Dietary supplementation with monosodium glutamate enhances milk production by lactating sows and the growth of suckling piglets.

This study was conducted to test the hypothesis that increasing dietary content of glutamate through addition of monosodium glutamate (MSG) enhances milk production by lactating sows and the growth of their offspring. Thirty multiparous sows (Landrace × Large White) were assigned randomly into one of three dietary groups: control (a corn- and soybean meal-based diet), the basal diet + 1% MSG, and the basal diet + 2% MSG. Diets were made isonitrogenous by the addition of appropriate amounts of L-alanine. Lactating sows had free access to drinking water and were fed twice daily their respective diets. The number of live-born piglets was standardized to 9 per sow at day 0 of lactation (the day of farrowing). On days 3, 15, and 29 of lactation, body weight and milk consumption of piglets were measured, and blood samples obtained from sows and piglets at 2 h and 1 h after feeding, respectively. Feed intake of sows did not differ (P > 0.05) among the three groups of sows. Concentrations of aspartate, glutamine, citrulline, arginine, tryptophan, proline, branched-chain amino acids, and glutamate were greater (P < 0.05) in the plasma of MSG-supplemented sows and their piglets than for controls. When compared with the control, dietary supplementation with 1-2% MSG increased (P < 0.05): concentrations of many free amino acids (including glutamate plus glutamine) and all protein-bound amino acids in milk; the milk intake of piglets by 14-25%; and daily weight gains of piglets by 23-44%. These results indicate that dietary supplementation with 1-2% MSG to lactating sows enhances milk production to support the growth of sow-reared piglets.

How Pectin Play a Role in Histological Changes by Monosodium Glutamate (MSG) in the Ovary of Mice?

BACKGROUND AND OBJECTIVE: The effects of pectin from the natural vitamins and herbs on the ovary of mice induced by monosodium glutamate (MSG) leads to over accumulations in living cells and finally produces cellular toxicity and damage, pectin helps to rapidly reduce this changes. MATERIALS AND METHODS: Cytotoxicity of monosodium glutamate was investigated histologically by using hematoxylin and eosin (H and E) stains. The animals received (MSG) in drinking water at a dose of 3 g kg-1 b.wt., in drinking water for three weeks. The ovary tissues were subjected to histological and morphological analysis. RESULTS: In female rats treated with a dose of MSG of 3 g kg-1 daily in drinking water clear toxicological effects on the ovary tissue were significantly obtained. The mice were then anesthetized, dissected the ovary samples were taken from female mice and kept in a 10% neutral formalin solution to make tissue slides after that examined under the microscope to see the differences. Sections showed the occurrence of several histopathological changes in the ovary. CONCLUSION: This study concluded that the effectiveness of pectin therapy on ovarian cells destroyed by the effect of monosodium glutamate, which has proven to be very effective in treating all affected and restoring tissue to normal.

Temporal profile of flavor enhancers MAG, MSG, GMP, and IMP, and their ability to enhance salty taste, in different reductions of sodium chloride.

We evaluated the temporal profile of the flavor enhancers monosodium glutamate (MSG), disodium inosinate (IMP), disodium guanylate (GMP), and monoammonium glutamate (MAG). We also evaluated the ability of these flavor enhancers to enhance salty taste in solutions containing different reductions of sodium chloride. Four experiments were conducted using Central Composite Rotational Design (CCRD) with focus on two objectives: concentration of flavor enhancers (0% to 1%) and reduction of sodium chloride content (0% to 100%). A 0.75% saline solution of NaCl was used as a control. In each experiment, the treatments were evaluated by the intensity of salty and umami tastes using an intensity scale. Treatments, selected according to the results of CCRD, were analyzed using time-intensity (TI) and temporal dominance of sensations (TDS) analyses. Glutamates (MSG/MAG) showed greater capacity to enhance salty taste than treatments containing nucleotides (IMP/GMP). The intensity of umami taste, using all the examined flavor enhancers, showed a similar sensory profile. Temporal perception curves (TI and TDS) of salty and umami tastes also showed a similar temporal profile. The glutamic acid amino acids were better able to improve salty taste than nucleotides in any range of sodium chloride reduction. Flavor enhancers showed greater ability to increase salty taste in smaller reductions in sodium chloride content. PRACTICAL APPLICATION: This research expand the knowledge about the ability to enhance the salty taste of flavor enhancers in different reductions in sodium content, Beside that, will provide information about the time profile of flavor enhancers. This study provides scientific technical information on the ability to intensify the salty taste of flavor enhancers and can assist the industry to develop new low sodium products and encourage the scientific community to conduct future research on this subject.

Quantitative analyses of the umami characteristics of disodium succinate in aqueous solution.

Disodium succinate (WSA) contributes to umami taste in seafoods and it is abundantly found in scallops. However, the actual application of WSA in foods is limited due to a lack of understanding of its taste characteristics and stability. In this study, two-alternative forced choice method was used to determine the relative umami intensity of WSA compared to monosodium glutamate, as well as the relative umami intensity under different conditions (pH and temperature). WSA concentration-taste intensity curve was established, which fitted well with a logarithmic-linear regression (R2 = 0.96). WSA exhibited the strongest umami intensity at 25 °C, 0.1% Na+ addition, and pH 7.5. It also had a good thermal stability, which met the needs of high temperature heating during food processing. In conclusion, this research provided useful information on umami characteristics of WSA and the results widen the application of WSA in the food industry.

Ectoine production with indigenous Marinococcus sp. MAR2 isolated from the marine environment.

Ectoine has fostered the development of products for skin care and cosmetics. In this study, we employed the marine bacterial strain Marinococcus sp. MAR2 to increase ectoine production by optimizing medium constituents using Response Surface Methodology (RSM) and a fed-batch strategy. The results from the steepest ascent and central composite design indicated that 54 g/L of yeast extract, 14.0 g/L of ammonium acetate, 74.4 g/L of sodium glutamate, and 6.2 g/L of sodium citrate constituted the optimal medium with maximum ectoine production (3.5 g/L). In addition, we performed fed-batch culture in the bioreactor, combining pH and dissolved oxygen to produce ectoine by Marinococcus sp. MAR2. The ectoine production, content, and productivity of 5.6 g/L, 10%, and 3.9 g/L/day were further reached by a fed-batch culture. Thus, the ectoine production by Marinococcus sp. MAR2 using RSM and fed-batch strategy shows its potential for industrial production.

Anammox-based processes: How far have we come and what work remains? A review by bibliometric analysis.

Nitrogen contamination remains a severe environmental problem and a major threat to sustainable development worldwide. A systematic analysis of the literature indicates that the partial nitritation-anammox (PN/AMX) process is still actively studied as a viable option for energy-efficient and feasible technology for the sustainable treatment of N- rich wastewaters, since its initial discovery in 1990. Notably, the mainstream PN/AMX process application remains the most challenging bottleneck in AMX technology and fascinates the world's attention in AMX studies. This paper discusses the recent trends and developments of PN/AMX research and analyzes the results of recent years of research on the PN/AMX from lab-to full-scale applications. The findings would deeply improve our understanding of the major challenges under mainstream conditions and next-stage research on the PN/AMX process. A great deal of efforts has been made in the process engineering, PN/AMX bacteria populations, predictive modeling, and the full-scale implementations during the past 22 years. A series of new and excellent experimental findings at lab, pilot and full-scale levels including good nitrogen removal performance even under low temperature (15-10 °C) around the world were achieved. To date, pilot- and full-scale PN/AMX have been successfully used to treat different types of industrial sewage, including black wastewater, sludge digester liquids, landfill leachate, monosodium glutamate wastewater, etc. Supplementing the qualitative analysis, this review also provides a quantitative bibliometrics study and evaluates global perspectives on PN/AMX research published during the past 22 years. Finally, general trends in the development of PN/AMX research are summarized with the aim of conveying potential future trajectories. The current review offers a valuable orientation and global overview for scientists, engineers, readers and decision makers presently focusing on PN/AMX processes.

Current Sodium Intakes in the United States and the Modelling of Glutamate's Incorporation into Select Savory Products.

Most Americans have dietary sodium intakes that far exceed recommendations. Given the association of high sodium with hypertension, strategies to reduce sodium intakes are an important public health target. Glutamates, such as monosodium glutamate, represent a potential strategy to reduce overall intakes while preserving product palatability; therefore, this project aimed to model sodium replacement with glutamates. The National Cancer Institute method was used to estimate current sodium intakes, and intakes resulting from glutamate substitution (25%-45%) in a limited set of food groups for which substitution is possible. Data sets for individuals aged ≥1 year enrolled in the U.S. National Health and Nutrition Examination Survey 2013-2016 (n = 16,183) were used in the analyses. Glutamate substitution in accordance with the U.S. Department of Agriculture's food codes was modeled by conservatively altering estimates of sodium intake reductions derived from the published, peer-reviewed literature. The addition of glutamates to certain food categories has the potential to reduce the population's sodium intake by approximately 3% overall and by 7%-8% among consumers of ≥1 product category in which glutamates were substituted for sodium chloride. Although using glutamates to substitute the amount of sodium among certain food groups may show modest effects on intakes across the population, it is likely to have a more substantial effect on individuals who consume specific products.

Investigation of Monosodium Glutamate Alternatives for Content of Umami Substances and Their Enhancement Effects in Chicken Soup Compared to Monosodium Glutamate.

This research aimed to compare the effects of monosodium glutamate (MSG) and its alternatives on sensory characteristics of chicken soup. High-performance liquid chromatography analysis was carried out to quantify umami substances in potential MSG alternatives. Two mushroom extracts (CE and MC), one tomato extract (TC), and one yeast extract (YE) powders were selected due to their high equivalent umami concentration (EUC). These extracts together with MSG were then applied individually at four different levels (CE, MC, TC, MSG: 0.05%, 0.1%, 0.2%, 0.4%; YE: 0.0125%, 0.025%, 0.05%, 0.1%) in chicken soup in order to compare their impact on major sensory attributes using the degree of difference from control (DODC) test. Our results showed that all four extracts at all the usage levels exhibited an enhancement effect on the overall flavor, meaty flavor, saltiness, and umami taste. The extent of enhancement depended on the type of the alternative and its usage level. Higher levels of MSG alternatives (except YE) suppressed the chicken flavor. YE had similar enhancement effects as MSG on umami and salty tastes already at lower usage levels. At the lowest concentration, TC showed a stronger enhancement effect than MSG, but its effect on most attributes decreased as the usage dose increased. Compared to CE, the other mushroom extract MC resembled MSG at most levels. Overall, the closest synergistic effect in chicken soup was noted with 0.1% MSG, 0.1% MC, and 0.025% YE. PRACTICAL APPLICATION: This study compared the enhancement effects of MSG and selected alternatives in chicken soup. Results will help food manufacturers who would like to replace MSG with natural umami substances in soup products to enhance flavor and reduce sodium chloride.

Establishment of new assessment method for the synergistic effect between umami peptides and monosodium glutamate using electronic tongue.

In order to investigate the synergistic effect between umami peptides and monosodium glutamate (MSG), a new assessment method was established using electronic tongue. After 36 kinds of umami peptides synthesized by peptide solid phase synthesis, their taste characteristics were preliminarily explored by electronic tongue technology, and then the umami intensity was ranked before and after addition of MSG, using a concentration of 0.35% of MSG as control. In addition, the sensory evaluation was utilized to verify the results of the electronic tongue. Finally, the umami intensity and the synergistic effect of umami peptides and MSG were also investigated by the aroma chicken model (ACM). Results showed that peptide Lys-Gly-Ser-Leu-Ala-Asp-Glu-Glu (KE-8) and Arg-Leu (RL) have the strongest umami taste, Asp-Asp-Asp (DDD) and Glu-Ser-Val (ESV) have the strongest synergistic effect with MSG, which could increase the umami intensity. The ESV and Glu-Asp-Asp (EDD) showed the strongest synergistic effect with ACM. The evaluation method could provide the objective data for further investigating for the synergistic theory.

Electrochemical detection of monosodium glutamate in foodstuffs based on Au@MoS2/chitosan modified glassy carbon electrode.

We report an amperometric immunosensor for the detection of monosodium glutamate (MSG) using a glassy carbon electrode modified with gold nanoparticle decorated on a molybdenum disulfide/chitosan (Au@MoS2/Ch) nanocomposite. In the present detection technique, Au@MoS2/Ch was used as a conductive matrix and anti-glutamate antibody was immobilized on to its surface via carbodiimide coupling method. Chemical and morphological attributes of the various components of the immunosensor were confirmed by UV-vis spectroscopy, SEM, TEM and XRD analysis. Electrochemical characterizations were carried out by CV, DPV and EIS. Overall results showed the effective fabrication of highly conductive Au@MoS2/Ch nanocomposite for sensitive electrochemical detection of MSG. A linear relationship was perceived between the change in current and concentration of MSG. The relationship was found to be consistent in the detection range of 0.05-200 µM. Statistical validation of the assay showed limit of detection and limit of quantification values as 0.03 and 0.1 µM, respectively (R2 = 0.99).

Optimized cultural conditions of functional yogurt for γ-aminobutyric acid augmentation using response surface methodology.

Yogurt, a functional dairy food product, is an effective medium for delivering beneficial functional ingredients. One ingredient, γ-aminobutyric acid (GABA), has growing appeal in the development of functional foods for its potential in reducing the risk of diabetes, hypertension, and stress as a bioactive agent. However, the concentration of GABA in existing food products is remarkably low. We developed a functional yogurt rich in GABA using Streptococcus thermophilus fmb5. The GABA yield of yogurt was enhanced by optimization of culture conditions using single factor and response surface methods. The results showed that culture temperature, monosodium glutamate concentration, and culture time are the 3 main factors that affect GABA yield. The optimal culture conditions were determined as follows: 38.8°C for culture temperature, 20 g/L of monosodium glutamate, and 120 h of culture time. Under the above optimal conditions, the actual yield of GABA production was maximized at 9.66 g/L, which was 1.2 times or higher than that of from any single factor treatment. The GABA concentration, viable bacteria number, and water-holding capacity of GABA-rich yogurt were stable throughout the whole storage time. The results show that producing yogurt with Streptococcus thermophilus fmb5 and the optimized culture conditions will achieve high GABA concentrations that maximize health benefits to consumers.

A survey of free glutamic acid in foods using a robust LC-MS/MS method.

An effective and simultaneous liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used with the aim of quantifying monosodium glutamate (MSG) in foodstuffs, such as chips, taste cubes, sauces and soups. The results were linear (R2 = 1), with very low LOD and LOQ values, 1.0 µg/kg, 5.0 µg/kg, respectively. Excellent repeatability and reproducibility were also achieved. This highly sensitive and robust LC-MS/MS technique was applied successfully for the detection and quantification of MSG in a wide variety of foodstuffs. MSG contents ranged from 0.01 g/100 g to 15.39 g/100 g in food samples. Importantly, determination of free glutamic acid in the daily diet could also prevent various side effects associated with consumption of excess free glutamic acid.

In-capillary derivatization with o-phthalaldehyde in the presence of 3-mercaptopropionic acid for the simultaneous determination of monosodium glutamate, benzoic acid, and sorbic acid in food samples via capillary electrophoresis with ultraviolet detection.

For the rapid simultaneous determination of monosodium glutamate (MSG), benzoic acid (BA), and sorbic acid (SA) in canned food and other processed food samples, we developed a method that combines in-capillary derivatization with separation by capillary electrophoresis. This method employs the rapid derivatization of MSG with o-phthalaldehyde (OPA) in the presence of 3-mercaptopropionic acid (3-MPA) and enables the detection of the resulting OPA-MSG derivative and of non-derivatized BA and SA at 230nm. The composition of the background electrolyte and the parameters of derivatization and separation are as follows: 25mM borax containing 5mM OPA and 6mM 3-MPA, separation voltage 25mV, injection at 30mbar for 20s, and column temperature 25°C. Because of the high reaction rate and suitably adapted effective electrophoretic mobilities, band broadening due to the derivatization reaction at the start of the separation process is kept to a minimum. The optimized method is validated with respect to LOD, LOQ, linearity, recovery, and precision. This method can be applied to real samples such as soy, fish, oyster and sweet and sour chili sauces after application of appropriate clean-up steps. Mechanisms of zone broadening and zone focusing are discussed showing the validity of the employed theoretical approach regarding the dependence of the peak shape for OPA-MSG on the concentration of MSG in the sample.

Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively.

Evaluation of umami taste in mushroom extracts by chemical analysis, sensory evaluation, and an electronic tongue system.

Seventeen edible mushrooms commercially available in Korea were analysed for their umami taste compounds (5'-nucleotides: AMP, GMP, IMP, UMP, XMP; free amino acids: aspartic, glutamic acid) and subjected to human sensory evaluation and electronic tongue measurements. Amanita virgineoides featured the highest total 5'-nucleotide content (36.9 ± 1.50 mg/g), while monosodium glutamate-like components (42.4 ± 6.90 mg/g) were highest in Agaricus bisporus. The equivalent umami concentration (EUC) ranged from 1.51 ± 0.42 to 3890 ± 833 mg MSG/g dry weight; most mushrooms exhibited a high umami taste. Pleurotus ostreatus scored the highest in the human sensory evaluation, while Flammulina velutipes obtained the maximum score in the electronic tongue measurement. The EUC and the sensory score from the electronic tongue test were highly correlated, and also showed significant correlation with the human sensory evaluation score. These results suggest that the electronic tongue is suitable to determine the characteristic umami taste of mushrooms.

Umami compounds enhance the intensity of retronasal sensation of aromas from model chicken soups.

We examined the influence of taste compounds on retronasal aroma sensation using a model chicken soup. The aroma intensity of a reconstituted flavour solution from which glutamic acid (Glu), inosine 5'-monophosphate (IMP), or phosphate was omitted was significantly lower (p<0.05) than that of the model soup. The aroma intensity of 0.4% NaCl solution containing the aroma chicken model (ACM) with added Glu and IMP was significantly higher (p<0.05) than that of 0.4% NaCl solution containing only ACM. The quantitative analyses showed that adding monosodium glutamate (MSG) to aqueous aroma solution containing only ACM enhanced the intensity of retronasal aroma sensation by 2.5-folds with increasing MSG concentration from 0% to 0.3%. Sensation intensity using an umami solution with added MSG and IMP was significantly higher than that with only MSG when the MSG concentration was 0.05%, 0.075%, or 0.1%. However, it plateaued when MSG concentration was beyond 0.3%.

Monosodium glutamate in chicken and beef stock cubes using high-performance liquid chromatography.

In this survey monosodium glutamate (MSG) levels in chicken and beef stock cube samples were determined. A total number of 122 stock cube samples (from brands A, B, C, D) were collected from local markets in Ankara, Turkey. High-performance liquid chromatography with diode array detection (HPLC-DAD) was used for quantitative MSG determination. Mean MSG levels (±SE) in samples of A, B, C and D brands were 14.6 ± 0.2 g kg⁻¹, 11.9 ± 0.3 g kg⁻¹, 9.7 ± 0.1 g kg⁻¹ and 7.2 ± 0.1 g kg⁻¹, respectively. Differences between mean levels of brands were significant. Also, mean levels of chicken stock cube samples were lower than in beef stock cubes. Maximum limits for MSG in stock cubes are not specified in the Turkish Food Codex (TFC). Generally the limit for MSG in foods (except some foods) is established as 10 g kg⁻¹ (individually or in combination).

[Research on the surface-enhanced Raman spectrum of sodium sulfide nonahydrate and its application in monosodium glutamate detecting].

The surface-enhanced Raman spectrum of sodium sulfide was studied and the structure vibration information was obtained. The raman characteristic peak at 472 cm(-1) was selected to evaluate enhanced effects. Gold colloid was used as active substrate, The relationship between gold nanoparticle size and enhanced efficiency was analysised and the optimum size for SERS is 97 nm. The surface enhanced Raman scattering spectra of sodium sulfide at different concentrations were also presented. The results indicated that SERS spectra of sodium sulfide can be found even the concentration reach 10(-6) g x mL(-1). The performance of active substrate is related with the ratio of sample and gold colloid. In the real situation, 1 g monosodium glutamate was added to 10mL sodium sulfide solution with different concentration and then SERS spectra of these samples were collected respectively. The lever of qualitative detection can reach 10mg x kg(-1). And due to the simple procedure in sample preparation, this method is of great potential in on-line qualitative detection.

Stability of monosodium glutamate in green table olives and pickled cucumbers as a function of packing conditions and storage time.

The effects of different packing conditions and storage times on the stability of monosodium glutamate (MSG) added to two different fermented vegetables (Spanish-type green table olives and pickled cucumbers) were studied. Factors such as packaging material (glass bottle versus plastic pouch), heat treatment (pasteurisation versus non-pasteurisation), and the presence or not of a preservative compound (potassium sorbate) were considered. The MSG content of pickled cucumbers was stable for up to 1 year of storage in all packing conditions studied. The MSG content also remained stable in pasteurised green table olives. On the contrary, MSG was extensively degraded (>75% degradation) after 54 weeks of storage in unpasteurised green olives with a higher degradation rate in glass bottles compared with plastic pouches. In the presence of potassium sorbate, MSG was also considerably degraded in olives packed in plastic pouches (>50% degradation), but hardly degraded in glass bottles. The results indicate that MSG degradation in olives is due to the action of both lactic acid bacteria and yeasts, with the formation of γ-aminobutyric acid as the major end-product.

Monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine improve the sensory quality of fermented cooked sausages with 50% and 75% replacement of NaCl with KCl.

Fermented cooked sausages were produced by replacing 50% and 75% of NaCl with KCl and adding monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine. The manufacturing process was monitored by pH and water activity measurements. The sodium and potassium contents of the resulting products were measured. The color values (L*, a* and b*), texture profiles and sensory profiles were also examined. Replacing 50% and 75% NaCl with KCl depreciated the sensory quality of the products. The reformulated sausages containing monosodium glutamate combined with lysine, taurine, disodium inosinate and disodium guanylate masked the undesirable sensory attributes associated with the replacement of 50% and 75% NaCl with KCl, allowing the production of fermented cooked sausages with good sensory acceptance and approximately 68% sodium reduction.