Carnosine is a dipeptide synthesized in the body from β-alanine and L-histidine. It is found in high concentrations in the brain, muscle, and gastrointestinal tissues of humans and is present in all vertebrates. Carnosine has a number of beneficial antioxidant properties. For example, carnosine scavenges reactive oxygen species (ROS) as well as alpha-beta unsaturated aldehydes created by peroxidation of fatty acid cell membranes during oxidative stress. Carnosine can oppose glycation, and it can chelate divalent metal ions. Carnosine alleviates diabetic nephropathy by protecting podocyte and mesangial cells, and can slow down aging. Its component, the amino acid beta-alanine, is particularly interesting as a dietary supplement for athletes because it increases muscle carnosine, and improves effectiveness of exercise and stimulation and contraction in muscles. Carnosine is widely used among athletes in the form of supplements, but rarely in the population of cardiovascular or diabetic patients. Much less is known, if any, about its potential use in enriched food. In the present review, we aimed to provide recent knowledge on carnosine properties and distribution, its metabolism (synthesis and degradation), and analytical methods for carnosine determination, since one of the difficulties is the measurement of carnosine concentration in human samples. Furthermore, the potential mechanisms of carnosine’s biological effects in musculature, metabolism and on immunomodulation are discussed. Finally, this review provides a section on carnosine supplementation in the form of functional food and potential health benefits and up to the present, neglected clinical use of carnosine.
The botanical origin of starch is of importance in industrial applications and food processing because it may influence the properties of the final product. Current microscopic methods are time-consuming. Starch consists of an origin-dependent amylose/amylopectin ratio. Triiodide ions bind characteristically to the amylose and amylopectin depending on the botanical origin of the starch. The absorbance of the starch-triiodide complex was measured for wheat, potato, corn, rye, barley, rice, tapioca and unknown origin starch, and within the different cultivars. Each starch sample had specific parameters: starch-triiodide complex peak wavelength maximum (λmax/nm), maximum absorbance change at λmax (ΔA) and λmax shift towards the unknown origin starch sample values. The visible absorption spectra (500-800 nm) for each starch sample were used as a unique fingerprint, and then elaborated by cluster analysis. The cluster analysis managed to distinguish data of two clusters, a cereal type cluster and a potato/tapioca/rice starch cluster. The cereal subclusters extensively distinguished wheat/barley/rye starches from corn starches. Data for cultivars were mostly in good agreement within the same subclaster. The proposed method that combines cluster analysis and visible absorbance data for starch-triiodide complex was able to distinguish starch of different botanical origins and cultivars within the same species. This method is simpler and more convenient than standard time-consuming methods.
A new solid‐state sensor for potentiometric determination of surfactants with a layer of multi‐walled carbon nanotubes was prepared. As a sensing material, 1,3‐didecyl‐2‐methylimidazolium–tetraphenylborate ion‐pair was used. The investigated sensor showed a Nernstian response for both dodecylbenzenesulphonate (DBS, 57.6 mV/decade of activity between 5 × 10−7 to 1 × 10−3 M) and sodium lauryl sulfate (LS, 58.4 mV/decade of activity between 2 × 10−7 to 2 × 10−3 M). It responded in 8–10 s for each ten‐fold concentration change in the range of 1 × 10−6 to 3 × 10−3 M. The detection limits for DS and DBS were 2 × 10−7 and 3 × 10−7 M, respectively. The sensor revealed a stable response (signal drift 2.6 mV/h) and exhibited satisfactory selectivity performances for LS over most of the anions generally used in surfactant‐based commercial detergents. The main application of this sensor was the end‐point determination in potentiometric titrations of anionic surfactants. The (diisobutyl phenoxy ethoxy ethyl)dimethyl benzyl ammonium chloride (Hyamine), cetyltrimethylammonium bromide, hexadecylpyridinium chloride monohydrate (HDPC) and 1,3‐didecyl‐2‐methylimidazolium chloride were tested as potential cationic titrants, and all exhibited analytically usable titration curves with well‐defined equivalence points. The standard solution of HDPC was used as a cationic titrant by all potentiometric titrations. The operational life‐time of the sensor described was prolonged to more than 3 months.
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