Showing papers in "Critical Reviews in Food Science and Nutrition in 1988"

The chemistry of lysozyme and its use as a food preservative and a pharmaceutical.

Abstract: The chemistry and use of lysozyme as a food preservative and a pharmaceutical are reviewed. Lysozyme inhibits the growth of deleterious organisms, thus prolonging shelf life. Chemicals used to improve the preservative effect of lysozyme and those that inhibit the enzyme are discussed, along with the stability of lysozyme in various chemical environments. Lysozyme has been used to preserve fresh fruits and vegetables, tofu bean curd, seafoods, meats and sausages, potato salad, cooked burdock with soy sauce, and varieties of semihard cheeses such as Edam, Gouda, and some Italian cheeses. Lysozyme added to infant‐feeding formulas makes them more closely resemble human milk. Lysozyme has been used clinically in the treatment of periodontitis, administered in chewing gum, and implemented to prevent tooth decay. It has also been administered to patients suffering from cancer for its analgesic effect and has been used as a potentiating agent in antibiotic therapy.

Natural astringency in foodstuffs--a molecular interpretation.

Abstract: The structures of plant polyphenols (vegetable tannins) are briefly reviewed. Their interactions with proteins, polysaccharides, and the alkaloid caffeine are discussed at the molecular level, and these fundamental properties are related to the quality of astringency that polyphenols possess. The various ways in which astringency may be modified and ultimately lost are outlined in relation to the aging of red wines, the formation of nonbiological hazes in beers and lagers, and the ripening of fruit.

Pleurotus mushrooms. Part II. Chemical composition, nutritional value, post‐harvest physiology, preservation, and role as human food

Abstract: The topic is reviewed under the following headings: chemical composition of fruit bodies (moisture, carbohydrates, proteins + free amino acids, lipids, minerals, vitamins, nucleic acids, organic acids, flavour constituents); composition of the mycelium; evaluation of nutritional value; postharvest physiology; preservation (storage of fresh mushrooms, freezing preservation, storage of pickle preparation, dehydration, canning, processing of Pleurotus stipes); and role of mushrooms as human food (contribution to human nutrition, as a slimming food, cost of mushroom protein, bioconversion efficiency, potentiality for production and consumption in different parts of the world, future of Pleurotus). [See FSTA (1988) 20 8J129 for part 1B.]

Soy flavor and its improvement

Abstract: A highly characteristic and often undesirable flavor associated with soy protein materials largely explains the slower‐than‐expected progress over recent years in the development of high‐protein foods based on soya. Apart from the inherent flavor of the bean, different flavors are produced on processing and on storage. Major problems are the absence of an attractive positive flavor, the presence of off‐flavors of several kinds, the tenacious binding of such flavors to the soy protein molecules, and the difficulties of removing and/or masking these unacceptable qualities. This review provides a reappraisal of current literature evidence relating to each of these aspects and summarizes published patents of processes for soy flavor improvement.

Molecular aspects, physiological function, and clinical significance of metallothioneins.

Abstract: Metallothioneins (MTs) are well-characterized low molecular weight, heat-stable cytosolic proteins with exceptional high content of cysteinyl sulfur and are known to bind heavy metals like cadmium (Cd), zinc (Zn), and copper (Cu). Since these proteins are induced on exposure to heavy metals, it is now accepted that they have a detoxifying role during heavy metal toxicity. It has also been suggested that the primary function of Mt is in the homeostasis of the essential metals Zn and Cu. Recently, a role MT in selenium metabolism in primates has been established. Further, MT has gained considerable importance in the clinical disorders related to trace metal metabolism.

Radiation preservation of foods of plant origin. Part VI. Mushrooms, tomatoes, minor fruits and vegetables, dried fruits, and nuts.

Abstract: In this concluding article in the series on the technological feasibility of ionizing radiation treatment for shelf life improvement of fruits and vegetables, the present status of research on several commodities that have not been dealt with earlier is discussed. The commodities include mushrooms, tomatoes, pineapples, lychees, longans, rambutans, mangostenes, guavas, sapotas, loquats, ber, soursops, passion fruits, persimmons, figs, melons, cucumbers, aubergines, globe artichokes, endives, lettuce, ginger, carrots, beet roots, turnips, olives, dates, chestnuts, almonds, pistachios, and other dried fruits and nuts. Changes induced by irradiation on metabolism, chemical constituents, and organoleptic qualities are considered while evaluating the shelf life. The commodities have been grouped into those showing potential benefits and those not showing any clear advantages from radiation treatment. Shelf life improvement of mushrooms and insect disinfestation in dried fruits, nuts, and certain fresh fruits appears to have immediate potential for commercial application.

Food biotechnology review: traditional solid-state fermentations of plant raw materials--application, nutritional significance, and future prospects.

Abstract: This review on the use of indigenous solid-state fermentations (SSF) describes the microbiological transformation of plant raw materials into highly nutritious foods and flavor-enhancing ingredients. Traditional fermented foods from most countries of the world may be classified into the following categories: fungal fermentation followed by brining, SSF principally using bacteria, lactic acid fermentation followed by fungal fermentation, production of fermented doughs, alcoholic fermentation, and fermented food ingredients. Scientific studies of the principles behind SSF, identification of the essential microorganisms, development of suitable and versatile equipment, control of the process, and quality control of the substrate and final product can very well lead to a substantial increase at a world level in the availability and consumption of these fermented foods. The application of modern biotechnology in some countries is already changing the ancient methods of making fermented foods.

Pleurotus mushrooms. Part IB. Pathology, in vitro and in vivo growth requirements, and world status.

Abstract: Part IB of this review discusses growth abnormalities and diseases of the fruit bodies, as well as containments in the substrates that affect the quality and yield of the fruit bodies. The means and methods to overcome these problems during culturing of Pleurotus on commercial scales are described. In vitro growth requirements and prospects of producing mycelium on organic wastes in liquid culture are discussed. The effects of changes in the nutrients of growth substrate on the yield and quality of fruit bodies in vivo are brought out. Status of culturing Pleurotus in different parts of the world is evaluated. Finally, a critical consideration of the scope and problems of Pleurotus cultivation technology is given.

Nutritional requirements of the aged.

Abstract: The age of the population continues to increase. At the turn of the century, 4% (about 3.1 million people) were 65 years of age or older. Today the percentage has increased to 12%, or 27.4 million people, and the prediction for the 21st century may increase to 17 to 20%. It should be noted that the number of individuals 85 years of age and older, as well as those over the age of 100, is increasing rapidly. The nutritional problems of the elderly are related to physiological decline, to low economic status and limited food consumption, and to a multitude of disease processes and the therapeutic regimens prescribed to cure or treat those illnesses. Examined as a group, the elderly at first appear to be less uniform in their health status than younger members of the population. However, only 10% of the elderly population contributes to the disproportionate (30%) expenditure of health care services. A majority of the elderly are normal, healthy individuals. Yet, with each decade of life the percentage of the elderly population needing additional care increases. The national nutritional surveys (National Food Consumption Survey and the National Health and Nutrition Examination Surveys, I and II) used entirely different methodologies, but reported very similar findings. The mean intake of this population was actually quite good, revealing low intakes of calcium and iron in the elderly female population. However, the standard deviation of the intake data strongly suggests a major portion of the population is at nutritional risk. For more than 30% of the population, nutrient intakes below two thirds of the recommended dietary allowances (RDA) occurred for calories, calcium, and vitamin A, while for more than 20% of the population, iron and vitamin C were at risk. Although the data evaluating the effects of age on the nutritional requirements of the elderly are limited, careful interpretation of the existing assessment and intervention efforts can provide some basic guidelines. Generalities about calorie intake must be avoided, and emphasis must be placed on calorie needs. Enhanced activity should be encouraged. Protein intake for the majority of elderly exceeds the RDA, but with increased age a greater amount of high quality protein is needed to maintain nitrogen balance. The group at greatest risk is the poor elderly who may not be able to afford enough high quality protein. Increased consumption of complex carbohydrates serves several functions including decreased caloric density and enhanced nutrient intake. Decreasing total dietary fat decreases caloric intake and indirectly decreases dietary cholesterol.(ABSTRACT TRUNCATED AT 400 WORDS)

Cheese industry development and research in Argentina.

Abstract: Research and development projects concerning cheese industry in Argentina are described in this study. Regional strains of lactic acid bacteria were isolated from different ecological pockets and their taxonomic profiles were determined. Proteolytic and acid activity as well as diacetyl production were analyzed. Results obtained depended on the species and strains under consideration. The cell permeabilization using 20 to 40% ethanol improved the acid production by lactic acid bacteria. Freeze-drying was used for culture preservation. The optimal conditions for obtaining the highest survival rate were determined. Best results were obtained by using 0.75 M adonitol as a cryoprotectant. The rehydration conditions to be used depended on the bacterial species. Freeze-dried cultures showed good viability and activity up to 1 year of storage at 4 degrees C.