Salivary metabolomic profile associated with cariogenic risk in children.

OBJECTIVES: To identify the metabolomic differences in the saliva of healthy children versus children with active carious lesions and to estimate the predictive capacity of a model based on the salivary metabolomic profile. METHODS: A study of cases (n = 31) and controls (n = 37) was designed for children aged between 6 and 12 (mean age of the cases: 8.9; controls: 8.7). The said children attended public health centers in Valencia, Spain. Intraoral examinations were performed by a single examiner using ICDAS II diagnostic criteria. Unstimulated total saliva samples were analyzed by nuclear magnetic resonance (NMR) spectroscopy. RESULTS: The dft index for cases was 2.84 while it was 0.19 for the control group, the DMFT index was 1.13 and 0.11, respectively. The predictive model generated by the multivariate PLS-DA analysis projects a separation between the cases and the controls on the score chart with a predictive capacity and generating an area under the curve of 0.71. The metabolites: 3-methyl-2-oxovalerate, 3-hydroxybutyrate, lactate, acetone, citrate, ornithine, ethanolamine, taurine, proline, glycine, mannose, glucose, 1-6-Anhydro-ß-d-glucose and citraconate, are those that show greater significance in the model. In the controls, glycine (Cohen's d = 0.430) and glucose (Cohen's d = 0.560) present higher means compared to the cases. On the contrary, taurine (Cohen's d= -0.474) and mannose (Cohen's d= -0.456) show higher means in cases compared to controls. CONCLUSIONS: Our findings show a difference in the salivary metabolomic profiles, specifically in the groups of saccharides and amino acids, suggesting an association of these with the level of caries risk. CLINICAL SIGNIFICANCE: The results reported in the present study reinforce the use of salivary metabolomics as a research method for the search for salivary biomarkers that allow the evaluation of caries risk in patients. Furthermore, it brings us closer to a personalized medicine that will help in dental caries prevention strategies.

Analysis of Taurine in Infant Formulas and Adult Nutritionals by Hydrophilic Interaction Liquid Chromatography-Mass Spectrometry: First Action 2022.03.

BACKGROUND: Taurine is recognized as an essential growth factor and as being critical in the maintenance of functional tissue regulation. OBJECTIVE: To evaluate the analytical performance of a hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for compliance with AOAC Standard Method Performance Requirements (SMPR®) for taurine analysis described in SMPR 2014.013. METHOD: Following protein precipitation with Carrez solutions, taurine is extracted and separated by HILIC with detection by triple quadrupole MS using multiple reaction monitoring (MRM). Stable isotope labeled (SIL) taurine internal standard is used for quantification to correct for losses in extraction and variations in ionization in the ion source. RESULTS: The method was shown to meet the requirements specified in the SMPR with a linear range of 0.27-2700 mg/hg RTF (ready-to-feed), a limit of detection of 0.14 mg/hg RTF, acceptable recovery of 97.2-100.1%, and acceptable repeatability of 1.6-6.4% relative standard deviation. Additionally, the method was found to have no statistically significant bias compared with reference values for National Institute of Standards and Technology (NIST) 1849a certified reference material (CRM) (P-value = 0.95) and 1869 CRM (P-value = 0.31), and with results from AOAC 997.05 (P-value = 0.10). CONCLUSIONS: A recent review of the method and validation data by the Stakeholder Program on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) found that this method met all the criteria for analysis of taurine specified in SMPR 2014.013 and voted to adopt this method as First Action AOAC Official MethodSM2022.03. HIGHLIGHTS: A method for the analysis of taurine in infant formulas and adult nutritionals by HILIC-MS/MS is described. A single-laboratory validation (SLV) study demonstrated the applicability of the method to meet requirements of SMPR 2014.013. In December 2022, the SPIFAN ERP voted to adopt this method as First Action AOAC Official Method 2022.03.

Rapid Analysis of Taurine in Infant Formula and Adult Nutritionals by Hydrophilic Interaction Liquid Chromatography-Mass Spectrometry.

BACKGROUND: Taurine is recognized as an essential growth factor and as being critical in the maintenance of functional tissue regulation. OBJECTIVE: A rapid compliance method for the analysis of taurine that is applicable to infant formula and milk-based nutritional products is described. METHOD: Following protein precipitation with Carrez solutions, taurine in the sample extract is separated by hydrophilic interaction liquid chromatography (HILIC) with detection by triple quadrupole mass spectrometry using multiple reaction monitoring (MRM). Stable isotope-labeled taurine internal standard is used for quantification to correct for losses in extraction and variations in ionization in the ion source. RESULTS: The method was shown to be accurate, with acceptable recovery of 99.6% (range = 91.1-106.5%). Results for National Institute of Standards and Technology (NIST)-certified reference materials showed no statistical bias for NIST 1849a (P = 0.96) and NIST 1869 (P = 0.88) when compared with reference values. No bias was found when results were compared with those of an international reference method, AOAC Official MethodSM997.05 (P = 0.18). Repeatability was estimated to be 3.1% RSDr (range: 2.4-4.0%, HorRat: 0.3), and intermediate precision was estimated to be 4.9% RSDiR (range: 2.2-7.7%). CONCLUSIONS: Successful single-laboratory validation demonstrates that this rapid method is suitable for use in high-throughput laboratories as part of routine product compliance release testing of taurine in nutritional products. HIGHLIGHTS: A method for the analysis of taurine in infant formula and adult nutritionals by hydrophilic interaction liquid chromatography-mass spectrometry (LC-MS) is described. The method is suitable for use in high-throughput laboratories for routine product compliance testing of taurine. A single-laboratory validation study demonstrated the method to be accurate, precise, and fit for purpose.

[Metabolomics study on the difference of tongue coating metabolites between patients with intra-oral halitosis and healthy individual].

PURPOSE: To analyze the difference of metabolites of tongue coating between patients with intra-oral halitosis and healthy individuals by untargeted metabolomics, and to explore significant differences in metabolites of intra-oral halitosis as biomarkers. METHODS: The untargeted metabolomics of tongue coating samples from 12 patients with intra-oral halitosis and 12 healthy individuals were studied by liquid chromatography and mass spectrometry combined with principal component analysis and orthogonal partial least squares discriminant analysis. The value of variable importance in projection ＞1 and P＜0.05 of Student's t test in the orthogonal partial least squares-discriminant analysis model were used as the criteria to screen and determine the differential metabolites. RESULTS: There were differences in the metabolites of tongue coating between patients with intra-oral halitosis and healthy individuals, and 11 different metabolites were identified. They were valyl-arginine, glycine-phenylalanine, tryptophyl-proline, deoxyadenosine, 4,5-dihydroniveusin A, N-acetyl-DL-tryptophan, paramethasone acetate, cyclopentanol, [(2-hexylcyclopentylidene) amino]thiourea, L-pipecolic acid and taurine. In the intra-oral halitosis group, the expressions of Glycine-phenylalanine and N-acetyl-DL-tryptophan were significantly up-regulated, while the expressions of taurine were significantly down-regulated. CONCLUSIONS: There are differences in the metabolites of tongue coating between patients with intra-oral halitosis and healthy individuals. The differential metabolites with diagnostic value may be used as diagnostic markers of intra-oral halitosis.

Quantification and identification of bile acids in saliva by liquid chromatography-mass spectrometry: Possible non-invasive diagnostics of Barrett's esophagus?

Bile acids are a group of steroid compounds essential for lipid digestion. However, when bile acids are refluxed into the stomach and the esophagus, during the so called duodenogastroesophageal reflux, they can have a detrimental effect on the esophageal epithelium and cause pathological changes of esophageal tissue, e.g., Barrett's esophagus (BE). The levels of bile acids in saliva could therefore serve as possible biomarkers for the diagnostics of BE. In this work, we focused on optimization of sample collection and preparation by solid-phase extraction and subsequent quantification of 11 bile acids (unconjugated, glycine-conjugated) in saliva from healthy volunteers and BE patients by ultra-high-performance liquid chromatography coupled to triple-quadrupole tandem mass spectrometry. Moreover, high resolution MS (Orbitrap-MS) was utilized for identification of new bile acids in saliva. Methods for saliva collection including simple spitting and the Salivette® saliva collection system were compared; the latter was found to be unsuitable due to excessive retention of bile acids in the cotton swab. Methanol with 0.1% formic acid were selected for protein precipitation and bile acid extraction prior to SPE. Separation was performed in gradient elution of methanol and 0.1% formic acid in less than 10 min. Saliva from BE patients contained higher levels of almost all bile acids, and the tested groups could be distinguished by principal component analysis. In untargeted analysis by high resolution MS, taurine-conjugated bile acids and glycine-conjugated dihydroxy-bile acid sulfate were identified in saliva from healthy volunteers. We propose that analysis of salivary bile acids including taurine conjugates could be applicable in diagnostics of BE, following a larger clinical study.

Consequences of zinc deficiency on zinc localization, taurine transport, and zinc transporters in rat retina.

The colocalization of taurine and zinc transporters (TAUT, ZnTs) has not been explored in retina. Our objective is to evaluate the effect of the intracellular zinc chelator N,N,N,N-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN) on zinc localization and colocalization TAUT and ZnT-1 (of plasma membrane), 3 (vesicular), and 7 (vesicular and golgi apparatus) in layers of retina by immunohistochemistry. To mark zinc, it was used cell-permeable fluorescent Zinquin ethyl ester. Specific first and secondary antibodies, conjugated with rhodamine or fluorescein-isothiocyanate were used to mark TAUT and ZnTs. The fluorescence results were reported as integrated optical density (IOD). Zinc was detected in all layers of the retina. The treatment with TPEN produced changes in the distribution of zinc in layers of retina less in the outer nuclear layer compared with the control. TAUT was detected in all layers of retina and TPEN chelator produced decrease of IOD in all layers of retina except in the photoreceptor compared with the control. ZnT 1, 3, and 7 were distributed in all retina layers, with more intensity in ganglion cell layer (GCL) and in the layers where there is synaptic connection. For all transporters, the treatment with TPEN produced significant decrease of IOD in layers of retina least in the inner nuclear layer for ZnT1, in the photoreceptor for ZnT3 and in the GCL and outer plexiform layer for ZnT7. The distribution of zinc, TAUT, and ZnTs in the layers of retina is indicative of the interaction of taurine and zinc for the function of the retina and normal operation of said layers. HIGHLIGHTS: Taurine and zinc are two molecules highly concentrated in the retina and with relevant functions in this structure. Maintaining zinc homeostasis in this tissue is necessary for the normal function of the taurine system in the retina. The study of the taurine transporter and the different zinc transporters in the retina (responsible for maintaining adequate levels of taurine and zinc) is relevant and novel, since it is indicative of the interactions between both molecules in this structure.

Prevalence and Amounts of Common Ingredients Found in Energy Drinks and Shots.

BACKGROUND: Energy drinks are one of the most popular packaged beverage products consumed within the United States (US). Energy drinks are considered a functional beverage, a category that also includes sports drinks and nutraceutical beverages. PURPOSE: The focus of the current study was to examine the nutrition fact panels of the top selling commercially available energy drink and energy shot products within the US to characterize common ingredient profiles to help establish a standard definition and ingredient profile of energy drinks and energy shots for consumers, health care practitioners, and researchers. METHODS: The top 75 commercially available energy drinks and shots were identified and compiled from multiple commercial retail websites as of September 2021. For the purpose of this study, an energy drink must have met the following criteria: (A) marketed as an energy drink; (B) purported to improve energy, focus, or alertness; (C) not sold as a dietary supplement (no supplement fact panels); (D) manufactured as a pre-packaged and ready-to-drink beverage; and (E) contains at least three of (1) caffeine, (2) B-vitamins, (3) sugar, (4) taurine, (5) creatine, (6) quercetin, (7) guarana, (8) ginseng, (9) coenzyme Q10, or (10) branched chain amino acids. Energy shots must have met similar criteria to be included: (A) marketed as an energy shot; (B) purported to improve energy, focus, or alertness; (C) sold as a dietary supplement; (D) manufactured as a pre-packaged beverage with a small volume (<3.5 mL); and (E) contains at least three of the ingredients stated above. RESULTS: Twenty energy shots and fifty-five energy drinks were included in this analysis. The number of ingredients per product (mean ± SD) was 18.2 ± 5.7, with 15 products containing proprietary blends with undisclosed ingredient amounts. The relative prevalence and average amounts of the top ingredients were as follows: caffeine (100%; 174.4 ± 81.1 mg), vitamin B6 (72%; 366.9 ± 648.1 percent daily value (%DV)), vitamin B3 (67%; 121.44 ± 69.9% DV), vitamin B12 (67%; 5244.5 ± 10,474.6% DV), vitamin B5 (37.3%; 113.6 ± 76.6% DV), and taurine (37.3%; amounts undisclosed). CONCLUSIONS: Our findings suggest a high prevalence of caffeine and B-vitamins in these energy products, with many of the formulations containing well above the recommended daily value of B-vitamins.

A survey of the reactivity of in vitro diagnostic bilirubin reagents developed in Japan using artificially prepared bilirubin materials: A comparison of synthetic delta, unconjugated, and taurine-conjugated bilirubin.

BACKGROUND: In vitro diagnostic bilirubin reagents based on oxidation with bilirubin oxidase or vanadic acid for total and direct-reacting bilirubin are widely used in Japan; however, their reactivity to unconjugated and conjugated bilirubin and delta bilirubin has not been completely disclosed by manufacturers. We used artificially prepared bilirubin materials to investigate the reactivity with four in vitro diagnostic bilirubin reagents. METHODS: Porcine unconjugated bilirubin solution, chemically synthesized ditaurobilirubin solution, and chemically synthesized delta bilirubin solution were used as surrogates of naturally occurring unconjugated bilirubin, conjugated bilirubin, and delta bilirubin, respectively. The total bilirubin and direct-reacting bilirubin concentrations were measured by three bilirubin oxidase methods and one vanadic acid method, and the observed concentrations were compared with those obtained by the diazo-based reference measurement procedure. RESULTS: The unconjugated bilirubin and delta bilirubin concentrations were similar when any of the four in vitro diagnostic bilirubin reagents were used during total bilirubin measurement. This was consistent with reference measurement procedure and exhibited a converged inter-method variation. Compared with reference measurement procedure, significantly low ditaurobilirubin concentrations were observed by the in vitro diagnostic bilirubin reagents despite the converged inter-method variation. In delta bilirubin measurement, some reagents reacted doubtfully with unconjugated bilirubin, while showed lower ditaurobilirubin concentrations than its corresponding total bilirubin concentration. Reactivity with delta bilirubin was different for each method including reference measurement procedure. Some reagents were developed to react less with delta bilirubin and others to strongly react with delta bilirubin. CONCLUSIONS: We revealed the reactivity of IVD-TB and IVD-DB reagents to artificially prepared bilirubin materials, and their consistency with reference measurement procedure. The delta bilirubin data results vary depending on the reagents used.

Trihydroxycholanoyl-taurine in brains of rodents with hepatic encephalopathy.

Hepatic encephalopathy (HE), a neurological disease resulting from liver failure, is difficult to manage and its causes are unclear. Bile acids have been postulated to be involved in the provenance and progression of various diseases including HE. Hence, the characterization of bile acid profiles in the brains of subjects with and without liver failure can provide important clues for the potential treatment of HE. Nanoflow ultra-performance liquid chromatography electrospray ionization ion mobility mass spectrometry (UPLC-ESI-IM-MS) is a highly sensitive method for detection of specific molecules, such as bile acids in brain samples, at biologically relevant concentrations. We used UPLC-ESI-IM-MS to characterize bile acid profiles in brain samples from seven "healthy" control rodents and 22 "diseased" rodents with liver failure (i.e., induced HE). An isomer of trihydroxycholanoyl-taurine was detected in brain tissue samples from both rats and mice with induced HE; however, this isomer was not detected in the brains of healthy rats and mice. Our findings were confirmed by comparing IM arrival times (AT), exact mass measurements (m/z), and mass spectral fragmentation patterns of the experimentally observed suspected species to standards of trihydroxycholanoyl-taurine isomers. Moreover, In Silico Fractionation was employed to provide an additional analytical dimension to verify bile acid identifications.

Electrophoretic determination of taurine.

An electrophoretic method (on-line coupled capillary isotachophoresis and capillary zone electrophoresis) with conductometric detection for the determination of free taurine in selected food and feed is described. Taurine is converted to isethionic acid by van Slyke method. Under optimized conditions (leading electrolyte: 5 mM HCl, 10 mM glycylglycine, and 0.05% 2-hydroxyethyl cellulose solution, pH 3.2; terminating electrolyte: 10 mM citric acid; background electrolyte: 50 mM acetic acid, 20 mM glycylglycine, and 0.1% 2-hydroxyethyl cellulose solution, pH 3.7), isethionic acid is separated from other sample components in anionic mode and detected using a conductimeter within 15 minutes. The performance method characteristics, such as linearity (25 - 1250 ng/mL), accuracy (99 ± 9%), repeatability (3.9%), reproducibility (4.3%), limits of detection (3 ng/mL) and quantification (10 ng/mL) were evaluated. By analysing 20 food and pet food samples the method was proved suitable for routine analysis. High sensitivity and selectivity, short analysis time and low costs are significant features of the presented method.

An investigation of glutamate quantification with PRESS and MEGA-PRESS.

Glutamate is an important neurotransmitter. Although many studies have measured glutamate concentration in vivo using magnetic resonance spectroscopy (MRS), researchers have not reached a consensus on the accuracy of glutamate quantification at the field strength of 3 T. Besides, there is not an optimal MRS protocol for glutamate measurement. In this work, both simulation and phantom scans indicate that glutamate can be estimated with reasonable accuracy (<10% error on average) using the standard Point-RESolved Spectroscopy (PRESS) technique with TE 30 ms; glutamine, however, is likely underestimated, which is also suggested by results from human scans using the same protocol. The phantom results show an underestimation of glutamate and glutamine for PRESS with long TE and MEGA-PRESS off-resonance spectra. Despite the underestimation, there is a high correlation between the measured values and the true values (r > 0.8). Our results suggest that the quantification of glutamate and glutamine is reliable but can be off by a scaling factor, depending on the imaging technique. The outputs from all three PRESS sequences (TE = 30, 68 and 80 ms) are also highly correlated with each other (r > 0.7) and moderately correlated (r > 0.5) with the results from the MEGA-PRESS difference spectra with moderate to good shimming (linewidth < 16 Hz).

Age-related decline in the taurine content of the skin in rodents.

Taurine, a sulfur-containing amino acid, occurs at high concentrations in the skin, and plays a role in maintaining the homeostasis of the skin. We investigated the effects of aging on the content and localization of taurine in the skin of mice and rats. Taurine was extracted from the skin samples of hairless mice and Sprague Dawley rats, and the taurine content of the skin was determined by high-performance liquid chromatography (HPLC). The results of the investigation revealed that the taurine content in both the dermis and epidermis of hairless mice declined significantly with age. Similar age-related decline in the skin taurine content was also observed in rats. In contrast, the taurine content in the sole remained unchanged with age. An immunohistochemical analysis also revealed a decreased skin taurine content in aged animals compared with younger animals, although no significant differences in the localization of taurine were observed between the two age groups. Supplementation of the drinking water of aged mice with 3% (w/v) taurine for 4 weeks increased the taurine content of the epidermis, but not the dermis. The present study showed for the first time that the taurine content of the skin decreased with age in mice and rats, which may be related to the impairment of the skin homeostasis observed with aging. The decreased taurine content of the epidermis in aged animals was able to be rescued by taurine supplementation.

Use of alternative protein sources for fishmeal replacement in the diet of largemouth bass (Micropterus salmoides). Part II: effects of supplementation with methionine or taurine on growth, feed utilization, and health.

Fishmeal has long been a staple protein feedstuff for fish, but its global shortage and high price have prompted its replacement with alternative sustainable sources. In this experiment involving largemouth bass (a carnivorous fish), a new mixture of feedstuffs (45% poultry byproduct meal, 30% soybean meal, 15% blood meal, and 10% krill shrimp meal) was added to low (14.5%) fishmeal diets along with 0.0%, 0.5% taurine, 0.5% methionine, or 0.5% taurine plus 0.5% methionine (dry matter basis). The positive control diet [65.3% fishmeal (46% crude protein on dry matter basis)] and all low-fishmeal diets contained 40% true protein and 10% lipids. There were 3 tanks per treatment group (20 fish/tank). Fish with the mean initial body weight of 16.6 g were fed to satiety twice daily. Compared with the unsupplemented low-fishmeal group, supplementing either 0.5% methionine or 0.5% methionine plus 0.5% taurine to the low-fishmeal diet improved (P < 0.05) the growth, feed utilization, retention of dietary protein and lipids, and health of largemouth bass, reduced (P < 0.05) the occurrence of black skin syndrome from ~ 40 to ~ 10%. Histological sections of tissues from the fish with black skin syndrome showed retina degeneration, liver damage, and enteritis in the intestine. Compared with methionine supplementation, supplementing 0.5% taurine alone to the low-fishmeal diet did not affect the growth or feed efficiency of fish and had less beneficial effects (P < 0.05) on ameliorating the black skin syndrome. These results indicated that: (a) the basal low-fishmeal diet was inadequate in methionine or taurine; and (b) dietary supplementation with methionine was an effective method to improve the growth performance, feed efficiency, and health of largemouth bass. Further studies are warranted to understand the pathogenesis of the black skin syndrome in largemouth bass.

Alcohol mixed with energy drinks: what about taurine?

RATIONALE: Since energy drinks (EDs) were marketed to the general public as recreational and soft drinks, mixing these with alcohol has become a popular practice, especially in the younger population. Alcohol mixed with EDs (AmEDs) is a particularly alarming combination, given the evidence that consistently associate these drinks with increased risk behaviours and greater alcohol consumption. Caffeine and taurine are commonly found in EDs. In contrast to caffeine, the studies on taurine psychoactive properties and how this amino acid influences ethanol intake alone or in combination with caffeine are not so numerous. OBJECTIVES: We summarised relevant and available data on the studies focusing on taurine as a psychoactive agent and its influence on ethanol (EtOH)-induced behaviours. Given the increased risk that represents mixing alcohol with energy drinks, we put emphasis on the research exploring the impact of these combinations on motivated behaviour towards EtOH consumption. RESULTS: The research on taurine properties on motivated behaviour towards EtOH consumption is limited, and mostly all done in combination with caffeine or other molecules. This makes it difficult to elucidate the effect of this amino acid when combined with alcohol. CONCLUSIONS: Incomplete understanding of the properties and effects of AmEDs is unavoidable until more studies are performed on the influence of taurine on motivation to consume alcohol. Taurine should be further explored, particularly in regard to its potential beneficial applications, motivational properties and synergies with other psychoactive ingredients (i.e. caffeine).

Association of taurine with ovarian follicular steroids and postpartum anestrus condition in Murrah buffaloes.

Taurine is an abundant intracellular beta-amino acid majorly synthesized in the liver and transported through plasma. In mammals, taurine was reported to be involved in various physiological functions, including the enhancement of testosterone levels, the major estradiol precursor. Therefore, we hypothesize that taurine levels are associated with ovarian follicular steroids as well as with a reproductive problem called postpartum anestrus (PPA) in dairy buffaloes. To understand the taurine levels and its possible role in buffalo ovarian follicles, a correlation was established among taurine, estradiol, and testosterone levels in the ovarian follicular fluid. For this purpose, buffalo ovaries were obtained from the slaughterhouse, and follicular fluid samples were collected from small (<4 mm), medium (4-8 mm) and large (>8 mm) follicles. Taurine and steroid levels in the follicular fluid were analyzed by TLC and ELISA, respectively. Taurine and testosterone levels were significantly (P < 0.05) higher in the follicular fluid of small and medium follicles than large follicles, whereas the estradiol levels were significantly (P < 0.001) higher in the large follicles. Thus, taurine showed a positive correlation (r = 0.75) with testosterone and a negative correlation (r = -0.77) with estradiol in buffalo follicular fluid, indicating its possible role in testosterone function during follicular development. Interestingly, significantly (P < 0.001) lower plasma taurine levels in PPA (n = 50) than normal cyclic (n = 50) buffaloes represented its association with PPA. Therefore, our present study recommends the need for future nutrition studies on taurine supplementation to PPA buffaloes.

Imaging Mass Spectrometry Reveals the Changes in the Taurine Conjugates of Dihydroxycholanoic Acid During Hepatic Warm Ischemia and Reperfusion in a Rat Model.

Warm ischemia and reperfusion injury (IRI) is a prognostic factor in donation after cardiac death donor transplantation. However, a reliable method to predict IRI before transplantation has not been established. The aim of this study was to identify predictive markers of hepatic IRI by simultaneous measurement of endogenous molecules using matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). Rats were subjected to hepatic warm ischemia (70%) for 30 or 90 minutes and subsequent reperfusion. The livers were collected at the end of ischemia and 1 hour, 6 hours, and 24 hours after reperfusion. The liver tissue sections were applied to IMS (m/z 200-2000). Candidate molecules were identified by tandem mass spectrometry. Imaging mass spectrometry (IMS) revealed a significant increase in the taurine conjugates of dihydroxycholanoic acid (TDHCA) during ischemia and a tendency to return to the basal level after reperfusion. Notably, high-resolution measurements revealed focal accumulation of TDHCA in the intrahepatic bile duct with ischemic time. In conclusion, IMS is a useful method to detect minute changes provoked by ischemia, which are barely detectable in assays involving homogenization. Accordingly, focal accumulation of TDHCA during ischemia may be a candidate marker for predicting later IRI.

Detecting Low Concentrations of Nitrogen-Based Adulterants in Whey Protein Powder Using Benchtop and Handheld NIR Spectrometers and the Feasibility of Scanning through Plastic Bag.

Nitrogen-rich adulterants in protein powders present sensitivity challenges to conventional combustion methods of protein determination which can be overcome by near Infrared spectroscopy (NIRS). NIRS is a rapid analytical method with high sensitivity and non-invasive advantages. This study developed robust models using benchtop and handheld spectrometers to predict low concentrations of urea, glycine, taurine, and melamine in whey protein powder (WPP). Effectiveness of scanning samples through optical glass and polyethylene bags was also tested for the handheld NIRS. WPP was adulterated up to six concentration levels from 0.5% to 3% w/w. The two spectrometers were used to obtain three datasets of 819 diffuse reflectance spectra each that were pretreated before linear discriminant analysis (LDA) and regression (PLSR). Pretreatment was effective and revealed important absorption bands that could be correlated with the chemical properties of the mixtures. Benchtop NIR spectrometer showed the best results in LDA and PLSR but handheld NIR spectrometers showed comparatively good results. There were high prediction accuracies and low errors attesting to the robustness of the developed PLSR models using independent test set validation. Both the plastic bag and optical glass gave good results with accuracies depending on the adulterant of interest and can be used for field applications.

Dietary taurine incorporation to high plant protein-based diets improved growth, biochemical, immunity, and antioxidants biomarkers of African catfish, Clarias gariepinus (B.).

Plant protein (PP) sources are generally used in high levels in fish diets. Mostly, PP sources are deficient in taurine; hence, there is a need for its supplementation to fish fed high PP diets. Therefore, effects of dietary taurine were examined on growth performance, feed utilization, immunity, and antioxidant parameters of African catfish, Clarias gariepinus (B.). Fish (10.3 ± 0.4 g) were fed on diets (40% crude protein) containing different taurine levels of 0 (control), 10, 20, 30, or 40 g/kg diet for 12 weeks. Fish fed a taurine-free diet (the control) with high PP sources showed poor growth as compared with these fed taurine-enriched diets where taurine stimulatory effects were observed on fish growth and feed intake. Feed conversion ratio and fish survival rate were not significantly differed among different treatments. Fish fed taurine-enriched diets showed also higher levels of serum glucose, cholesterol, total protein, albumin, globulin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, and creatinine over that fed the control diet. Furthermore, lysozyme and respiratory burst activities as well as superoxide dismutase and catalase activities were significantly elevated in fish fed taurine-enriched diets (P < 0.05) and their highest levels were observed in fish fed 30 g/kg diet. Additionally, taurine deposition in fish muscles was positively correlated with dietary taurine levels (P < 0.05). The present study concludes that taurine is a limiting factor for growth, immunity, and antioxidants responses of African catfish fed high PP-based diets and it should be incorporated in its diets with an optimum level of 20 g/kg diet.

Extracting bio-zinc and taurine from Pinctada martensii meat.

Recently, intensive processing of marine resources has attracted considerable attention. In order to further utilize the byproducts of aquatic shellfish (Pinctada martensii meat) with high value, this study proposes a method of extracting zinc and taurine from P. martensii meat. Zinc was first extracted from P. martensii meat with an ultrasonic crusher, and then taurine was further extracted by ultrasonic-assisted water extraction from the remaining shellfish. After optimization, the biological zinc extraction rate reached 8.63%, and the taurine extraction rate reached 0.71%. Meanwhile, the parameters for cation exchange separation and taurine purification were optimized, in which the injection volume, pH value, and elution rate were set to 8.0 mL, 4.5, and 3.0 mL/min, respectively. Ultimately, the purity the extracted taurine reached 98.16%. This study provides a novel method for the extraction of biological zinc and taurine by deep processing of shellfish meat.

1H NMR Metabolic Profile of Scyphomedusa Rhizostoma pulmo (Scyphozoa, Cnidaria) in Female Gonads and Somatic Tissues: Preliminary Results.

The Mediterranean basin is one of the regions heavily affected by jellyfish bloom phenomena, mainly due to the presence of scyphozoans, such as Rhizostoma pulmo. The jellyfish have few natural predators, and their bodies represent an organic-rich substrate that can support rapid bacterial growth with great impact on the structure of marine food webs. In Asiatic countries, jellyfish are widely studied for their health benefits, but their nutritional and nutraceutical values still remain poorly characterized. In this study, the differences in the 1H NMR spectroscopy metabolic profiles of R. pulmo female gonads and body fractions (including umbrella and oral arms), in different sampling periods, were studied. For each body compartment both lipid and aqueous extracts were characterized and their 1H NMR metabolic profiles subjected to multivariate analysis. From a statistical analysis of the extracts, a higher contents of ω-3 polyunsaturated fatty acids (PUFAs), amino acid and osmolytes (homarine, betaine, taurine) with important roles in marine invertebrates were observed in female gonads, whereas umbrella and oral arms showed similar metabolic profiles. These results support a sustainable exploitation of the jellyfish for the extraction of bioactive compounds useful in nutraceutical, nutricosmetics, and functional food fields.