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Optimal growth and development are the primary objectives of pediatric nutrition. Dietary habits and food choices to support both oral health and systemic health are similar. Each emphasizes structured meal patterns and food choices. The oral health professional has a responsibility to screen for diet-related disorders and to treat or refer as appropriate.
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, are brought into better synchrony with the sciences.
By means of the cited formula, integral indices of potential coherence of the following pairs of brain structures were calculated: hippocampus--frontal cortex, amygdala--frontal cortex, hippocampus--amygdala. In food-procuring behavior of dogs, the values of these indices increase simultaneously with the increase of the level of functional state of the brain structures. The values become higher under the action of a signal with a greater informational significance for alimentary need satisfaction than under the action of a signal with lesser informational significance.
Ovalbumin, a non-inhibitory member of serine proteinase inhibitors (serpin), is transformed into a heat-stabilized form, S-ovalbumin, under elevated pH conditions. The structural mechanism for the S-ovalbumin formation has long been a puzzling question in food science and serpin structural biology. On the basis of the commonly observed serpin thermostabilization by insertion of the reactive center loop into the proximal beta-sheet, the most widely accepted hypothetical model has included partial loop insertion. Here we demonstrate, for the first time, the crystal structure of S-ovalbumin at 1.9-A resolution. This structure unequivocally excludes the partial loop insertion mechanism; the overall structure, including the reactive center loop structure, is almost the same as that of native ovalbumin, except for the significant motion of the preceding loop of strand 1A away from strand 2A. The most striking finding is that Ser-164, Ser-236, and Ser-320 take the d-amino acid residue configuration. These chemical inversions can be directly related to the irreversible and stepwise nature of the transformation from native ovalbumin to S-ovalbumin. As conformational changes of the side chains, significant alternations are found in the values of the chi 1 of Phe-99 and the chi 3 of Met-241. The former conformational change leads to the decreased solvent accessibility of the hydrophobic core around Phe-99, which includes Phe-180 and Phe-378, the highly conserved residues in serpin. This may give a thermodynamic advantage to the structural stability of S-ovalbumin.
While better hygiene controls and vaccinations have diminished the occurrence of infectious diseases in humans, food-borne diseases have increased. Thus sterilization of food products is of prime importance. The introduction of new technologies applied to food has necessitated new methods for the control of food safety and food quality. This review aims to point out the importance of immunochemistry in the identification of structural changes induced in food proteins during food processing. New technologies have introduced the use of additives in food products, therefore it is important to identify and quantify such additives, even after complete hear denaturation. Toxic chemicals, toxins and pesticides which can contaminate food products before or during processing should also be identified. Finally, the use of immunochemical tests as a control of sterilization procedures in heterogeneous foodstuffs is discussed.
Estimates of post-mortem interval based on forensic analysis of the age of blowfly larvae on a corpse, are generated from standardised larval development curves. These are derived from studies of the growth of larvae reared, usually, on liver and at a range of temperatures. However, it is possible that the species or organ on which the larvae feed, might significantly alter the rate of growth. The present study therefore compared the development of the blowfly Lucilia sericata (Meigen) (Diptera: Calliphoridae) fed on lung, liver and heart, from both cows and pigs. Half of the tissue samples used were liquidised while half were not, to assess whether structural differences in the food source were important. Larvae grew significantly faster and gave rise to larger adults when reared on pig compared to cow tissue and when reared on lung and heart compared to liver. Larvae completed feeding and wandered from the food source 31h earlier and grew 2mm longer when reared on lung compared to liver. Tissue structure had no or little effect on development. For the forensic entomologist, these results highlight the importance of recording the position of larvae removed from a body and the care that should be used when extrapolating development rates from standard curves based on larvae fed on only a single medium, particularly where that is liver.
Using a single-blade ultrasonic cutting device, a study of ultrasonic cutting of three very different materials is conducted using specimens of cheese, polyurethane foam and epoxy resin. Initial finite element models are created, based on the assumption that the ultrasonic blade causes a crack to propagate in a controlled mode 1 opening, and these are validated against experimental data from three point bend fracture tests and ultrasonic cutting experiments on the materials. Subsequently, the finite element model is developed to represent ultrasonic cutting of a multi-layered material. Materials are chosen whose properties allow a model to be developed that could represent a multi-layer food product or biological structure, to enable ultrasonic cutting systems to be designed for applications both in the field of food processing and surgical procedures. The model incorporates an estimation of the friction condition between the cutting blade and the material to be cut and allows adjustment of the frequency, cutting amplitude and cutting speed.
The decision to eat, and to eat particular foods, varies for different individuals and situations. Individual differences in food likes and desires develop throughout life because of differing food experiences and attitudes. There are many internal and external cues, not just stimulation from foods or hunger, which can trigger the immediate desire to eat or orient eating toward certain foods. Food desires and intake are an outcome of interactions between these cues and more stable individual physiological and psychological characteristics. Overweight and obese individuals show a tendency toward greater liking and selection of energy-dense foods, which may contribute to development and maintenance of these conditions. However, although liking (pleasure from eating) is an important part of food choice, it may make only a modest contribution to overall variation in food choice and eating behaviors. Indeed, difficulties of weight control may reflect problems with cues and motivations to eat, rather than with heightened pleasure derived from eating. Paradoxically, individuals highly concerned with food intake and weight control may be particularly susceptible to thoughts, emotions, and situational cues that can prompt overeating and undermine their attempts to restrain eating. Repeat dieting, high day-to-day fluctuations in intakes, and attempts to enforce highly rigid control over eating all seem to be counterproductive to weight control efforts and may disrupt more appropriate food choice behaviors. Longer-term weight maintenance solutions and programs that offer a degree of structuring of the personal food environment, while retaining flexibility in choices, therefore, may be particularly beneficial in weight management.
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Complementary deoxyribonucleic acid (cDNA) encoding goldfish preproghrelin was identified using rapid amplification of the cDNA ends (RACE) and reverse transcription (RT)-polymerase chain reaction (PCR). The 490 bp cDNA encodes a 103 amino acid preproghrelin which has a 26 amino acid signal region, 19 amino acid mature peptide and a 55 amino acid C-terminal peptide region. The mature peptide region of goldfish ghrelin has two putative cleavage sites and amidation signals (GRR); one after 12 amino acids and the other after 19 amino acids. The serine (S) in the second amino acid position in the "active core" of ghrelin is substituted with threonine (T). The goldfish ghrelin gene has four exons and three short introns and resembles the human ghrelin gene. Ghrelin messenger RNA (mRNA) expression was detected in the brain, pituitary, intestine, liver, spleen and gill by RT-PCR followed by Southern blot analysis, and in the intestine by Northern blot. Intracerebroventricular (ICV) injection of n-octanoylated goldfish ghrelin (1-19) stimulates food intake in goldfish.
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The 31P-NMR spectra of the proteophosphomannan (PPM) and also that of mildly hydrolyzed PPM demonstrated phosphomonoester (in both preparations), acid labile and acid stable phosphodiester linkage, and polyphosphate. Decreasing in size by pronase digestion, separation, purification and characterization of the high and low molecular phosphates by 31P-NMR spectroscopy and chemical analysis revealed the mannan protein is phosphorylated in the N-glycosidically linked carbohydrate parts and in the O-glycosidically linked oligosaccharides. Another phosphate serves as a bridge between the serine of the protein and mannose, mannobioses and mannotrioses and between the threonine and a lipophilic acylglycerid unit. The origin of the polyphosphates has been discussed.
BACKGROUND AND AIM: To evaluate the effects on postprandial lipemia (PPL), of three fat rich meals, with similar composition but different physical structure (liquid, semisolid and solid). METHODS AND RESULTS: Eight type 2 diabetic patients of both genders (6M/2F), age 51+/-9 yrs (M+/-SD), BMI 29+/-3 kg/m2, with fasting plasma glucose levels 145+/-24 mg/dL, cholesterol 200+/-38 mg/dL and triglyceride 110+/-45 mg/dL. Participants consumed in the morning, after a 12-hour fast and at 1-week intervals, three test meals with similar volume and composition [protein 36 g, lipid 30 g, carbohydrate 115 g, energy 3556 kJ (850 Kcal)] but with the main source of fat represented by foods with different physical structure (milk, mozzarella-cheese, butter). Each patient underwent gastric emptying measurements by echography; plasma FFA, triglycerides, glucose and insulin were evaluated at baseline and every hour for six hours after each meal. Fasting plasma glucose, cholesterol and triglyceride concentrations were similar at the baseline of the three test meals. Average increases in postprandial plasma triglyceride levels after butter (88+/-8 mg/dL) and mozzarella-cheese (104+/-56 mg/dL) were not different than after milk (98+/-53 mg/dL). The plasma triglyceride peak was also similar after the three test meals but peak time after butter (315+/-42 min; p<0.01) and mozzarella-cheese (277+/-31 min; p<0.02) was significantly delayed compared to milk (225+/-28 min). Gastric emptying rate was similar after butter and milk (14+/-2, 13+/-6 mL/h) and significantly faster after mozzarella-cheese (18+/-5 mL/h; p<0.03). CONCLUSIONS: While the physical structure of fat-rich foods has no major effect on postprandial plasma triglyceride concentrations, it is able to influence the timing of triglyceride peak; gastric emptying time does not play a major role in modulating the postprandial response of triglycerides and glucose.
Food allergy (hypersensitivity) is a form of adverse food reaction in which the reaction is caused by an immunological response to a food. Most immediate allergic reactions to food are IgE-mediated. The prevalence of food allergy in the general population without the oral allergy syndrome is about 1-2%. Although many foods have been described to cause an allergic reaction, only a few are responsible for the majority of hypersensitivity symptoms. Based on continuous studies by B. Wüthrich, Allergy Unit of the Dermatology Department, University Hospital, Zurich, celery (42%) followed by dairy products (16%), carrot (13%), hen's egg (12%) and fish (7%) is by far the major source of food allergy in Switzerland. In adults food hypersensitivity is mainly due to cross-reactivity between inhalative and food allergens. Pathophysiologically, IgE antibodies induced by aeroallergens recognize structurally similar components in certain foods even from taxonomically unrelated plants. Following an accurate allergological examination, oral provocation tests are considered the most conclusive procedures to establish diagnosis. The only proven form of management in food allergy is strict elimination of the offending food. Food-allergic patients must be provided with emergency medications. Identification of allergens and their characterization finally will improve our understanding for pathophysiologic mechanisms of food allergy.
To assess which membrane properties are modulated by the action of food restriction, characteristics of liver membrane structures of ad libitum-fed and food restricted Fischer 344 rats were analyzed over a wide age range. The results show that the yields of mitochondrial and microsomal membranes decreased in ad libitum-fed rats, but this age-related loss did not occur in food restricted rats until 30 months. Changes in membrane fatty acid composition which occurred with age were substantially modified by food restriction. Linoleic acid content progressively decreased in the membranes of ad libitum-fed rats with a concomitant increase of docosapentaenoic acid while an opposite pattern of change occurred in food restricted rats. Furthermore, food restriction maintained a low docosahexaenoic acid level in microsomes at all ages studied. While serum tocopherol increased markedly with age, there was little change in membrane tocopherol content in ad libitum-fed rats.