Chemical Composition Of Foods Research Articles

Research in the Agricultural Research Service/USDA: Introduction and Early History

a period of intensive skirmishing and skillful diplomacy had finally resulted in the appropriation (6). Dr. Atwater, already the Director of the Connecticut Agricultural Experiment Station, was appointed as Chief of Nutrition Investigations in the USDA’s Office of Experiment Stations. In the 10 y that Atwater headed the program, he coordinated or conducted work in 4 areas: types and amounts of foods consumed by different groups; chemical composition of foods; effects of cooking and food processing on nutritional quality; and amounts and types of nutrients people need to function at their best. These accomplishments led to his accoladeasthe‘‘FatherofNutritionScience’’intheUnitedStates. The human nutrition investigations were moved to Washington, DC, when Atwater retired in 1906 and the laboratory was put into the Office of Home Economics. The scientifically distinguished record proceeded in synchrony through the succeeding decades with discoveries of the vitamins and essential mineral elements. The energy metabolism work at the USDA was the lead in the nutrition field, but important work on human requirements for essential fatty acids, vitamin G (which became riboflavin), vitamin A requirements of adults, and human utilization of calcium from spinach also was accomplished.

Food quality triggers the reproductive mode in the cyclical parthenogen Daphnia (Cladocera)

Cyclic parthenogenesis (heterogony) is a widespread reproductive mode found in diverse taxa such as digenean trematodes, gall wasps, gall midges, aphids, cladocerans and rotifers. It is of particular interest as it combines the advantages of asexual reproduction (rapid population growth) and sexual reproduction (recombination). Usually sexual reproduction is initiated when, or slightly before, environmental conditions deteriorate, and often results in the production of resting stages. The optimal timing of diapause induction must thus be under strong natural selection. Using the cladoceran Daphnia as a model system, we show here for the first time that the switch from parthenogenetic to sexual reproduction in a cyclical parthenogenetic organism can be influenced by the chemical composition of food. Under crowding conditions Daphnia reproduced parthenogenetically with subitaneous eggs when fed the algal species Cryptomonas sp., but started the production of resting eggs when fed with the green algal species Scenedesmus obliquus. Supplementation experiments with lipids and especially proteins showed that the induction of resting egg production in two clones of different Daphnia species was due to a dietary deficiency in the green alga. Hence, the low food quality induced a switch in the reproductive mode that may contribute to optimal timing of the sexual reproduction of Daphnia in nature. Furthermore, our results have two other major implications: first, they suggest that protein compounds should be added to the list of diet constituents potentially limiting or influencing Daphnia reproduction. Second, we show that the role of food quality goes far beyond the up to now documented effects of food quality on somatic growth and trophic transfer efficiency of herbivores: due to its effects on sexual reproduction and the production of resting eggs, food quality might influence genetic diversity and long-term persistence of Daphnia in lakes.

Historical Perspectives

Robert McCance and Elsie Widdowson have a special place in the history of neonatal science. Their use of experimentation and observation of human infants and many other species built much of the knowledge of perinatal physiology, particularly that related to nutrition and renal function, which underpins modern neonatology. Neither was a clinical pediatrician, but they had a major influence on the first wave of neonatologists trained in the United Kingdom in the 1960s and 1970s. Their stories show how the combination of intellectual curiosity and practical skill can lead to new knowledge in unexpected directions. Robert McCance was born in Northern Ireland in 1898. He joined the newly formed Royal Naval Air Service in the First World War and flew an observation aircraft launched from a gun turret on a battleship. After the war, he worked on a farm for 6 months before studying natural sciences at the University of Cambridge from 1919 to 1922. He joined the biochemistry laboratory of Fredrick Gowland Hopkins (1929 Nobel laureate in Medicine for his work on vitamins and beriberi) and obtained his PhD. In 1926, McCance moved to King's College Hospital, London, to complete his clinical training in medicine and worked part-time in the biochemical and diabetic department. This was the era before insulin, and he worked on separating different carbohydrates in cooked fruits and vegetables. It was important to know which carbohydrates could be metabolized as fuel (eg, glucose, fructose, sucrose) and which could not (eg, polysaccharides now classed as fiber). He progressed to analyzing the content of meat and fish. In 1933, while sampling joints of meat in the hospital kitchens, he met Elsie Widdowson, a trainee dietitian, and their 60-year scientific partnership began. Elsie Widdowson was born in 1906 in southeast London. She was inspired by her chemistry teacher at …

Effect of domestic processing on bioactive compounds

Nowadays, most of the consumed foods are rarely ready for direct consumption. Food can be purchased at the local supermarket as fresh raw product such as meat, fruit, fish etc. or as manufactured product after an industrial processing (canned meat, dried fish, packed fruit etc.). But later on, both food types are usually submitted to culinary treatments which will transform the selected food into a cooked dish ready to eat. Domestic methods of food processing have been developed over the centuries to make the final product more attractive in flavour, appearance, taste and consistency. But, until the last centuries, none of the gourmets realize that at the same time, the cooking process was making their foods more digestible, microbiologically safer and more or less nutritive depending on the selected cooking technology. Besides consumer preferences, the selected cooking method is an important factor affecting not only the food chemical composition, but also the intake of bioactive compounds under normal dietary conditions. Therefore, in this work, the different culinary treatments and domestic cooking methods will be compared to define the optimal process to reduce the degradation of biologically active metabolites present in foods commonly consumed as an elaborated dish. Compounds such as carotenoids, glucosinolates, flavonoids and other phenolic compounds, ω-3 fatty acids, tocopherols, phytosterols, etc. have been pointed as bioactive compounds beneficial for human health. Apparently, they are able to prevent cardiovascular diseases (CVD), tumour formation, hiper-cholesterolemia in blood and other deleterious disorders. An adequate domestic practice might help to increase in taking of those functional molecules enhancing their functionality and reducing the risk of chronic diseases.

M74 Syndrome in Baltic Salmon and the Possible Role of Oxidative Stresses in Its Development: Present Knowledge and Perspectives for Future Studies

Baltic salmon suffer from maternally transmitted yolk-sac fry mortality syndrome--M74. The incidence of M74 varies considerably on a year to year basis. In the 1990s the mortalities were 50-80% but in 2003-2005, below 10%. Before death, M74-affected fry have several typical symptoms. M74-eggs are characterized by low thiamine and carotenoid content, and affected fry show signs of oxidative stress. Although M74 is associated with thiamine deficiency and the symptoms of the fry can be alleviated with thiamine, the underlying causes of the syndrome have remained a mystery. We have studied the symptoms of M74 at the molecular level by investigating the global gene expression patterns using cDNA microarray and have quantified the changes in transcriptional regulation in M74-affected and healthy yolk-sac fry. Our and previous results suggest that M74 in Baltic salmon yolk-sac fry results from oxidative stresses disturbing several different developmental molecular pathways. Because the M74 syndrome is of maternal origin, factors in the Baltic Sea during salmon feeding and migration, i.e., the chemical composition of food, may be decisive in the development of M74. The possible mechanisms by which oxidative stresses may develop in adult salmon are discussed in the review.

Content of a novel online collection of traditional east African food habits (1930s-1960s): data collected by the Max-Planck-Nutrition Research Unit, Bumbuli, Tanzania.

Knowledge of traditional African foods and food habits has been, and continues to be, systematically extirpated. With the primary intent of collating data for our online collection documenting traditional African foods and food habits (available at: www.healthyeatingclub.com/Africa/), we reviewed the Oltersdorf Collection, 75 observational investigations conducted throughout East Africa (i.e. Tanzania, Kenya, and Uganda) between the 1930s and 1960s as compiled by the Max Planck Nutrition Research Unit, formerly located in Bumbuli, Tanzania. Data were categorized as follows: (1) food availability, (2) chemical composition, (3) staple foods (i.e. native crops, cereals, legumes, roots and tubers, vegetables, fruits, spices, oils and fats, beverages, and animal foods), (4) food preparation and culture, and (5) nutrient intake and health status indicators. Many of the traditional foods identified, including millet, sorghum, various legumes, root and tubers, green leafy vegetables, plant oils and wild meats have known health benefits. Food preparatory practices during this period, including boiling and occasional roasting are superior to current practices which favor frying and deep-frying. Overall, our review and data extraction provide reason to believe that a diversified diet was possible for the people of East Africa during this period (1930s-1960s). There is a wealth of knowledge pertaining to traditional East African foods and food habits within the Oltersdorf Collection. These data are currently available via our online collection. Future efforts should contribute to collating and honing knowledge of traditional foods and food habits within this region, and indeed throughout the rest of Africa. Preserving and disseminating this knowledge may be crucial for abating projected trends for non-communicable diseases and malnutrition in Africa and abroad.

Composição química e compostos bioativos presentes na polpa e na amêndoa do pequi (Caryocar brasiliense, Camb.)

O conhecimento da composição química dos alimentos é fundamental para se avaliarem a disponibilidade de nutrientes e o seu consumo por populações. Neste trabalho, o pequi (Caryocar brasiliense, Camb.) foi caracterizado pela composição centesimal e pela presença de compostos bioativos na polpa e na amêndoa. Os dados do perfil lipídico mostram alto teor de lípides tanto na polpa quanto na amêndoa, destacando-se nos mesmos a presença dos ácidos graxos insaturados, predominando o ácido oléico como principal componente entre os ácidos graxos. Foi observada também a relação entre os elevados teores de ácidos graxos insaturados com os compostos fenólicos e carotenóides presentes, tendo a polpa quantidades mais expressivas dessas substâncias quando comparada à amêndoa, além de conter uma quantidade superior de fibra alimentar. Os resultados obtidos abrem a perspectiva de se utilizar o pequi como fruto que apresenta, na sua composição, compostos importantes para a formulação de uma dieta saudável.

Constraints of feeding on Salicornia ramosissima by wigeon Anas penelope: an experimental approach

The coastal marshes of the Charente-Maritime (western France) are a major wintering area for wigeon Anas penelope. In these marshes, wigeon feed mainly on grasses, while foraging on Salicornia (a fleshy, succulent halophyte) is uncommon. In order to understand the reason for this under-exploitation, an experimental study was carried out with captive wigeon in autumn 1998 on a Salicornia ramosissima marsh in the Charente- Maritime. Birds were unable to maintain their body weight when feeding on Salicornia. Measurements of food chemical composition and metabolisability, as well as instantaneous intake rate of the birds (g/min) could not explain these weight losses. However, the time budget of wigeon revealed that they spent a maximum of 10-11 h per 24 h consuming Salicornia, whereas 18-19 h would have been needed to meet their daily energy requirements. The daily foraging time on Salicornia may have been limited by physiological constraints due to: (1) a high ash content (mainly salt, about 34% of dry matter), and/or (2) a digestive bottleneck, because of the waxy cuticle covering the leaves, which is likely to have constrained processing rate of Salicornia ears in the gut of birds. In the discussion, we address the question of the potential geographical differences in the use of Sal- icornia by birds.

Seed constraint to cultivation and productivity of African indigenous leaf vegetables

Non-availability of improved seeds constitutes a major constraint to the cultivation and productivity of the indigenous leaf vegetables (ILVs) of Africa. Research on African ILVs has focused mainly on the ethnobotany, collection, preservation, and the assessment of food value and chemical composition of the ILVs. No serious breeding and seed production research has been done on the ILVs. This paper examines some factors underlying the lack of interest in the production of ILVs seeds, the problem associated with local seed processing and the way to organize a seed production programme for the ILVs.

Wine Distillates: Practical Operating Recipe Formulation for Stills

Consumer perceptions of flavors are associated with the chemical composition of foods. However, consumer preferences change; therefore, it is necessary for food manufacturers to be able to adapt their products. Unlike in aged spirits, the chemical composition of young spirits is determined during distillation; therefore, this is where distillers must tailor their operating recipes to the new trends. Even for an experienced distiller, the complexity of the process makes adapting the operating recipe far from straightforward. In this study, we developed a methodology for generating practical recipes that makes use of computer simulations and optimization techniques. We used Pisco Brandy, a young Muscat wine distillate from Chile and Peru as our case study. Even so, because our methodology is independent of the chemical composition of the broth, it can be applied throughout the industry. Drawing on the experience and preferences of industry enologists, we designed a preferred distillate and used our methodology to obtain the appropriate recipe. This recipe was validated in lab scale experiments, and we obtained a much closer distillate to the desired prescription than commercial products.

Seed constraint to cultivation and productivity of African indigenous leaf vegetables

Non-availability of improved seeds constitutes a major constraint to the cultivation and productivity of the indigenous leaf vegetables (ILVs) of Africa. Research on African ILVs has focused mainly on the ethnobotany, collection, preservation, and the assessment of food value and chemical composition of the ILVs. No serious breeding and seed production research has been done on the ILVs. This paper examines some factors underlying the lack of interest in the production of ILVs seeds, the problem associated with local seed processing and the way to organize a seed production programme for the ILVs.

Public health in Central America.

IN LATIN AMERICA, THERE HAS long been a running debate over the relative effectiveness of “vertical” rather than “horizontal” programs in public health. In the 1950s, when this photograph was taken, the Pan American Sanitary Bureau (forerunner of the Pan American Health Organization, or PAHO) was engaged in vertical malaria, yaws, and smallpox eradication campaigns under the direction of Fred L. Soper, a former Rockefeller Foundation officer, who directed the Bureau from 1947 to 1959.1 This image from the Soper archives provides evidence that, despite the predominant emphasis on technical interventions that characterized the disease eradication campaigns, there was also another approach to public health. Here, a visiting nurse from the Institute of Nutrition in Magdalena, Guatemala, is examining a child suffering from a scalp infection. In the 1950s, visiting nurses working in shantytowns and rural areas were a new development in Central American public health. The institute organized some of the first community-based health programs that would later become a central aspect of horizontal primary health care programs in the 1970s and 1980s. The Pan American Sanitary Bureau and the ministers of health of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama first decided to create the Institute of Nutrition in 1946 and then formally inaugurated it in September 1949. The institute conducted pioneering clinical and epidemiological studies and interventions aimed at identifying and correcting dietary deficiencies in Central America, and it developed some of the first studies on the chemical composition of foods used by the population. Early on, the institute viewed undernutrition as a major health problem—closely associated with poverty—that was responsible for retarding the growth of children and making them vulnerable to infectious diseases. The institute emphasized the value of vitamin supplements in correcting some of these problems. Today, the institute is known as the Instituto de Nutrition de Centro America y Panama (INCAP) and serves as a PAHO/World Health Organization (WHO) Regional Center, with field offices in all the Central American countries, including Belize.2

Food Chemical Composition: Dietary Significance in Food Manufacturing

Food Chemical Composition: Dietary Significance in Food Manufacturing

A study on the mineral depletion of the foods available to us as a nation over the period 1940 to 1991.

In 1927 a study at King's College, University of London, of the chemical composition of foods was initiated by Dr McCance to assist with diabetic dietary guidance. The study evolved and was then broadened to determine all the important organic and mineral constituents of foods, it was financed by the Medical Research Council and eventually published in 1940. Over the next 51 years subsequent editions reflected changing national dietary habits and food laws as well as advances in analytical procedures. The most recent (5th Edition) published in 1991 has comprehensively analysed 14 different categories of foods and beverages. In order to provide some insight into any variation in the quality of the foods available to us as a nation between 1940 and 1991 it was possible to compare and contrast the mineral content of 27 varieties of vegetable, 17 varieties of fruit, 10 cuts of meat and some milk and cheese products. The results demonstrate that there has been a significant loss of minerals and trace elements in these foods over that period of time. It is suggested that the results of this study cannot be taken in isolation from recent dietary, environmental and disease trends. These trends are briefly mentioned and suggestions are made as to how the deterioration in the micronutrient quality of our food intake may be arrested and reversed.

Food Chemical Composition: Dietary Significance in Food Manufacturing (Key Topics in Food Science and Technology, No. 6)

Food Chemical Composition: Dietary Significance in Food Manufacturing (Key Topics in Food Science and Technology, No. 6)

Quantificação de fibra alimentar em algumas populações de cubiu (Solanum sessiliflorum dunal), camu-camu (Myrciaria dubia (H.B.K) Mc Vaugh) e açaí (Euterpe oleracea mart)

Considerando a relevância da fibra alimentar na proteção, manutenção e recuperação da saúde e a escassez de tabelas de composição química dos alimentos no que se refere a frutos amazônicos, determinou-se o teor de fibra alimentar em algumas populações de cubiu (Solanum sessiliflonun Dunal), camu-camu (Myrciaria dubia (H.B.K) Mc Vaugh) e açaí (Euterpe oleracea Mart) pelo método enzímico-gravimétrico. Os frutos tiveram diversas procedências: cubiu, da Estação Experimental do INPA/CPCA, camu-camu do município de Barcelos e ao longo da bacia do Rio Amazonas e açaí da bacia do Rio Solimões. Verificou-se que a concentração de fibra alimentar total e insolúvel nas amostras de açaí provenientes de Benjamin Constant (7,66±0,33 g e 6,60±0.IX g) e Anamã (7,45±0,25 g e 6,51±0,04 g), foi significativamente maior (p<0,05), quando comparada com os de outras procedências. Com relação ao cubiu, as maiores concentrações de fibra alimentar total foram detectadas nas amostras Alejo (4,38±0,0 g) e ACSI (3,88±0,18 g), salientando-se que fração analisada inclui a casca, cuja contribuição foi significativamente maior (p<0,05) nas frações insolúvel, solúvel e total. Da mesma forma, os teores de fibra alimentar total (6,18±0,25 g) e insolúvel (5,08±0,14 g) da casca do camu-camu, foram superiores aos encontrados nas demais amostras. Portanto, os frutos analisados apresentaram um potencial relevante como fonte de fibra alimentar, sendo mais uma opção para contribuir na adequação nutricional da população Amazônica e do país.

ペントース関連物質および糖アルコールの栄養特異性

A recent trend has been to use commonly available foods in the prevention of disease. Such application is dependent on a food chemical and physical composition. We investigated functional ac tivity of substances derived from pentose when given in combination with various saccharides to rats. We observed that pentose-derivatives (fructosylxylosides, xylitol, some nucleosides) had a sup pressive effect on the elevation of blood glucose and insulin levels in rats given sucrose or soluble starch. The effect was due to the inhibition of disaccharide hydrolases. We also found that fructo sylxylosides and adenosine enhanced mineral (calcium and magnesium) absorption when given in combination with sucrose.

Influence of diet on acid-base balance.

It is well established that diet and certain food components have a clear impact on acid-base balance. For adults, the following factors are involved: 1) the chemical composition of foods (i.e., their content of protein, chloride, phosphorus, sodium, potassium, calcium, and magnesium), 2) the different intestinal absorption rates of the relevant nutrients, 3) the metabolic generation of sulfate from sulfur-containing amino acids, 4) the grade of dissociation of phosphorus at the physiologic pH of 7.4, and 5) the ionic valence of calcium and magnesium. All these factors allow us to estimate the potential renal acid load (PRAL) of any given food or diet. The PRAL (calculated for a 24-hour period), together with a relatively constant daily amount of urinary excreted organic acids (in healthy subjects proportional to body surface area or body weight), yields the daily net acid excretion. This article provides an overview of the current concepts of diet influences on acid-base balance and also focuses on the underlying physiologic and biochemical basis as well as on relevant clinical implications.

Carbohydrates and risk of stomach cancer in Uruguay

Carbohydrates and risk of stomach cancer in Uruguay

Net alkali requirement of foods of different acidogenicities in a continuous culture system

Maintaining blood pH within a narrow range is the first priority of an animal compared with the other body functions (Erdman et al., 1982). Under normal forage feeding conditions, maintenance of rumen, blood and cellular pH within safe ranges poses no problem for the animal. However, the inclusion of high levels of readily fermentable carbohydrates is often necessary to meet the energy requirements of high producing ruminants. Unfortunately, these foods can result in low rumen pHs which can have adverse effects on animal health and performance. When saliva flow is inadequate to counteract excessive ruminal acidity, the use of buffers may be justified. The in vivo studies reviewed by Muller and Kilmer (1979) have shown that the responses to the addition of buffers to dairy cow rations has been variable and inconclusive.Part of the reason for this uncertainty is because buffer requirements cannot be accurately predicted from the chemical composition of foods, since measurements such as buffering capacity (BC) take no account of changes during fermentation such as the production of volatile fatty acids (VFA), ammonia and the disappearance of the fibre which confers BC. An in vitro approach was adopted for this work since it is difficult to conduct in vivo experiments in this area, owing to the health risks to cows as well as difficulties in distinguishing diet effects because of the strategies employed by cows to overcome excess acidity (e.g. eating rate, salivation, rumination).