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PubMed1997

Intracerebroventricular injection of mammalian and chicken glucagon-like peptide-1 inhibits food intake of the neonatal chick.

Glucagon-like peptide-1 (GLP-1), structurally similar to glucagon, is synthesized from a larger precursor, preproglucagon, and has been postulated to be a novel incretin. Recently, it was reported that central administration of GLP-1 decreased food intake in rats. The amino acid sequences of GLP-1 are identical in all mammals, and chicken GLP-1 exhibits a high homology with mammalian GLP-1. The aim of this study was to elucidate whether central injection of mammalian or chicken GLP-1 inhibits food intake in the chick, and to compare their effects. Intracerebroventricular administration of mammalian and chicken GLP-1 strongly inhibited food intake of chicks. However, the suppressive effect of both GLP-1 on food intake was similar. These results show that GLP-1 with a variety of amino acid sequences may be the most potent inhibitor of food intake in the chicken.

Amino Acid Sequence↗

PubMed2001

Sugar-Ester Nonionic Microemulsion: Structural Characterization.

Surfactants containing sugar components and fatty acids satisfy the quality standards for food application. The food grade sugar ester in this study is a commercial sucrose monoester of stearic acid (abbreviated SES), the oil phase consists of a 1:1 mixture of n-tetradecane and l-butanol. The originally planned food grade oil, a medium chain triglyceride, is substituted by tetradecane because tetradecane is available as a fully deuterated product, which is necessary for some structural investigations. The investigated system is solid at room temperature, but liquefies and structures into a homogeneous microemulsion when heated to above 37 degrees C. The structural characterization of such microemulsions is the aim of this work. The established methods for this purpose are scattering methods, such as small-angle scattering of X-rays and neutrons and dynamic light scattering. These scattering techniques can be used to obtain valuable information on the size, shape, and internal structure of colloids and complex fluids. We started our investigation with the pseudobinary system SES, tetradecane and l-butanol, varying the SES content. The scattering results show that the sugar ester form inverse globular micelles in the oil phase. The size of these micelles is about 6 nm. While the size is nearly constant in a wide SES concentration regime (5 up to 40% surfactant), the volume or aggregation number increases significantly with SES. This is explained by an increasing replacement of l-butanol molecules by sugar-ester molecules in the micelles formed. Moreover, it can be shown that these micelles strongly overlap. Their center-to-center distance is about 3.8 nm at 40% SES at a micellar diameter of 6 nm. The micellar overlap leads to a highly reduced diffusion of the micelles as was found with dynamic light scattering. When incorporating water in the micellar core, the micelles swell up to about 10 nm and the shape of the aggregates becomes more and more elongated with higher water content. Copyright 2001 Academic Press.

Journal Article↗

PubMed1992

Psychological Effects of Vertical Banded Gastroplasty on Pathologically Obese Patients.

For a period of 2 years the authors have examined on 16 pathologically obese patients the psychological effects of the weight loss resulting from vertical banded gastroplasty. At the time of surgery the patients' average age was 41 years. The patients' average weight of 125.9 kg (range 110-150 kg) decreased after surgery to 89 kg, showing a decrease of 36.9 kg (range 20-69 kg). The postoperative compliance has been good despite the fact that the remaining gastric capacity allows for the ingestion of only 50-70 ml of food. Psychological results, obtained through consultations, semi-structured interviews and a series of tests, brought to light remarkable changes directly proportional to the weight loss achieved. Psychic well-being, self-esteem, and improvements in the interpersonal relations within the family and work environments represent in summary the positive results of the weight loss achieved by patients with no other possibility (voluntary) to keep their food intake under control (which we termed 'food addiction'). The patients abandon their depressive traits and achieve a degree of confidence that preserves them from stress and anxiety. Patients improve their social mobility, and for many the sexual relations with the partner become more frequent and intense. The weight loss plays an indispensable role within itself but additionally is associated with a general normalization of all physical parameters. Also, it starts an avalanche of positive events which break the vicious cycle: aesthetic inadequacy-anxiety/depression-food-excess weight.

Journal Article↗

PubMed2005

Nutrient-limited food webs with up to three trophic levels: feasibility, stability, assembly rules, and effects of nutrient enrichment.

Community structure is controlled, among multiple factors, by competition and predation. Using the R* rule and graphical analysis, we analyse here the feasibility, stability and assembly rules of resource-based food webs with up to three trophic levels. In particular, we show that (1) the stability of a food web with two plants and two generalist herbivores does not require that plants' resource exploitation abilities trade-off with resistance to the two herbivores, and (2) food webs with two plants and either one generalist herbivore and a carnivore or two generalist herbivores and two generalist carnivores are not feasible because of cascade competition between top consumers. The relative strength of species interactions and the relative impacts of plants and herbivores on factors which control their growth also play a critical role. We discuss how community structure constrains assembly rules and yields cascades of extinctions in food webs.

Animals↗

PubMed2026

AI-driven snapshot hyperspectral imaging for on-line sorting systems in food industry: From real-time sensing to intelligent decision-making.

High-throughput food sorting requires rapid, non-destructive detection of external defects, foreign materials, and internal quality attributes in heterogeneous food matrices. Conventional scanning hyperspectral imaging may suffer from motion-induced spatial-spectral mismatches, whereas snapshot hyperspectral imaging (S-HSI) captures spectral images within a single integration time. However, its advantage is limited by trade-offs in resolution, signal-to-noise ratio (SNR), reconstruction uncertainty, and calibration stability, which are further amplified by variable tissue structure, surface reflection, moisture, and fat distribution in foods. This review critically examines artificial intelligence (AI)-driven S-HSI for on-line food sorting within a sensing-representation-decision-execution framework. Compact architectures are compared according to their physical constraints, food-sorting suitability, and ability to support mapping between spectral responses and physicochemical quality attributes. AI strategies are reviewed for spectral reconstruction, image restoration, spatial-spectral representation, band selection, uncertainty-aware decision-making, and edge implementation. AI can partially compensate for snapshot-specific limitations, but current evidence remains largely limited to laboratory or prototype studies. Future work should link system performance to food safety and quality outcomes by reporting throughput, decision latency, calibration drift, missed-detection risk, false-rejection cost, and closed-loop sorting success.

Hyperspectral Imaging↗

PubMed2005

Category content and structure in schizophrenia: an evaluation using the instantiation principle.

In numerous studies, researchers have suggested anomalies in semantics in patients with schizophrenia. In this study, the authors addressed whether one such anomaly might reflect a difference in knowledge content or in the structure or organization of this information. Using a category member production task and a typicality rating task, the authors assessed knowledge content and found that patients' and control participants' knowledge about categories of foods and animals was very similar. In terms of structure, their findings from a mathematical model of category judgment (the instantiation model; E. Heit & L. W. Barsalou, 1996) revealed a similar category structure in patients and control participants. In conclusion, the authors suggest that the content and organization of categories in patients with schizophrenia is similar to that in healthy control participants.

Adult↗

PubMed2003

Minimising waste in the food and drink sector: using the business club approach to facilitate training and organisational development.

The aim of the East Anglian Waste Minimisation in the Food And Drink Industry Project was to develop waste minimisation capability in food and drink sector companies by providing a structured training programme and consultancy support to participating members of a business club. The business club forum provided the structure within which interactive training and development sessions were delivered. Expertise and assistance in implementing waste minimisation and waste management programmes was given to member companies at their sites. The project resulted in pound 1,800,000 per annum of identified savings with pound 1,100,000 of verified savings already achieved. Training and development contributed fundamentally to these project outcomes and achievements. The structured training package used three different approaches or methods. Teaching and workshop sessions were used to present interactive training on waste minimisation practice. These were supplemented by interactive 'report-back' sessions where the 'project champions' presented progress reports to the club on waste minimisation at their sites. An overview of the business club approach is described, together with an account of the successes and challenges of applying a structured training and development programme and the barriers to waste minimisation that were overcome. Training effectiveness was measured according to reaction, learning, application and impact.

Beverages↗

PubMedDate not supplied

Spore dispersal of a resupinate ectomycorrhizal fungus, Tomentella sublilacina, via soil food webs.

Patterns of fungal spore dispersal affect gene flow, population structure and fungal community structure. Many Basidiomycota produce resupinate (crust-like) basidiocarps buried in the soil. Although spores are actively discharged, they often do not appear to be well positioned for aerial dispersal. We investigated the potential spore dispersal mechanisms of one exemplar of this growth form, Tomentella sublilacina. It is a widespread ectomycorrhizal fungus that sporulates in the soil organic horizon, can establish from the spore bank shortly after disturbance, but also can be a dominant species in mature forest stands. We investigated whether its spores could be dispersed via spore-based food webs. We examined external surfaces, gut contents and feces from arthropod fungivores (mites, springtails, millipedes, beetles, fly larvae) and arthropod and vertebrate predators (centipedes, salamanders) from on and around T. sublilacina sporocarps. Spore densities were high in the guts of many individuals from all fungivore groups. Centipede gut contents, centipede feces and salamander feces contained undigested invertebrate exoskeletons and many apparently intact spores. DAPI staining of spores from feces of fungivores indicated that 7-73% of spores contained intact nuclei, whereas spores from predators had lower percentages of intact nuclei. The spiny spores often were lodged on invertebrate exoskeletons. To test the viability of spores that had passed through invertebrate guts we used fecal droppings of the millipede Harpaphe haydeniana to successfully inoculate seedlings of Pinus muricata (Bishop pine). These results indicate the potential for T. sublilacina spore dispersal via invertebrates and their predators in soil food webs and might help to explain the widespread distribution of this species. It is likely that this is a general mechanism of dispersal for fungi producing resupinate sporocarps, indicating a need to develop a fuller understanding of the linkages of soil food webs and spore dispersal.

Animals↗

PubMed2002

Pediocin PA-1, a wide-spectrum bacteriocin from lactic acid bacteria.

Pediocin PA-1 is a broad-spectrum lactic acid bacteria bacteriocin that shows a particularly strong activity against Listeria monocytogenes, a foodborne pathogen of special concern among the food industries. This antimicrobial peptide is the most extensively studied class Ila (or pediocin family) bacteriocin, and it has been sufficiently well characterized to be used as a food biopreservative. This review focuses on the progress that have been made in the elucidation of its structure, mode of action, and biosynthesis, and includes an overview of its applications in food systems. The aspects that need further research are also addressed. In the future, protein engineering, genetic engineering and/or chemical synthesis may lead to the development of new antimicrobial peptides with improved properties, based on some features of the pediocin PA-1 molecule.

Amino Acid Sequence↗

PubMedDate not supplied

Interventions to prevent and control food-borne diseases associated with a reduction in traveler's diarrhea in tourists to Jamaica.

BACKGROUND: In 1996 a study found that approximately one in four tourists to Jamaica were affected with traveler's diarrhea (TD) during their stay. That year the Ministry of Health initiated a program for the prevention and control of TD. The aim of this ongoing program was to reduce attack rates of TD from 25% to 12% over a 5-year period by improving the environmental health and food safety standards of hotels. METHODS: Hotel-based surveillance procedures for TD were implemented in sentinel hotels in Negril and Montego Bay in 1996, Ocho Rios in 1997, and Kingston in 1999. A structured program provided training and technical assistance to nurses, food and beverage staff, and environmental sanitation personnel in the implementation of Hazard Analysis Critical Control Point principles for monitoring food safety standards. The impact of interventions on TD was assessed in a survey of tourists departing from the international airport in Montego Bay in 1997-1998 and from the international airport in Kingston in 1999-2000. The impact of the training and technical assistance program on food safety standards and practices was assessed in hotels in Ocho Rios as of 1998 and in Kingston from 1999. RESULTS: At the end of May 2002, TD incidence rates were 72% lower than in 1996, when the Ministry of Health initiated its program for the prevention and control of TD. Both hotel surveillance data and airport surveillance data suggest that the vast majority of travelers to Kingston and southern regions are not afflicted with TD during their stay. The training and technical assistance program improved compliance to food safety standards over time. CONCLUSION: Interventions to prevent and control TD in visitors to Jamaica are positively associated with a reduction in TD in the visitor population and improvements in food safety standards and practices in hotels.

Adolescent↗

PubMed2000

The structure of an insect chymotrypsin.

The South American imported fire ant (Solenopsis invicta), without natural enemies in the United States, widely infests the southern United States, causing more than a half billion dollars in health and agriculture-related damage annually in Texas alone. Fire ants are resistant to most insecticides, so control will require a more fundamental understanding of their biochemistry and metabolism leading to the design of selective, ecologically safe insecticides. The 4th instar larvae play a crucial role in the nutrition of the colony by secreting proteinases (especially chymotrypsin) which digest food products for the entire colony. The first structure of an ant proteolytic enzyme, fire ant chymotrypsin, was determined to atomic resolution (1.7 A). A structural comparison of the ant and mammalian structures confirms the "universality" of the serine proteinase motif and reveals a difference at residues 147-148, which are proteolytically removed in the bovine enzyme but are firmly intact in the ant chymotrypsin, suggesting a different activation mechanism for the latter. Likewise, the absence of the covalently attached propeptide domain (1-15) further suggests an uncharacteristic activation mechanism. The presence of Gly189 in the S1 site is an atypical feature of this chymotrypsin and is comparable only to human leukocyte elastase, hornet chymotrypsin and fiddler crab collagenase. Binding studies confirm the chymotrypsin nature of this novel enzyme.

Amino Acid Sequence↗

PubMed2003

Effects of chronic variate stress on feeding behavior and on monoamine levels in different rat brain structures.

Chronic variate stress was seen to decrease the ingestion of sweet food when compared to control rats. Brain monoamines are known to be involved in the control of food intake, serotonin appears to be involved in the mechanisms of satiety, and dopamine in mediating appetite or approach behaviors triggered by incentive stimuli associated with rewards. The effect of chronic variate stress on cerebral levels of monoamines was also studied in rats. Increased levels of DOPAC were observed in the frontal cortex and in the hippocampus and an increased 5-HIAA/5-HT ratio was also observed in this latter structure. In the hypothalamus, levels of HVA and DOPAC were decreased, as well as the DOPAC/DA ratio, while no difference was found in amygdala. During the treatment, there were no differences in the consumption of water and regular food between stressed and control animals. An increase in the adrenal weight was observed at the end of the treatment. The results suggest that emotional changes, such as exposure to stress situations can influence feeding behavior, chronic variate stress causes decreased ingestion of sweet food and decreased dopaminergic neurotransmission in hypothalamus. Increased dopamine metabolite levels in the cortex and hippocampus were also observed and some of these modifications may be related to alterations in feeding behavior.

Animals↗

PubMed2004

Soy saponins and the anticancer effects of soybeans and soy-based foods.

While the cancer protective effect of soy-based diets has been the subject of numerous studies, the constituents of soy that may give rise to this effect remain elusive. Recent publications describing anticancer activity of crude and purified soybean saponins have sparked a renewed interest in these compounds. In this review, I summarize the epidemiological studies concerning the cancer protective effects of soy and the efforts to elucidate the constituents responsible for this effect. The recent reports of the anticancer activity of soy saponins is placed in context with reports of promising anticancer activity of structurally related non-dietary saponins from other legumes. While recent studies have demonstrated a direct effect of soy saponins on cancer cells, alternative mechanisms of cancer prevention by these agents are also discussed. It is concluded that the soy saponins may represent promising leads both in terms of elucidating the soy constituents involved in the cancer protective effect of soy as well as in the discovery of anticancer agents with novel mechanisms of action.

Animals↗

PubMed2002

Do street food vendors sell a sufficient variety of foods for a healthful diet? The case of Nairobi.

This study examined whether street food vendors sell a sufficient variety of foods for a healthful diet. It was hypothesized that vendors sold only low-cost food groups to enable the buyer to afford the food while the vendor also made a profit. A structured questionnaire was administered to 580 vendors in three selected locations. Data included product names, ingredients, methods of preparation, and the sex of the vendor. A little more than half of the vendors (53%) sold food of only one group; 44% sold cereals. Overall, 36% of vendors, mostly men, sold only carbohydrate products. The percentage of vendors selling foods of more than one group was higher in the working area (53%) than in the slum area (43%, p < .05), and it was higher in both of these areas taken together than in the lower-middle income area (21%, p < .001). Micronutrient and mixed-nutrient products were associated with female vendors. Although a slight majority of all street vendors sell foods of only one group, women vendors are capable of supplying a sufficient variety of food groups that consumers can afford. It appears that consumer purchasing power dictates the food groups provided by vendors, especially cereal-based-foods. A policy on micronutrient fortification of cereal flours and fats used in popular street food preparation needs to be considered. This could be coupled with consumer and vendor education programs focusing on the importance of healthful diets.

Africa South of the Sahara↗

PubMed2005

Improving packaged food quality and safety. Part 1: synchrotron X-ray analysis.

The objective was to demonstrate, as an example of an application, the potential of synchrotron X-ray analysis to detect morphological alterations that can occur in barrier packaging materials and structures. These changes can affect the packaging barrier characteristics when conventional food preservation treatments are applied to packaged food. The paper presents the results of a number of experiments where time-resolved combined wide-angle X-ray scattering and small-angle X-ray scattering analysis as a function of temperature and humidity were applied to ethylene-vinyl alcohol co-polymers (EVOH), polypropylene (PP)/EVOH/PP structures, aliphatic polyketone terpolymer (PK) and amorphous polyamide (aPA) materials. A comparison between conventional retorting and high-pressure processing treatments in terms of morphologic alterations are also presented for EVOH. The impact of retorting on the EVOH structure contrasts with the good behaviour of the PK during this treatment and with that of aPA. However, no significant structural changes were observed by wide-angle X-ray scattering in the EVOH structures after high-pressure processing treatment. These structural observations have also been correlated with oxygen permeability measurements that are of importance when guaranteeing the intended levels of safety and quality of packaged food.

Environmental Exposure↗

PubMed1999

Cross-reactivity and epitope analysis of Pru a 1, the major cherry allergen.

A high percentage of birch pollen allergic patients experiences food hypersensivity after ingestion of fresh fruits and vegetables. The cross-reactivity of the major allergens of sweet cherry (Pru a 1), apple (Mal d 1), pear (Pyr c 1), celery tuber (Api g 1) and carrot (Dau c 1) is due to structural similarities which are reflected by high amino acid sequence identities with Bet v 1a, the major birch pollen allergen. Apart from a strong cross-reactivity to Bet v 1a, IgE inhibition experiments with Mal d 1, Pru a 1 and Api g 1 demonstrated the presence of common and different epitopes among the tested food allergens. Secondary structure prediction of all investigated allergens indicated the presence of almost identical structural elements. In particular, the 'P-loop' region is a common domain of the pollen related food allergens and of pathogenesis related proteins. To identify the IgE binding epitopes, five overlapping recombinant Pru a 1 fragments representing the entire amino acid sequence with lengths of approximately 60-120 residues were investigated. Weak IgE binding capacity was measured exclusively with Pru a IF4 (1-120) by immunoblotting, whereas none of the fragments showed allergenicity in the rat basophil leukaemia cell mediator release assay. Site-directed mutagenesis experiments with Pru a 1 revealed that amino acid S112 is critical for IgE binding of almost all patients sera tested. This reduced IgE binding was also observed with a single point mutant of Bet v 1a (S112P) and thus indicated serine 112 as an essential residue for preserving the structure of a cross-reactive IgE epitope. Moreover, two Pru a 1 mutants with an altered 'P-loop' region, showed a lowered IgE binding capacity for IgE from a subgroup of allergic patients. The investigation of essential features for preserving cross-reactive IgE-epitopes provides the structural basis for understanding the clinically observed cross-allergenicity between pollen and fruits. Moreover, non-anaphylactic allergen fragments or variants derived from the IgE-inducing pollen allergens may serve as useful tools for a new strategy of specific immunotherapy.

Allergens↗

PubMed2006

Chemistry of gluten proteins.

Gluten proteins play a key role in determining the unique baking quality of wheat by conferring water absorption capacity, cohesivity, viscosity and elasticity on dough. Gluten proteins can be divided into two main fractions according to their solubility in aqueous alcohols: the soluble gliadins and the insoluble glutenins. Both fractions consist of numerous, partially closely related protein components characterized by high glutamine and proline contents. Gliadins are mainly monomeric proteins with molecular weights (MWs) around 28,000-55,000 and can be classified according to their different primary structures into the alpha/beta-, gamma- and omega-type. Disulphide bonds are either absent or present as intrachain crosslinks. The glutenin fraction comprises aggregated proteins linked by interchain disulphide bonds; they have a varying size ranging from about 500,000 to more than 10 million. After reduction of disulphide bonds, the resulting glutenin subunits show a solubility in aqueous alcohols similar to gliadins. Based on primary structure, glutenin subunits have been divided into the high-molecular-weight (HMW) subunits (MW=67,000-88,000) and low-molecular-weight (LMW) subunits (MW=32,000-35,000). Each gluten protein type consists or two or three different structural domains; one of them contains unique repetitive sequences rich in glutamine and proline. Native glutenins are composed of a backbone formed by HMW subunit polymers and of LMW subunit polymers branched off from HMW subunits. Non-covalent bonds such as hydrogen bonds, ionic bonds and hydrophobic bonds are important for the aggregation of gliadins and glutenins and implicate structure and physical properties of dough.

Amino Acid Sequence↗

PubMed1983

Evaluation of nutrient value and a classification of food products of animal origin in accordance with reconsidered water/protein ratio.

Water/protein ratio, criterion of evaluation of comparative nutrive value of meat products, fully used at present in some European countries, does not take into account the nutritive value of protein from the structure. This work presents a reconsideration of the evaluation of food proteinogenic value, on the basis of numerous analytical data from collagen dosing and setting of collagen/protein ratio as well as from biological tests on laboratory animals, thus correcting the amount of total protein and, implicitly, water/protein ratio. Tables of these products structure and classification in accordance with water/protein ratio are given.

Animals↗