Korean Journal for Food Science of Animal Resources最新文献

This study aims to investigate the protective effects of kefir against myocardial infarction induced by isoproterenol (ISO). The rats were randomly divided into 4 groups, each group consisting of 8 rats. The control group, the kefir group (5 mL/kg/d kefir administered to rats as intra-gastric gavage for 60 d), the ISO group (100 mg/kg ISO was administered to rats, s.c. on 61. and 62. d), and kefir+ISO group (5 mL/kg/d kefir was administered to rats intra gastric gavage for 60 days prior to ISO, 100 mg/kg in two doses on day 61 and 62). 12 h after the last ISO dose, all rats were decapitated and their blood samples were collected. Cardiac tissue was reserved for histopathological examination. creatine kinase (CK), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triglycerides, total cholesterol,very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) and glucose were measured by autoanalyzer, whole blood malondialdehyde (MDA), glutathione (GSH) and plasma advanced oxidation protein products (AOPP) levels were measured spectrophotometrically. It was determined that in the group of kefir+ISO, the levels of AST (p<0.001), CK (p<0.001), LDH (p<0.001), MDA (p<0.001) and AOPP (p<0.001) were decreased, while the GSH (p<0.05) increased, compared to ISO group. There were no significant changes in lipid profile and glucose levels between these two groups. In conclusion, by examining cardiac enzymes and histopathological changes in cardiac tissue, it can be concluded that the administration of kefir in myocardial infarction induced by ISO can protect the heart with its antioxidant characteristic and minimize the toxic damage created by ISO.

This study was undertaken to find the optimum soy-peptone, glucose, yeast extract, and magnesium sulfate amounts for the maximum growth of Lactobacillus plantarum JNU 2116 and to assess the effects of these medium factors through the use of response surface methodology. A central composite design was used as the experimental design for the allocation of treatment combinations. In the analysis of the experiment, due to a significant lack of fit of the second-order polynomial regression model that was used at first, cubic terms were added to the model, and then two-way interaction terms were deleted from the model since they were found to be all statistically insignificant. A relative comparison among the four factors showed that the growth of L. plantarum JNU 2116 was affected strongly by yeast extract, moderately by glucose and peptone, and slightly by magnesium sulfate. The estimated optimum amounts of the medium factors for the growth of L. plantarum JNU 2116 are as follows: soy-peptone 0.213%, glucose 1.232%, yeast extract 1.97%, and magnesium sulfate 0.08%. These results may contribute to the production of L. plantarum L67 as a starter culture that may have potential application in yogurt and fermented meat products.

This study was conducted to determine the effects of NaCl concentration and cooking temperature on the color and pigment characteristics of presalted ground chicken breasts. Four treatments with different salt concentrations (0%, 1%, 2%, and 3%) were prepared and stored for 7 d prior to cooking. Each sample was cooked to four endpoint temperatures (70°C, 75°C, 80°C, and 85°C). The salt concentration affected the color and pigment properties of the cooked ground chicken breasts. As the salt concentration increased, the cooking yield and residual nitrite content also increased. However, the samples with 1%, 2%, and 3% NaCl showed similar nitrosyl hemochrome and total pigment contents. Among the products containing salt, the samples with 3% NaCl showed the lowest percentage myoglobin denaturation (PMD) and the lowest CIE a* values. The cooking temperature had limited effects on the pigment properties of cooked ground chicken breasts. The oxidation-reduction potential and residual nitrite contents increased with cooking temperature, while the PMD, nitrosyl hemochrome, total pigment contents and CIE a* values were similar in the samples cooked at different temperatures. These results indicated that the addition of up to 2% salt to ground chicken breasts and storage for 7 d could cause the pink color defect of cooked products. However, the addition of 3% NaCl could reduce the redness of the cooked products.

The objective of this study was to evaluate the efficacy of alkaline-treated sugarcane bagasse fiber on physicochemical and textural properties of meat emulsion with different fat levels. Crude sugarcane bagasse fiber (CSF) was treated with calcium hydroxide (Ca(OH₂)) to obtain alkaline-treated sugarcane bagasse fiber (ASF). The two types of sugarcane bagasse fiber (CSF and ASF) were incorporated at 2% levels in pork meat emulsions prepared with 5%, 10% and 20% fat levels. Alkaline-treatment markedly increased acid detergent fiber content (p=0.002), but significantly decreased protein, fat, ash and other carbohydrate contents. ASF exhibited significantly higher water-binding capacity, but lower oil-binding and emulsifying capacities than CSF. Meat emulsions formulated with 10% fat and 2% sugarcane bagasse fiber had equivalent cooking loss and textural properties to control meat emulsion (20% fat without sugarcane bagasse fiber). The two types of sugarcane bagasse fiber had similar impacts on proximate composition, cooking yield and texture of meat emulsion at the same fat level, respectively (p>0.05). Our results confirm that sugarcane bagasse fiber could be a functional food ingredient for improving physicochemical and textural properties of meat emulsion, at 2% addition level. Further, the altered functional properties of alkaline-treated sugarcane bagasse fiber had no impacts on physicochemical and textural properties of meat emulsions, regardless of fat level at 5%, 10% and 20%.

Hypercholesterolemia is one of the primary risk factors for cardiovascular diseases. The use of lactobacilli probiotics to reduce blood cholesterol levels have been extensively reported. However, more information is needed to evaluate the possible mechanisms involved and to identify possible targets for further therapeutic development. In this study, strains of lactobacilli were screened based on the ability to assimilate cholesterol, and prevention of cholesterol accumulation in hepatic (HepG2) and intestinal (HT-29) cells. Cell free supernatant (CFS) from Lactobacillus plantarum DR7 showed a higher ability to assimilate cholesterol, reduction in cholesterol accumulation in both HepG2 and HT-29 cells, accompanied by reduced mRNA expression of HMG-CoA reductase (HMGCR) in HepG2 (p<0.05), compared to other lactobacilli. The reduction of HMGCR expression was also diminished in the presence of an AMPK inhibitor (Compound C), suggesting that L. plantarum DR7 exerted its effect via the AMPK pathway, typically via the phosphorylation of AMPK instead of the AMPK mRNA expression in HepG2 (p<0.05). Altogether, our present study illustrated that lactobacilli could exert cholesterol lowering properties along the AMPK pathway, specifically via phosphorylation of AMPK that led to reduced expression of HMGCR.

We investigated microbial and quality changes in wrap-packaged dry-aged beef after completion of aging and subsequent storage in a refrigerator. After 28 days of dry aging (temperature, 4°C; RH, approximately 75%; air flow velocity, 2.5 m/s), sirloins were trimmed, wrap-packaged, and stored at 4°C for 7 days. Analyses of microbial growth, pH, volatile basic nitrogen (VBN), 2-thiobarbituric acid-reactive substance (TABRS), and instrumental color, myoglobin, and sensory evaluation were conducted on days 0, 3, 5, and 7. The results show that the number of total aerobic bacteria (TAB), yeast, and lactic acid bacteria increased with an increase in storage days, whereas no change in the growth of mold was observed during 7 days of storage. Based on the legal standard for TAB count, the estimated shelf-life of wrap-packaged dry-aged beef was predicted to be less than 12.2 days. However, the shelf-life should be less than 6.3 days, considering the result of sensory quality (odor, taste, and overall acceptance). No significant change in visible appearance was also observed during 7 days of storage. The results suggest that the present quality indicators for meat spoilage (pH, VBN, and TBARS) should be re-considered for dry-aged beef, as its characteristics are different from those of fresh and/or wet-aged beef.

The effect of high egg intake on metabolic syndrome (MetS), a major risk factor for cardiovascular disease (CVD), has not been clearly elucidated. This study was conducted to review the literature related to egg consumption and the risk of metabolic disease as well as to examine the association between high egg intake and MetS in Korean adults. A literature review was conducted using published papers in PubMed and EMBASE through December 2017. We have reviewed 26 articles, which were associated with egg consumption and metabolic diseases, and found that the results were controversial. Therefore, we analyzed data from 23,993 Korean adults aged 19 yrs and older. MetS was defined based on criteria from the Adult Treatment Panel III. Egg consumption of 4-6 times/wk and 1 time/day were significantly associated with reduced prevalence of MetS (Odds ratio (OR)=0.82; 95% Confidence interval (CI)=0.71-0.95 for 4-6 times/wk, OR=0.83; 95% CI=0.69-0.99 for 1 time/day) compared to those who consumed eggs less than once monthly. However, consuming two or more eggs per day was not associated with MetS. As for the components of MetS, an egg intake of once daily decreased the prevalence of abdominal obesity and an intake of 2-7 eggs weekly was shown to prevent a reduction in the high-density lipoprotein cholesterol levels. This study suggests that while consuming eggs 4-7 times weekly is associated with a lower prevalence of MetS, consuming two or more eggs daily is not associated with a reduced risk for MetS.

To shorten the production cycle of Zaodan, this study first pickled Zaodan by a novel technology - vacuum decompression technology. Vacuum decompression technology could reduce the pickling time of Zaodan from 20 wk to about 9 wk. The protein content, moisture and pH of the Zaodan egg white gradually decreased with a concomitant increase in salt during the pickling process. The total sulfhydryl group (SH) group content of the egg white proteins was increased to 2.43×10^-3 mol/L after being pickled for 30 d, whereas the content of disulphide bonds (SS) was reduced to 23.35×10^-3 mol/L. The surface hydrophobicity was lowest after pickling for 30 d. In addition, great changes occurred in the secondary structure of the egg white proteins after pickling for 20 d. The disappearance of ovomucin was noticeable based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis.

This research was to evaluate microbial contamination levels in meat samples at hazard analysis critical control point (HACCP)-implemented processing plants that produce beef, pork, and chicken. During a period of about a year, a total of 178 samples (76 from beef, 89 from pork, and 13 from chicken) were obtained from raw materials (21.3%) and final products (78.7%). All samples were determined for each 25 g homogenized one. Samples were analyzed to determine the total aerobic plate count (APC), coliform count (CC), and E. coli count (ECC). By month, APC levels were the highest in September and the lowest in February (p<0.001). In comparison among season, APC levels in meat samples were the highest in the summer and the lowest in winter (p<0.001). By month, the highest CC prevalence was found in August, followed by October and then July (p<0.001). By season, the highest CC was obtained in summer, followed by autumn and then spring (p<0.001). All samples were negative for ECC. There was a direct correlation between the product form and coliform presence (p<0.001). In addition, there was a positive correlation between the APC and CC (r=0.261). The APCs in analyzed samples ranged from below <10¹ CFU/g to <10⁷ CFU/g. In conclusion, the month and season had significant effects on microbial contamination levels at HACCP implemented processing plants. Interrelationships between (i) the product form and coliform, (ii) the APC and CC were revealed.

This study was conducted to evaluate the effects of pre and post-rigor marinade injections on some quality parameters of Longissimus dorsi (LD) muscles. Three marinade formulations were prepared with 2% NaCl, 2% NaCl+0.5 M lactic acid and 2% NaCl+0.5 M sodium lactate. In this study marinade uptake, pH, free water, cooking loss, drip loss and color properties were analyzed. Injection time had significant effect on marinade uptake levels of samples. Regardless of marinate formulation, marinade uptake of pre-rigor samples injected with marinade solutions were higher than post rigor samples. Injection of sodium lactate increased pH values of samples whereas lactic acid injection decreased pH. Marinade treatment and storage period had significant effect on cooking loss. At each evaluation period interaction between marinade treatment and injection time showed different effect on free water content. Storage period and marinade application had significant effect on drip loss values. Drip loss in all samples increased during the storage. During all storage days, lowest CIE L* value was found in pre-rigor samples injected with sodium lactate. Lactic acid injection caused color fade in pre-rigor and post-rigor samples. Interaction between marinade treatment and storage period was found statistically significant (p<0.05). At day 0 and 3, the lowest CIE b* values obtained pre-rigor samples injected with sodium lactate and there were no differences were found in other samples. At day 6, no significant differences were found in CIE b* values of all samples.