Arecae pericarpium extract induces porcine lower-esophageal-sphincter contraction via muscarinic receptors

Background Gastroesophageal reflux disease (GERD) is associated with lower esophageal sphincter (LES) incompetence. In some patients, GERD is refractory to acid reduction therapy which is the main treatment for GERD. So far, medications that can increase LES tone are few. Arecae pericarpium (A. pericarpium) is a medication in Traditional Chinese Medicine known to promote intestinal motility. Methods We investigated the effect of A. pericarpium extracts on porcine LES motility. In addition, we used tetrodotoxin (TTX) and atropine to study the underlying mechanism of A. pericarpium extracts-induced contractions of LES. Results The results of this study showed that A. pericarpium extracts and their main active ingredient, arecoline, can induce the contractions of porcine LES sling and clasp muscles in a dose-response manner. TTX did not have an inhibitory effect on the contractions induced by A. pericarpium extracts and arecoline in LES. However, atropine significantly inhibited A. pericarpium extracts- and arecoline-induced contractions of LES. Conclusion A. pericarpium extracts can induce the contractions of porcine LES in a dose dependent manner, possibly through muscarinic receptors, and hence, may be worth developing as an alternative therapy for GERD.

Modelling and optimization of free fatty acid reduction in bulk palm cooking oil

Bulk cooking oil from palm oil processing is one of the biodiesel materials which is available in large quantities. The pre-treatment process can be done by adding 100 mesh activated zeolite adsorbent as a substitute for the esterification process to reduce free fatty acid (FFA). The purpose of this research was to model and optimize the zeolite concentration and adsorption time to reduce free fatty acids in bulk palm cooking oil. This study used a response surface method with a central composite design (CCD), resulting in 13 experimental combinations of two factorial treatments, i.e. the concentration of zeolite adsorbent and adsorption time. The zeolite concentration and the adsorption time with an upper limit of 30% and 120 minutes and a lower limit of 10% and 60 minutes had a significant effect on the FFA reduction. The best model was a quadratic model. The testing of validation data used the recommended optimum combination, i.e. the zeolite concentration of 10.59% and the adsorption time of 101.57 minutes resulting in a deviation of 5.37% between the predicted data and the actual data.

Application of a New Dehydroascorbic Acid Reducing Agent in the Analysis of Vitamin C Content in Food

The analysis of total vitamin C content in food is most frequently performed by reducing dehydroascorbic acid to ascorbic acid, which is then assayed with the technique of high-performance liquid chromatography combined with spectrophotometric detection. Tris(2-carboxyethyl)phosphine is currently the only agent in use that efficiently reduces dehydroascorbic acid at pH < 2. Therefore, there is a continued need to search for new reducing agents that will display a high reactivity and stability in acidic solutions. The objective of the study was to verify the applicability of unithiol and tris(hydroxypropyl)phosphine for a reducing dehydroascorbic acid in an extraction medium with pH < 2. The conducted validation of the newly developed method of determining the total content of vitamin C using tris(hydroxypropyl)phosphine indicates its applicability for food analysis. The method allows obtaining equivalent results compared to the method based on the use of tris(2-carboxyethyl)phosphine. The low efficiency of dehydroascorbic acid reduction with the use of unithiol does not allow its application as a new reducing agent in vitamin C analysis.

Influence of Alcoholic and Malolactic Fermentation on the Level of Biogenic Amines in Wine

Introduction. The concentration of biogenic amines is an important indicator of the safety of food products, especially winemaking. In grape wines, this concentration varies widely depending on the grape variety, its microbiological state, processing technology, the race of yeast and bacteria of malolactic fermentation, conditions of alcoholic and malolactic fermentation, etc. This research is aimed at determining the effect of the production technology of dry white and red wines on the concentration of biogenic amines. Study objects and methods. The mass concentration of biogenic amines was determined by the method of high-performance capillary electrophoresis using a Kapel 105R in laboratory-obtained samples of dry white wine from the Chardonnay grape variety and table dry red wine from the Cabernet-Sauvignon grape variety. Results and discussion. The dry white wine samples revealed high concentrations of tyramine (1.12 mg/dm³), phenylethydamine (0.58 mg/dm³), and histamine (0.57 mg/dm³), while the red wine samples demonstrated tyramine (0.62 mg/dm³), histamine (0.45 mg/dm³), putrescine (0.43 mg/dm³), and cadaverine (0.38 mg/dm³). The white wine samples had optimal pH values (3.2–3.6) with minimal formation of biogenic amines. The red wine samples, especially those obtained by heat treatment, had a lower concentration of biogenic amines, especially volatile biogenic amines, i.e. methylamine and phenylethylamine. The greatest formation of biogenic amines occurred during the acid reduction process: under the effect of enzymes of malolactic bacteria, biogenic amines formed as a result of decarboxylation of amino acids. Conclusion. The technology of production of table dry white and red wines affects the concentration of biogenic amines. To reduce the level of biogenic amines in the finished product, each stage of vinification has to be controlled, especially the stages of fermentation and acid reduction (temperature and pH). The race of yeast and lactic acid bacteria cannot include those that produce biogenic amines or introduce them in minimal quantities.

Alcohol dehydrogenases AdhE and AdhB with broad substrate ranges are important enzymes for organic acid reduction in Thermoanaerobacter sp. strain X514

Background The industrial production of various alcohols from organic carbon compounds may be performed at high rates and with a low risk of contamination using thermophilic microorganisms as whole-cell catalysts. Thermoanaerobacter species that thrive around 50–75 °C not only perform fermentation of sugars to alcohols, but some also utilize different organic acids as electron acceptors, reducing them to their corresponding alcohols. Results We purified AdhE as the major NADH- and AdhB as the major NADPH-dependent alcohol dehydrogenase (ADH) from the cell extract of the organic acid-reducing Thermoanaerobacter sp. strain X514. Both enzymes were present in high amounts during growth on glucose with and without isobutyrate, had broad substrate spectra including different aldehydes, with high affinities (< 1 mM) for acetaldehyde and for NADH (AdhE) or NADPH (AdhB). Both enzymes were highly thermostable at the physiological temperature of alcohol production. In addition to AdhE and AdhB, we identified two abundant AdhA-type ADHs based on their genes, which were recombinantly produced and biochemically characterized. The other five ADHs encoded in the genome were only expressed at low levels. Conclusions According to their biochemical and kinetic properties, AdhE and AdhB are most important for ethanol formation from sugar and reduction of organic acids to alcohols, while the role of the two AdhA-type enzymes is less clear. AdhE is the only abundant aldehyde dehydrogenase for the acetyl-CoA reduction to aldehydes, however, acid reduction may also proceed directly by aldehyde:ferredoxin oxidoreductase. The role of the latter in bio-alcohol formation from sugar and in organic acid reduction needs to be elucidated in future studies.