Korean Journal for Food Science of Animal Resources最新文献

The aim of this study was to evaluate the effects of pork and tuna levels on the quality characteristics of frankfurters and to establish a suitable percentage of added tuna. The levels of pork meat (PM) and yellow-fin tuna (YFT) in the test frankfurters were as follows: 100% PM (control), 90% PM+10% YFT (T1), 80% PM+20% YFT (T2), 70% PM+30% YFT (T3), 60% PM+40% YFT (T4), and 50% PM+50% YFT (T5). The pH of the frankfurter batters significantly decreased with increasing tuna levels, because the pH of the tuna is lower than that of the pork. The water holding capacity did not differ significantly in frankfurters containing up to 30% tuna, whereas that of the 40% tuna-containing frankfurter was significantly lower than the control. Cooking loss did not differ significantly. At up to 10% tuna, apparent viscosity did not differ significantly, whereas at 20% tuna, it was significantly lower than the control. Fat separation and total expressible fluid separation at up to 30% tuna did not differ from the control; however, when more than 30% was added, higher losses were observed. The hardness of frankfurters containing more than 40% tuna was lower than that of the control, but there was no significant difference in springiness. The overall acceptability of frankfurters manufactured with up to 30% tuna did not differ significantly from the control. These results suggest that the addition of 30% tuna does not affect the quality of frankfurters made from pork.

The concern about the possibility of food can be a vehicle for the transmission of Clostridium difficile to humans has been raised recently due to the similarities among the strains isolated from patients, foods and food animals. In this study, therefore, the prevalence of C. difficile was investigated in beef and chicken meat products collected from 57 different butcher shops, markets and fast food restaurants in Sakarya province of Turkey. Two out of 101 samples (1.98%) was positive for C. difficile indicating a very low prevalence. The pathogen was isolated from an uncooked meatball sample and a cooked meat döner sample, whereas not detected in chicken meat samples. The meatball isolate was resistant to vancomycin and tetracycline, while the cooked meat döner isolate was resistant to vancomycin and metronidazole. Both isolates were sensitive to moxifloxacin and clindamycin. Toxins A and B were not detected. This study reveals the presence of C. difficile in further processed beef products in Turkey.

This study was carried out to establish shelf life for pork cutlet of ground meat and pork lard by using various quality indicators and to understand how quality changes in these products are accelerated by temperature. The samples were selected and purchased from markets in Korea, and the chosen quality indicators were total aerobic counts and coliform group in microbiological analyses, thiobarbituric acid reactive substances assay, volatile basic nitrogen, pH, acid value, and peroxide value in physical chemical analyses, and sensory evaluation. The pork cutlet samples were stored at -18℃, -6℃, and -1℃, whereas pork lard samples were stored at 10℃, 25℃, 35℃, and 45℃. These temperature conditions were set to real distribution conditions. The samples were then analyzed using various models including of reaction orders, arrhenius equation, and Q₁₀ value. The quality limits for each sample were calculated, and shelf life was estimated. The results of this experiment highlighted the importance of temperature control during the distribution process of these products and revealed that temperature is a useful parameter for the establishment of a basic database for shelf life.

Bromodomain-containing protein 2 (BRD2) is a nuclear serine/threonine kinase involved in transcriptional regulation. We investigated the expression and association of the BRD2 gene as a candidate gene for meat quality traits in Berkshire pigs. BRD2 mRNA was expressed at relatively high levels in muscle tissue. Statistical analysis revealed that the c.1709G>C polymorphism of the BRD2 gene was significantly associated with carcass weight, meat color (a*, redness), protein content, cooking loss, water-holding capacity, carcass temperatures 4, 12 and 24 h postmortem, and the 24 h postmortem pH in 384 Berkshire pigs. Therefore, this polymorphism in the porcine BRD2 gene may be used as a candidate genetic marker to improve meat quality traits in pigs.

Myogenic factor 5 (MYF5) plays an important role in regulating skeletal muscle fiber characteristics, consequently affecting meat production and quality. We identified a novel p.A41P mutation in exon1 of the porcine MYF5 gene by direct sequencing. The mutation was predicted to be destabilizing in protein structure based on the resultant amino acid substitution. We estimated the significant substitution effect of p.A41P on the energy stabilization of Myf5 protein structure. Then, we demonstrated that the mutation in Yorkshire population significantly affected muscle fiber type I composition (p<0.05), loin-eye area of lean meat content (p<0.05) and filter-fluid uptake of meat quality (p<0.01). Furthermore, dominant effects significantly influenced total muscle fiber number (p<0.05). This study suggests that the novel p.A41P mutation in porcine MYF5 may be a valuable genetic marker to affect the muscle fiber characteristics and consequently improve meat production quality and quantity.

In this study, an immuno-magnetic bead (IMB)-based assay was developed to simultaneously detect Escherichia coli, Staphylococcus aureus, and Salmonella spp. and was tested in four animal-derived foods: beef, ham, egg, and ricotta cheese. The IMB-based assay exhibited good specificity by binding to five E. coli serotypes [capture efficiency (CE) average (avg.) 90.4%], five S. aureus strains (CE avg. 91.4%), and five Salmonella serotypes (CE avg. 95.4%) but not binding to non-target bacteria (CE<10%). Furthermore, the assay detected all three pathogens with a detection limit of 10 CFU/g without the need for enrichment or additional platforms. Since the results demonstrated that the IMB-based assay can effectively separate and enrich target bacteria from a variety of animal-derived food matrixes, the assay exhibits good specificity for potential use in providing rapid, immunological, presumptive identification of pathogenic bacteria.

Bifidobacterium is recognized as one of the most beneficial microorganisms in our gut. Many researches on bifidobacteria have been done to understand their roles in the gut. The objective of the present study was to develop a bioluminescent labelling plasmid vector for bifidobacteria to facilitate their visualization in vitro, in situ, and in vivo. A plasmid replicon (2.0 kb) of plasmid pFI2576 previously identified from B. longum FI10564 was amplified by PCR and cloned into pUC19 plasmid vector (2.68 kb). The cloned replicon was subcloned into pTG262 (luc⁺ ) recombinant plasmid vector (7.4 kb) where a luciferase gene (luc⁺ ) from pLuc2 (8.5 kb), an Escherichia coli and lactobacilli shuttle vector, was inserted into pTG262 plasmid vector. The final recombinant DNA, pTG262::pFI2576 rep (luc⁺ ), was transferred into a B. catenulatum strain. This recombinant strain showed 3,024 relative luminescence units at OD₆₀₀ value of 0.352. Thus, this recombinant plasmid construct can be broadly used for labelling bifidobacteria.

The objective of this study was to provide preliminary data for food industry by investigating the distribution of microorganisms in raw materials and sausage examining the effect of heating temperature on sausage quality. Total microbes in sausage ranged 2.21-3.11 Log CFU/g. Bacillus pumilus, B. licheniformis, Staphylococcus saprophyticus, and Enterococcus faecalis were detected on sausage. Total microbes in raw materials was 1.59-7.16 Log CFU/g. Different types of microorganisms were found depending on raw materials, with B. pumilus and B. subtilis were being detected in both raw materials and sausage. Total microbes in sausage after heating was in the range of 1.10-2.22 Log CFU/g, showing the trend of decrease in total microbe with increasing heating temperature, although the decrease was not significant. With increasing heating temperature, pH and hardness were also increased. The yield of sausage manufactured at 85°C was 95.42% while that manufactured at 65°C was 96.67%. Therefore, decreasing heating temperature during sausage production might increase yield and save energy without microbiological effect.

Lamb has long been considered a traditional meal within Australia; however as consumer preferences have changed since the 1950's, consumption of lamb has decreased from the 1980's. This is the result of changing societal roles, particularly for females, decreasing household sizes and increasing awareness of the impact of food choices on human health. Since the 1980's improvement of farm practices and increases in genetic gains has addressed part of this decline by increasing the amount of lean meat and decreasing fat in lamb retail cuts. Yet, this has created a challenge for the industry to utilise the larger carcases now being produced. Thus, a whole value chain approach to increasing consumption has been undertaken through several research programs to create cuts which suit the modern consumer, examine nutritional and eating quality and increase adoption of value added cuts. Therefore, this paper outlines this history of changing consumer patterns and the consequent research to address these changes.

The objective of this study was to determine the minimum enrichment time for different types of food matrix (pork, beef, and fresh-cut lettuce) in an effort to improve Escherichia coli detection efficiency. Fresh pork (20 g), beef (20 g), and fresh-cut lettuce (20 g) were inoculated at 1, 2, and 3 Log CFU/g of Escherichia coli. Samples were enriched in filter bags for 3 or 5 h at 44.5°C, depending on sample type. E. coli cell counts in the samples were enriched in E. coli (EC) broth at 3 or 5 h. One milliliter of the enriched culture medium was used for DNA extraction, and PCR assays were performed using primers specific for uidA gene. To detect E. coli (uidA) in the samples, a 3-4 Log CFU/mL cell concentration was required. However, E. coli was detected at 1 Log CFU/g in fresh pork, beef, and fresh-cut lettuce after 5, 5, and 3-h enrichment, respectively. In conclusion, 5-h enrichment for fresh meats and 3-h enrichment for fresh-cut lettuce in EC broth at 44.5°C, and PCR analysis using uidA gene-specific primers were appropriate to detect E. coli rapidly in food samples.