Showing papers in "Critical Reviews in Food Science and Nutrition in 1998"
TL;DR: The aim of this review is to summarize and analyze the vast and sometimes conflicting literature on tannins and to provide as accurately as possible the needed information for assessment of the overall effects of tannin effects on human health.
Abstract: Tannins (commonly referred to as tannic acid) are water-soluble polyphenols that are present in many plant foods. They have been reported to be responsible for decreases in feed intake, growth rate, feed efficiency, net metabolizable energy, and protein digestibility in experimental animals. Therefore, foods rich in tannins are considered to be of low nutritional value. However, recent findings indicate that the major effect of tannins was not due to their inhibition on food consumption or digestion but rather the decreased efficiency in converting the absorbed nutrients to new body substances. Incidences of certain cancers, such as esophageal cancer, have been reported to be related to consumption of tannins-rich foods such as betel nuts and herbal teas, suggesting that tannins might be carcinogenic. However, other reports indicated that the carcinogenic activity of tannins might be related to components associated with tannins rather than tannins themselves. Interestingly, many reports indicated negative association between tea consumption and incidences of cancers. Tea polyphenols and many tannin components were suggested to be anticarcinogenic. Many tannin molecules have also been shown to reduce the mutagenic activity of a number of mutagens. Many carcinogens and/or mutagens produce oxygen-free radicals for interaction with cellular macromolecules. The anticarcinogenic and antimutagenic potentials of tannins may be related to their antioxidative property, which is important in protecting cellular oxidative damage, including lipid peroxidation. The generation of superoxide radicals was reported to be inhibited by tannins and related compounds. The antimicrobial activities of tannins are well documented. The growth of many fungi, yeasts, bacteria, and viruses was inhibited by tannins. We have also found that tannic acid and propyl gallate, but not gallic acid, were inhibitory to foodborne bacteria, aquatic bacteria, and off-flavor-producing microorganisms. Their antimicrobial properties seemed to be associated with the hydrolysis of ester linkage between gallic acid and polyols hydrolyzed after ripening of many edible fruits. Tannins in these fruits thus serve as a natural defense mechanism against microbial infections. The antimicrobial property of tannic acid can also be used in food processing to increase the shelf-life of certain foods, such as catfish fillets. Tannins have also been reported to exert other physiological effects, such as to accelerate blood clotting, reduce blood pressure, decrease the serum lipid level, produce liver necrosis, and modulate immunoresponses. The dosage and kind of tannins are critical to these effects. The aim of this review is to summarize and analyze the vast and sometimes conflicting literature on tannins and to provide as accurately as possible the needed information for assessment of the overall effects of tannins on human health.
1,687 citations
TL;DR: The protein-polysaccharide complexes exhibit better functional properties than that of the proteins and polysaccharides alone, and could be attributed to the simultaneous presence of the two biopolymers, as well as the structure of the complexes.
Abstract: Food proteins and polysaccharides are the two key structural entities in food materials. Generally, interactions between proteins and polysaccharides in aqueous media can lead to one- or two-phase systems, the latter being generally observed. In some cases of protein-polysaccharide net attraction, mainly mediated through electrostatic interactions, complex coac-ervation or associative phase separation occurs, giving rise to the formation of protein-polysac-charide complexes. Physicochemical factors such as pH, ionic strength, ratio of protein to polysaccharide, polysaccharide and protein charge, and molecular weight affect the formation and stability of such complexes. Additionally, the temperature and mechanical factors (pressure, shearing rate, and time) have an influence on phase separation and time stability of the system. The protein-polysacchaide complexes exhibit better functional properties than that of the proteins and polysaccharides alone. This improvement could be attributed to the simultaneou...
782 citations
TL;DR: The concept of thermal death time and the standard methods of calculating the safety of commercial heat preservation processes are also based on this assumption as discussed by the authors, however, at least some of the semilogarithmic survival curves which have been considered linear are in fact slightly curved.
Abstract: The heat inactivation of microbial spores and the mortality of vegetative cells exposed to heat or a hostile environment have been traditionally assumed to be governed by first-order reaction kinetics. The concept of thermal death time and the standard methods of calculating the safety of commercial heat preservation processes are also based on this assumption. On closer scrutiny, however, at least some of the semilogarithmic survival curves, which have been considered linear are in fact slightly curved. This curvature can have a significant effect on the thermal death time, which is determined by extrapolation. The latter can be considerably smaller or larger depending on whether the semilogarithmic survival curve has downward or an upward concavity and how the experimenter chooses to calculate decimal reduction time. There are also numerous reports of organisms whose semilogarithmic survival curves are clearly and characteristically nonlinear, and it is unlikely that these observations are all due to a ...
698 citations
TL;DR: The combination of synthetic and edible packagings was proposed to increase the efficiency of food quality preservation by the packaging to contribute to the protection of the environment.
Abstract: (1998). Edible Films and Coatings: Tomorrow's Packagings: A Review. Critical Reviews in Food Science and Nutrition: Vol. 38, No. 4, pp. 299-313.
685 citations
TL;DR: Control of the muscle enzyme systems, mainly proteases and lipases, is essential for the standardization of the processing and/or enhancement of flavor quality of dry-cured ham.
Abstract: The processing of dry-cured ham is very complex and involves numerous biochemical reactions that are reviewed in this article. Muscle proteins undergo an intense proteolysis, resulting in a great number of small peptides and high amounts of free amino acids. The enzymes responsible of these changes are proteinases (cathepsins B, D, H, and L and, to a less extent, calpains) and exopeptidases (peptidases and aminopeptidases). Muscle and adipose tissue lipids are also subject to intense lipolysis, generating free fatty acids by the action of lipases that, in a second stage, are transformed to volatiles as a result of oxidation. Sensory profiles of dry-cured ham are strongly affected by these enzymatic reactions. In addition, the activity levels of the muscle enzymes significantly depend on the properties of raw ham, such as age and crossbreeding as well as the process conditions such as temperature, time, water activity, redox potential, and salt content. Thus, the control of the muscle enzyme systems, mainly proteases and lipases, is essential for the standardization of the processing and/or enhancement of flavor quality of dry-cured ham.
406 citations
TL;DR: Carotenoids contribute to the yellow, orange, and red colors of the skin, shell, or exoskeleton of aquatic animals and are the most widespread pigments found in nature.
Abstract: Color plays a major role in the overall acceptability of food products. It is considered one of man's basic experiences that a particular foodstuff has to be of a distinct color in order to be edible. The color of a seafood is the first characteristic noted by the consumer and is directly related to the subsequent acceptance or rejection of it. Carotenoids contribute to the yellow, orange, and red colors of the skin, shell, or exoskeleton of aquatic animals. Indeed, they are the most widespread pigments found in nature, as they occur in bacteria, yeasts, mold, all green plants, and many animals, and therefore various functions have been attributed to them. From anthropocentric consideration, the most significant aspect of carotenoids is the color they impart to our food and environment. In animals, the carotenoids are also associated with reproductive organs and hence the hatching success and survival of alevins.
368 citations
TL;DR: A more detailed knowledge of the properties of maltodextrins is necessary in order for their use to be considered as sufficiently effective and desirable in a number of known food applications and for novel development purposes.
Abstract: Compositional, physicochemical, and structural properties of maltodextrins and the most important advances that have been made are critically reviewed. Individual topics focuses on the maltodextrin production, carbohydrate composition, and dextrose equivalent determination, factors that alter the polysaccharide properties, the molecular arrangement, the mechanisms and complex physicochemical changes of maltodextrins such as water interaction (hygroscopicity, precipitation, turbidity, bound and free water) and the role of molecular interactions for a network formation. Of particular importance is the information concerning the network structure of maltodextrins gels (degree of crystallinity, crystallite size, aggregation) and the involvement of linear and branched chains for the network formation. Rheological properties have become a desirable tool to predict and understand their structural and functional properties, in single and in mixed systems with other macromolecules. These advances are assessed together with the structural development of food products and processes. Their main food applications, particular advantages, recent commercial directions, and modifications together with potential problems are also discussed. As food ingredients, maltodextrins are a valuable production tool, but still with considerable promises. Nevertheless, a more detailed knowledge of the properties of maltodextrins is necessary in order for their use to be considered as sufficiently effective and desirable in a number of known food applications and for novel development purposes.
280 citations
TL;DR: The wide diffusion of 2-thiobarbituric acid (TBA) in the scientific literature is due to the TBA assay, or TBA test, which has been employed in the determination of autoxidative alterations of fats and oils.
Abstract: The wide diffusion of 2-thiobarbituric acid (TBA) in the scientific literature is due to the TBA assay, or TBA test, which has been employed in the determination of autoxidative alterations of fats and oils. Two processes occur in autoxidation, generally: the free radical and the photo-oxidation mechanisms. The better studied is the free radical mechanism. The hydroperoxiepidioxides and bicycloendoperoxides are malonaldehyde (MDA) precursors. The absorption spectrum obtained with oxidized fatty foods is like the spectrum obtained when TBA and MDA react. However, during the secondary phase of the autoxidation process other aldehydes (alkanals, 2-alkenals, dienals) are formed which react with TBA, and they are responsible for off-flavors. Three kinds of pigments (yellow, orange, red adducts) are involved. Also, aromatic aldehydes, which constitute the flavor profile of diverse fruits and essential oils, form with TBA the characteristic arylidene-2-TBA acids. Other substances, such as ketones, ketosteroids, acids, esters, sugars, imides and amides, amino acids, oxidized proteins, pyridines, pyrimidines, and vitamins can react with TBA; they are named TBARS (substances that react with TBA), and form principally in meats and meat derivatives. Several organic or bio-organic acids, as shikimic and sorbic acids, react photometrically with TBA if a Malaprade reaction takes place before. A structural study of the red adduct TBA-MDA has been carried out.
264 citations
TL;DR: Barley Chemistry and Value-Added Processing is concerned with the physical properties of barley and its use in value-added processing, as well as its applications in food and beverage formulations.
Abstract: (1998). Barley: Chemistry and Value-Added Processing. Critical Reviews in Food Science and Nutrition: Vol. 38, No. 2, pp. 123-171.
175 citations
TL;DR: Textural properties of raw tomatoes and most processed tomato products are reviewed in this article and may be measured using both sensory and objective tests.
Abstract: Knowledge of the textural properties of processing tomatoes is crucial to ensuing product accept- ability; measurement, control, and optimization of these properties through judicious selection of varieties and control of unit operations results in products that the consumer prefers. It is important to first define the terms texture, rheology, consistency, and viscosity prior to discussing principles of their measurement. The textural properties of processing tomatoes may be measured using both sensory and objective tests, and the latter may be either destructive or nondestructive in nature. The unique anatomy of tomato fruit (peel, pericarp, columella, and locules) in part dictates the method of texture measurement. Numerous factors, including variety, maturity, genetic modification, cultural particles, and environmental conditions, processing conditions, and calcium addition affect the textural integrity of tomatoes. Textural properties of raw tomatoes and most processed tomato products are reviewed in this article.
170 citations
TL;DR: Based on the requirements for individual fat components by different segments of the population, including infants, adults, and patients, ideal fats can be formulated to meet their needs by using specific novel fat sources and lipid modification techniques.
Abstract: Rapid improvements in the understanding of the nutritional requirements of both infants and adults has led to new developments in the modification of fats and oils. Specific targets include the improvement in growth and development of infants, treatment of disease in adults, and disease prevention. Efforts have been focussed on the production of structured lipids using medium-chain acids and long-chain polyunsaturated fatty acids (PUFAs), as well as the concentration of long-chain PUFAs from new and existing sources. Short- and medium-chain fatty acids are metabolized differently than long-chain fatty acids and have been used as a source of rapid energy for preterm infants and patients with fat malabsorption-related diseases. Long-chain PUFAs, specifically docosahexaenoic acid and arachidonic acid, are important both in the growth and development of infants, while n-3 PUFAs have been associated with reduced risk of cardiovascular disease in adults. Based on the requirements for individual fat components by different segments of the population, including infants, adults, and patients, ideal fats can be formulated to meet their needs. By using specific novel fat sources and lipid modification techniques, the concentrations of medium-chain, long-chain saturated, and long-chain polyunsaturated fatty acids as well as cholesterol can be varied to meet the individual needs of each of these groups. While genetic modification of oilseeds and other novel sources of specific lipid components are still being developed, chemical and lipase-catalyzed interesterification reactions have moved to the forefront of lipid modification technology. Fractionation of fats and oils to provide fractions with different nutritional properties has potential, but little work has been performed on the nutritional applications of this method. The choice of suitable lipid modification technologies will depend on the target lipid structure, production costs, and consumer demand. A combination of some or all of the present lipid modification techniques may be required for this purpose.
TL;DR: The activities of this fermentation product of dietary fiber may contribute substantially to the decreased incidence of bowel cancer that has been associated with fiber intake.
Abstract: A number of components present in the diet, although nutritionally nonessential, have been discovered to have beneficial effects toward both general health and disease prevention/protection. One such nutrient, butyric acid, can be derived in large quantities from bacterial fementation of dietary fiber in the bowel and is also a component of bovine milk. In gut fermentation, the production of butyric acid defines its delivery point; thus, the synthesis and site of action of butyric acid are in close proximity and have frustrated the investigation of its activities in vivo. Recent research has, however, revealed a number of activities of butyric acid toward isolated cells. In particular, its ability to modify nuclear architecture and induce death by apoptosis in colon cancer cells is arousing great interest. Butyric acid changes the structure of chromatin through its effects on posttranslational modifications, key modifications being acetylation and phosphorylation of the nuclear histones. Butyric acid can also modify the differentiation state of cells, and in the case of cancerous colonic cells overcomes their resistance to normal programmed death. Thus, the activities of this fermentation product of dietary fiber may contribute substantially to the decreased incidence of bowel cancer that has been associated with fiber intake.
TL;DR: This paper presents an integrated approach to the development of Reduced-Fat Food Emulsions and explains the rationale for this approach, as well as some of the challenges faced in developing this approach.
Abstract: (1998). An Integrated Approach to the Development of Reduced-Fat Food Emulsions. Critical Reviews in Food Science and Nutrition: Vol. 38, No. 6, pp. 511-536.
TL;DR: The standards and specifications for the quality and composition of tomato concentrates are reviewed, and the volatiles responsible for flavor and odor have been identified to the point where the natural odor of tomato paste can be imitated.
Abstract: The standards and specifications for the quality and composition of tomato concentrates are reviewed. The main quality parameters of tomato puree and paste are color, consistency and flavor. Overall, there is an absence of standardization of methods and instruments to define quality. While color can now be measured objectively, there are currently no standard color requirements for tomato concentrates. Rheological measurements on both tomato juice and concentrates are reviewed; the power law finds wide applicability, although other rheological characteristics, particularly time dependency, have received far less attention and there has been little effort to relate rheological understanding to the commonly used empirical tests such as consistency measurements. The volatiles responsible for flavor and odor have been identified to the point where the natural odor of tomato paste can be imitated. Attempts to develop objective methods as a substitute for sensory assessment are reviewed.
TL;DR: A review of the most recent studies concerning beta-carotene retention in carrots during processing and storage is presented in this paper, where the trans form of beta carotene in carrots is replaced by the cis form during processing.
Abstract: Beta-carotene acts as a pro-vitamin A or anti-cancer compound. Carrots contain the highest amount of beta-carotene of common fruits and vegetables, but each year 25% of carrot production is lost in the U.S. during processing and storage, while, at the same time, the market demand increases. This article is a review of the most recent studies concerning beta-carotene retention in carrots during processing and storage. Reducing the water activity by adding some aw lowering ingredients results in poor shelf-life. Drying or freezing gives better retention during storage than reducing the water activity, if the process is well controlled. Canning or freeze-drying were shown to be more effective. The trans form of beta-carotene in carrots is replaced by the cis form during processing. Beta-Carotene can be extracted from carrots, but the half-life of free beta-carotene is reduced to 2 d in the juice extract at room temperature. By encapsulation methods,the half-life can be increased by 6 months.
TL;DR: Fed-batch fermentation can be used as an alternative process to avoid increases in lactose concentration and prevent the catabolite repression of the respiratory enzyme synthesis during aerobic fermentation, thus allowing for high biomass yields.
Abstract: Whey waste is a major problem for the dairy industry. Finding alternative means to reduce its pollution potential and produce high value-added bioingredients has been attempted by many researchers. Kluyveromyces marxianus var. marxianus is a dairy yeast that produces beta-galactosidase, allowing for whey fermentation. Also, K. marxianus has been proposed as a source of: (1) oligonucleotides, used as flavor enhancers in food products; (2) oligosaccharides, used as prebiotics to stimulate the growth of Bifidobacterium sp. in the animal and human intestines; and (3) oligopeptides, immunostimulators added to dairy products that are released in the wort after whey protein proteolysis. Fed-batch fermentation can be used as an alternative process to avoid increases in lactose concentration and prevent the catabolite repression of the respiratory enzyme synthesis during aerobic fermentation, thus allowing for high biomass yields. The relevance of these factors on yeast fermentation of whey is summarized in this critical review.
TL;DR: The paper stresses the need for a systematic study of not only the quoted products, but also a number of other fermented cassava products that have not been well documented.
Abstract: Fermentation of cassava is an important processing technique followed in different parts of the world. Although fermentation is known to bring about vast changes in the physicochemical and functional properties of the tubers, attempts have seldom been made to consolidate and critically analyze the available information. Glaring inconsistencies and contradictions noticeable in some of the results reflect the differences and variations in the artisanal processes followed in the preparation of these products. It also stresses the need for a systematic study of not only the quoted products, but also a number of other fermented cassava products that have not been well documented.
TL;DR: The present review focuses on epoxy resins use in the food industry as surface coatings for food and beverage cans, and in particular on their chemical stability in relation to their toxicology and sensorial effects on foods.
Abstract: BADGE-based epoxy resins have been commercially available for more than 40 years. They are extremely versatile, finding applications in many fields in both thermal and ambient cure applications. The present review focuses on their use in the food industry as surface coatings for food and beverage cans, and in particular on their chemical stability in relation to their toxicology and sensorial effects on foods. The implications of these properties of epoxy resins for prospective EU legislation on plastic coatings for food contact is discussed.
TL;DR: (1998).
Abstract: (1998). Science, Education, and Technology: New Frontiers for Health. Critical Reviews in Food Science and Nutrition: Vol. 38, No. 5, pp. 397-419.
TL;DR: This review discusses changes and lessons learned in the food safety sciences over the last 4 decades and how the regulatory and legislative segments of the infrastructure are brought into better synchrony with the sciences.
Abstract: Most sciences and technologies related to food safety have advanced exponentially over the 40 years since passage in the U.S. of the Food Additive Amendment of 1958 to the Federal Food, Drug and Cosmetic (FD&C) Act. Effective regulatory decision making places a high premium on competent professional and administrative judgement applied to sound scientific data. This review discusses changes and lessons learned in the food safety sciences over the last 4 decades. Other segments of the safety and compliance infrastructure necessary to assure that the public receives safe and wholesome foods have not kept pace with the new scientific knowledge. The quality of foods in our marketplace can be improved only after the regulatory and legislative segments of the infrastructure, discussed in a companion symposium paper,8 are brought into better synchrony with the sciences.