Proteolytic Activity of Silkworm Thorn (Cudrania tricuspidata) Fruit for Enzymatic Hydrolysis of Food Proteins.

This study aimed to isolate the proteolytic fraction from the silkworm thorn fruit (Cudrania tricuspidata) through ethanol precipitation at different ratios, and to determine its proteolytic activity and optimal activity conditions. Furthermore, the hydrolysis characteristics and antioxidant activity of soy protein isolate (SPI) and whey protein concentrate (WPC) hydrolyzates obtained through the enzymatic hydrolysis of freeze-dried silkworm thorn fruit powder (SF) were evaluated. For isolation and partial purification of proteolytic fraction, the water-solubilized fraction of the silkworm thorn fruit was purified through ethanol precipitation at four different ratios of 1:1, 1:2, 1:4, and 1:6 (v/v). The protein recovery rate, caseinolytic activity, protein pattern, and optimal activity (pH, temperature, and inhibitors) of fractional ethanol precipitate obtained from the silkworm thorn fruit (ESF) were evaluated. The proteolytic fraction obtained from silkworm thorn fruit exhibited a major protein band around 65-70 kDa and showed the highest proteolytic activity at a 1:4 ratio of ethanol precipitation (p < 0.05). The optimal activity of the measured enzyme fraction was determined to be at pH 9.0 and 50 °C, and the proteolytic activity of ESF was almost inhibited by phenyl methyl sulphonyl fluoride (PMSF, 2 mM), a serine protease inhibitor. Compared to Alcalase and papain, extensively used as commercial enzymes, the silkworm thorn fruit powder was less effective in hydrolyzing SPI and WPC. Nevertheless, SPI and WPC hydrolyzates mediated with silkworm thorn fruit powder showed even better antioxidant activities than those mediated with Alcalase and papain. Thus, our results show the potential application of silkworm thorn fruit as a novel source of plant protease for producing human-grade protein hydrolyzates.

A Comparative Study on the Carcass and Meat Chemical Composition, and Lipid-Metabolism-Related Gene Expression in Korean Hanwoo and Brindle Chikso Cattle.

The objective of this study was to elucidate the effect of cattle breed on carcass and meat chemical composition, fatty acid profiles, and lipid-metabolism-related genes. For this study, same-age Hanwoo and Chikso steers (n = 6 per breed) reared under identical conditions were used. Immediately after slaughter, muscle tissues were collected for analysis of mRNA expression. At 24 h post-mortem, the carcasses were assessed for carcass traits (marbling score, meat yield, etc.), and meat quality and fatty acid profiles in the longissimus lumborum (LL) and semimembranosus (SM) muscles. The results showed that no differences in the slaughter weight, dressing rate, back-fat thickness, trimmed fat, and total meat yield occurred between the two breeds (p > 0.05). However, Hanwoo cattle had a higher marbling score, intramuscular fat (IMF) content, and expression level of lipid-metabolism-related genes such as lipoprotein lipase, peroxisome proliferator-activated receptor gamma, and fatty acid binding protein 4, compared with Chikso (p < 0.05). Contrastingly, Chikso had a higher total unsaturated fatty acid content and expression level of stearoyl CoA desaturase 1 (p < 0.05). It may be said that the difference in the expression levels of lipid-metabolism-related genes could be the molecular factors underlying IMF deposition and fatty acid profile differences in the beef from the two breeds.

Hepatic arterial infusion in combination with systemic chemotherapy in patients with hepatic metastasis from colorectal cancer: a randomized phase II study - (NCT05103020) - study protocol.

BACKGROUND: Although 80% of patients with metastatic colorectal cancer (CRC) experience liver metastases, only 10-25% undergo resection at the time of diagnosis. Even in initially unresectable conditions, if appropriate treatment is provided, such as surgical conversion through a combination of hepatic arterial infusion (HAI) chemotherapy and systemic chemotherapy (sys-CT), better overall survival can be expected. Therefore, this study aims to evaluate the efficacy of HAI oxaliplatin in combination with sys-CT plus targeted therapy in patients with unresectable CRC with liver-only metastasis. METHODS: This is a single-center, randomized, open-label phase II trial (NCT05103020). Patients with untreated CRC, who have liver-only metastases and for whom liver resection is potentially possible but deemed infeasible at the time of initial diagnosis by a multidisciplinary team, will be eligible. Patients will be randomly assigned in a 1:1 ratio to either the combined HAI oxaliplatin and modified systemic 5-fluorouracil, folinic acid, and irinotecan (FOLFIRI) plus targeted therapy group or the systemic FOLFIRI plus targeted therapy group. Both regimens will be repeated every 2 weeks for a total of 12 cycles. The primary objective of this study is to compare the rate of conversion to liver resection. The surgical conversion rate is expected to increase by 25% with HAI oxaliplatin in combination with sys-CT plus targeted therapy (40% in the experimental arm versus 15% in the control arm) (power, 80%; two-sided alpha-risk, 5%). The secondary objectives include overall survival, progression-free survival, and objective response rate. DISCUSSION: This is the first randomized controlled trial to investigate the efficacy of HAI oxaliplatin in combination with sys-CT plus targeted therapy as first-line treatment from the initial diagnosis in patients with unresectable CRC with liver-only metastasis, aiming to significantly increase the surgical conversion rate. TRIAL REGISTRATION: ClinicalTrials.gov, (NCT05103020). Trial registration date: November 2, 2021.

Randomized comparison of in vivo performance of TearLab® and I-PEN® osmometry in normal dogs.

OBJECTIVE: To compare tear film (TF) osmolarity measured using TearLab® and I-PEN® osmometers in the same dogs without any ocular surface disease. ANIMAL STUDIED: Fifty-two dogs (98 eyes) of different breeds were evaluated. PROCEDURES: Tear film (TF) osmolarity was evaluated at 2-min intervals. The test was randomly determined, and single measurements were performed using each osmometer. Subsequently, complete ophthalmologic examinations were performed based on Schirmer tear test-1 (STT-1) analysis, tear film breakup time (TFBUT), and slit-lamp biomicroscopy. For each osmometer, the mean ± standard deviation of the TF osmolarity was calculated, and a paired Student's t-test was used to compare the values obtained. Pearson correlation analysis was performed to assess the association between osmolarity and other values such as STT-1, TFBUT, and age. RESULTS: Tear film osmolarity determined using TearLab® (340.42 ± 15.87 mOsm/L) and I-PEN® (321.58 ± 17.39 mOsm/L) were significantly different (p < .001). However, statistical significance could not be confirmed between osmolarity and other values, such as STT-1, TFBUT, and age. CONCLUSIONS: In dogs, the TF osmolarity values obtained using TearLab® tend to be higher than those obtained using I-PEN®, contrary to that observed in humans. These findings can serve as a reference for establishing normal values for each osmometer for clinical use in measuring TF osmolarity in dogs.

Evaluation of the Chemosensoric Properties of Commercially Available Dog Foods Using Electronic Sensors and GC-MS/O Analysis.

Pet owners think of their animals as part of their family, which further promotes the growth of the pet food market, encouraging pet owners to select nutritious, palatable, and high-quality foods for pets. Therefore, the evaluation of taste and volatile compounds in pet foods is essential to improve palatability. In this study, the sensory characteristics of taste and odor compounds in 10 commercially available dry dog foods were investigated using electronic tongue (E-tongue), electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). Dry dog foods were separated based on the sensory properties of taste and volatile compounds through the multivariate analysis of integrated results of the E-tongue and E-nose. A total of 67 odor active compounds were detected through GC-MS and GC-O, and octanal, nonanal, 2-pentyl furan, heptanal, and benzaldehyde were identified as key odor compounds which may have positive effects on food intake. The multivariate analysis was used to classify samples based on key odor compounds. Volatile compounds responsible for aroma properties of samples were evaluated using GC-O and multivariate analysis in this present study for the first time. These results are expected to provide fundamental data for sensory evaluation in producing new dog foods with improved palatability.

Computed tomographic findings may be useful for differentiating small intestinal adenocarcinomas, lymphomas, and spindle cell sarcomas in dogs.

An improved understanding of the CT characteristics for histologically confirmed primary intestinal tumors would be helpful for guiding prognosis and treatment plans in affected dogs. This retrospective, multi-center, analytical study aimed to evaluate the CT characteristics for the differentiation of adenocarcinoma, lymphoma, and spindle cell sarcoma (SCS) in dogs. Thirty-seven dogs who underwent contrast CT and histopathological examinations were included (adenocarcinomas, n = 11; lymphomas, n = 12; SCS, n = 14). Quantitative and qualitative CT parameters, including tumor morphology, contrast enhancement pattern, Hounsfield unit (HU) value, and presence or absence of intraabdominal lymphadenopathy, were evaluated for each included small intestine tumor CT case. Adenocarcinomas tended to show endophytic growth, intestinal obstruction, and a heterogeneous enhancement pattern. Lymphomas tended to show exophytic growth, contrast enhancement of the intestinal tumor mucosal layer, a homogeneous enhancement pattern, and the presence of lymphadenopathies in the abdominal cavity. SCSs tended to show lobulated growth, a large cystic portion within the tumor, a heterogeneous enhancement pattern, a large size with fat stranding sign, and lower HU values in postcontrast images. Cut-off values of the minimum diameter/fifth lumbar vertebral mid-body height (≥5.80; area under the curve [AUC] = 0.97, P < 0.001) and minimum HU value/HU value of the aorta (≤0.26; AUC = 0.96, P < 0.001) were derived to discriminate SCS from the two other tumor types. In conclusion, contrast CT characteristics may be useful in differentiating small intestinal adenocarcinomas, lymphomas, and SCSs in dogs.

Irradiation with 590-nm yellow light-emitting diode light attenuates oxidative stress and modulates UVB-induced change of dermal fibroblasts.

Recently, light-emitting diode (LED)-based devices have emerged as effective and safe tools for the treatment of photoaged skin. However, few studies have been conducted to elucidate the underlying mechanism behind the effect on photoageing of LED light. In this study, we induced photoageing of human dermal fibroblasts (HDFs) with Ultraviolet B (UVB) irradiation and evaluated the ability of 590-nm LED radiation to induce recovery from oxidative stress, restore collagen formation and regulate inflammatory changes. Photoageing was induced in cultured human dermal fibroblasts (HDFs) using UVB irradiation of 50 mJ/cm2 . Then, the photoaged HDFs were irradiated with LED using a custom-built 590-nm LED device which emits light with an intensity of 38 mW/cm2 (irradiated for 900 s with 34.2 J/cm2 of total energy). LED irradiation significantly attenuated UVB-induced reactive oxygen species generation and UVB-induced phosphorylation of JNK, c-Fos and c-Jun. In addition, the procollagen levels were recovered significantly, and MMP-9 levels were significantly suppressed after LED irradiation. The UVB-induced phosphorylation levels of NF-κB and pro-inflammatory enzyme COX-2 also significantly decreased. Our results suggest that 590-nm yellow light irradiation may be an effective and safe anti-oxidative and anti-inflammatory treatment modality for photoaged skin.

Changes in concentrations and characteristics of asbestos fibers dispersed from corrugated asbestos cement sheets due to stabilizer treatment.

Asbestos management in Korea has, to date, focused exclusively on dismantlement and removal; however, the effective management of asbestos in public facilities and rural dwellings is also critical. This study compares eight different asbestos stabilization treatments and their effectiveness in reducing asbestos fiber dispersion from weathered corrugated asbestos cement sheets (CACS) under different wind conditions. The effectiveness of the different asbestos stabilizers was assessed in order to identify the characteristics of fibers dispersed from treated CACS samples. The impact of wind speed on the concentration and composition of the dispersed fibers was also evaluated. For all wind speeds, the concentration of the fibers dispersed from the CACS samples that were treated with stabilizers decreased relative to the untreated CACS. These results show that asbestos concentrations were considerably reduced following stabilizer treatment and that treated CACS dispersed fewer asbestos fibers relative to untreated CACS. The results of this study will be useful for the development of strategies regarding the appropriate management of asbestos in public buildings.

Effects of red glasswort as sodium chloride substitute on the physicochemical properties of pork loin ham.

OBJECTIVE: This study was conducted to evaluate the effect of red glasswort (RG) (Salicornia herbacea L.) curing on the physicochemical, textural and sensory properties of cooked pork loin ham (M. longissimus thoracis et lumborum). METHODS: All treatments were cured with different salt and RG powder levels. RG0 treatment was prepared with only 4% NaCl (w/w) as a control, and RG25, 3% NaCl:1% RG (w/w); RG50, 2% NaCl:2% RG (w/w); RG75, 1% NaCl:3% RG (w/w); RG100, 0% NaCl:4% RG (w/w) treatments were prepared sequentially. All samples were individually vacuum packaged in polyethylene bags and stored for 7 d at 3°C±1°C. RESULTS: The results showed that as the rate of RG substitution increased, pH value, redness, myofibrillar protein solubility, and myofibrillar fragmentation index increased (p<0.05), but salt concentration and shear force decreased (p<0.05). However, there were no significant differences in cooking loss and moisture content. In terms of sensory evaluation, RG100 exhibited higher scores in tenderness and juiciness than RG0 (p<0.05). CONCLUSION: The partial substitution of NaCl by RG could improve the physicochemical properties, textural and sensory characteristics of cooked pork loin. Therefore, it is suggested that RG as a natural salt replacer could be an effective ingredient for developing low-sodium cured hams.

Comparative effects of dry-aging and wet-aging on physicochemical properties and digestibility of Hanwoo beef.

OBJECTIVE: The purpose of this study was to investigate the effects of aging methods (AM) i.e. dry-aging (DA) and wet-aging (WA) on the physicochemical properties and in vitro digestibility of proteins in beef short loin. METHODS: Short loins (M. longissmus lumborum), were trimmed and boned-out on the fifth day postmortem, from a total of 18 Hanwoo, which were purchased from a commercial slaughterhouse. Short loins were separated randomly grouped into one of the three treatments: control, WA (1°C, 7 days), and DA (1°C, 0.5 m/s, 85% relative humidity [RH], 30 days). RESULTS: Dry-aged beef (DAB) exhibited higher pH, water holding capacity (WHC), myofibrillar fragmentation index (MFI), and digestibility, however lower lightness, redness, and yellowness values, cooking loss, and shear force (SF), than those of wet-aged beef (WAB) (p<0.05). The myosin light chain band intensity of DAB was higher than that of control and WAB in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The in vitro digestibility of aged beef was highly (p<0.001) correlated to physicochemical properties except WHC. The correlation coefficient between AMs and WHC was higher than that between AM and SF (p<0.05) or MFI (p<0.001). A high correlation was observed between SF and MFI (p<0.001). CONCLUSION: Thus, we believe that DAB is more advantageous than WAB owing to its high digestibility and WHC and low SF.

Meat quality attributes and oxidation stability of loin chops from finishing gilts and cull sows.

The objective of this study was to compare the meat quality attributes, color stability, and lipid oxidation of loin chops from finishing gilts and cull sows in a three-way crossbreeding system: landrace × large white × duroc finishing gilts (n = 20) and landrace × large white sows (n = 20). No significant differences in pH, proximate composition, or total collagen content were found between the two pig groups. However, sow loin chops exhibited different quality characteristics for color, cooking loss, protein solubility, and shear force, in which an increased cooking loss and shear force might be associated with a lower heat-soluble collagen content compared to the gilt loin chops (p < 0.05). Moreover, more rapid changes in redness and chroma during 7 days of aerobic display were observed in the sow loin chops (p < 0.05). Therefore, the results presented here highlight the possibility of issues regarding color and tenderness in sow meat compared to retail pork produced from finishing gilts.

Efficacy of tumbling in soy sauce marination of pork loins: effects of tumbling time and temperature.

The objectives of this study were to determine the effects of tumbling time on the processing characteristics of soy sauce marinated pork loins, and to compare its efficacy at two different tumbling temperatures. In experiment I, pork loins (M. longissimus thoracis et lumborum) were pumped to 115% (w/w) of original sample weight with soy sauce solution (75%, w/w) and tumbled for 0, 1, 3, and 5 h. In experiment II, the soy sauce pumped pork loins were tumbled at two different temperatures (- 1 and 4 °C) for 4 h. The pH, color characteristics, water-holding capacity, protein solubility, and shear force of pork loins tumbled with soy sauce marinade were determined. An increase in tumbling time increased the cooked pH and yellowness of soy sauce marinated pork loins (p < 0.05). Protein solubility, particularly that of total and salt-soluble proteins, increased with increasing tumbling time (p < 0.05), and a tumbling time of at least 3 h may guarantee excellent water-holding capacity and shear force. In addition, low tumbling temperature of - 1 °C could positively contribute to the improvement of water-holding capacity and shear force of soy sauce marinated pork loins. In conclusion, this current study indicates that the efficacy of tumbling in soy sauce marination of pork loins is affected by tumbling time and temperature, moreover, tumbling at - 1 °C for at least 3 h could be an effective method in the experimental operating condition.

The impact of disease severity on paradoxical association between body mass index and mortality in patients with acute kidney injury undergoing continuous renal replacement therapy.

BACKGROUND: Association between high body mass index (BMI) and survival benefit is confounded by comorbid conditions such as nutritional status and inflammation. Patients with acute kidney injury (AKI), particularly those receiving continuous renal replacement therapy (CRRT), are highly catabolic and more susceptible to loss of energy. Herein, we evaluated whether disease severity can modify the relationship between BMI and mortality. METHODS: We conducted an observational study in 1144 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. Patients were categorized into four groups; underweight (< 18.5 kg/m2), normal (18.5-22.99 kg/m2), overweight (23.0-24.99 kg/m2), and obesity (≥25 kg/m2) according to BMI classification by the Committee of Clinical Practice Guidelines and Korean Society for the Study of Obesity. More severe disease was defined as sepsis-related organ failure assessment (SOFA) score of ≥ a median value of 12. The study endpoint was death that occurred within 30 days after the initiation of CRRT. RESULTS: The mean age was 63.2 years and 439 (38.4%) were females. The median BMI was 23.6 (20.9-26.2) kg/m2. The obese group were younger and higher SOFA score than normal BMI group. In a multivariable Cox regression analysis, we found a significant interaction between BMI and SOFA score (P <  0.001). Furthermore, obese patients were significantly associated with a lower risk of death as compared to normal BMI group after adjusting confounding factors [hazard ratio (HR), 0.81; 95% confidence interval (CI), 0.68-0.97; P = 0.03]. This association was only evident among patients with high severity (HR, 0.61; 95% CI, 0.48-0.76, P <  0.001). In contrast, in those with low severity, survival benefit of high BMI was lost, whereas underweight was associated with an increased risk of death (HR, 1.74; 95% CI, 1.16-2.60; P = 0.007). CONCLUSION: In this study, we found a survival benefit of high BMI in AKI patients undergoing CRRT, particularly in those with more disease severity; the effect was not observed in those with less disease severity.

Effect of natural pre-converted nitrite sources on color development in raw and cooked pork sausage.

OBJECTIVE: The effect of pre-converted nitrites from natural sources (spinach, lettuce, celery, and red beet) on color development in raw and cooked pork sausage was investigated in this study. METHODS: The pork sausage was manufactured with six treatments: NC (negative control, nitrite free), PC (positive control, 150 ppm sodium nitrite), FS (3.0% fermented spinach extracts), FL (3.0% fermented lettuce extracts), FC (3.0% fermented celery extracts), and FR (3.0% fermented red beet extracts). RESULTS: The pH value of the pre-converted nitrites groups was lower than those treated with 150 ppm sodium nitrite (p<0.05). The color values of raw and cooked pork sausage added with pre-converted nitrite showed slightly lower and/or similar lightness, lower redness, and higher yellowness values than PC. Color development (redness values) of cooked samples added with FS was higher than those of the NC and other treatments (FL, FC, and FR). Additionally, treatments with FS and FL were most effective for reducing thiobarbituric acid reactive substances and volatile basic nitrogen than the NC. CONCLUSION: Effects of natural nitrites from fermented vegetables on shelf stability of raw and cooked pork sausages were investigated. Fermented spinach extract was much more useful for maintaining the color development, but also inhibiting lipid and protein oxidation of cooked pork sausage. Therefore, pre-converted nitrite from spinach as a natural nitrite could be used as another natural nitrite source for making processed meat products.

Nobiletin attenuates neurotoxic mitochondrial calcium overload through K+ influx and ΔΨm across mitochondrial inner membrane.

Mitochondrial calcium overload is a crucial event in determining the fate of neuronal cell survival and death, implicated in pathogenesis of neurodegenerative diseases. One of the driving forces of calcium influx into mitochondria is mitochondria membrane potential (ΔΨm). Therefore, pharmacological manipulation of ΔΨm can be a promising strategy to prevent neuronal cell death against brain insults. Based on these issues, we investigated here whether nobiletin, a Citrus polymethoxylated flavone, prevents neurotoxic neuronal calcium overload and cell death via regulating basal ΔΨm against neuronal insult in primary cortical neurons and pure brain mitochondria isolated from rat cortices. Results demonstrated that nobiletin treatment significantly increased cell viability against glutamate toxicity (100 µM, 20 min) in primary cortical neurons. Real-time imaging-based fluorometry data reveal that nobiletin evokes partial mitochondrial depolarization in these neurons. Nobiletin markedly attenuated mitochondrial calcium overload and reactive oxygen species (ROS) generation in glutamate (100 µM)-stimulated cortical neurons and isolated pure mitochondria exposed to high concentration of Ca2+ (5 µM). Nobiletin-induced partial mitochondrial depolarization in intact neurons was confirmed in isolated brain mitochondria using a fluorescence microplate reader. Nobiletin effects on basal ΔΨm were completely abolished in K+-free medium on pure isolated mitochondria. Taken together, results demonstrate that K+ influx into mitochondria is critically involved in partial mitochondrial depolarization-related neuroprotective effect of nobiletin. Nobiletin-induced mitochondrial K+ influx is probably mediated, at least in part, by activation of mitochondrial K+ channels. However, further detailed studies should be conducted to determine exact molecular targets of nobiletin in mitochondria.

Axin is expressed in mitochondria and suppresses mitochondrial ATP synthesis in HeLa cells.

Many recent studies have revealed that axin is involved in numerous cellular functions beyond the negative regulation of ß-catenin-dependent Wnt signaling. Previously, an association of ectopic axin with mitochondria was observed. In an effort to investigate the relationship between axin and mitochondria, we found that axin expression suppressed cellular ATP production, which was more apparent as axin expression levels increased. Also, mitochondrial expression of axin was observed using two axin-expressing HeLa cell models: doxycycline-inducible ectopic axin expression (HeLa-axin) and axin expression enhanced by long-term treatment with XAV939 (HeLa-XAV). In biochemical analysis, axin is associated with oxidative phosphorylation (OXPHOS) complex IV and is involved in defects in the assembly of complex IV-containing supercomplexes. Functionally, axin expression reduced the activity of OXPHOS complex IV and the oxygen consumption rate (OCR), suggesting axin-mediated mitochondrial dysfunction. Subsequent studies using various inhibitors of Wnt signaling showed that the reduction in cellular ATP levels was weaker in cases of ICAT protein expression and treatment with iCRT3 or NSC668036 compared with XAV939 treatment, suggesting that XAV939 treatment affects ATP synthesis in addition to suppressing Wnt signaling activity. Axin-mediated regulation of mitochondrial function may be an additional mechanism to Wnt signaling for regulation of cell growth.

Dementia is a risk factor for major adverse cardiac and cerebrovascular events in elderly Korean patients initiating hemodialysis: a Korean national population-based study.

BACKGROUND: Dementia is common in end-stage renal disease (ESRD) patients on hemodialysis (HD) and is associated with worse outcomes. This study aimed to investigate the risk of major adverse cardiac and cerebrovascular event (MACCE) in elderly patients with dementia initiating HD. METHODS: Using the database from the Health Insurance Review & Assessment Service, we analyzed 10,171 patients aged 65 years or older who had initiated dialysis from 2005 to 2008. MACCE was defined as a composite outcome of all-cause mortality, nonfatal acute myocardial infarction, target vessel revascularization, and nonfatal ischemic and hemorrhagic stroke. The Kaplan-Meier method and Cox proportional hazards model were used, and further comparisons using propensity-score matching at 1:2 ratio were also performed. RESULTS: A total of 303 elderly patients (3.0%) had dementia at initiating HD. During follow-up, dementia was a significant predictor of MACCE after adjustment for confounding variables. In addition, further analyzed in the propensity-score matched groups, dementia was an independent predictor of both nonfatal ischemic stroke and all-cause mortality. CONCLUSIONS: Dementia is an independent risk factor for mortality and ischemic stroke in elderly ESRD patients initiating HD. Patients with dementia who start dialysis should be closely monitored to reduce the risk of mortality and ischemic stroke.

Effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg meat during display storage.

BACKGROUND: The present study aimed to evaluate the effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg during display storage. Two hundred and forty, 1-day-old male chicks (5 birds per pen) were subjected to four treatments in a 2 (thermoneutral condition at 21 °C and cyclic heat stress at 32-21-32 °C for 10 h day-1 ) × 2 (regular diet with 0 or 0.25 g kg-1 Bacillus subtilis) factorial design. Chickens were harvested at day 46, and pairs of whole legs were collected at 1 day postmortem. The chicken legs were deboned, ground, tray-packaged with oxygen-permeable film, and displayed for 3 days. RESULTS: Heat stress and probiotic supplementation had no impact on pH, water-holding capacity, color, protein functionality, lipid lipolysis and lipid/protein oxidation stability (P > 0.05). Display storage increased the pH and lipid oxidation of ground chicken legs (P < 0.05). In addition, protein oxidation occurred during display storage, as determined via an increased carbonyl group (P = 0.0109) and reduced thiol group (P < 0.0001). CONCLUSION: The results of the present study indicate that chronic heat stress and probiotic supplementation had no practical adverse impact on protein functionality and oxidative stability of ground chicken leg meat. © 2017 Society of Chemical Industry.

Effects of aging and freezing/thawing sequence on quality attributes of bovine Mm. gluteus medius and biceps femoris.

OBJECTIVE: The effects of aging and freezing/thawing sequence on color, physicochemical, and enzymatic characteristics of two beef muscles (Mm. gluteus medius, GM and biceps femoris, BF) were evaluated. METHODS: Beef muscles at 3 d postmortem were assigned to four different combinations of aging and freezing/thawing sequence as follows; aging at 2°C for 3 wk (A3, never-frozen control), freezing at -28°C for 2 wk then thawing (F2, frozen/thawed-only), aging at 2°C for 3 wk, freezing at -28°C for 2 wk then thawing (A3F2), and freezing at -28°C for 2 wk, thawing then further aging at 2°C for 3 wk (F2A3). RESULTS: No significant interactions between different aging/freezing/thawing treatments and muscle type on all measurements were found. Postmortem aging, regardless of aging/freezing/thawing sequence, had no impact on color stability of frozen/thawed beef muscles (p<0.05). F2A3 resulted in higher purge loss than F2 and A3F2 treatments (p<0.05). A3F2 and F2A3 treatments resulted in lower shear force of beef muscles compared to F2 (p<0.05). Although there was no significant difference in glutathione peroxidase (GSH-Px) activity, F2A3 had the highest ß-N-acetyl glucominidase (BNAG) activity in purge, but the lowest BNAG activity in muscle (p<0.05). GM muscle exhibited higher total color changes and purge loss, and lower GSH-Px activity than BF muscle. CONCLUSION: The results from this present study indicate that different combinations of aging/freezing/thawing sequence would result in considerable impacts on meat quality attributes, particularly thaw/purge loss and tenderness. Developing a novel freezing strategy combined with postmortem aging will be beneficial for the food/meat industry to maximize its positive impacts on tenderness, while minimizing thaw/purge loss of frozen/thawed meat.

Impacts of post-mortem ageing prior to freezing on technological and oxidative properties of coarse ground lamb sausage in a model system.

OBJECTIVE: The objective of this study was to evaluate the effects of ageing time of lamb loins prior to freezing on technological characteristics and oxidation stability of coarse ground lamb loin sausage using in a model system. METHODS: Lamb loins (M. longissimus lumborum, n = 25) were aged at -1.5°C for 0, 1, 2, 3, and 8 wk and then frozen for the remaining days (a total of 30 wk). The aged/frozen/thawed lamb loins were ground, and model sausages were formulated with 75% aged/frozen/thawed lamb loin, 25% water, 1.5% sodium chloride (NaCl) and 0.3% sodium tripolyphosphate. The pH and thaw/purge loss of aged/frozen/thawed lamb loins were evaluated, and protein functionality (protein solubility and emulsifying capacity), water-holding capacity and textural properties of model sausages were determined. Cooked model sausages were vacuum-packaged in a plastic bag and displayed under continuous fluorescent natural white light (3°C±1°C). Colour and lipid oxidation of the cooked model sausages were evaluated on 0 and 21 d of display storage. RESULTS: Ageing prior to freezing had no impact on pH and purge/thaw loss of lamb loins and the colour of cooked sausages (p>0.05) made from the loins. Lamb loins aged for at least 3 wk prior to freezing numerically improved total and myofibrillar protein solubilities (p>0.05) and emulsion activity index (p = 0.009) of meat batter, but decreased cooking loss (p = 0.003) and lipid oxidation (p<0.05) of model sausages. CONCLUSION: This study suggests that post-mortem ageing of raw meat prior to freezing could improve water-holding capacity and lipid oxidative stability of sausage made from the meat.