Hack-Youn Kim

Quality of frankfurter-type sausages with added pig skin and wheat fiber mixture as fat replacers.

Pig skin and wheat fiber mixture (PSFM) were assessed as fat replacers in frankfurter-type sausages. The addition of PSFM increased the moisture and protein content in the sausage because of the water binding capacity in wheat fiber and protein content in pig skin. The sausage sample containing 20% PSFM had 50% less fat, 32% fewer calories, and showed 39.5% less cooking loss than those of the control (p<0.05). High PSFM content resulted in more stable meat emulsions and increased hardness, cohesiveness, gumminess, and chewiness. No significant differences were observed in color, flavor, tenderness, juiciness, warm-off flavor, and overall acceptability between the control and sausage sample with PSFM by the sensory panel. Therefore, PSFM could be used as fat replacers to obtain lower calories, and higher moisture, protein contents, and emulsion stability than in low-fat frankfurter-type sausages without PSFM.

Effects of kimchi and smoking on quality characteristics and shelf life of cooked sausages prepared with irradiated pork.

The combined effects of kimchi powder (KP) and smoking (SM) on the quality characteristics and shelf life of cooked sausage prepared with 10 kGy irradiated pork (IP) were studied. The cooked sausages were formulated with single or combined treatment of 0.5% KP and SM (70°C for 30 min). IP+KP+SM treatment showed increased redness, hardness, gumminess, and chewiness, but decreased cooking yield. As for sensory evaluation, treatment with both KP and SM was effective to mask the radiolytic off-flavor. Moreover, the cooked sausage treated with both KP and SM had the highest color, flavor, and overall acceptance (P<0.05), where the differences of flavor patterns were verified by using an electronic nose. During chilled storage for 4 weeks, the combined treatment is effective to retard lipid oxidation, formation of volatile compound, and total microbial number due to the addition of KP. Therefore, usages of KP and SM can provide improved quality characteristics and shelf life of cooked sausage prepared with IP.

Antioxidant effects of soy sauce on color stability and lipid oxidation of raw beef patties during cold storage.

This study was conducted to evaluate the antioxidant effects of soy sauce on lipid oxidation and color stability of raw beef patties. Raw beef patties were formulated with four solutions such as NaCl (sodium chloride solution), NaCl/SS (1:1 ratio of sodium chloride and soy sauce solution), SS (soy sauce solution), or SS/A (soy sauce solution combined with 0.05% ascorbic acid) in the same salt concentration. Addition of soy sauce resulted in the decreased pH, lightness, and increased yellowness. Treatment SS/A had the lowest percent of metmyoglobin during storage (P<0.05). A reduction (P<0.05) in the 2-thiobarbituric acid, peroxide, and conjugated diene concentration as result of soy sauce addition were observed in treatments SS and SS/A at the end of the storage period. There were no differences (P>0.05) in free fatty acid concentration at the end of storage. The combined addition of soy sauce and ascorbic acid greatly improved (P<0.05) color stability and retarded lipid oxidation.

Tenderization effect of soy sauce on beef M. biceps femoris

This study was conducted to evaluate the tenderization effect of soy sauce on beef M. biceps femoris (BF). Five marinades were prepared with 4% (w/v) sodium chloride and 25% (w/v) soy sauce solutions (4% salt concentration) and mixed with the ratios of 100:0 (S0, pH 6.52), 75:25 (S25, 5.40) 50:50 (S50, 5.24), 25:75 (S75, 5.05), and 0:100 (S100, 4.85), respectively. The BF samples which were obtained from Hanwoo cows at 48 h postmortem (n=24) were marinated with five marinades for 72 h at 4°C (1:4 w/w), and the effects of soy sauce on tenderness were evaluated. Soy sauce marination resulted in a decrease in the pH value of the BF sample. However, there were no significant differences in the water holding capacity (P<0.05). The S100 treatment showed the significant (P<0.05) increase in collagen solubility and myofibrillar fragmentation index, contributing to decreased shear force compared to S0 (control). Reduction in intensity of few myofibrillar protein bands were observed for S100 treatment compared to control using SDS-PAGE. Scanning electron microscopy revealed breakdown of connective tissue surrounding muscle fibers of the S100 treatment. The tenderization effect of soy sauce may attribute various mechanisms such as increased collagen solubility or proteolysis which depend on soy sauce level in marinade.

Antioxidative properties of onion peel extracts against lipid oxidation in raw ground pork

Onion peels extracted with various concentrations of ethanol were examined for their extraction yield, total phenolic content, DPPH scavenging activity, and reducing power. Onion peel extracted with 50% ethanol exhibited higher extraction yields, total phenolic content, and DPPH scavenging activity than extracts from distilled water, 70 or 95% ethanol. Thus, the antioxidative efficiency to inhibit lipid oxidation of ascorbic acid (0.05%) and 50% ethanol extract of onion peel (0.05, 0.1, and 0.2%) in raw ground pork was investigated during chilled storage (16 days). The pH of the samples decreased considerably during storage (p<0.05). Addition of ethanol onion peel extract significantly improved the thiobarbituric acid reactive substances and peroxide values in raw ground pork meat (p<0.05). Therefore, onion peel extract by 50% ethanol is a very effective inhibitor of lipid oxidation and has potential as a natural antioxidant in raw ground pork.

Effects of soy sauce on physicochemical and textural properties of tumbled chicken breast

The objective of this study was to evaluate the effects of soy sauce on the physicochemical and textural properties of tumbled chicken breasts. Chicken breasts marinated with distilled water (Con), 4% NaCl solution, 4% NaCl and lactic acid solution (pH 4.9), and soy sauce solution (4% salt concentration and pH 4.9) were vacuum tumbled at 3°C for 60 min. The chicken breast marinated with soy sauce solution showed lower lightness and higher redness and yellowness due to the color of the soy sauce. The acidic marinades led to a decrease in pH value of tumbled chicken breast. The acidic marinades increased collagen solubility of sample compared with 4% NaCl solution, resulting in decreased shear force. Water-holding capacity, marination and cooking yields, and solubility of myofibrillar proteins were mainly affected by the presence of salt in the marinade, rather than by pH alternation. Our results suggested that soy sauce marination can improve the tenderness of tumbled chicken breast.

Physicochemical properties of M. longissimus dorsi of Korean native pigs

BackgroundThe meat quality of Korean native pigs (KNP) and crossbred pigs (LYD; Landrace × Yorkshire × Duroc) was examined to generate data useful for selecting native pigs for improved pork production.MethodsFifty Korean native pigs (KNP) and 50 crossbred pigs (LYD) were tested. Loin samples (M. longissimus dorsi) of the two breeds were analyzed to determine meat quality and sensory properties.ResultKNP had a higher moisture content than LYD (p < 0.05); however, it had significantly lower crude fat and ash content than that of LYD (p < 0.001). KNP had significantly higher shear force than LYD (p < 0.01). KNP also showed significantly higher cooking loss than LYD (p < 0.05). KNP had a lower L* value than LYD (p < 0.05); however, it had a markedly higher a* and b* value than LYD (p < 0.001). KNP showed significantly higher linoleic acid, linolenic acid, and arachidonic acid content than LYD (p < 0.05). Although KNP had significantly better flavor and overall palatability than LYD, it was less tender than LYD (p < 0.01).ConclusionKNP had a markedly higher a* value than LYD. KNP had significantly higher shear force than LYD. The total unsaturated fatty acid content was higher in KNP than in LYD.

Effects of Fat Levels on Changes in Flavor Pattern of Irradiated Pork Patties

The effects of fat levels on changes in flavor pattern of irradiated pork patties were evaluated by using electronic nose. Total peak amount decreased with increasing fat level and irradiation dose, and the increased fat level and irradiation dose influenced the formation of new peaks at latter retention time. For the principal component analysis, the irradiated pork patties with containing higher fat level were clearly separated from the other treatments. The irradiation dose also affected the position of spot in identical fat level. It is possible to distinguish the changes in flavor patterns due to fat content and irradiation dose by using electronic nose.

Effects of chicken feet gelatin extracted at different temperatures and wheat fiber with different particle sizes on the physicochemical properties of gels

Abstract The objectives of this study were to determine the effects of 1) the extraction temperature (65, 75, 85, and 95°C) of chicken feet gelatin (CFG) and 2) CFG extracted at different temperatures and wheat fiber (WF) with different particle sizes (80, 250, and 500 &mgr;m) on the physicochemical properties of the resultant gels. Raw chicken feet (CF) were swelled by treatment of an acidic solution [i.e., 0.1 N HCl (pH 2)]. The CFG was extracted from the swelled CF at different temperatures. Samples of 4% CFG or a mixture of 3% CFG and 3% WF were prepared using distilled water at 42 ± 1°C and then cooled to form gels. The physicochemical properties of the prepared CFG or the gel with CFG and WF were then investigated. The results indicate that the extraction yield, protein content, and L* values for the CFG samples significantly increased as the extraction temperature increased, whereas the viscosity, melting point, and a* values decreased. For the gel with CFG and WF, the gel strength, melting point, viscosity, and L* and b* values were significantly affected (P < 0.05) by the extraction temperature of CFG, but they partially were not affected (P > 0.05) by the particle size of WF. The gel with WF and extracted CFG at 65°C had the highest (P < 0.05) gel strength, melting point, viscosity, and a* values. In conclusion, CFG or the gel with CFG and WF could be utilized to prepare gelatins or gel with different physicochemical properties by controlling the extraction temperature or particle size of WF, depending on the specific application. Moreover, with its distinct physicochemical properties, the gel with CFG and WF could possibly be used as a non‐meat ingredient for fat replacement.

Effects of swelled pig skin with various natural vinegars on quality characteristics of traditional Korean blood sausages ( Sundae )

This study evaluated effects of swelled pig skin (SPS) with various natural vinegars (Bokbunja, brown rice, cider, and lemon vinegars) on the quality of the Korean traditional blood sausages. Adding SPS with various natural vinegars resulted in increased moisture content, cooking loss, L* values, and a* values and decreases in fat, protein content (p<0.05), hardness and thiobarbituric acid-reactive substance values in the meat product samples compared to those in the control. Treatments containing SPS with various natural vinegars decreased the warmed-over flavor but increased the tenderness. These results indicate that SPS with various natural vinegars would improve the quality characteristics and inhibit lipid oxidation of traditional Korean blood sausages.