Individual Food Components Research Articles

Component Interactions for Efficacy of Functional Foods

The study of functional foods appears to hold the promise of improved quality of life, particularly for older persons who fight chronic disease. Many laboratories are studying the mechanisms of action of individual bioactive food components; but, relatively few studies are concerned with the interaction of the many components found in a single food or with a comparison between effects of the putative major bioactive component and the whole food. This overview is an introduction to the papers that follow, which were given as a symposium at the 2004 Experimental Biology meetings and which address the interactive effects of bioactive food components, particularly those in soy, broccoli, berries, and tomatoes. However, conclusions to be drawn go further than these 4 foods. The studies act as examples, identifying needed areas of focus in the study of functional foods and specifically the need for research into functional foods to encompass 3 areas of study: strength in chemical analysis, mechanistic studies carried out in cell culture, and animal studies comparing effects of dietary exposure to purified components and whole foods. Together, data from these 3 areas can give the solid scientific basis needed, so that clinical studies can be properly planned and executed.

Vascular viewpoint

Question: Does adherence to a Mediterranean diet improve total mortality, as well as mortality due to coronary heart disease (CHD) and cancer? Population: Men and women aged 20 86 years from all geographic areas within Greece. Subjects having CHD, cancer, and diabetes mellitus at the time of enrollment were excluded. Design and methods: A cohort of 28 572 participants was recruited as part of the European Prospective Investigation into Cancer and Nutrition (EPIC) and 22 043 were followed prospectively for a median duration of 44 months. Baseline measurements of diet were obtained using a validated semi-quantitative food-frequency questionnaire, and adherence was determined using an aggregate 10-point scale (from zero to nine, indicating greater adherence with increasing score) devised a priori to incorporate nine prominent components of the traditional Mediterranean diet. A binary value was assigned based on the relative consumption of presumed beneficial or detrimental components. Participants whose consumption of beneficial components (vegetables, legumes, fruits and nuts, cereal, fish, ratio of monounsaturated to saturated fats) was above sex-specific medians were assigned a score of one. Participants whose consumption was below-median were assigned a score of zero. Detrimental components (meat and poultry, dairy) were scored in the opposite fashion -participants whose consumption was above-median were assigned a score of zero, and participants whose consumption was below-median were assigned a score of one. Scoring of alcohol intake was based on whether consumption was within beneficial sex-specific consumption ranges (males, 10 50 g per day; females, 5 25 g per day). Cause of death was obtained from death certificates and official records, and was classified by physicians blinded to diet score. Cox proportional hazards regression models were used to measure the association between studied food groups, adherence to the Mediterranean diet and mortality after adjustment for age, sex, energy expenditure, smoking status, anthropomorphic measures, and other confounding factors. Results: Over the follow-up period, 81 139 person-years were accrued and 275 deaths were recorded. Adherence to the Mediterranean diet was inversely related to mortality. A two-point increase in the aggregate score resulted in an adjusted hazard ratio for death of 0.75 (95% confidence interval [CI], 0.64 to 0.87). Mortality due to CHD (adjusted hazard ratio, 0.67 [95% CI, 0.47 to 0.94]) and mortality due to cancer (adjusted hazard ratio, 0.76 [95% CI, 0.59 to 0.98]) were also inversely associated with a two-point increase in the aggregate score. Consumption of individual food components in the Mediterranean diet was generally not associated with total mortality. Consumption of fruit and nuts (adjusted hazard ratio 0.82 [95% CI, 0.70 to 0.96]) and the ratio of monounsaturated fats to saturated fats (adjusted hazard ratio 0.86 [95% CI, 0.76 to 0.98]), however, were associated with reduced mortality. Conclusion: Adherence to the Mediterranean diet is associated with a significant reduction in total mortality, CHD, and cancer mortality. Individual components of the diet are not generally predictive of total mortality, suggesting that multiple dietary components are necessary to yield the most protective effect.

Nutrients, foods, and dietary patterns as exposures in research: a framework for food synergy

Evidence is synthesized that foods and food patterns act synergistically to influence the risk of several chronic diseases. Whole-grain consumption and risk of disease are presented as a model of food synergy. Food synergy is defined as additive or more than additive influences of foods and food constituents on health. Risk appears to be lower with consumption of whole grain than of refined grain; that is, benefit accrues when all edible parts of the grain are included (bran, germ, and endosperm). It appears that phytochemicals that are located in the fiber matrix, in addition to or instead of the fiber itself, are responsible for the reduced risk. Risk is further reduced if whole-grain foods are consumed in a diet otherwise high in plant foods. To gain full understanding of the pathways by which food synergies work, it is desirable to use several "top down" approaches, starting with the larger units, namely foods or food patterns, and working down to smaller units that provide protection from disease. Study of foods, food patterns, and individual nutrients or food components in reducing disease risk is seen as complementary. Epidemiologic, clinical trial, and in vitro approaches to such research are needed.

The leafy vegetable amaranth (Amaranthus gangeticus) is a potent inhibitor of calcium availability and retention in rice-based diets.

Improvement in the nutritional quality of Bangladeshi rice-based diets is sought through increasing the amounts of vegetables, fish and legumes consumed. The aim of the present study was to compare the effects of rice-based diets on selected parameters of Ca and P availability and retention in young, growing rats. The study was designed as a randomised balance trial with five diets, eight animals per diet, and two balance periods of 1 week each. Apart from diet 1, which was a pure rice diet, the other four diets were composite diets and included the leafy vegetable, amaranth leaves (Amaranthus gangeticus), the small fish, mola (Amblypharyngodon mola), and lentils (Lens culinaris) in different amounts to simulate the average rural rice-based diet, the recommended diet, the recommended diet diluted with starch, and the recommended diet excluding amaranth leaves. The inclusion of amaranth leaves, mola and lentils significantly improved N and growth retention in the rats compared with the pure rice diet. However, a minor addition of amaranth (0.66 g/100 g DM) significantly reduced the fractional Ca absorption and retention. Femur bone mass and Ca and P densities were significantly lower in the rats fed the diets that included amaranth leaves. The observed inhibitory effect of the amaranth leaves on Ca absorption and utilisation was probably due to the oxalate content. It is concluded that the formulation of a recommended diet cannot be based only on nutrient content values of individual food components due to interactions between nutrients and anti-nutrients in the diet.

The dynamics of moisture migration in packaged multi-component food systems I: shelf life predictions for a cereal–raisin system

A theory is developed for the kinetics of moisture migration in packaged multi-component food mixtures, such as cereal–fruit mixtures, mixed candy or freeze dried instant meals. The theory assumes the individual food components to be characterised by their initial water activities, isotherm slopes and a function describing the time course of moisture uptake under constant humidity conditions; the step-response functions. When specifying the product properties compositions and net weight and package parameters such as area and water vapour permeability, the time development of internal moisture redistribution and water uptake into the package can be calculated. Calculations on realistic packages containing a cereal–raisin mixture show that the headspace water activity attains the water activity of the cereal flakes within one minute. On a timescale of one year the processes of moisture transfer from raisins to cereals and permeations through the package film take place. For the raisin–cereal mixtures under consideration the product moisture transfer from raisin to cereals limits quality. Shelf life calculations based on the kinetic theory show that product composition and package permeability optimal for the overall product quality can be identified. The calculations demonstrate that information from focused experiments on individual food components can be used to predict storage stability on a number of mixtures and under different conditions.

The dynamics of moisture migration in packaged multi-component food systems II: analytical solutions and comparison to experimental moisture transfer rate results

The previously proposed kinetic theory of moisture migration in packaged multi-component systems is developed further and tested against experimental data. Two simplified analytical solutions suitable for implementation without special purpose software have been found. The first solution concerns the case where the moisture exchange of one component is rate limiting. The other solution describes the situation where all components are characterized by the same moisture uptake dynamics (response function). The numerical calculations using the full theory as well as the solution assuming same sorption dynamics of all components are shown to be in accordance with experimental data for the moisture transfer in closed systems containing binary or ternary mixtures of raisins, roasted almonds, peanuts and banana chips. The calculations show that the headspace water activity is distinctly different from the water activities of the components at any time indicating that no single component sorption process is rate limiting. The implications of the theory are that the information of dynamics of moisture sorption of the individual food components under constant humidity conditions can be utilized in simple expressions for the time development of component moisture contents with the possibility of making shelf life calculations on any combinations of the food components.

Food Composition Program of AFROFOODS

An African Network of Food Data System (AFROFOODS) as part of the International Network of Food Data Systems (INFOODS) was established in September 1994 in Ghana. This was followed by a meeting in Dakar (Ghana) during May 1995 during which activities were reestablished. Capacity building and training in analytical methods and compilation of food composition data were identified as a pre-requisite for progress during both the meetings. During a workshop in May 1996 a module on Food Composition and Hygiene for an MSc in Food and Nutrition Sciences in developing countries for the Network of European Agricultural Universities (NATURA)-NECTAR group as part of an EU-financed program was drawn up. The module was based on the existing Food Composition Course of Wageningen Agricultural University and was first tested in South Africa during 1997 at the University of the Western Cape. The 2nd ECSAFOODS course was held in 1999 at the Agricultural Research Council (ARC) in Pretoria, South Africa, with a third course planned for 2002. During an AFROFOODS meeting that was held in Pretoria, South Africa, six working groups were elected (June 2001), namely for: training, analytical procedures, communication and dissemination, use of food composition databases, food legislation, standards and regulations and data compilation. AFROFOODS seem to lag behind other data centers with regard to the progress they have made during the same time period. Capacity building in the AFROFOODS region stays one of the major priorities for the immediate future, to equip people to assist their own countries in reaching the ultimate goal of being able to compile good-quality food composition tables that reflect the individual food components in the diet of the different people within the country. Current member countries of the Africa region (51 in total 2 2 Djibouti, Somalia and Western Sahara not included. ) are Algeria 3 3 Algeria, Egypt, Libya, Mauritania, Morocco, Sudan and Tunisia belong both to the Africa region and to the Near East Region. , Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Cape Verde, Central African, Republic, Chad, Comoros, Democratic Republic of Congo, Republic of the Congo, Côte d'Ivoire, Egypt, Equatorial Guinea, Eritrea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea Bissau, Kenya, Lesotho, Liberia, Libya, Madagascar, Malawi, Mali, Mauritania, Mauritius, Morocco, Mozambique, Namibia, Niger, Nigeria, Rwanda, Sao Tome and Principe, Senegal, Seychelles, Sierra Leone, South Africa, Sudan, Swaziland, United Republic of Tanzania, Togo, Tunisia, Uganda, Zambia, Zimbabwe.

Recent Trends in the Evaluation of Functional Foods

The specific health benefits of individual food components have been recognised for centuries, but only relatively recently has there been a determined effort by pioneering individuals in Countries such as Japan, to take advantage of the huge public health benefits that are on offer. It is a sad fact that in almost all Countries that have adopted Legislation or Codes of Practice, it is the pressure derived from exaggerated health claims on food products that lead to controls. Absurd product health claims created with little or no regard for the scientific evidence results in the Authorities fi ghting a rearguard action to limit claims, rather than adopting an initial neutral attitude and approach that would lead to fresh thinking. In the European Economic Community, current National practices and legislation in the 15 Member States effectively create different approaches towards food fortification, food supplements, herbal products and the availability of non-prescription products. In the absence of a specific Directive from Brussels, it is not surprising that the majority of EU Member States have in place, or are currently working on National Codes of Practice in an attempt to control foods that carry health messages. In an attempt to harmonise the basic requirements for controls on functional foods, the CIAA has produced a pan-European document that sets out the principle requirements. We also need to consider the effect that officially recognising health claims for food will have on specialised product sectors where a surprising degree of freedom already exists for health claims. In my paper I will compare individual Codes of Practice and Legislation and discuss representative examples of food and supplement products. I will point out the current advantages for some market sectors, together with the failings in well-established legislation that can prevent the marketing of bona fide foods with health claims.

Influence of food matrix on absorption of flavour compounds by linear low-density polyethylene: proteins and carbohydrates

The influence of oil and food components in real food products on the absorption of four flavour compounds (limonene, decanal, linalool and ethyl 2-methyl butyrate) into linear low-density polyethylene (LLDPE) was studied using a large volume injection GC in vial extraction method. Model food systems and real food products investigated included oil/water emulsions, oil/casein models, oil/pectin models, skim milk and whole milk. A small amount of oil (50 g l-1) had a major influence on the amount of flavour absorption. Because of solubilization of the more apolar flavour compounds limonene, decanal and linalool into the oily phase, only the remaining flavour compounds in the aqueous phase were available for absorption by LLDPE. After 14 days of exposure, absorption of limonene and decanal decreased by 97°and that of linalool by 86ÐDue to a salting out effect, absorption of the less apolar ethyl 2-methylbutyrate (E2MB) first increased with increasing oil concentration, but decreased at higher oil concentrations (>2.5 g l-1). Oil/casein and oil/pectin models showed that the more apolar flavour compounds were mainly dissolved in the oily phase and that the compounds present in the aqueous phase could interact with casein or pectin. Oil influenced the level of flavour absorption by LLDPE to a much greater extent than pectin or casein. However, the low amount of fat (1.11 g l-1) in skim milk had no influence on the absorption of flavour compounds. Only the proteins in skim milk (especially casein) decreased the absorption of limonene and decanal, because the fat was probably entrapped. Whole milk, which contained a higher concentration of (free) fat, suppressed the absorption of all flavour compounds by LLDPE to the same extent as was found for the oil model solutions. In general, absorption results from skim milk and whole milk were in good agreement with the results of the investigated model solutions containing individual food components.

Influence of food matrix on absorption of flavour compounds by linear low-density polyethylene: oil and real food products

The influence of oil and food components in real food products on the absorption of four flavour compounds (limonene, decanal, linalool and ethyl 2-methyl butyrate) into linear low-density polyethylene (LLDPE) was studied using a large volume injection GC in vial extraction method. Model food systems and real food products investigated included oil/water emulsions, oil/casein models, oil/pectin models, skim milk and whole milk. A small amount of oil (50 g l-1) had a major influence on the amount of flavour absorption. Because of solubilization of the more apolar flavour compounds limonene, decanal and linalool into the oily phase, only the remaining flavour compounds in the aqueous phase were available for absorption by LLDPE. After 14 days of exposure, absorption of limonene and decanal decreased by 97°and that of linalool by 86ÐDue to a salting out effect, absorption of the less apolar ethyl 2-methylbutyrate (E2MB) first increased with increasing oil concentration, but decreased at higher oil concentrations (>2.5 g l-1). Oil/casein and oil/pectin models showed that the more apolar flavour compounds were mainly dissolved in the oily phase and that the compounds present in the aqueous phase could interact with casein or pectin. Oil influenced the level of flavour absorption by LLDPE to a much greater extent than pectin or casein. However, the low amount of fat (1.11 g l-1) in skim milk had no influence on the absorption of flavour compounds. Only the proteins in skim milk (especially casein) decreased the absorption of limonene and decanal, because the fat was probably entrapped. Whole milk, which contained a higher concentration of (free) fat, suppressed the absorption of all flavour compounds by LLDPE to the same extent as was found for the oil model solutions. In general, absorption results from skim milk and whole milk were in good agreement with the results of the investigated model solutions containing individual food components.

Dietary vitamin e in an atherogenic hamster model

Regular consumption of fruits, vegetables and cereals moderates development of coronary heart disease and atherosclerosis in humans, possibly as a result of antioxidants present in these foods. The aim of this study was to develop a hamster model sufficiently sensitive to test the effects of nutritional rather than pharmacological amounts of food components on the development of atherosclerosis. The effect of vitamin E on aortic lipid deposition was investigated in hamsters fed a hypercholesterolemic diet containing per kilogram 2 g cholesterol, 90 g butterfat, 35 g vitamin E-stripped corn oil, 25 g fish oil and either the minimum requirement of 3 international units (IU) vitamin E or 30 IU. After 30 weeks, lipoprotein cholesterol fractions did not differ between groups, and the 6:1 LDL-cholesterol : HDL-cholesterol ratio was atherogenic. Early atherosclerosis was measured by lipid staining of aortic arch sections with oil red O and quantified by a photomicroscopy color-scanning technique. The area of lipid deposits in the 30 IU vitamin E group (7.9 ± 1.3%, mean ± SEM) was 58% less than in the 3 IU vitamin E group (18.7 ± 4.4%, p < 0.03). Hamsters fed a mixture of saturated and n-6 and n-3 polyunsaturated fatty acids plus cholesterol became hypercholesterolemic and were sensitive to vitamin E with respect to development of atherosclerosis. This model provides a tool to test atheroprotective effects of individual food components in vivo.

Rapid assessment of food/package interactions by electrochemical impedance spectroscopy (EIS)

Food components migrating through organic layers are able to influence the adhesive properties of multilayer materials. In the case of coated metal substrates the interaction stability may be reduced by delamination and subsequent corrosion processes during storage. Impedance spectroscopy can be used to give a very early indication of a reduced interaction stability of a packaging material by measuring the delamination tendency. Applications are presented for laminated aluminium foil material. The delamination is induced by a cathodic treatment of samples prepared from the package. A comparison is made of material with no contact and with only a few days contact with the filled product. Main applications are foreseen as the replacement of long‐term storage tests to establish the compatibility of food and package material and to work out the specific influence of individual food components.

Cholecystokinin bioactivity in human plasma. Molecular forms, responses to feeding, and relationship to gallbladder contraction.

A sensitive and specific bioassay for the measurement of cholecystokinin (CCK) in human plasma was developed to determine the molecular forms of CCK in circulation, CCK responses to feeding, and the physiologic role of CCK in gallbladder contraction. First, plasma was quantitatively extracted and concentrated with octadecylsilylsilica, and the extracts were then assayed for their ability to stimulate amylase release from isolated rat pancreatic acini. Acini were highly sensitive to CCK whereas gastrin reacted only weakly in this system. With the assay, plasma levels of cholecystokinin octapeptide (CCK-8) bioactivity as low as 0.2 pM were detectable. CCK bioactivity in plasma was inhibited by the CCK antagonist, bibutyryl cyclic guanosine monophosphate, and was eliminated by immunoadsorption with an antibody directed against the carboxyl terminus of CCK. Detection of fasting levels of CCK was possible in all individuals tested and averaged 1.0 +/- 0.2 pM (mean +/- SE, n = 22) CCK-8 equivalents. Plasma CCK biological activity was normal in patients with gastrin-secreting tumors. After being fed a mixed liquid meal, CCK levels rose within 15 min to 6.0 +/- 1.6 pM. The individual food components fat, protein, and amino acids were all potent stimulants of CCK secretion; in contrast, glucose caused a significant but smaller elevation in plasma CCK levels. Gel filtration studies identified three major forms of CCK bioactivity in human plasma: an abundant form that eluted with CCK-33, a smaller form that eluted with CCK-8, and an intermediate form that eluted between CCK-33 and CCK-8. Ultrasonic measurements of gallbladder volume indicated that this organ decreased 51% in size 30 min after feeding a mixed liquid meal. This contraction occurred coincidentally with the increase in plasma CCK levels. Next CCK-8 was infused to obtain CCK levels similar to postprandial levels. This infusion caused a decrease in gallbladder volume, similar to that seen with a meal. The present studies indicate, therefore, that CCK can be bioassayed in fasting and postprandial human plasma. These studies also suggest that CCK may be an important regulator of gallbladder contraction.

The radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods

Abstract An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the α,α'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The α,α'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and bacterial products. All of the available data strongly sug...

Release of motilin by oral and intravenous nutrients in man.

Motilin is a hormonal peptide found in the duodenum and jejunum which potently influences gastrointestinal tract motility. Its role in human physiology is not yet established. After a standard hospital lunch the plasma concentration of motilin showed a small, transient, but significant rise in 28 healthy subjects. Individual food components either stimulated (oral fat) or suppressed release (oral glucose). Plasma motilin levels were, in addition, altered to an equal extent by intravenous nutrients, with glucose and amino acids suppressing release, and intravenous fat causing a significant rise in plasma concentration. These results demonstrate a consistent response to food stimuli, whether oral or intravenous. The release mechanism appears to be complicated and after a balanced meal, containing food components which both stimulate and suppress release, there is only a small net change.

Use of sulphur analysis in the prediction of the the protein value of Middle-Eastern diets.

AbstractA rapid procedure for the analysis of sulphur in foodstuffs is described and is compared with the barium chloranilate procedure.The prediction of the protein value of Middle‐Eastern diets from the S : N ratio has been compared with that obtained by rat‐feeding experiments. the agreement found depends more on the relationship with protein quantity than with any quality measurement. Furthermore, the correlation between S : N ratio and SAA (sulphur‐containing amino acid) score was not significant for 22 diets where SAA data were available. Calculation shows that the proportion of total sulphur from methionine and cystine can show large variations both for individual food components and also for mixed diets. the S : N prediction procedure does not appear to be suitable for Middle‐Eastern diets.