ABSTRACT
Microwave spectroscopy has been applied in numerous non-food industry applications, and recently also in the food industry, for non-destructive measurements. In this study, a dry-cured ham model was designed and chemical analyses were performed for determining water activity, water content and salt content (sodium chloride) for all samples. These chemical parameters were also measured using microwave spectroscopy, with a rectangular microwave cavity resonator. Results indicate that microwave spectroscopy may be a promising technique for determination of water activity, salt content and water content in dry-cured ham using either reflected or transmitted signals.
Subject(s)
Food Analysis/methods , Food Quality , Meat Products/analysis , Meat/analysis , Microwaves , Animals , Desiccation , Muscle, Skeletal/chemistry , Salts/analysis , Spectrum Analysis , Swine , Water/analysisABSTRACT
The aim of this study was to find potential biomarkers for meat tenderness in bovine Longissimus thoracis muscle and to compare results from isobaric Tag for Relative and Absolute Quantitation (iTRAQ) and 2-dimensional gel electrophoresis (2-DE) analysis. The experiment included 4 tender and 4 tough samples, based on shear force measurements at 7 d postmortem, from young Norwegian red (NRF) bulls, taken at 1 h postmortem. A number of the proteins which have previously been related to tenderness were found to change in abundance between tender and tough samples, both in iTRAQ (P < 0.1) and 2-DE analysis (P < 0.05). Furthermore, 3 proteins that have not previously been related to tenderness were found to change significantly in abundance between tender and tough meat samples in the present study. These include proteins related to control of flux through the tricarboxylate cycle [2-oxoglutarate dehydrogenase complex component E2 (OGDC-E2)], apoptosis (galectin-1) and regulatory role in the release of Ca(2+) from intracellular stores (annexin A6). Even though the overlap in significantly changing proteins was relatively low between iTRAQ and 2-DE analysis, certain proteins predicted to have the same function were found in both analyses and showed similar changes between the groups, such as structural proteins and proteins related to apoptosis and energy metabolism.
Subject(s)
Electrophoresis, Gel, Two-Dimensional/veterinary , Food Analysis/methods , Meat/standards , Muscle Proteins/chemistry , Muscle, Skeletal/chemistry , Animals , Biomarkers , Cattle/physiology , Food Technology , MaleABSTRACT
Transport in the colon of the domestic fowl switches from sodium-linked hexose and amino acid cotransport on high-salt intake to amiloride-sensitive sodium channel expression on low-salt (LS) diets. The present experiments were designed to investigate the role of aldosterone in suppression of the colonic sodium-glucose luminal cotransporter (SGLT). LS-adapted hens were resalinated with or without simultaneous aldosterone treatment. Changes in the electrophysiological responses and SGLT protein expression levels were examined at 1, 3, and 7 days of treatment. Serum aldosterone levels fell from approximately 400 pmol/l in LS-adapted hens to values below the detection limit (<44 pmol/l) after 1 day of resalination. At the same time, glucose-stimulated short circuit current (I(SC)) increased from 20.9 +/- 8.7 to 56.3 +/- 15.5 microA/cm(2), whereas amiloride-sensitive I(SC) decreased from -68.9 +/- 12.7 microA/cm(2) on LS to +0.6 +/- 12.0 microA/cm(2). Glucose-stimulated I(SC) increased further at 3 and 7 days of resalination, whereas amiloride-sensitive I(SC) remained suppressed. When resalinated birds were simultaneously treated with aldosterone, the LS pattern of high amiloride-sensitive I(SC) and low glucose-stimulated I(SC) was maintained. Immunoblotting results from the same tissues demonstrated that SGLT-like protein expression increased following resalination. Aldosterone treatment completely blocked this effect. These results demonstrate that aldosterone suppresses both activity and protein expression of hen colonic SGLT. Resalination either through decreased aldosterone or other factors may be able to activate SGLT activity independently of increases in protein expression.
Subject(s)
Aldosterone/metabolism , Colon/metabolism , Monosaccharide Transport Proteins/metabolism , Aldosterone/pharmacology , Amiloride/pharmacology , Animals , Biological Transport, Active/drug effects , Biological Transport, Active/physiology , Blotting, Western , Chickens , Colon/drug effects , Female , Glucose/metabolism , Glucose/pharmacology , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Intestinal Mucosa/ultrastructure , Ion Transport/drug effects , Ion Transport/physiology , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/biosynthesis , Monosaccharide Transport Proteins/antagonists & inhibitors , Monosaccharide Transport Proteins/biosynthesis , Monosaccharide Transport Proteins/drug effects , Sodium Chloride, Dietary/pharmacology , Sodium-Glucose Transporter 1 , Water-Electrolyte Balance/drug effects , Water-Electrolyte Balance/physiologyABSTRACT
Inheritance of the colors black, brown, and red in Icelandic cattle was studied. The three colors are produced by two loci, Extension (E) and Agouti (A), with three alleles at the E locus: E(d) for dominant black; E+, intermediate, which allows expression of A locus alleles; and e for recessive red color. Two alleles are postulated at the A locus: A+, producing brown, and a, producing recessive black (nonagouti) when homozygous in E+/- animals. The dominant and recessive types of black are indistinguishable from each other phenotypically. The A alleles are only able to express their effect in E+/- genotypes. The E and A loci in cattle are postulated to be homologous to the E and A loci in the mouse.
