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Food Proteins (food + protein)
Selected AbstractsClassification and Antihypertensive Activity of Angiotensin I-Converting Enzyme Inhibitory Peptides Derived from Food ProteinsJOURNAL OF FOOD SCIENCE, Issue 4 2000H Iroyukifujita ABSTRACT: Angiotensin I-converting enzyme (ACE)-inhibitory peptides from the thermolysin digest of chicken muscle and the peptic digest of ovalbumin were isolated. However, some of them failed to show antihypertensive activity in spontaneously hypertensive rats (SHR). To clarify this discrepancy, ACE-inhibitory peptides from various sources were preincubated with ACE before measurement of ACE-inhibitory activity and classified into 3 groups: (1) inhibitor type, IC50 values of peptides that are not affected after preincubation with ACE; (2) substrate type, peptides that are hydrolyzed by ACE to give peptides with weaker activity; and (3) prodrug-type inhibitor, these peptides are converted to true inhibitors by ACE or gastrointestinal proteases. Peptides belonging to the 1st and the 3rd groups exert antihypertensive activities even after oral administration in SHR. [source] Could Bt transgenic crops have nutritionally favourable effects on resistant insects?ECOLOGY LETTERS, Issue 3 2003Ali H. Sayyed Abstract We present an idea that larvae of some Bacillus thuringiensis (Bt,) resistant populations of the diamondback moth, Plutella xylostella (L.), may be able to use Cry1Ac toxin derived from Bt as a supplementary food protein. Bt transgenic crops could therefore have unanticipated nutritionally favourable effects, increasing the fitness of resistant populations. This idea is discussed in the context of the evolution of resistance to Bt transgenic crops. [source] In vitro determination of digestible and unavailable protein in edible seaweedsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2002Isabel Goñi Abstract Edible seaweeds are considered a complementary source of food protein for human and animal nutrition. The physiological effects of seaweed protein depend on the degree of enzymatic digestion of protein in the small intestine and bacterial fermentation in the large intestine. The objective of this work was to estimate total, digestible, fermentable and unavailable protein in some red and brown seaweeds. Brown seaweeds Fucus vesiculosus, Laminaria digitata and Undaria pinnatifida and red seaweeds Chondrus crispus and Porphyra tenera were treated with pepsin and pancreatin to separate digestible protein. Residues containing indigestible protein were inoculated for 24,h with rat caecal droppings, and protein contents were evaluated in the non-fermented residue. Protein content in the seaweeds ranged from 8.9 to 25% of dry matter. Digestible protein was the major protein fraction (69%) only in P tenera; in the other seaweeds, this fraction ranged from 15 to 45%. Significant amounts of unavailable protein were found in all samples (2,24%). The distribution of total protein among the three fractions, ie digestible, fermentable and unavailable protein, could yield information about the physiological and metabolic consequences of the intake of seaweed proteins. © 2002 Society of Chemical Industry [source] Metabolism of Maillard reaction products by the human gut microbiota , implications for healthMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 9 2006Kieran M. Tuohy Abstract The human colonic microbiota imparts metabolic versatility on the colon, interacts at many levels in healthy intestinal and systemic metabolism, and plays protective roles in chronic disease and acute infection. Colonic bacterial metabolism is largely dependant on dietary residues from the upper gut. Carbohydrates, resistant to digestion, drive colonic bacterial fermentation and the resulting end products are considered beneficial. Many colonic species ferment proteins but the end products are not always beneficial and include toxic compounds, such as amines and phenols. Most components of a typical Western diet are heat processed. The Maillard reaction, involving food protein and sugar, is a complex network of reactions occurring during thermal processing. The resultant modified protein resists digestion in the small intestine but is available for colonic bacterial fermentation. Little is known about the fate of the modified protein but some Maillard reaction products (MRP) are biologically active by, e. g. altering bacterial population levels within the colon or, upon absorption, interacting with human disease mechanisms by induction of inflammatory responses. This review presents current understanding of the interactions between MRP and intestinal bacteria. Recent scientific advances offering the possibility of elucidating the consequences of microbe-MRP interactions within the gut are discussed. [source] New food sources of essential trace elements produced by biotechnology facilitiesBIOTECHNOLOGY JOURNAL, Issue 10 2007Vladimir K. Mazo Abstract Population satiety with trace elements (TE) is a problem that is widely discussed in nutrition science. For optimal nutrition, the form of TE eaten in food is very important. Organic forms of TE in nutrition are appropriate as human metabolism has adapted to these kinds of nutrients during species evolution. This is now considered a reason for the beneficial use of biotechnologically produced TE sources in human food. Advanced matrixes for TE incorporation are unicellular organisms such as yeast, lactobacilli and Spirulina. Addition of inorganic salts at certain concentrations into cultivation media enables the mineral ions to incorporate into the microbial biomass. As a consequence, the biomass becomes enriched with organic forms of incorporated TE, which are presented by their complexes with amino acids, proteins and probably lipids and polysaccharides. In addition, a new direction of research has made good advances, in which technology has been developed for production of organic forms of TE through complex formation between transition metals (zinc, copper, manganese, chromium, iron) with amino acids and peptides formed during enzymatic hydrolysis of food protein. This brief review discusses the results demonstrating the advances in the biotechnological production of new TE sources, to obtain food components destined for wide prophylaxis of TE deficiency or for dietary treatment of the adverse consequences of these deficiencies. [source] CCR6 has a non-redundant role in the development of inflammatory bowel diseaseEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2003Rosa Varona Abstract Antigen-loaded tissues such as the intestinal mucosa must simultaneously elicit appropriate immune response to innocuous bacteria and food proteins, and to potentially harmful antigens. Impairment of the mechanisms controlling this response may mediate the excessive immune reaction that can lead to tissue destruction and inflammatory intestinal diseases, including inflammatory bowel disease. The intestinal epithelium influences local immune responses through the expression of adhesion molecules, costimulatory factors, cytokines and chemokines. CCL20, a ,-chemokine expressed in epithelia from colon and other intestinal tissue, plays a role in immune responses of intestinal mucosa, as deduced from the defects in intestinal leukocyte homeostasis shown by mice lacking CCR6, the CCL20 receptor. We studied the response of CCR6-deficient mice in two models of inflammatory bowel disease. The data show that absence of CCR6 resulted in less severe intestinal pathology in animals treated with dextran sodium sulfate. Conversely, CCR6 deficiency alters leukocyte homeostasis and the cytokine environment in the intestinal mucosa; these changes are sufficient to confer susceptibility to trinitrobenzene sulfonic acid-induced intestinal inflammation in the otherwise resistant C57BL/6J mouse strain. These results suggest that the CCR6/CCL20 axis has a critical, non-redundant role in the in vivo control of immune responses in the intestine. [source] Mechanisms of natural tolerance in the intestine.INFLAMMATORY BOWEL DISEASES, Issue 4 2004Implications for inflammatory bowel disease Abstract Tolerance, the regulated inability to respond to a specific immunologic stimulant, is a physiological event important to normal immune function. Just as loss of tolerance to self-proteins results in autoimmune diseases, we assert that loss of tolerance to commensal flora in the intestinal lumen leads to inflammatory bowel disease (IBD). Mechanisms through which the mucosal immune system establishes and remains hyporesponsive toward the presence of food proteins and commensal flora, which we define as natural tolerance, are discussed. In addition to the contributions by commensal flora, the innate host defense and the adaptive immune systems promote natural tolerance to sustain normal mucosal homeostasis. Understanding the molecular and cellular events that mediate natural tolerance will lead to more advanced insights into IBD pathogenesis and improved therapeutic options. [source] Protein Stabilization of Emulsions and FoamsJOURNAL OF FOOD SCIENCE, Issue 3 2005Srinivasan Damodaran ABSTRACT: Proteins play an important role as macromolecular surfactants in foam and emulsion-type food products. The functioning of proteins in these applications is determined by their structure and properties in the adsorbed layers at air-water and oil-water interfaces. In addition, because typical food proteins are mixtures of several protein components, interaction between these components in the adsorbed layer also impacts their ability as surfactants to stabilize dispersed systems. In this paper, recent progress in our understanding of the molecular mechanisms involved in the formation and stability of protein-stabilized foams and emulsions has been reviewed. [source] Binding of olive oil phenolics to food proteinsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2005Are Hugo Pripp Abstract In this paper we investigate the interaction of phenolics extracted from olive oil with different food proteins (sodium caseinate, bovine serum albumin, ,-lactoglobulin and gelatin). Binding parameters are estimated using different experimental techniques: gel filtration, HPLC, isothermal titration calorimetry and NMR diffusion measurements. For comparison, the binding properties of gallic acid and tannic acid are also studied. The affinity of olive oil phenolics for the different food proteins is found to be relatively weak (compared with tannic acid). Binding constants are measured for the different phenolics in the extract: tyrosol and hydroxytyrosol do not (or very weakly) bind to the proteins, whereas other phenolics in the extract had binding constants of the order 102,104M,1. The binding parameters determined have been discussed in relation to the possible effect of proteins on sensory properties (bitterness) of food emulsions containing olive oil. Copyright © 2004 Society of Chemical Industry [source] Aluminium per se and in the anti-acid drug sucralfate promotes sensitization via the oral routeALLERGY, Issue 6 2009R. Brunner Background:, Aluminium (ALUM) is used as experimental and clinical adjuvant for parenteral vaccine formulation. It is also contained in anti-acid drugs like sucralfate (SUC). These anti-acids have been shown to cause sensitization to food proteins via elevation of the gastric pH. The aim of this study was to assess the oral adjuvant properties of ALUM, alone or contained in SUC, in a BALB/c mouse model. Methods:, Mice were fed SUC plus ovalbumin (OVA) and compared with groups where ALUM or proton pump inhibitors (PPI) were applied as adjuvants. The humoral and cellular immune responses were assessed on antigen-specific antibody and cytokine levels. The in vivo relevance was investigated in skin tests. Results:, The highest OVA-specific immunoglobulin G1 (IgG1) and IgE antibody levels were found in mice fed with OVA/SUC, followed by OVA/ALUM-treated animals, indicating a T helper 2 (Th2) shift in both groups. Antibody levels in other groups revealed lower (OVA/PPI-group) or baseline levels (control groups). Positive skin tests confirmed an allergic response in anti-acid or adjuvant-treated animals. Conclusions:, Our data show for the first time that ALUM acts as a Th2-adjuvant via the oral route. This suggests that orally applied SUC leads to an enhanced risk for food allergy, not only by inhibiting peptic digestion but also by acting as a Th2-adjuvant by its ALUM content. [source] The clinical significance of food specific IgE/IgG4 in food specific atopic dermatitisPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 1 2007Geunwoong Noh Food is closely associated with the pathogenesis of atopic dermatitis. Food allergy is usually mediated by IgE antibody to specific food proteins and determination of specific IgE antibody is the basis of the common diagnostic test for food allergy. IgG4 have been reported as blocking antibody and the protective effects of blocking antibody may be clear in inhalant allergy. However, the role of IgG4 in food allergy is still a matter of debate. In this study, the clinical significance of food allergen-specific IgE/IgG4 in atopic dermatitis was investigated and compared with that of IgE. A total of 97 patients who fulfilled the diagnostic criteria for atopic dermatitis participated in this study. Skin prick test and allergy patch test were performed. Specific IgE and IgG4 concentration were measured using allergy protein chip, ,AllergyChip'. Double blinded placebo controlled food challenge test (DBPCFC) was performed for the diagnosis of allergy to milk, egg white, wheat, and soybean. DBPCFCs for milk, egg white, soybean, and wheat were performed. The positive rates were 31.7% (19/60) in milk, 36.7% (18/49) in egg white, 30.4% (7/23) in soybean, and 34.8% (8/23) in wheat. Mean IgE/IgG4 levels in DBPCFC (+) subjects is higher than those in DBPCFC (,) subjects in all food items studied. Of them, there were significantly different between two groups in egg white and wheat (Egg white in DBPCFC (+) vs. (,): 0.4 ± 0.3 vs. 0.2 ± 0.2, wheat in DBPCFC (+) vs. (,): 1.2 ± 1.2 vs. 0.3 ± 0.3, p < 0.05). Allergen-specific IgE/IgG4 may provide one of the clues to understand the mechanism of food allergy in atopic dermatitis. The present study suggests that protein microarray can be one of the useful methods to assess ongoing status of allergic diseases. [source] Characterization of covalent addition products of chlorogenic acid quinone with amino acid derivatives in model systems and apple juice by high-performance liquid chromatography/electrospray ionization tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2008Susanne Schilling High-performance liquid chromatography (HPLC) coupled to electrospray ionization tandem mass spectrometry (ESI-MSn) was used to study the covalent interactions between chlorogenic acid (CQA) quinone and two amino acid derivatives, tert -butyloxycarbonyl-L-lysine and N -acetyl-L-cysteine. In a model system at pH 7.0, the formation of covalent addition products was demonstrated for both derivatives. The addition product of CQA dimer and tert -butyloxycarbonyl-L-lysine was characterized by LC/MSn as a benzacridine structure. For N -acetyl-L-cysteine, mono- and diaddition products at the thiol group with CQA quinone were found. In apple juice at pH 3.6, covalent interactions of CQA quinone were observed only with N -acetyl-L-cysteine. Taking together these results and those reported by other groups it can be concluded that covalent interactions of amino side chains with phenolic compounds could contribute to the reduction of the allergenic potential of certain food proteins. Copyright © 2008 John Wiley & Sons, Ltd. [source] Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potentialCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2006T. Eiwegger Summary Background The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. Methods An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. Results In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments Mr L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-,/IL-13 ratio and IFN-,/IL-4 ratio of CFSElow CD4+ T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. Conclusion Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein. [source] | ||||||||||||||||