Il Suk Kim

RNA-Seq approach for genetic improvement of meat quality in pig and evolutionary insight into the substrate specificity of animal carbonyl reductases.

Changes in meat quality traits are strongly associated with alterations in postmortem metabolism which depend on genetic variations, especially nonsynonymous single nucleotide variations (nsSNVs) having critical effects on protein structure and function. To selectively identify metabolism-related nsSNVs, next-generation transcriptome sequencing (RNA-Seq) was carried out using RNAs from porcine liver, which contains a diverse range of metabolic enzymes. The multiplex SNV genotyping analysis showed that various metabolism-related genes had different nsSNV alleles. Moreover, many nsSNVs were significantly associated with multiple meat quality traits. Particularly, ch7:g.22112616A>G SNV was identified to create a single amino acid change (Thr/Ala) at the 145th residue of H1.3-like protein, very close to the putative 147th threonine phosphorylation site, suggesting that the nsSNV may affect multiple meat quality traits by affecting the epigenetic regulation of postmortem metabolism-related gene expression. Besides, one nonsynonymous variation, probably generated by gene duplication, led to a stop signal in porcine testicular carbonyl reductase (PTCR), resulting in a C-terminal (E281-A288) deletion. Molecular docking and energy minimization calculations indicated that the binding affinity of wild-type PTCR to 5α-DHT, a C21-steroid, was superior to that of C-terminal-deleted PTCR or human carbonyl reductase, which was very consistent with experimental data, reported previously. Furthermore, P284 was identified as an important residue mediating the specific interaction between PTCR and 5α-DHT, and phylogenetic analysis showed that P284 is an evolutionarily conserved residue among animal carbonyl reductases, which suggests that the C-terminal tails of these reductases may have evolved under evolutionary pressure to increase the substrate specificity for C21-steroids and facilitate metabolic adaptation. Altogether, our RNA-Seq revealed that selective nsSNVs were associated with meat quality traits that could be useful for successful marker-assisted selection in pigs and also represents a useful resource to enhance understanding of protein folding, substrate specificity, and the evolution of enzymes such as carbonyl reductase.

Irradiation and additive combinations on the pathogen reduction and quality of poultry meat

Reduction of foodborne illnesses and deaths by improving the safety of poultry products is one of the priority areas in the United States, and developing and implementing effective food processing technologies can be very effective to accomplish that goal. Irradiation is an effective processing technology for eliminating pathogens in poultry meat. Addition of antimicrobial agents during processing can be another approach to control pathogens in poultry products. However, the adoption of irradiation technology by the meat industry is limited because of quality and health concerns about irradiated meat products. Irradiation produces a characteristic aroma as well as alters meat flavor and color that significantly affect consumer acceptance. The generation of a pink color in cooked poultry and off-odor in poultry by irradiation is a critical issue because consumers associate the presence of a pink color in cooked poultry breast meat as contaminated or undercooked, and off-odor in raw meat and off-flavor in cooked meat with undesirable chemical reactions. As a result, the meat industry has difficulties in using irradiation to achieve its food safety benefits. Antimicrobials such as sodium lactate, sodium diacetate, and potassium benzoate are extensively used to extend the shelf-life and ensure the safety of meat products. However, the use of these antimicrobial agents alone cannot guarantee the safety of poultry products. It is known that some of the herbs, spices, and antimicrobials commonly used in meat processing can have synergistic effects with irradiation in controlling pathogens in meat. Also, the addition of spices or herbs in irradiated meat improves the quality of irradiated poultry by reducing lipid oxidation and production of off-odor volatiles or masking off-flavor. Therefore, combinations of irradiation with these additives can accomplish better pathogen reduction in meat products than using them alone even at lower levels of antimicrobials/herbs and irradiation doses. Effects of irradiation and additive combinations on the pathogen reduction and quality of poultry meat will be discussed in detail.

Effects of Sweet Persimmon Powder Type on Quality Properties of Low Salted Pork Patties during Cold Storage

Four different pork patties were made with two levels, HP/FP-3% and HP/FP-6%, containing 3.0 and 6.0% HP (hot air dried sweet persimmon powder)/FP (freeze-dried sweet persimmon powder), respectively. After manufacture, the meat patties were packaged with polyvinyl wrap and stored at 4 for 8 days. CTL (control) and HP-3% meat patties were significantly (p 0.05) different among the meat patty samples. The value of pH, L* and a* values were decreased as the cold storage time increased in all treatments (p<0.05). WHC (water holding capacity) of CTL and HP-6% and cooking loss of HP-3% were significantly (p<0.05) decreased with increased storage period. The diameter and thickness of all meat patties decreased with increasing the storage period. VBN (volatile basic nitrogen) values of all meat patties were increased (p<0.05) with increased storage period. TBARS (thiobarbituric acid reactive substance) of treatments were higher than that of CTL during whole storage time. The number of microorganisms (Total plate counts, Escherichia coli.) were maintained below 4.61 log10 CFU/cm 2 during

Effect of Hot-Air Dried Tomato Powder on the Quality Properties of Pork Patties during Cold Storage

ABSTRACT The effects of hot air dried tomato powder on the physicochemical and sensory properties of meat patties were studied. The control (C, no addition) and 4 treatments with addition of hot air dried tomato powder (T1, 0.25; T2, 0.50; T3, 0.75; and T4, 1.00%) were prepared and stored for 7 days at 5. The pH values of T4 were significantly lower (p 0.05) than that of control. a* and b* of T4 were the highest (p<0.05) among the all products. Total plate counts (TPC) increased (p<0.05) significantly as the storage period increased. The result of TPC showed the range of 5.48 (T2)~6.98 (C) log CFU/g at the 7 day of storage. Sensory panels evaluated that pork patties containing hot air dried tomato powder had the slightly higher score in overall acceptability. (

Dietary cholesterol affects lipid metabolism in rabbits

Effects of dietary cholesterol [0 (control), 1, 2, 4, or 8 g cholesterol/kg diet for 12 weeks] on lipid contents and fatty acid compositions in red blood cell (RBC) membranes and plasma of rabbits and pathological changes and lipid oxidation in their livers were determined. Contents of total lipid and unsaturated fatty acids in RBC membrane and plasma of rabbits fed ≥4 and ≥2 g dosages, respectively, were significantly higher (p<0.05) than those of the control, and their increases were dosage-dependent. Accumulations of neutral lipids in centrolobular regions of livers in rabbits fed ≥2 g were dosage-dependent. Lipid oxidation in liver of rabbits fed 8 g was >2 times higher (p<0.05) than those fed lower dosages. The results indicated that dietary cholesterol can modify lipid metabolisms of rabbits, including biosynthesis and transportation of lipids and fatty acids and incorporation of fatty acid into RBC membranes.

The Influence of Spices on the Volatile Compounds of Cooked Beef Patty.

The aim of this study is to examine the influences of spices on the amounts and compositions of volatile compounds released from cooked beef patty. Beef patty with 0.5% of spice (nutmeg, onion, garlic, or ginger powder, w/w) was cooked by electronic pan until they reached an internal temperature of 75℃. A total of 46 volatile compounds (6 alcohols, 6 aldehydes, 5 hydrocarbons, 6 ketones, 9 sulfur compounds, and 14 terpenes) from cooked beef patties were detected by using purgeand- trap GC/MS. The addition of nutmeg, onion, or ginger powder significantly reduced the production of the volatile compounds via lipid oxidation in cooked beef patty when compared to those from the control. Also, the addition of nutmeg and garlic powder to beef patty generated a lot of trepans or sulfur volatile compounds, respectively. From these results, the major proportion by chemical classes such as alcohols, aldehydes, hydrocarbons, ketones, sulfur compounds, and terpenes was different depending on the spice variations. The results indicate that addition of spices to the beef patty meaningfully changes the volatile compounds released from within. Therefore, it can be concluded that spices can interact with meat aroma significantly, and thus, the character of each spice should be considered before adding to the beef patty.

The effects of replacement of antibiotics with by-products of oriental medicinal plants on growth performance and meat qualities in fattening pigs

The effect of by-products of oriental medicinal plants (OMP; T1) containing 0.03% herb extracts (T2) or 0.1% aminolevulinic acid (T3) on the production performance of swine during the finishing period and on its meat quality were investigated. No significant differences were found in the weight gain, feed intake and feed conversion rate among the tested groups (P > 0.05). But the treated group showed higher (P < 0.05) moisture and ash and lower protein than the control group. The T3 group showed a lower meat cholesterol content (38.42 mg/100 g) compared to the other groups (P < 0.05). The vitamin E content of the muscle in the treated groups was higher compared to the control group. No antibiotic content was detected in all treated and control samples. The values of the volatile basic nitrogen (VBN) and thiobarbituric acid reactive substance (TBARS) of the treated groups were significantly lower (P < 0.01) than the control group. The treated groups had significantly better (P < 0.05) sensory-test scores for color, flavor, off-flavor and total acceptability compared to the control group.

Comparison of Physicochemical and Sensory Properties of Branded Pork by Feeding Probiotics and Crossbred between Korean Native and Wild Pigs

This study was carried out to investigate the physicochemical and sensory properties of branded pork by feeding probiotics and crossbred between Korean native and wild pigs. Crude protein contents showed in order of Brand A>Brand B>control (P

Changes of Quality Properties of Pork Loaves with Chemical-free Sweet Persimmon Powder during Chilled Storage at 5

Four different pork loaves were made with two levels, HP/FP-3% and HP/FP-6%, containing 3.0 and 6.0% HP (hot air dried sweet persimmon powder) / FP (freezer dried sweet persimmon powder), respectively. HP and FP (3% and 6%) were added into ground pork loin separately. A control without persimmon powder were used for comparison. Patties were cooked to 74 in electric oven, after cooling, the aerobic packaged meat loaves were stored at 5 . The moisture and crude ash were higher in the FP-6%, and the crude protein and crude fat were no different among the samples. The pH in control sample was significantly higher (p<0.05) than those of treatment group, however no significant difference was found among the 4 treatments. The TBARS (thiobarbituric reactive substance) values of all samples showed a tendency of increasing value along the storage days. The TBARS and a* value increased (p<0.05) as the addition ratio of HP/FP increased, respectively. With regard to microorganisms, the number of total aerobic bacteria were lower than 3.11 log10 CFU/g. In sensory evaluation, meat loaves containing persimmon powder resulted in a high overall acceptability, although they were not significantly different in overall

Alteration of Porcine Serum Albumin Levels in Pork Meat by Marination in Kiwi or Pineapple Juice and Subsequent Pan Broiling.

This study was conducted to evaluate the changes in porcine serum albumin (PSA), a major allergen, which occur when raw pork ham is marinated with kiwi or pineapple juice, and/or when the ham is pan broiled at 300℃ for 4 min after marination. In this study, raw pork ham was soaked for 4 h or 8 h in marinades containing commercial marinating sauce only, commercial marinating sauce and 7% kiwi juice, or commercial marinating sauce and 7% pineapple juice. When the meat was marinated and then pan-broiled, pork ham meat protein was significantly denatured and hydrolyzed, and the level of PSA in the meat was significantly reduced. The PSA contents of pork broiled without marination, pork that had been marinated in commercial marinating sauce alone, pork that had been marinated in commercial marinating sauce with kiwi juice, and pork that had been marinated in commercial marinating sauce with pineapple juice, were 95.4, 43.3, 14.3, and 5.4 ng/mL, respectively (p<0.05). Marinating with pineapple juice was more effective than marinating with kiwi juice; and marination for 8 h was more effective than marinating for 4 h. These results indicate that the level of PSA in pork ham is effectively reduced, when the meat is first marinated in sauces that contain kiwi or pineapple extracts for 8 h, rather than 4 h, and then cooked. Further study is needed to determine whether marinated pork meat reduces allergenicity in vivo, as well.