Total Amino Acid Nitrogen Research Articles

Investigating the temporal evolution of physicochemical attributes and flavorome profiles in Sichuan shai vinegar utilizing diverse aging techniques

Sichuan shai vinegar (SSV) is an acidic condiment with a long history and unique flavor. Aging is an important production process that determines the unique flavor of shai vinegar. This study compared the differences in physicochemical properties, volatile flavor, and non-volatile flavor substances between the constant temperature aging and natural aging methods of SSV Cupei. The results showed that the total acid and amino acid nitrogen content in naturally aged vinegar was higher than that in constant temperature aged vinegar. Furthermore, 20 different volatile flavor substances and 65 different non-volatile flavor substances were obtained after 21 and 25 days of constant temperature aging and 1, 3, and 5 years of natural aging SSV samples. This indicates that the temperature environment during natural aging was more moderate, allowing acidic compounds to form and stably exist in the aging environment. Correlation analysis further demonstrated that there were more differentiated non-volatile substances significantly related to the Maillard reaction under constant temperature aging condition and related to antioxidant activity under natural aging condition. The results of this study provide a comprehensive understanding of the characteristics and applications of the two aging methods of SSV and guide strategy for factories in the selection of aging methods.

Comparative analysis of the microbiota succession and flavor formation in spontaneously fermented fish sauces made with silvery pomfret (Pampus argenteus) and little yellow croaker (Larimichthys polyactis)

Our study delved into exploring the bacterial profiles and volatile compounds during the fermentation of two distinct fish sauces, i.e., Larimichthys polyactis (LP) and Pampus argenteus (PA), and a co-occurrence network was employed to investigate the underlying relationship between flavor and microorganisms. The pH (6.97–5.66) remarkably declined while the total volatile basic nitrogen (TVB-N, 92.36–116.55 mg/100 mL) and amino acid nitrogen (AAN, 104.49–638.68 mg/100 mL) contents gradually rose with the fermentation of LP and PA samples. Bacterial community analysis revealed that Psychrobacter was the dominant genus before LP fermentation, and its relative abundance was gradually occupied by Staphylococcus after 7M. The most dominant genus before PA fermentation was Photobacterium, while Virgibacillus emerged as the predominant genera of PA samples after 7M. Seven main volatile compounds made salient contributions (VIP ≥1.0, ROAV ≥1.0) to the flavor of LP- and PA-fermented samples, respectively. Among them, three typical genera (Tetragenococcus, Streptococcus and Staphylococcus) and four specific genera (Tetragenococcus, Psychrobacter, Vagococcus and Lactobacillus) were the core microorganisms contributing to flavor compounds in LP and PA samples, respectively. Therefore, acquiring insight into the microbes responsible for key flavors in multi-variety fermented fish sauces could provide essential indicators for optimizing commercial fermentation processes.

PECULIARITIES OF THE INFLUENCE OF TYLOZIN ON THE METABOLISM OF PROTEINS AND AMINO ACIDS IN CHICKEN

Over the last decade, poultry farming, both for meat and eggs, has been widely developed in our country. Poultry products are widely used in the diets of the population. In this problem, it is necessary to observe the careful application of antimicrobial drugs to productive animals, as they are used by humans and not to disturb the ecosystem and not cause the formation of resistant microflora. Taking into consideration that veterinary medicine should be more preventive than curative, the problems of poultry treatment are poorly described, it was decided that it is necessary to work with healthy organisms. Because the physiological reactivity of the body changes with pathologies even without medical interventions. Methods of using macrolides and other pharmacological agents in sick animals and poultry are described in the literature, but there are not enough works that would highlight the data on the effect of this agent on protein and amino acid metabolism in healthy chickens. In addition, it is known that metabolic processes in poultry take place with a fairly high intensity, and this is definitely reflected in the amount of doses of various drugs, and antibiotics in particular. Medicines in the bird's body, accordingly, are biotransformed more quickly and removed from the body faster with droppings and eggs, others accumulate in various organs and muscles. Therefore, it is important to know how the biosynthesis of the main proteins and the level of free amino acids changes under the action of the antimicrobial agent Tylozin on the days of administration and in the period after the administration of the antibiotic. The results of the research are informative. The work is devoted to the study of the influence of an antimicrobial drug from the pharmacological group of macrolides on the metabolism of amino acids and proteins in chickens in a comparative aspect. At the same time, egg production in laying hens aged 140-150 days was taken into account. The influence of different doses of Tylosin on the protein and amino acid composition of chickens during the period of use and after the end of drug administration was studied. It was established that changes in the metabolism of total protein, its fractions and amino acid nitrogen in the blood serum occur naturally, long-term, in different directions and, proportionally, depend on the dose of the drug. The effect of the drug was studied in minimum, average and maximum doses.

Effect of Different Salt Additions on the Flavor Profile of Fermented Ciba Pepper

Salt is a key ingredient that can both enhance the taste and extend the shelf life of fermented vegetables. However, it is important to note that excessive salt levels can have adverse effects on consumer health. This study aimed to investigate the impact of various salt additions (2%, 4%, 6%, 8%, and 10% wt/wt) on the flavor profile of fermented ciba pepper, a traditional Chinese fermented chili sauce, using gas chromatography–ion mobility spectrometry (GC-IMS) in combination with an electronic nose (E-nose). Fermented ciba pepper samples were prepared with different salt additions: 2% (LJA), 4% (LJB), 6% (LJC), 8% (LJD), and 10% (LJE) (wt/wt). The physicochemical and sensory properties of the fermented ciba pepper samples were evaluated. Sensory evaluation indicated that LJC and LJD received higher scores compared to the other groups. The total acid and amino acid nitrogen contents displayed contrasting trends with the salt additions (p < 0.05). The E-nose analysis successfully differentiated the flavor profiles of the ciba pepper samples fermented with varying salt additions. Additionally, the GC-IMS analysis identified a total of 72 volatile compounds, including 14 alcohols, 21 esters, nine aldehydes, four acids, eight ketones, three terpenes, and eight other substances. Notably, the ciba pepper samples with lower salt additions exhibited higher levels of alcohols, aldehydes, and esters. In conclusion, the addition of salt during the fermentation process significantly influenced the formation of flavor compounds in ciba pepper. This study provides valuable insights into ciba pepper fermentation with different salt additions and offers prospects for the development of low-salt fermented ciba pepper products.

Decoding the molecular basis for temperature control by metabolomics to improve the taste quality of soy sauce fermented in winter

This study aimed to explore the material basis of the temperature-controlled fermentation method (30 °C) to improve the taste quality of soy sauce fermented in winter under 200 tons industrial scale by quantitative description analysis (QDA), physicochemical and metabolomic analysis. Results showed that the taste of soy sauce fermented at controlled temperature (SSCT) was superior to that of soy sauce fermented at room temperature (SSRT), especially the intensity of umami, kokumi, and sweet. The contents of total nitrogen and amino acid nitrogen in SSCT were significantly higher. 49 non-volatile compounds (13 organic acids, 10 sugars, 9 sugar alcohols, 15 amino acids and 2 others) were identified by GC-MS derivatization, classified according to the taste characteristics and taste active value (TAV) was calculated. The total TAV of sweet and umami substances increased while the total TAVs of sour substances decreased for SSCT. Moreover, out of the 191 peptides/amino acids derivates detected by UPLC-MS/MS, where 34 compounds had large differences. Some umami compounds (Fru-Glu, Fru-Val and Fru-pGlu) and kokumi compounds (γ-Glu-Leu, γ-Glu-Ile) were significantly higher in SSCT. These results revealed the intrinsic reasons for the improved quality of temperature-controlled soy sauce and provided a theoretical basis for the exploration and industrial application of temperature control on soy sauce fermentation.

Evaluation of bacterial and fungal communities during the fermentation of pine needle.

To improve the quality and organoleptic properties of fermented pine needle, the physiological parameters and microbial communities must be explored. In this study, high-throughput sequencing was used to explore bacterial and fungal communities during the fermentation process of pine needle after adding starter culture of 0.8% activated dry yeast and Lactobacillus fermentum CECT5716 and Bifidobacterium Breve M-16V. During the fermentation, the total flavonoid (from 0.049 to 111.404mg/L) and polyphenol (from 19.412 to 183.399mg/L) contents increased rapidly from 0 to 15 days. The total sugar increased from 0 to 3 days fermentation with a range from 3.359mg/mL to 45.502mg/mL in yeast fermentation stage, and reached the maximum value on day 3. The content of total acid (39.167g/L) and amino acid nitrogen (1.185g/L) gradually increased during the entire fermentation process and reached a maximum on day 7 of bacterial fermentation. Firmicutes and Proteobacteria phyla were the predominant bacteria in all time periods. At the genus level, well-known Lactobacillus was the most abundant bacterial strain on day 3, followed by Gluconobacter. The Acetobacter constituted more than 50% of the total bacterial abundance on day 1, but it decreased with the fermentation process. Exploration of fermented pine needle microbial community structure will expand the knowledge about their microbiota to manipulate the microbial community and improve their quality and organoleptic properties using different microbial recipes.

Study on the relationship between the degradation degrees of enzymatically extruded glutinous rice and the qualities of fermented Chinese rice wine

To help to control the qualities of Chinese rice wine brewed by enzymatically extruded glutinous rice, the correlation between the degradation degrees of extrudates and the qualities of Chinese rice wine were fully studied. Dextrose equivalent (DE), extent of gelatinization (GE), water solubility/absorption index (WSI/WAI), degree of polymerization (DP) distribution and scanning electron microscopy (SEM) of glutinous rice extruded respectively with 0.5‰, 1.0‰, 1.5‰ and 2.0‰ thermostable α-amylase (TS-αA)/mesophilic α-amylase (MS-αA) were determined. Surprisingly, more TS-αA decreased DE value while more MS-αA increased DE value. Both α-amylases reduced WSI with more enzymes. Besides, more TS-αA promoted GE while more MS-αA decreased GE. The contents of DP1, DP3, DP5, DP6, DP7 and other DP fundamentally affected the qualities of Chinese rice wine. DP1 content was significantly negatively correlated with total sugar and amino acid nitrogen, and positively correlated with alcohol degree. The contents of DP3, DP5 and DP6 were significantly positively correlated with amino acid nitrogen, and negatively correlated with alcohol degree. The contents of DP7 and other DP had a very positive correlation with total sugar. It's expected to control the qualities of Chinese rice wine by adjusting the relevant DP's contents.

Effect of two-step fermentation with lactic acid bacteria and Saccharomyces cerevisiae on key chemical properties, molecular structure and flavor characteristics of horseradish sauce

To enhance the quality or, in other words, increase the variety of horseradish sauce, two-step fermentation using lactic acid bacteria (LAB) and Saccharomyces cerevisiae is proposed for the production of the sauce. Total phenolics, acids and amino acid nitrogen contents were determined and used to assess the fermentation efficiency, while antioxidant activities, profiles of amino acids and volatile flavor compounds was used to indicate the quality of the sauce. Molecular structure determination as well as electronic tongue and sensory analyses were also conducted. Adding S. cerevisiae after 48 h of LAB fermentation resulted in higher fermentation efficiency. The sauce was noted to be fermented more fully, with increased content of amino acids by 23.10% compared with unfermented samples; its DPPH radical scavenging ability and reducing power increased by 26.26% and 33.33%, respectively. The contents of alcohols, esters and acids increased in the sauce. The electronic tongue and sensory evaluation showed that the sauce had good sensory quality.

볶음쌀을 첨가한 메주 사용이 간장의 품질에 미치는 영향

This study examined the quality characteristics of ‘Ganjang’ prepared with ‘Meju’ containing roasted rice additives (0%, 10%, 30%, 50%) for improving the flavor of traditional ‘Ganjang’. The differences between the flavor-enhanced ‘Ganjang’ and their traditional counterparts were also analyzed. The total nitrogen and amino acid nitrogen contents of the ‘Ganjang’ prepared using ‘Meju’ containing roasted rice additives decreased with increasing amount of roasted rice additives. Reducing sugar content was the highest in ‘Ganjang’ in which 30% roasted rice was added to ‘Meju’ Analysis of the free amino acids in ‘Ganjang’ showed that contents of the amino acids with a bitter tastes during ‘Ganjang’ production decreased upon the addition of roasted rice; among the amino acids with a sweet taste, threonine content was high, and the glutamic acid content with a savory taste was similar. Additionally, E-nose and E-tongue analyses showed that there were differences between ‘Ganjang’ prepared using ‘Meju’ with roasted rice additives and the existing ‘Ganjang’. E-nose analysis suggested that such differences originated due to the fruity odors of ethyl acetate and tert-butyl acetate and the roasting odor of pyrazine in ‘Ganjang’ with roasted rice additives. E-tongue analysis exhibited high SWS sensor values, which responds to sweetness. Therefore, this study confirmed the use of roasted rice for taste improvement, which increased the sweet tastes and, fruity and roasting odors during the production of traditional ‘Ganjang’.

The Application of Capillary Electrophoresis on the Characterization of Protein in Royal Jelly

The objective of this study was to characterize the protein fractions in royal jelly made from Apis mellifera ligustica from middle and southern areas of Taiwan. The total nitrogen content of fresh royal jelly was 2.46%, and the total amino acid nitrogen was 2.34%, suggesting that the nitrogen compound in royal jelly was mostly derived from protein . The nitrogen content of free amino acid in royal jelly was 0.11%, and the amino type nitrogen was 0.20%, indicating that the protein in royal jelly existed mainly in the form of large moleculars. To characterize the protein, royal jelly was dissolved in 0.1 M phosphate buffer(pH 7.0), followed by centrifugation, ammonia sulfate precipitation and dialysis to separate the protein into water soluble and water insoluble fractions. Water soluble fraction accounts for more than 60 % of the total protein in royal jelly, and was further investigated by DEAE-Sephacel, SDS-PAGE and capillary electrophoresis. By DEAE-Sephacel, two fraction peaks (F1 and F2) were identified and collected. By SDS-PAGE, F1 fraction was further separated into two bands, and the molecular weight was determined to be 50 KDa and 44 KDa, whereas F2 fraction was shown to have only one band with molecular weight of 55 KDa. By capillary zone electrophoresis, four poorly-separated peaks were observed in F1 fraction, and two well-separated peaks in F2 fraction. By capillary gel electrophoresis, two peaks were identified in F1 fraction, of which the molecular weight was estimated to be 59 KDa and 73 KDa. By contrast, only one peak was identified in F2 fraction, of which the molecular weight was estimated to be 118 KDa. However, by capillary isoelectric focusing, 6 peaks were identified in F1 fraction with pI of 6.9, 6.7, 6.3, 5.9, 5.7 and 5.5, respectively. Of that, pI of 4.8 and 4.7 were identified in F2 fraction.

Preparation, Characterization and Application of Lubricating Protein Filler for Sustainable Leather Production

ABSTRACT In this study, collagen hydrolyzate was obtained from bovine shaving wastes of leather production with the alkali hydrolysis reaction. Total amino acid, total carbon and total nitrogen amounts of liquid collagen hydrolyzate (CH) were determined. Fourier-transform infrared spectroscopy (FTIR) characterization of collagen hydrolyzate was performed. Obtained CH was emulsified with hydrogenated castor and amino functional silicone oils to prepare lubricating protein filler (LPF). Particle size and zeta potential of the LPF were analyzed. 10%, 15%, and 20% LPF was used in the retanning/fatliquoring process of chromium tanned bovine leathers. Performance characterizations of leathers treated with LPFs were carried out with tensile strength, tear strength, filling efficiency, light fastness, shrinkage, and denaturation temperature analyses. Moreover, bounded fat content in leather was also determined. Results showed the increased thermal stability, strength performance and good filling effect in leather by application of the prepared LPF. Consequently, LPF had a good potential as natural retanning/fatliquoring agent via achieving reuse of the solid leather wastes and providing satisfactory leather properties and cleaner production by one product itself.

Recovery of Chitin and Protein from Shrimp Head Waste by Endogenous Enzyme Autolysis and Fermentation

The industrial processing of shrimp produces massive quantities of solid waste that is a notable source of animal protein, chitin, carotenoids, and other bioactive compounds that are not appropriately utilized. In the present study, chitin and protein extraction from shrimp head with autolysis and fermentation using Bacillus licheniformis were investigated. The results showed that when shrimp heads were autolyzed with a natural pH at 50°C for 4 h, the total amino acid nitrogen in the supernatant was 5.01 mg mL−1. Then, when a 50% (v/m) inoculum of the hydrolysate was incubated at 60°C for 10 h, a deproteinization rate of 88.3% could be obtained. The fermented supernatant was processed into a dry protein powder, while the residues were demineralized by 10% citric acid for chitin. The recovered protein powder contained 5.5% moisture, 11.5% ash, and 66.7% protein, while the chitin contained 3.5% moisture, 2.1% ash, and 3.1% protein. In addition, amino acids, minerals, heavy metals, the degree of acetylation, microstructure, and Fourier-transform infrared (FT-IR) spectroscopy results were analyzed. Furthermore, the statistics of the large scale trial after treatment with 20 kg of shrimp heads were analyzed. Thus, this work made the shrimp waste utilization environmentally sound and valuable.

Soil pH Buffering Capacity and Nitrogen Availability Following Compost Application in a Tropical Acid Soil

ABSTRACTTropical acid soils are highly weathered as they exist under tropical environment with high rainfall and temperature throughout the year, which affects nitrogen availability. Soil organic nitrogen is important in estimating soil nitrogen availability. The combined use of urea and compost in this study was carried out to decrease sole dependence on urea, buffer soil acidification, and reduce nitrogen losses through leaching. Thus, soil buffering capacity, incubation, and organic nitrogen fractionation studies were conducted to determine soil buffering capacity, availability of total nitrogen, organic fractions nitrogen, and inorganic nitrogen in soil after 90 days of incubation following compost. Soil pH, buffering capacity, total nitrogen, organic nitrogen fractions, exchangeable ammonium, and available nitrate were higher in all treatments with compost and combined use of urea and compost. Total hydrolyzable nitrogen, ammonium-nitrogen, (ammonium + amino sugar)-nitrogen, amino sugar-nitrogen, and amino acid-nitrogen were higher in soils with urea and compost suggesting that decomposition of soil organic fractions nitrogen into inorganic nitrogen (ammonium and available nitrate was affected by the addition of urea and compost. Urea can be amended with compost to regulate availability nitrogen in soil for crop use.

Gross chemical profile and calculation of nitrogen-to-protein conversion factors for nine species of fishes from coastal waters of Brazil

The amino acid composition and contents of nitrogen, phosphorus, lipid, carbohydrate and protein were determined in muscles of Dactylopterus volitans, Genypterus brasiliensis, Mullus argentinae, Paralichthys patagonicus, Percophis brasiliensis, Pinguipes brasilianus, Rhizoprionodon lalandii, Rhizoprionodon porosus, and Urophycis cirrata. The samples showed low carbohydrate content (<3.5% dry weight in all species) and were rich in protein (>66% dry weight in all species). The percentage of total lipid varied widely among species, and M. argentinae showed the highest concentrations (16%). The percentage of nitrogen and phosphorus was high and similar among species, with overall average values of 13.3% and 1.2%, respectively. The amino acids composition was similar among the animals, with glutamic acid and lisine as the most abundant amino acid and histidine in low concentrations. Among species, the content of proteinaceous nitrogen was high, with an average of 96.8% of the total nitrogen. From data of total amino acid and total nitrogen, specific nitrogen-to-protein conversion factors were calculated for each species. The nitrogen-toprotein conversion factors ranged from 5.39 to 5.98, with an overall average of 5.71. These findings showed that the traditional conversion factor of 6.25 overestimates the actual protein content and should be avoided.

Development of theRhodiola rosea FuquandRhodiola roseasoy sauce, and the determination of their functional properties

A mixed starter, composed of high-quality Rhodiola rosea Fuqu, was developed. Compared with normal Fuqu, Rhodiola rosea Fuqu demonstrated higher spore numbers, spore germination rates, protease activity, liquefying amylase activity and total acid and amino acid nitrogen. Specifically, the spore number was 1.36 times that of regular Fuqu. Protease activity, liquefying amylase activity, total acid and amino acid nitrogen were 0.475 g/100 mL, 104.16 U/g dry Qu, 35.67 mmol/L and 26.08 g/100 mL, respectively. These values were 21.48, 7.41, 6.07 and 67.82% higher than the regular Fuqu. The Rhodiola rosea soy sauce indices were also better than those for the control. The DPPH scavenging abilities of R. rosea soy sauce, control soy sauce, market soy sauce 1 and market soy sauce 2 were 74.25, 44.01, 34.73 and 11.38%, respectively. The total phenolic content in these four samples was 387.38, 309.23, 212.85 and 202.60 mg GAE/g, respectively. As observed with the DPPH and total phenolic assay, the R. rosea soy sauce showed the highest antioxidant capacity. A simple, rapid, and sensitive determination method of salidroside in R. rosea Fuqu and R. rosea soy sauce using HPLC-ESI-MS/MS was developed and validated with multiple reaction monitoring in the negative mode.

Effects of elevated CO2 on the extractable amino acids of leaf litter and fine roots

Elevated atmospheric CO2 concentrations can change chemistry and input rate of plant tissue to soil, potentially influencing above- and below-ground biogeochemical cycles. Given the important role played by leaf and root litter chemistry in controlling ecosystem function and vulnerability to environmental stresses, we investigated the hydrolyzable amino acid distribution and concentration in leaf and fine root litter among control and elevated CO2 treatments at the Rhinelander free air CO2 enrichment (FACE) experiment (WI, USA). We extracted hydrolyzable amino acids from leaf litter and fine (< 2 mm) roots at three depths for both control and elevated CO2 plots. We found that elevated CO2 decreased the proportion of total leaf amino acid carbon (C), but had no effect on total leaf amino acid nitrogen (N). There was no treatment effect for total root amino acid N or amino acid C for any depth. The decrease in leaf amino acids is probably a result of the shift of protein compounds to more structural compounds. Despite the decrease in leaf amino acid C concentrations, the overall increase in annual plant production under elevated CO2 would result in an increase in plant amino acids to the soil.

Effects of Dietary Glutamine on the Homeostasis of CD4+ T Cells in Mice with Dextran Sulfate Sodium-Induced Acute Colitis

This study investigated the effects of dietary glutamine (Gln) on T-helper (Th) and T regulatory (Treg) cell homeostasis and colonic inflammatory mediator expression in mice with dextran sulfate sodium (DSS)-induced colitis. Mice were randomly assigned to 4 groups with 2 normal control (C and G) and 2 DSS-treated groups (DC and DG). The C and DC groups were fed a common semipurified diet, while the G and DG groups received an identical diet except that part of the casein was replaced by Gln, which provided 25% of the total amino acid nitrogen. Mice were fed the diets for 10 days. On day 6, mice in the normal control groups were given distilled water, while those in the DSS groups were given distilled water containing 1.5% DSS for 5 d. At the end of the experiment, the mice were sacrificed for further examination. Results showed that DC group had higher plasma haptoglobin, colonic weight, immunoglobulin G, inflammatory cytokine and nuclear factor (NF)-κB protein levels. Gln administration lowered inflammatory mediators and NF-κB/IκBα ratio in colitis. Compared with the DC group, the percentages of interleukin-17F and interferon-γ in blood and transcription factors, T-bet and RAR-related orphan receptor-γt, gene expressions in mesenteric lymph nodes were lower, whereas blood Foxp3 was higher in the DG group. Also, DG group had lower colon injury score. These results suggest that Gln administration suppressed Th1/Th17 and Th-associated cytokine expressions and upregulated the expression of Tregs, which may modulate the balance of Th/Treg and reduce inflammatory reactions in DSS-induced colitis.

Glutamine modulates acute dextran sulphate sodium-induced changes in small-intestinal intraepithelial γδ-T-lymphocyte expression in mice

The present study investigated the effect of glutamine (Gln) on dextran sulphate sodium (DSS)-induced changes in the expression of small-intestinal intraepithelial lymphocyte (IEL) γδ-T cells in mice. Mice were randomly assigned to a normal control (NC) group and two DSS-treated groups. The NC group and one of the DSS-treated groups (DSS-C) were fed a common semi-purified diet, while the other DSS-treated group (DSS-G) was fed an identical diet, except that part of casein was replaced by Gln, which provided 25% of total amino acid nitrogen. After being fed the diets for 10d, mice in the NC group were given distilled water, while the DSS-treated groups were given distilled water containing 2·5% DSS for 5d. At the end of the experiment, the mice were killed. The small-intestinal IEL γδ-T-cell subset was isolated for further analysis. The results indicated that DSS treatment resulted in a lower percentage of small-intestinal IEL γδ-T cells and higher mRNA expressions of interferon-γ, TNF-α, IL-17, complement 5a receptor and keratinocyte growth factor in IEL γδ-T cells. Gln administration increased the proportion of small-intestinal IEL γδ-T cells, and the expression levels of immunomodulatory mediator genes in IEL γδ-T cells were lower in the DSS-treated mice. The histological findings indicated that the immunoreactive intensity of the tight junction protein ZO-1 in the small-intestinal mucosa was higher in the DSS-G group than in the DSS-C group. These results indicate that pretreatment with Gln increases the proportion of small-intestinal IEL γδ-T cells and down-regulates γδ-T-cell-expressed inflammatory mediators, which may consequently ameliorate the severity of DSS-induced small-intestinal epithelial injury.

Soybean meal substitution with a yeast-derived microbial protein source in dairy cow diets

The objective of this study was to examine the effects substituting soybean meal with a yeast-derived microbial protein (YMP) on rumen and blood metabolites, dry matter intake, and milk production of high-producing dairy cows. Sixteen Holstein cows (12multiparous and 4 primiparous), 93±37 DIM (mean ± SD) at the beginning of the experiment, were used in a 4×4 Latin square design with four 28-d periods. Cows were blocked by parity and production, with 1 square consisting of 4 animals fitted with rumen cannulas. Basal diets, formulated for 16.1% crude protein and 1.56Mcal/kg of net energy for lactation, contained 40% corn silage, 20% alfalfa hay, and 40% concentrate mix. During each period, cows were fed 1 of 4 treatment diets corresponding to YMP (DEMP; Alltech Inc., Nicholasville, KY) concentrations of 0, 1.14, 2.28, and 3.41% DM. Soybean meal (44% CP) was replaced by YMP to attain isonitrogenous and isoenergetic diets. Dietary treatments had no effect on pH and on most ruminal volatile fatty acid concentrations, with the exception of isovalerate, which decreased linearly with the addition of YMP. Rumen ammonia concentration decreased linearly, whereas free amino acids, total amino acid nitrogen, and soluble proteins weighing more than 10kDa showed a cubic response on rumen N fractionation. A quadratic response was observed in oligopeptides that weighed between 3 and 10kDa and peptides under 3kDa when expressed as percentages of total amino acids and total nitrogen. Although nonesterified fatty acid concentration in blood did not differ between treatments, β-hydroxybutyrate and plasma glucose increased linearly as YMP increased. Dry matter intake showed a cubic effect, where cows fed 1.14, and 3.41% YMP had the highest intake. Milk production was not affected by YMP, whereas a trend was observed for a quadratic increase for 4% fat-corrected milk and energy-corrected milk. Medium- and long-chain fatty acid concentrations in milk increased quadratically, which elicited similar effects on milk fat concentration and yield. Total solids percentage and yield, and milk urea nitrogen also showed quadratic effects as YMP increased in the diet. No effects were observed on feed efficiency, milk protein, and lactose percentage or yield. A complementary in vitro study demonstrated a quadratic tendency for apparent and true dry matter digestibility as YMP was added to the diet. It was concluded that the substitution of soybean meal with YMP increased the percentage of total solids in milk and tended to improve energy-corrected and fat-corrected milk production in high-producing dairy cows consuming high-forage diets.

Effects of dietary glutamine on inflammatory mediator gene expressions in rats with streptozotocin-induced diabetes

ObjectivesThis study investigated the effects of glutamine (Gln) supplementation on gene expressions of inflammatory mediators and cytokines associated with T-helper cell type 17 (Th17) regulation in diabetic rats. MethodsThere were one normal control group and two diabetic groups in this study. Rats in the normal control group were fed a regular chow diet. One diabetic group (DM) was fed a common semipurified diet, and the other diabetic group received a diet in which part of the casein was replaced by Gln (DM-Gln), which provided 25% of the total amino acid nitrogen for 8 wk. Diabetes was induced by an intraperitoneal injection of nicotinamide followed by streptozotocin. Rats with blood glucose levels exceeding 200 mg/dL were considered diabetic. Blood samples and blood mononuclear cells of the animals were collected at the end of the study for further analysis. ResultsGene expressions of transforming growth factor-β1 and interleukin-17A did not differ in blood mononuclear cells among the three groups. Expressions of interleukin-6, interleukin-23, monocyte chemotactic protein-1, and the receptor of the advanced glycated endproducts gene were higher in blood mononuclear cells and the ratio of reduced to oxidized glutathione was lower in erythrocytes in the DM group than in the normal control group. Messenger RNA expressions of these genes were lower, whereas the ratio of reduced to oxidized glutathione was higher in the DM-Gln group than in the DM group. ConclusionSupplemental dietary Gln increased the antioxidant potential and downregulated the expressions of inflammatory mediators. However, Th17 might not be an important involved pathway and the regulatory effect of Gln on Th17 immune response was not obvious in this animal model.