Combining Conventional Organic Solvent Extraction, Ultrasound-Assisted Extraction, and Chromatographic Techniques to Obtain Pure Betanin from Beetroot for Clinical Purposes.

Red beetroot extract (E162) is a natural colorant that owes its color to betanin, its major red pigment. Betanin displays remarkable antioxidant, anti-inflammatory, and chemoprotective properties mediated by its structure and influence on gene expression. However, the betanin employed in most preclinical assays is a beetroot extract diluted in dextrin, not pure betanin, as no isolated compound is commercially available. This makes its use inaccurate concerning product content estimates and biological effect assessments. Herein, a combination of conventional extraction under orbital shaking and ultrasound-assisted extraction (UAE) to purify betanin by semi-preparative HPLC was performed. The employed methodology extracts betalains at over a 90% yield, achieving 1.74 ± 0.01 mg of pure betanin/g beetroot, a 41% yield from beetroot contents increasing to 50 %, considering the betalains pool. The purified betanin exhibited an 85% purity degree against 32 or 72% of a commercial standard evaluated by LC-MS or HPLC methods, respectively. The identity of purified betanin was confirmed by UV-Vis, LC-MS, and 1H NMR. The combination of a conventional extraction, UAE, and semi-preparative HPLC allowed for betanin purification with a high yield, superior purity, and almost three times more antioxidant power compared to commercial betanin, being, therefore, more suitable for clinical purposes.

Efficacy of Quaternary Ammonium Compounds for Control of Individual and Mixed Cultures of Escherichia coli with High- and Low-Quaternary Ammonium Compounds Resistance.

Escherichia coli is a well-characterized micro-organism in scientific literature. Similarly, quaternary ammonium compounds (QACs) are historical sanitizers in food processing. However, the use of QACs has been questioned due to bacterial resistance in some studies. Therefore, this study aimed to compare effects of single and mixed cultures of E. coli strains of different serogroups with either high (six strains) or low (five strains) resistance to QACs. Twenty-five combinations of strains with either high (H)- or low (L)-QAC resistance were analyzed (H + H vs. L + L). After exposure to QAC, combinations with statistical differences (p < 0.05) compared with individuals were selected and an inactivation model determined using GInaFit®. Only one combination of two strains (C23 and C20) with low-QAC resistance (mixture T18) had greater resistance (p < 0.05) than the individual isolates. The combination T18 and individual strain C23 presented a Weibull model, whereas the other isolated strain (C20) presented a biphasic inactivation model with a shoulder. Whole genome sequencing determined that unlike C20, C23 carried yehW, which may have led to Weibull inactivation. Possibly, very rapid interaction of C20 with the QAC favored increased survival of C23 and overall persistence of the T18 mixture. Consequently, our results indicate that individual E. coli with low-QAC resistance can synergistically interfere with QAC inactivation.

Whole-Genome Draft Assemblies of Difficult-to-Classify Escherichia coli O157 and Non-O157 Isolates from Feces of Canadian Feedlot Cattle.

Forty-eight Escherichia coli strains were chosen due to variable detection of stx or serogroup by PCR. Although all strains were initially determined to be Shiga toxin-producing Escherichia coli (STEC), their genomes revealed 11 isolates carrying stx 1a, stx 1b, stx 2a, and/or stx 2b Assembled genome sizes varied between 4,667,418 and 5,556,121 bp, with N 50 values between 79,648 and 294,166 bp and G+C contents between 50.3% and 51.4%.

Purification of caprine oligosaccharides at pilot-scale.

The purification of caprine milk oligosaccharides (COS) by membrane filtration has been hampered by the low concentration of target COS and high concentration of lactose. In addition, their molecular weight proximity hinders the recovery of a COS fraction with high degree of purity and recovery yield. In this work, the recovery of a high purity COS concentrate was obtained by the optimization of an integrated approach including complete lactose hydrolysis, fermentation of the resulting monosaccharides and nanofiltration. All carbohydrates were quantified using High Performance Anion Exchange Chromatography with Pulsed Amperometric Detection (HPAEC PAD). Defatted goat whey was ultrafiltered with discontinuous diafiltrations to increase the recovery of COS in the whey permeate which was then subsequently concentrated by nanofiltration. COS recovery yields of 75% with negligible amounts of monosaccharides (0.3% of the initial amount of lactose in the whey permeate) were achieved. A final retentate containing 67.6 and 34.4% of acidic and neutral oligosaccharides respectively was obtained from caprine milk.

Acute l-arginine supplementation increases muscle blood volume but not strength performance.

l-Arginine (L-arg) is an amino acid precursor to nitric oxide (NO). Dietary supplements containing L-arg have been marketed with the purpose of increasing vasodilation, thereby elevating blood flow to the exercising muscle and enhancing the metabolic response to exercise. Our goal was to identify the acute effect of L-arg supplementation on biceps strength performance, indicators of NO production (nitrite and nitrate - NOx), and muscle blood volume (Mbv) and oxygenation (Mox) during recovery from 3 sets of resistance exercise. Fifteen males participated in a randomized, double-blind, placebo-controlled study. After withdrawing resting blood samples, the subjects were supplemented with 6 g of L-arg (ARG) or placebo (PLA). Monitoring of Mbv and Mox with near-infrared spectroscopy began 30 min after supplementation and lasted for 60 min. The exercise protocol (3 sets of 10 maximal voluntary contractions of isokinetic concentric elbow extension at 60°·s(-1), 2-min rest between sets) was initiated 80 min after supplementation. Blood samples were drawn at 30, 60, 90, and 120 min after supplementation. Repeated measures ANOVA showed that Mbv significantly (p ≤ 0.05) increased in ARG compared with the PLA during the recovery period of each set of resistance exercise. NOx, Mox, peak torque, total work, and set total work were not significantly different between groups. We found that acute L-arg supplementation increases Mbv during recovery from sets of resistance exercise with no increase in strength performance. It is still premature to recommend nutritional supplements containing L-arg as an ergogenic aid to increase muscle strength during resistance training in healthy subjects.