviews production, trade, processing, chemistry, and evaluation of quality. Botany, world varieties, agronomy, crop improvement and potential are reviewed briefly with emphasis on the yield of functional components. Processing for the market, international trade patterns, and factors influencing them are discussed. Derived products such as ginger powder, syruped ginger, volatile oil, and oleoresin are discussed in greater detail. The increasing world demand for quality products of added value such as the oleoresin and volatile oil show prospects for their production in the growing countries. The chemistry of the components which contribute aroma and pungency that characterize ginger is critically reviewed. The second part deals with evaluation of quality. The physico-chemical parameters prescribed as a measure of quality for ginger and its products in the existing standards can assure only hygienic quality and purity, and possibly the source, when new parameters such as GC-fingerprints are included. The importance of sensorily evaluating flavor quality is emphasized to understand the variation in flavor quality required by the industrial and retail markets. Related areas, such as problems in sensory evaluation of intense flavored substances, objective flavor profile analysis, and correlation of instrumental and sensory data, are discussed and our recent work in this area is summarized. Areas where more research are needed are indicated. Other areas briefly discussed are functional, physiological, and toxicological properties in use of ginger; biosynthetic aspects of the components stimulating flavor; and structure and pungency and chemistry of spices from allied species and genera. A comprehensive bibliography is provided to aid in further study and research.

Functionality of muscle constituents in the processing of comminuted meat products

Abstract: Emulsification through the creation of a fat dispersion and formation of an interfacial protein membrane at the fat-water interface is not the sole aspect responsible for comminuted meat "emulsion" stability. In addition, water binding which occurs initially during myofibrillar protein extraction from tissue disruption, and later during entrapment within the heat-induced protein gel matrix, must be included. The criteria that affect formation of the gel matrix adds another aspect, in that conditions for optimum protein-protein interaction also influence ultimate water and fat stabilization. Rheological considerations are in their infancy and will require future study, particularly during the transformation of a "flowing" batter into a "nonflowing" solid product. This review has been aimed at emphasizing that the myofibrillar protein component is the predominant constituent involved in an interactive role with water, fat, and itself, in forming the ultimate stabilized comminuted meat matrix.

Review of Apple Flavor--State of the Art

Abstract: The retention flavor is of utmost importance during the harvesting, handling and/or further processing of apples. The complexity of the natural flavor of the apple or essence derived therefrom is attributed in part to the variety, post-harvest treatment, storage, and process manipulation. Some 266 volatile components isolated from apples include alcohols, esters, aldehydes, ketones, ethers, acids, bases, acetals, and hydrocarbons. This review is a survey of the literature published during the last 10 to 15 years and includes the contribution of peel to flavor, postharvest quality indices related to flavor, storage and dehydration effects on flavor, juice extraction methods, sensory evaluation, and volatile separation and identification techniques.

Chemical, biochemical, and biological significance of polyphenols in cereals and legumes

Abstract: Polyphenols in cereals and legumes have been receiving considerable attention largely because of their adverse influence on color, flavor, and nutritional quality. These compounds belong to the flavonoid and tannin groups and are mostly located in the seed coat or pericarp of the grains. The pearl millet flavonoids have been identified as C-glycosylflavones by the combined use of paper chromatography and UV spectroscopy. Although nontoxic, physiological and nutritional significance of these compounds occurring in high amounts in the pearl millet grain are still not clearly understood. In view of aesthetic quality, bleaching of the millet grains in acidic solution is recommended. A large proportion of current assays involves spectrophotometry of tannin or its chromogen and tannin-protein interaction. Sorghum and legume tannins have been characterized as condensed tannins. Several factors such as plant type, age of the plant or plant parts, stage of development, and environmental conditions govern the polyphenol contents in plants. Polyphenols are known to interact with proteins and form tannin-protein complexes leading to either inactivation of enzymes or making proteins insoluble. These are implicated in decreasing the activities of digestive enzymes, protein and amino acid availabilities, mineral uptake, vitamin metabolism, and depression of growth. Polyphenols are known to cause certain ultrastructural changes in the different parts of experimental animals. A correlation between dietary tannins and occurrence of esophageal cancer has been established. Bird resistance and seed germination in food crops have been correlated to high contents of polyphenols. The antinutritional activity of polyphenols can be reduced by removing polyphenols from the grains by chemical treatments or removing pericarp and testa by pearling. Treatment of alkaline reagents and ammonia can remove 90% of the polyphenols. Supplementation of polyphenols-rich diet with protein can alleviate the growth-depressing effect of polyphenols.

Ginger — chemistry, technology, and quality evaluation: Part 2

Abstract: Ginger is used in more ways than any other spice. This monograph, published in two parts, comprehensively reviews production, trade, processing, chemistry, and evaluation of quality. Botany, world varieties, agronomy, crop improvement, and potential are reviewed briefly with emphasis on the yield of functional components. Processing for the market, international trade patterns and factors influencing them are discussed. Derived products such as ginger powder, syruped ginger, volatile oil, and oleoresin are discussed in greater detail. The increasing world demand for quality products of added value such as the oleoresin and volatile oil show the prospects for their production in the growing countries. The chemistry of the components which contribute aroma and pungency that characterize ginger is critically reviewed. The second part deals with evaluation of quality. The physicochemical parameters prescribed as a measure of quality for ginger and its products in the existing standards, can assure only hygienic quality and purity, and possibly the source, when new parameters such as GC-finger prints are included. The importance of sensorily evaluating flavor quality is emphasized to understand the variation in flavor quality required by the industrial and retail markets. Related areas, such as problems in sensory evaluation of intense flavored substances, objective flavor profile analysis, correlation of instrumental and sensory data are discussed, and our recent work in this area is summarized. Areas where more research is needed are indicated. Other areas briefly discussed are functional, physiological, and toxicological properties in use of ginger; biosynthetic aspects of components stimulating flavor; structure and pungency and chemistry of spices from allied species and genera. A comprehensive bibliography is provided to aid in further study and research.

Nitrite, nitrite alternatives, and the control of clostridium botulinum in cured meats

Abstract: Historically, nitrite has been a component of meat-curing additives for several centuries. In recent years the safety of nitrite as an additive in cured meats has been questioned mainly because of the possible formation of carcinogenic nitrosamines. Nitrite has many important functions in meat curing including its role in color development, flavor, antioxidant properties, and antimicrobial activity. The inhibition of Clostridium botulinum growth and toxin production is an especially important antimicrobial property of nitrite. This review discusses the effects of processing, curing ingredients (especially nitrite), and storage of cured meats in relation to the control of C. botulinum. If nitrite is eliminated from cured meats or the level of usage decreased, then alternatives for the antibotulinal function of nitrite need to be considered. Several potential alternatives including sorbates, parabens, and biological acidulants are discussed.

Chemical and physical modification of proteins by the hydroxide ion.

Abstract: Proteins are exposed to alkaline conditions during solubilization and/or purification, during food storage and processing, in removal of toxic constituents, and for characterization. During alkali treatment, there are changes in solubility and aggregation, hydrolysis, elimination reactions involving the side chains of certain amino acids, racemization of amino acid residues, addition of compounds to proteins, fragmentation of the peptide chain, as well as modification or elimination of nonprotein constituents. The rates of these reactions are affected by pH, temperature, cations (in some cases), ionic strength (in some cases), protein concentration, and to some extent by the specific nature of the protein. The general mechanisms and stoichiometry of these reactions are described. Other constituents of high protein foods also undergo reactions in alkaline solutions and the products of these reactions may in turn react with proteins. We have described the effect of alkali on enediol formation and fragmentation of carbohydrates, the hydrolysis of lipids in alkaline solution and effect on rate of peroxidation of the polyunsaturated fatty acids, the oxidation of amino acid residues, especially methionine, the oxidation of phenols to benzoquinones, and the catalytic effect of metal ions in alkaline solutions. Alkali treatment is also used in the specific modification of proteins to distinguish between O-glycosyl and amide-linked glycosyl groups, to effect specific cleavage of peptide bonds via beta elimination, in the formation of anhydrotrypsin, anhydrochymotrypsin, anhydrosubtilisin and thiol-subtilisin, and in formation of intrachain crosslinking in proteins.

Carotenoids as food colorants

Abstract: The carotenoids are a chemically related group of pigments which occur widely and abundantly in nature. Fruits, vegetables and vegetable oils, dairy products, leaves, shrimp, lobster, the plumage of exotic birds, all contain carotenoids. Chemically, the carotenoids may be divided into carotenes, made up of carbon and hydrogen only, and oxycarotenoids containing oxygen in addition to carbon and hydrogen. The use of carotenoid‐containing plant extracts for coloring foods has been practiced for centuries and continues today. Advances in chemical synthesis resulted in the complete laboratory synthesis of beta carotene in 1950. Since then the commercial synthesis of several carotenoids has been accomplished. In the U.S. three of these commercially synthesized carotenoids, beta‐carotene, beta‐apo‐8'‐carotenal, and canthaxanthin, are accepted color additives for use in foods and are exempt from certification. These three carotenoids are also widely accepted for food use in other countries. This paper deals with ...

Buckwheat: structure, composition, and utilization.

Abstract: This is a review of production and cultivation methods of the accepted types and varieties of buckwheat. A brief description of seed characteristics and structure is followed by a detailed review of seed composition (carbohydrates, proteins, enzymes, lipids, and miscellaneous compounds) in mature and maturing buckwheat. A major part of the review deals with buckwheat uses as food, feed, honey, and rutin. Mechanical processing, thermal treatment, specific food uses, standard specifications, and changes during storage are covered. The review ends with a projection into the future and research needs.

Citrus fruits — Varieties, chemistry, technology, and quality evaluation. Part II. Chemistry, technology, and quality evaluation. A. Chemistry

Abstract: In Part 2 of this review on citrus fruits, the literature on chemistry, technology, and quality evaluation are critically considered. Sweet oranges, mandarin, grapefruit, lemon, and lime are generally used for processing. The literature on chemical components of citrus fruit which include sugars, polysaccharides, oraganic acids, nitrogenous constituents and lipids; carotenoids which contribute to color; vitamins and minerals, and flavonoids; limonoids, some of which impart bitterness to the juice; and the volatile components which contribute to aroma have been reviewed. Chilled and pasteurized juices, juice concentrates, and beverages are the important products manufactured commercially, and to a limited extent powdered citrus juices, canned segments, and marmalades. The literature on the manufacture of these products also as new types of juice and oil extractors; TASTE and other types of evaporators; tank farms to store juice and concentrate in bulk; aseptic filling in bulk containers and retail packs; alternate flexible and rigid containers other than glass and tin; and recovery of volatile flavoring constituents during juice processing are some of the important technological developments in the recent past and have been discussed. Bitterness in citrus juices and its control, composition of cloud, and its stability and changes during storage have been reviewed. Essential oils, pectin, frozen and dried juice sacs, dried pulp and molasses, flavonoids, seed oil, and meal are the important byproducts, the manufacture of which is given in essential details. Generally, consumers judge the product on the basis of its sensory attributes. The quality of finished product is dependent upon the raw materials used and control of processes. The U.S. Department of Agriculture (USDA) standards for different products, physicochemical and microbiological parameters prescribed as indices of quality of fruit, juice, concentrate, and other products; composition of essential oils; and aroma concentrates are discussed in relation to sensory quality. Analytical methods for compounds affecting quality, and methods for detection of adulteration in different citrus products are briefly reviewed. The importance of sensorily evaluating quality of citrus products to select and develop quality control indices is emphasized. Areas where further research are required are indicated. A comprehensive bibliography is provided to aid further study and research.

The microbiology of apples and apple products

Abstract: The apple industry has reached an annual production level of 8.5 billion pounds. CA storage of 25% of this crop has enabled a fresh market on a year-round basis. To achieve high quality in raw fruit and processed apple products, careful attention must be paid to maintaining a microbiologically stable environment. The ecology of the microflora associated with the apple is a reflection of the orchard, handling, harvesting, and storage practices. Yeasts predominate on orchard fruit, molds may become a storage problem, and bacteria cause spoilage, off flavors, and loss of quality in juice products. Despite the microbial problems inherent in producing of quality product, the apple industry is faced with the occurrence of patulin. Patulin, a mycotoxin produced by Penicillium and Aspergillus species, has been associated with damaged fruit. Decreased temperatures, coupled with CA storage; can deter mold growth and patulin production. Laboratory detection methods for derivations of patulin are able to detect microgram quantities. Means to eliminate patulin formed in apple products include addition of ascorbate and SO2, extending fermentation, or charcoal filtering. However, degradation products of patulin have not been evaluated toxicologically.

Application of near infrared spectrophotometry to the nondestructive analysis of foods: A review of experimental results

Abstract: The authors are reviewing here the development and the application of the nondestructive spectrophotometric analytical techniques applied to the agricultural commodities. Following a short description of the theoretical bases of this technique, the most significant applications are reviewed leading to the evolution of the first generation of instruments based on such principles. The applications of the specific instruments developed for on‐line measurements are summarized. The Grain Quality Analyzers actually marketed and their use in the determination of a wide range of components in foods are described. The experience gained by the research developed using such instruments has generated a new series of computerized instruments allowing for new methodologies and applications that are discussed and reviewed here. The state of the art and the development trends are briefly discussed, particularly referring to the research aimed to the extension of this technique to evaluate different chemical compounds in ...

Cassava as a food

Abstract: This review has attempted to examine information pertaining to the role of cassava (Manihot esculenta) as a major food source for a large part of the world population, particularly the countries of South America, Africa, and Asia, where it is primarily a major source of energy for 300 to 500 million people. Its cultivation, usually on small farms with little technology, is estimated to cover on an annual basis about 11 million hectares providing about 105 million tons, more than half of which is consumed by humans. The importance of cassava as an energy source can be seen by its growing demand in the European economic community countries where it forms up to 60% of the balanced diets for swine. Cassava is one of the crops that converts the greatest amount of solar energy into soluble carbohydrates per unit of area, thus 1 kg of moisture-free cassava meal may yield up to about 3750 kcal which would mean that a yearly production of 15 tons of cassava meal per hectare would yield some 56 million kcal. The major limitations of cassava as food appear to be its poor protein content and quality and the rapid post harvest deterioration of its roots which usually prevents their storage in the fresh state for more than a few days. However, in addition to its use for culinary purposes, cassava finds application in industrial products such as an adhesive for laundry purposes, for manufacturing paper, alcohol, butanol, dextrin, adhesive tape, textile sizing, and glue.

Legume‐based fermented foods: Their preparation and nutritional quality

Abstract: Legume-based fermented foods are very popular in the Southeast Asia, the Near East, and parts of Africa. They form an appreciable part of daily diet of people as a main source of protein, calories, and certain vitamins. Preparation of legume-based fermented foods has remained to some extent an art, and their nutritional quality has been of interest to both professionals and layman. The fermentation process helps not only in improving the organoleptic quality of legumes but also enhances nutritional quality. This review examines the production of various legume-based fermented foods and critically assesses their nutritional quality.

Post‐mortem stimulation of carcasses: Effects on biochemistry, biophysics, microbiology, and quality of meat

Abstract: The influence of post‐mortem electrical stimulation of carcasses on the physicochemical, ultrastructural, microbiological, and quality characteristics of meat have been described at length The latest views, based on the physiological, biochemical, and mechanical models that have been extended to explain the development of tension (contraction) in muscle are presented The mechanisms by which electrical stimulation causes improvement in certain quality characteristics of meat are considered with some new thoughts The significance of the mode of electrical flow through the carcass and how the various electrical parameters (electrode‐carcass contact, type of current, voltage, pulse characteristics) affect the rate of glycolysis have been explained The commercial implications of electrical stimulation in the meat industry are highlighted giving special emphasis to hot‐boning, energy conservation, and operator safety

Citrus fruits. Part II. Chemistry, technology, and quality evaluation. B. Technology

Abstract: In Part II of this review on citrus fruits, the literature on chemistry, technology, and quality evaluation are critically considered. Sweet oranges, mandarin, grapefruit, lemon, and lime are generally used for processing. The literature on chemical components of citrus fruit which include sugars, polysaccharides, organic acids, nitrogenous constituents and lipids; carotenoids which contribute to color; vitamins and minerals and flavonoids; limonoids, some of which impart bitterness to the juice; and the volatile components which contribute to aroma were reviewed in section A. Chilled and pasteurized juices, juice concentrates, and beverages are the important products manufactured commercially, and to a limited extent powdered citrus juices, canned segments, and marmalades. The literature on the manufacture of these products also as new types of juice and oil extractors; TASTE and other types of evaporators; tank farms to store juice and concentrate in bulk; aseptic filling in bulk containers and retail packs; alternate flexible and rigid containers other than glass and tin; and recovery of volatile flavoring constituents during juice processing are some of the important technological developments in the recent past and have been discussed in this section. Bitterness in citrus juices and its control, composition of cloud, and its stability and changes during storage have been reviewed. Essential oils, pectin, frozen and dried juice sacs, dried pulp and molasses, flavonoids, seed oil, and meal are the important byproducts, the manufacture of which is given in essential details. Generally, consumers judge the product on the basis of its sensory attributes. The quality of finished product is dependent upon the raw materials used and control of processes. In section C, the U.S. Department of Agriculture (USDA) standards for different products, physicochemical and microbiological parameters prescribed as indices of quality of fruit, juice, concentrate, and other products; composition of essential oils; and aroma concentrates are discussed in relation to sensory quality. Analytical methods for compounds affecting quality, and methods for detection of adulteration in different citrus products are briefly reviewed. The importance of sensorily evaluating quality of citrus products to select and develop quality control indices is emphasized. Areas where further research are required are indicated. A comprehensive bibliography is provided to aid further study and research.

Instrumental determination of flavor stability of fatty foods and its correlation with sensory flavor responses.

Abstract: The evaluation of flavor and the flavor stability of vegetable oils and products made from them has evolved from the purely subjective to the objective through the use of instrumental measurement techniques. An attempt has been made in this report to catalogue this evolution and put in perspective the advantages and limitations of both the sensory and the instrumental techniques. Multi‐laboratory collaborative studies have shown the viability of the instrumental approach and the utility of a number of methods for research and quality control. While the benchmark of consumer acceptance remains anchored in the subjective sensory responses, the instrumental objective methods are beginning to replace these for application to product and process evaluation. They have also provided insight into the identity of the flavor bearing components and their changes with time and temperature abuse. Recent utilization of mass spectrometry for analysis of the flavor components from vegetable oil containing products has pr...

Internal corrosion and shelf-life of food cans and methods of evaluation.

Abstract: Internal corrosion in food cans is characterized by metallic dissolution which is an electrochemical reaction. In lacquered cans, corrosion may also cause disruption in the continuity of the lacquer film. These reactions may cause organoleptic changes in the product, loss of vacuum, swelling, and leaking in extreme cases. In some instances the metal dissolution (i.e., lead) may give rise to toxicological problems. Therefore, these phenomena are often the limiting factor in the shelf life of canned products. Changes in color, texture, and sensoric properties of the foods, which take place simultaneously, affect the aesthetic and nutritional value of the product and thus its shelf life. These changes are often related to interactions with the container. For example, tin dissolution prevents browning and loss of ascorbic acid. Shelf life of canned foods is governed by the quality of the raw materials, the processing technology, quality of the container and storage conditions which will be reviewed in this paper. Can manufacturing technologies, mechanisms of electrochemical corrosion, methods of their measurement and prediction of shelf life will be discussed.

Food irradiation: the evaluation of commercialization opportunities.

Abstract: Successful commercial radiation applications are analyzed, and an evaluation is made of those factors present in each which led to its success. Common "success elements" were identified. Several potential food irradiation applications were then examined from that viewpoint, and some applications could be identified which appeared to contain those favorable elements or characteristics which could lead to successful early commercialization. Reasonable FDA clearance requirements are assumed.

Nutritional quality of meals served by selected foodservices

Abstract: A review of the nutritional quality of foods served by selected types of foodservices reveals the lack of information in this area. The foodservice industry is growing rapidly with new technological innovations and management practices. However, little effort has been made toward the nutrient quality of foods served by important foodservice operations. Foodservice operations are discussed from the institutional and commercial point of view. Under the institutional type, foodservices in nursing homes, hospitals, schools, colleges, and universities are discussed. Fast foodservices are primarily focused under commercial type of foodservices. Other discussions are based on nutrient contents of foods prepared in quantities. Lack of data pertaining to nutrient content of foods served by foodservice operations is evident.

Economics of food irradiation

Abstract: This article examines the cost competitiveness of the food irradiation process. An analysis of the principal factors--the product, physical plant, irradiation source, and financing--that impact on cost is made. Equations are developed and used to calculate the size of the source for planned product throughput, efficiency factors, power requirements, and operating costs of sources, radionuclides, and accelerators. Methods of financing and capital investment are discussed. A series of tables show cost breakdowns of sources, buildings, equipment, and essential support facilities for both a cobalt-60 and a 10-MeV electron accelerator facility. Additional tables present irradiation costs as functions of a number of parameters--power input, source size, dose, and hours of annual operation. The use of the numbers in the tables are explained by examples of calculations of the irradiation costs for disinfestation of grains and radicidation of feed.