Oxidant/Antioxidant Status of Breast Cancer Patients in Pre- and Post-Operative Periods.

BACKGROUND AND OBJECTIVES: The purpose of this study is to evaluate the level of oxidative stress before and after breast cancer surgery. MATERIALS AND METHODS: Malondialdehyde (MDA) level was tested using a thiobarbituric acid (TBA) assay based on the release of a color complex due to TBA reaction with MDA. The glutathione S-transferase (GST) activity was evaluated by enzymatic conjugation of reduced glutathione (GSH) with 1-chloro-2,4-dinitrobenzene. The level of total glutathione (reduced GSH and oxidized GSSG) was detected using a recycling system by 5,5-dithiobis(2-nitrobenzoic acid). The levels of the indices were determined in the serum of 52 patients before surgery, two hours and five days after surgery, and in 42 healthy women. RESULTS: In the patients over 50 years old the level of MDA was higher after surgery in comparison with before surgery, and GST activity was lower in comparison with the control. The GSH + GSSG level in both ages groups after surgery was lower than in the control. Significant differences of MDA level were detected in patients with stage III after surgery compared to the control. The level of GSH + GSSG was significantly lower in the patients with I-III stages compared to the control. CONCLUSION: The most expressed changes demonstrate the significance of MDA as a marker to evaluate oxidative stress in breast cancer patients. The degree of oxidative stress depends on the patient's age and stage of disease.

Effect of cold plasma on maintaining the quality of chub mackerel (Scomber japonicus): biochemical and sensory attributes.

BACKGROUND: Atmospheric cold plasma (ACP) has emerged as a potential alternative to traditional methods for non-thermal food decontamination. However, few data are available about ACP treatment for seafood. In this study, dielectric barrier discharge (DBD) was applied to generate CP, and the aim of the study was to investigate the effectiveness of DBD-ACP on improving the quality of chub mackerel on the basis of chemical, microbial and sensory characteristics. RESULTS: The effect of DBD-ACP on the quality of chub mackerel (Scomber japonicus) during storage was examined. Results revealed that the optimal voltage level and exposure time of this treatment were 60 kV and 60 s respectively, and such conditions exhibited excellent inactivation efficacy and weak influence on proximate chemical compositions. Variations in total viable count (TVC), sensory scores and total volatile basic nitrogen (TVB-N) indicated that ACP treatment extended the shelf life of chub mackerel to 14 days, whereas samples without this treatment exceeded the limits of the three parameters after 6 days. The slow development rates of peroxide value (PV) and thiobarbituric acid (TBA) value implied that lipid oxidation was also effectively retarded by ACP exposure. Scanning electron microscopy confirmed that CP could effectively delay the degradation of myofibrillar proteins and enhance the stability of tissue structures. CONCLUSION: The excellent antimicrobial efficacy of ACP treatment makes it a potential and promising alternative to other seafood preservation technology. This is the first report on the application of ACP to seafood, which is essential to perishable food storage. © 2018 Society of Chemical Industry.

Avocado Seed: A Comparative Study of Antioxidant Content and Capacity in Protecting Oil Models from Oxidation.

Increasingly, consumers want products containing little or no synthetic compounds. Avocado seeds, which are a residue of the food industry, could be used to obtain extracts with high antioxidant power. In the present study, the most popular radical scavenging methods are presented, establishing a comparison between them, besides working with two different extractions: pure methanol and ethanol⁻water (50:50 v/v). The radical scavenging assay methods ORAC and ABTS were performed, as well as a novel method: the reaction to methoxy radical, as determined by electron paramagnetic resonance (EPR). Peroxide value and thiobarbituric acid reactive compounds (TBARs) were used to monitor the oxidation of avocado seed oil, as well as the power of the avocado seed extract (ASE) to delay oil oxidation by oxidation induction time (OIT) and measured by differential scanning calorimetry (DSC). Radical scavenging methods have values between 1310⁻263 µmol TE/g of mass dissolved for ORAC and ABTS, respectively. The individual contribution of each of the compounds present in the extract was analyzed. The sum of all of them contributed up to 84% of the total radical scavenging activity. The concentration of 0.75% ASE causes a delay in the oxidation that is close to 80%, as measured by OIT. This implies that avocado seed residue may have a use as a natural antioxidant source, providing added value to organic waste.

Shelf-life extension of Pacific white shrimp using algae extracts during refrigerated storage.

BACKGROUND: Shrimp is a low-fat, high-protein aquatic product, and is susceptible to spoilage during storage. To establish an effective method for the quality control of Pacific white shrimp, the effects of polyphenols (PP) and polysaccharides (PS) from Porphyra yezoensis on the quality of Pacific white shrimp were assessed during refrigerated storage. Pacific white shrimp samples were treated with 5 g L-1 polyphenols, and 8 g L-1 polysaccharides, then stored at 4 ± 1 °C for 8 days. All samples were subjected to measurement of total viable count (TVC), pH, total volatile basic nitrogen (TVB-N), K-value, thiobarbituric acid (TBA), polyphenol oxidase (PPO) activity, and were also assessed by sensory evaluation. RESULTS: The results showed that PP, PS, and the mixture of polyphenols and polysaccharides (PP+PS) could inhibit the increase of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and K-value, and reduce total viable count (TVC) compared with the control group. PP could also inhibit polyphenol oxidase (PPO) activity. Sensory evaluation proved the efficacy of PP and PS by maintaining the overall quality of Pacific white shrimp during refrigerated storage. Moreover, PP+PS could extend the shelf-life of shrimp by 3-4 days compared with the control group. CONCLUSION: PP+PS could more effectively maintain quality and extend shelf-life during refrigerated storage. © 2016 Society of Chemical Industry.

Preparation of a porcine plasma protein composite film and its application.

To use blood released from slaughtering houses, a porcine plasma protein (PPP)/nanoclay composite film was prepared. The tensile strength and elongation at break values of the PPP composite film with 5% nanoclay were 10.01 MPa and 6.55%, respectively. The PPP composite film containing 1% grapefruit seed extract (GSE) was applied to pork meat, and the populations of inoculated Escherichia coli O157:H7 and Listeria monocytogenes in the pork meat packaged with the PPP composite film decreased by 0.8 and 1.0 log CFU/g, respectively, after 7 days of storage compared to the populations of the control. In addition, thiobarbituric acid values in the pork meat packaged with the PPP composite film were less than those of the control sample during storage. These results suggest that the PPP nanocomposite film containing 1% GSE can be used as a packaging material to maintain the quality of pork meat.

Antioxidant and anti hyperglycemic role of wine grape powder in rats fed with a high fructose diet.

BACKGROUND: Metabolic syndrome is a growing worldwide health problem. We evaluated the effects of wine grape powder (WGP), rich in antioxidants and fiber, in a rat model of metabolic syndrome induced by a high fructose diet. We tested whether WGP supplementation may prevent glucose intolerance and decrease oxidative stress in rats fed with a high fructose diet. METHODS: Male Sprague-Dawley rats weighing 180 g were divided into four groups according to their feeding protocols. Rats were fed with control diet (C), control plus 20 % WGP (C + WGP), 50 % high fructose (HF) or 50 % fructose plus 20 % WGP (HF + WGP) for 16 weeks. Blood glucose, insulin and triglycerides, weight, and arterial blood pressure were measured. Homeostasis model assessment (HOMA) index was calculated using insulin and glucose values. A glucose tolerance test was performed 2 days before the end of the experiment. As an index of oxidative stress, thiobarbituric acid reactive substances (TBARS) level was measured in plasma and kidney, and superoxide dismutase was measured in the kidney. RESULTS: Thiobarbituric acid reactive substances in plasma and renal tissue were significantly higher when compared to the control group. In addition, the area under the curve of the glucose tolerance test was higher in HF fed animals. Furthermore, fasting blood glucose, plasma insulin levels, and the HOMA index, were also increased. WGP supplementation prevented these alterations in rats fed with the HF diet. We did not find any significant difference in body weight or systolic blood pressure in any of the groups. CONCLUSIONS: Our results show that WGP supplementation prevented hyperglycemia, insulin resistance and reduced oxidative stress in rats fed with HF diet. We propose that WGP may be used as a supplement in human food as well.

Role of berberine in ameliorating Schistosoma mansoni-induced hepatic injury in mice.

BACKGROUND: Schistosomiasis is caused by helminth parasites of the genus Schistosoma. Berberine chloride (BER), an isoquinoline alkaloid, has been used in vivo for its antiparasitic, antioxidant and hepatoprotective properties. In this study, the protective effect of BER and praziquantel has been compared for the extent of schistosomiasis-induced oxidative stress in hepatic tissue of mice. RESULTS: S. mansoni was able to induce inflammation and injury to the liver, evidenced (i) by an increase in inflammatory cellular infiltrations, dilated sinusoids and vacuolated hepatocytes, (ii) by decreased levels of alanine and aspartate aminotransferases and increased levels of alkaline phosphatase, γ-glutamyl transferase in the liver homogenate, (iii) by increased production of nitric oxide and thiobarbituric acid reactive substances, and (iv) by lowered glutathione levels and decreased activities of catalase and superoxide dismutase, respectively. All these infection-induced parameters were significantly altered during BER treatment. In particular, berberine counteracted the S. mansoni-induced loss of glutathione and the activities of catalase and superoxide dismutase. CONCLUSION: Based on these results, it is concluded that berberine could ameliorate pre-existing liver damage and oxidative stress conditions due to schistosomiasis.

Lipid peroxides and glutathione status in human progenitor mononuclear (U937) cells following exposure to low doses of nickel and copper.

Effects of Cu(2+), Ni(2+) or Cu(2+) + Ni(2+) on lipid peroxide and glutathione (GSH) levels in U937 cells were investigated. Cells were treated with 0, 5, 10, and 20 µM of Cu(2+) and/or Ni(2+) and H(2)O(2) (0.01 mM) and incubated for 24 hours at 37°C. Lipid peroxides were measured by the thiobarbituric acid assay (TBA). GSH intracellular levels were assayed by the GSH assay kit from EMD/Calbiochem (San Diego, California, USA). Cu(2+) or Ni(2+) significantly (P < 0.01) increased lipid peroxides in a dose-dependent manner, compared to controls. The effect was more pronounced for Cu(2+), compared to the Ni(2+)-treated samples. Cu(2+) + Ni(2+) increased lipid peroxides in a significant (P < 0.001), dose-dependent manner, compared to Cu(2+) or Ni(2+) alone (i.e., ratio of 2.5:1-fold for combined versus single treatments, respectively). Cu(2+) or Ni(2+) significantly decreased GSH levels in U937 cells, with the effect being pronounced for Cu(2+). Cu(2+) + Ni(2+) metal ions significantly (P < 0.001) depleted cells of GSH in a dose-dependent manner. Ethylene diamine tetraacetic acid (EDTA) at 50 or 100 µM moderately reduced the Cu(2+)- or Ni(2+)-induced effects on GSH levels. Interestingly, GSH levels generally decreased to half (except for the combined metal dose of 20 µM at 100 µM EDTA) of its level at the highest metal concentration tested for both the single or combined treatments. In conclusion, multiple exposures of cells to metal ions may be lethal to cells, compared to their single treatments.

Downregulation of the renal and hepatic hydrogen sulfide (H2S)-producing enzymes and capacity in chronic kidney disease.

BACKGROUND: Oxidative stress and inflammation are constant features and major mediators of progression and cardiovascular complications of chronic kidney disease (CKD). Hydrogen sulfide (H(2)S) is an endogenous signaling gas, which possesses potent anti-oxidant, anti-inflammatory, anti-hypertensive and other regulatory functions. H(2)S is produced by cystathionine ß-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulphurtransferase (MST). Plasma H(2)S is reduced in humans with hypertension, atherosclerosis and end-stage renal disease (ESRD). Atherosclerosis, hypertension and ischemia/reperfusion-induced acute kidney injury are associated with and, in part, mediated by diminished tissue H(2)S in experimental animals. Expression of the H(2)S-producing enzymes is reduced in the circulating leukocytes of patients with ESRD. However, the effect of CKD on expression of H(2)S-producing enzymes in the diseased kidney and other tissues is unknown and was studied here. METHODS: Subgroups of rats were subjected to 5/6 nephrectomy or sham operation and observed for 6-12 weeks. Expression of H(2)S-producing enzymes and H(2)S-producing capacity was measured in kidney, liver and brain tissues. RESULTS: The CKD group exhibited oxidative stress and significant reduction of plasma H(2)S concentration. This was associated with marked reduction of H(2)S-producing capacity of the kidney and liver, marked downregulation of CBS, CSE and MST in the kidney and of CBS and CSE expression in the liver. However, expression of H(2)S-producing enzymes in the brain was not significantly altered in CKD rats. CONCLUSIONS: CKD is associated with significant reduction in plasma H(2)S concentration, diminished remnant kidney and liver tissue H(2)S-producing capacity and downregulation of the H(2)S-producing enzymes. Given the potent anti-oxidant, anti-inflammatory and cytoprotective properties of H(2)S, its deficiency may contribute to progression of CKD and the associated complications.

Functional and ultrastructural changes in Pseudomonas aeruginosa and Staphylococcus aureus cells induced by Cinnamomum verum essential oil.

AIMS: To study cellular damage induced by Cinnamomum verum essential oil in Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213. METHODS AND RESULTS: The effect of cinnamon bark essential oil on these two strains was evaluated by plate counts, potassium leakage, flow cytometry and transmission electron microscopy (TEM). Exposure to this oil induced alterations in the bacterial membrane of Ps. aeruginosa, which led to the collapse of membrane potential, as demonstrated by bis-oxonol staining, and loss of membrane-selective permeability, as indicated by efflux of K(+) and propidium iodide accumulation. Thus, respiratory activity was inhibited, leading to cell death. In Staph. aureus, cells treated with the oil entered a viable but noncultivable (VNC) state. The oil initially caused a considerable decrease in the metabolic activity and in the replication capacity of these bacterial cells. The loss of membrane integrity appeared later, as indicated by bis-oxonol and Propidium iodide (PI) staining. Data provided by TEM showed various structural effects in response to cinnamon essential oil. In Ps. aeruginosa cells, coagulated cytoplasmic material was observed, and intracellular material was seen in the surrounding environment, while oil-treated Staph. aureus showed fibres extending from the cell surface. CONCLUSIONS: Cinnamon essential oil damages the cellular membrane of Ps. aeruginosa, which leads to cell death. There is evidence of VNC Staph. aureus after exposure to the oil. SIGNIFICANCE AND IMPACT OF THE STUDY: Cinnamon essential oil shows effective antimicrobial activity and health benefits and is therefore considered a potential food additive. To use this oil as a natural food preservative, especially in combination with other preservation methods, a thorough understanding of the mechanism through which this oil exerts its antibacterial action is required.

Dietary inclusion level effects of distillers dried grains with solubles on broiler meat quality.

A completely randomized design with 7 replications (n = 7, treatments = 5 with 8 subsamples per treatment) was used to evaluate the effects of feeding various levels of distillers dried grains with solubles (DDGS; 0, 6, 12, 18, and 24%) on broiler breast and thigh meat quality. Broilers were harvested in a pilot scale processing plant with commercial prototype equipment at 42 d of age. The right half of each breast was evaluated for pH, instrumental color, cooking loss, proximate analysis, and tenderness. The left half of each breast was used for consumer acceptability testing. Thigh meat was evaluated for proximate composition, fatty acid composition, and TBA reactive substances. Breast meat from broilers that were fed DDGS had a higher (P < 0.05) pH than those from the control diet. In addition, the 18 and 24% DDGS treatments yielded breast meat with higher (P < 0.05) pH values than the 6% DDGS treatment. No differences existed (P > 0.05) among breast meat from the different treatments with respect to cooking loss, instrumental color, and consumer acceptability, but breast meat from the control (0% DDGS) treatment had slightly lower (P < 0.05) shear force than breast meat from the 18 and 24% DDGS treatments. In addition, no differences (P > 0.05) existed among proximate composition of breast and thigh meat from the control and DDGS treatments. As DDGS concentration increased, there was a linear increase (P < 0.05) in linoleic and polyunsaturated fatty acids, which indicates a greater potential for lipid oxidation. The TBA reactive substances values were greater (P < 0.05) for the 18 and 24% DDGS treatments at d 5 when compared with the control and 6% DDGS treatments, which indicates increased oxidation. Overall, data suggest that all treatments yielded high-quality breast meat and that thigh meat quality was similar among treatments containing 0 to 12% DDGS, but higher inclusion levels led to thigh meat that was more susceptible to oxidation.

Camel cocktail sausage and its physicochemical and sensory quality.

The objective of this study was to compare the nutritional values of camel semitendinosus muscles with those of calves. Then, sausages were made from camel meat, beef and equal proportions of each and stored at 4 degrees C for 45 days. The composition, physicochemical characteristics, sensory properties, and microstructure of the samples were evaluated. The proximate composition of meat from the two species was significantly different. Beef contained a significantly higher amount of vitamin E, whereas camel meat had better profile of fatty acid and higher iron content. Camel meat had a higher pH but similar myofibrillar protein content as beef. Sausages made from 100% camel meat also had higher pH and cooking yield along with higher a* (redness) and lower L* (lightness) than the others. 2-Thiobarbitoric acid values among these treatments were significantly different. Samples containing 50% of each meat had a higher resistance to shear force; however, panelists could not detect any significant difference in tenderness of the samples.

Antioxidant effect of diphenyl diselenide on oxidative stress caused by acute physical exercise in skeletal muscle and lungs of mice.

This study was designed to examine if diphenyl diselenide (PhSe)(2), an organoselenium compound, attenuates oxidative stress caused by acute physical exercise in skeletal muscle and lungs of mice. Swiss mice were pre-treated with (PhSe)(2) (5 mg kg(-1) day(-1)) for 7 days. At the 7th day, the animals were submitted to acute physical exercise which consisted of continuous swimming for 20 min. The animals were euthanized 1 and 24 h after the exercise test. The levels of thiobarbituric acid reactive species (TBARS), non-protein thiols (NPSH) and ascorbic acid and the activity of catalase (CAT) were measured in the lungs and skeletal muscle of mice. Glycogen content was determined in the skeletal muscle of mice. Parameters in plasma (urea and creatinine) were determined. The results demonstrated an increase in TBARS levels induced by acute physical exercise in the skeletal muscle and lungs of mice. Animals submitted to exercise showed an increase in non-enzymatic antioxidant defenses (NPSH and ascorbic acid) in the skeletal muscle. In lungs of mice, activity of CAT was increased. (PhSe)(2) protected against the increase in TBARS levels and ameliorated antioxidant defenses in the skeletal muscle and lungs of mice submitted to physical exercise. These results indicate that acute physical exercise caused a tissue-specific oxidative stress in the skeletal muscle and lungs of mice. (PhSe)(2) protected against oxidative damage induced by acute physical exercise in mice.

Investigation of lipid-derived formation of decadien-1-amine, 2-pentylpyridine, and acrylamide in potato chips fried in repeatedly used sunflower oil.

This study aimed to investigate lipid derived formations of decadien-1-amine, 2-pentylpyridine, and acrylamide in potato chips during frying. 2,4-Decadienal, a lipid derived carbonyl, was monitored in repeatedly used sunflower oil at different thermoxidation levels (0, 6, 12, 18, 24 h at 180 °C), and in potato chips prepared in. Formations of decadien-1-amine and 2-pentylpyridine were shown for the first time in potato chips. Frying oil had the highest concentration of 2,4-decadienal after thermal oxidation at 180 °C for 6 h. Expectedly, potato chips fried in this oil contained the highest concentration of 2,4-decadienal (29 mg/kg). There was a positive correlation (r2 = 0.73) between the concentrations of 2,4-decadienal and decadien-1-amine (relative concentration as peak area) formed in potato chips fried in repeatedly used sunflower oil. No 2-pentylpyridine was detected in potato chips fried in unoxidized oil, whereas its concentration ranged between 91 and 154 µg/kg in potato chips fried in oxidized oil. Acrylamide concentration of potato chips ranged between 525 µg/kg (fried in oxidized oil, 12 h) and 722 µg/kg (fried in unoxidized oil). A negative correlation (r2 = 0.70) was observed between the concentrations of 2,4-decadienal and acrylamide in potato chips. The results suggest that reactions of lipid derived carbonyls should be taken into account to understand better the modifcations of amino acids in fried products.

Preservative effects of fish gelatin coating enriched with CUR/ßCD emulsion on grass carp (Ctenopharyngodon idellus) fillets during storage at 4 °C.

This study investigated the effects of a novel edible coating combining fish gelatin with curcumin/ß-cyclodextrin (CUR/ßCD) emulsion on the quality of grass carp fillets (GCFs) during storage at 4 °C. For all samples, the quality parameters, including weight loss, pH, total volatile basic nitrogen (TVB-N), peroxide value (PV), thiobarbituric acid (TBA) value, SDS-PAGE, free amino acids (FAA), microbiological (total viable counts (TVC), Pseudomonas counts, yeasts and molds, and H2S-producing bacteria), color and sensorial characteristics, were tested periodically. The coatings containing CUR/ßCD emulsions exhibited better preservative effects than gelatin/ßCD coating. Therefore, fish gelatin coating enriched with CUR/ßCD emulsion can be used as an effective way to maintain the quality of GCF and extend its shelf life during storage at 4 °C.

The effect of high pressure-low temperature treatment on physicochemical properties in milk.

This study was carried out to investigate the effect of high pressure-low temperature (HPLT) treatment on physicochemical properties and nutrients in milk. The milk was treated at 200 MPa and -4 degrees C for 10, 20, and 30 min. Protease and lipase activities of HPLT-treated milk were highly inactivated compared with that of raw milk. Among time treatments, the 30-min treatment showed the lowest activities compared with others. Absorbance of thiobarbituric acid increased with time in HLPT-treated milks; however, no difference was observed between the raw milk and milk treated for 10 min. The concentrations of short-chain fatty acids except C(4) in HPLT-treated milks increased with time. The total free amino acids in HPLT-treated milks were greater than that of the raw milk for the 30-min treatment. L-Ascorbic acid, niacin, and riboflavin in HPLT-treated milks were significantly lower compared with concentrations in raw milk. For color, the L-value of HPLT-treated milks was significantly lower than that of the raw milk; however, there was no difference in the a-value for 10 min and in the b-value at 20 min between the raw milk and the HPLT-treated milks.

Developing a machine vision system for simultaneous prediction of freshness indicators based on tilapia (Oreochromis niloticus) pupil and gill color during storage at 4°C.

The study assessed the feasibility of developing a machine vision system based on pupil and gill color changes in tilapia for simultaneous prediction of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and total viable counts (TVC) during storage at 4°C. The pupils and gills were chosen and color space conversion among RGB, HSI and L∗a∗b∗ color spaces was performed automatically by an image processing algorithm. Multiple regression models were established by correlating pupil and gill color parameters with TVB-N, TVC and TBA (R2=0.989-0.999). However, assessment of freshness based on gill color is destructive and time-consuming because gill cover must be removed before images are captured. Finally, visualization maps of spoilage based on pupil color were achieved using image algorithms. The results show that assessment of tilapia pupil color parameters using machine vision can be used as a low-cost, on-line method for predicting freshness during 4°C storage.

Survey on the effects of electron beam irradiation on chemical quality and sensory properties on quail meat.

INTRODUCTION: Irradiation is one of the intervention strategies for effective control of food-borne pathogen microorganisms, which reduces microbial load and extends the meat shelf life. MATERIALS AND METHODS: This experimental study was carried out on quail meat. Quail meat samples were treated with electron beam irradiation at doses of 0.5, 1, and 3 kGy and stored at 4 ±â€¯1 °C for 15 days. Five days after irradiation, the chemical and organoleptic changes in the quail meat were evaluated for 15 days. Total volatile basic nitrogen and TBA were also measured to investigate chemical changes. RESULTS: Irradiation significantly reduced the amount of total volatile basic nitrogen in irradiated samples. Furthermore, the increase of TBA level was significant in irradiated samples, which had a direct correlation with irradiation dose and storage/shelf life duration. Despite the increase of thiobarbituric acid, irradiation had no significant effect on the sensory properties of quail meat. CONCLUSION: Irradiation of quilt meat resulted in extension of the meat shelf life to at least two weeks at refrigeration temperature by decreasing the corrosion-causing microorganisms and improving microbial quality, while the sensory properties of meat were preserved. Regarding the increase in the oxidation level at high doses of the electron beam and the absence of significant differences in the studied dosages in reducing the total amount of total volatile basic nitrogen, it is recommended to apply electron beam irradiation at doses of 1.5 and 3 kGy to extend the meat shelf life and preserve the quality/health of the quail meat.

pH-Insensitive FRET voltage dyes.

Many high-throughput ion channel assays require the use of voltage-sensitive dyes to detect channel activity in the presence of test compounds. Dye systems employing Förster resonance energy transfer (FRET) between 2 membrane-bound dyes are advantageous in combining high sensitivity, relatively fast response, and ratiometric output. The most widely used FRET voltage dye system employs a coumarin fluorescence donor whose excitation spectrum is pH dependent. The authors have validated a new class of voltage-sensitive FRET donors based on a pyrene moiety. These dyes are significantly brighter than CC2-DMPE and are not pH sensitive in the physiological range. With the new dye system, the authors demonstrate a new high-throughput assay for the acid-sensing ion channel (ASIC) family. They also introduce a novel method for absolute calibration of voltage-sensitive dyes, simultaneously determining the resting membrane potential of a cell.

The shelf life extension of refrigerated grass carp (Ctenopharyngodon idellus) fillets by chitosan coating combined with glycerol monolaurate.

A novel chitosan-based coating solution was prepared by combining glycerol monolaurate (GML) for shelf life extension of refrigerated grass carp fillets. The control and coated fillets were analyzed periodically for physicochemical (pH, thiobarbituric acid (TBA) value, total volatile basic nitrogen (TVB-N) value, K value, and shear force), microbiological (total viable counts (TVC), psychrophilic bacteria counts (PTC), Pseudomonads and H2S-producing bacteria) and sensorial characteristics. The results showed that chitosan-GML coated samples presented better quality preservation effects than chitosan coating alone. In addition, 2% chitosan enriched with 0.3% GML showed the significant (P<0.05) effectiveness in inhibiting microbial growth, nucleotide breakdown, the formation of alkaline components and texture deterioration, and maintaining sensory acceptability among the groups. These findings confirmed that chitosan coating enriched with GML was a promising method to extend the shelf life of refrigerated fillets.