Hyun-Woo Seo

Optimization of hydrolysis conditions for bovine plasma protein using response surface methodology

The purpose of this study was to establish optimal conditions for the hydrolysis of bovine plasma protein. Response surface methodology was used to model and optimize responses [degree of hydrolysis (DH), 2,2-diphenyl-1-picrydrazyl (DPPH) radical-scavenging activity and Fe(2+)-chelating activity]. Hydrolysis conditions, such as hydrolysis temperature (46.6-63.4 °C), hydrolysis time (98-502 min), and hydrolysis pH (6.32-9.68) were selected as the main processing conditions in the hydrolysis of bovine plasma protein. Optimal conditions for maximum DH (%), DPPH radical-scavenging activity (%) and Fe(2+)-chelating activity (%) of the hydrolyzed bovine plasma protein, were respectively established. We discovered the following three conditions for optimal hydrolysis of bovine plasma: pH of 7.82-8.32, temperature of 54.1 °C, and time of 338.4-398.4 min. We consequently succeeded in hydrolyzing bovine plasma protein under these conditions and confirmed the various desirable properties of optimal hydrolysis.

Effects of Addition of Green Tea Extracts on Physicochemical Properties of Seasoned Chicken with Soy Sauce during Cold Storage

The objective of this study was to investigate the effects of addition of green tea extracts on physicochemical properties and shelf-life of seasoned chicken with soy sauce during cold storage. Treatments (C, T1 and T2) containing various levels (0, 1 and 2%, respectively) of green tea extracts were manufactured, and we investigated pH, meat color (L * , a * , b * ), volatile basic nitrogen (VBN), thiobarbituric acid reactive substances (TBARS), total plate counts, fatty acid composition and sensory scores during cold storage for 16 days. T1 and T2 have more dark color than control during storage time. VBN, TBARS and total plate count of control were significantly higher than those of T1 and T2 at the latter storage time (p<0.05). Also, VBN, TBARS and total plate count of all treatments was increased with storage time. Linoleic acid was the highest value in control which had the highest value of TBARS in day 16 (p<0.05). Aroma value of control was significantly higher in storage time except day 16 than those of T1 and T2 (p<0.05). Acceptability value of control was significantly higher than those of T1 and T2 in day 4, 8 and 12 (p<0.05).

Supplementation of Pork Patties with Bovine Plasma Protein Hydrolysates Augments Antioxidant Properties and Improves Quality

This study investigated the effects of bovine plasma protein (PP) hydrolysates on the antioxidant and quality properties of pork patties during storage. Pork patties were divided into 4 groups: without butylated hydroxytoluene (BHT) and PP hydrolysates (control), 0.02% BHT (T1), 1% PP hydrolysates (T2), and 2% PP hydrolysates (T3). Pork patty supplemented with PP hydrolysates had higher pH values and lower weight loss during cooking than the control patties. Results showed that lightness and hardness both decreased upon the addition of PP hydrolysates. All samples containing BHT and PP hydrolysates had reduced TBARS and peroxide values during storage. In particular, 2% PP hydrolysates were more effective in delaying lipid oxidation than were the other treatments. It was concluded that treatment with 2% PP hydrolysates can enhance the acceptance of pork patty.

Cholesterol-lowering and lipid oxidation reduction potentials of traditional seasonings in Salchichon dry-fermented sausages.

Five different natural/traditional seasonings including doenjang (fermented soybean paste), gochu-jang (red pepper paste), fresh medium-hot and hot peppers, and garlic were used, and 1xa0% (w/w) each was incorporated into formulations of Salchichon fermented sausage type. After ripening for 51xa0days, the products were assessed for quality parameters, lipid oxidation, cholesterol content and sensory characteristics. In general, incorporation of the seasonings did not cause color or texture defects whereas it had beneficial effects on improvement of product’s quality; however the effects differed depending on each type of seasonings added. Noticeably, most treatments with the seasonings significantly reduced the lipid oxidation. Additionally, incorporating doenjang, gochu-jang, medium-hot peppers, hot peppers and garlic resulted in reduction of 32.03, 28.96, 36.30, 19.53 and 33.03xa0mg cholesterol/100xa0g sample, corresponding to 26.78, 24.21, 30.35, 16.33 and 27.61xa0%, respectively. Higher scores for the sensory traits such as aroma, taste, color and acceptability were also observed for the samples with seasonings. The current work demonstrated that the tested seasonings represent potentially natural ingredients for producing healthier Salchichon fermented sausages.

Effects of injection of hydrolysis plasma protein solution on the antioxidant properties in porcine M. Longissimus Lumborum.

BackgroundPlasma protein hydrolysates have been shown to possess antioxidant activity. However, no report has yet to examine the antioxidant effects of injection of plasma protein hydrolysates on meat quality. Therefore, in this study, the effects of injection of hydrolysis plasma protein solution on meat quality and storability were investigated in porcine M. longissimus lumborum.MethodsTwelve pigs were randomly selected at a commercial slaughter plant and harvested. Dissected loins were injected with one of five solutions: C- control (untreated), T1- 10xa0mM phosphate buffer solution (PBS), T2- 10xa0mM PBS with 0.01xa0% butylated hydroxytoluene, T3- 10xa0mM PBS with 5xa0% plasma proteins, and T4- 10xa0mM PBS with 5xa0% hydrolysis plasma proteins.ResultsT3 and T4 induced greater reduction in protein content of the loin muscle than other treatments. T2 resulted in the lowest pH as well as highest cooking loss. After a storage period of 3-7 days, both lightness and redness of meat were unaffected by all injection treatments. However, yellowness was significantly elevated by treatment with T4 relative to the control. T4 also resulted in the lowest shear force (a measure of meat toughness), suggesting improvement of texture or tenderness. Further, T4 resulted in the most stable TBARS values during storage, indicating that this treatment might retard rancidity in meat.ConclusionInjection of porcine M. longissimus lumborum with hydrolysis plasma protein solution could improve overall pork quality, including tenderness and storability.

Quality Properties of Sausages Made with Replacement of Pork with Corn Starch, Chicken Breast and Surimi during Refrigerated Storage.

This effect of replacing pork with corn starch, chicken breast and surimi on the chemical composition, physical, texture and sensory properties of sausage were investigated during storage. Five treatments of sausage such as; T1 (10:0:0, %), T2 (10:5:0, %), T3 (10:10:5, %), T4 (10:15:10, %) and T5 (10:20:15, %) were prepared with replacement of pork with corn starch, chicken breast and surimi. The sausage made with pork meat served as control (C). The sausage in the control had higher moisture and fat contents, but lower protein content than the treatments (p<0.05). The sausages in the T2 and T5 had decreased pH values after 3 wk storage (p<0.05). The lightness value was lowest in the T3, while the yellowness values were lowest in the T5 during the storage. The TBARS (2-thiobarbituric acid reactive substance) values were lowest in the control in all storage times (p<0.05). However, the sausage in the control had higher VBN (volatile basic nitrogen) value than the treatments during the 1 wk storage (p<0.05). All treatments had significantly higher hardness, cohesiveness, springiness, gumminess and chewiness values (p<0.05) than the control. The results indicated that corn starch, chicken breast and surimi can used as a pork replacer, that it also improves the physicochemical and texture properties of pork sausages.

Beneficial Effects of Traditional Seasonings on Quality Characteristics of Fermented Sausages

Though traditional seasonings are widely used in many dishes, however, no attention has been paid to the investigation of their effects on quality characteristics of food products. The present investigation was undertaken to study the effects of incorporating several traditional seasonings including doenjang (fermented soybean paste), gochu-jang (red pepper paste), fresh medium-hot, and hot peppers, and fresh garlic on the lipid oxidation, cholesterol content and sensory characteristics of fermented sausages. Six fermented sausage treatments (5 with 1% (w/w) each test seasoning and 1 without added test seasoning (control) were prepared. The addition of seasonings generally had beneficial effects on the improvement of fermented sausage’s quality however the effects differed depending on the each type of seasonings added. Significant lower pH values were found in all fermented sausages made with the seasonings while, lower levels of lipid oxidation were found in the treatments with hot peppers and garlic as compared with the control (p<0.05). The treatment with seasonings did not cause color or texture defects in the products whereas the sausages made with gochu-jang had significantly higher Commission International de l’Eclairagea* (redness) value in comparison with the control. Noticeably, incorporating doenjang, medium-hot peppers, hot peppers and garlic resulted in reduction of 26.50, 32.54, 47.04, and 48.54 mg cholesterol/100 g samples, respectively (p<0.05). Higher scores for the sensory traits such as aroma, taste, color and acceptability were also given for the sausages made with seasonings. The current work demonstrates that the test seasonings represent potentially natural ingredients to be used for producing healthier fermented sausages.

The effects of pre-and post-slaughter spray application with organic acids on microbial population reductions on beef carcasses

As an attempt to control bacterial cross-contamination of beef carcasses, in the present investigation acetic acid and lactic acid (3% v/v) were used for bacterial decontamination. For the decontamination, cows were sprayed with each above acid at two different stages; (i) on live animals hides, (ii) on carcass surfaces immediately after slaughter. Microbiological samples were taken on different hide areas of animals before spraying and on carcass surfaces at 24h after spraying. Meat quality traits were also analyzed on the sprayed animals. The detected microorganisms were identified using 16SrRNA gene sequencing. A diversity of bacterial species such as Staphylococcus, Shigella, Bacillus, Escherichia and Salmonella etc. were found on both external hide and carcass surface samples. The decontamination sprays significantly reduced the numbers (2-5 log unit) of all aforementioned bacterial species on carcass surfaces as compared with non-sprayed control. Thus, the two times-spray applications with the acid could be an effective tool for reducing bacterial cross-contaminations of beef carcass without adverse effect on meat quality.

Utilisation possibility of Enterococcus faecalis isolates from neonate's faeces for production of fermented sausages as starter cultures

Summary nThis study aimed at assessing the utilisation possibility of Enterococcus faecalis as starter cultures for production of fermented sausages. The E.xa0faecalis isolates isolated from faeces samples of 5-day-old healthy newborn babies, identified by 16SrDNA sequencing and free from virulence determinants as proven by genomic sequencing, were used for fermented sausages production as starter culture. Six treatments (four inoculated with four different E.xa0faecalis isolates, one with commercial starter culture and one control) were prepared. The inoculation with E.xa0faecalis showed a stronger acidification compared with the control. The treatments with E.xa0faecalis showed significantly higher flavour and acceptability scores in comparison with the control or commercial starter culture. Both of commercial starter culture and E.xa0faecalis were positive with tyramine. Apart from the amine production, the inoculation with E.xa0faecalis generally improved the acidifying activity and flavour of the products, suggesting their application potentials in fermented sausages production as starter cultures.

Physicochemical Characteristics of Beef Jerky Cured with Salted-fermented Anchovy and Shrimp

The aim of this study is to evaluate the availability of salted and fermented fish (SFF) including salted and fermented anchovy (SFA) and shrimp (SFS) as a marinade of beef jerky. In curing solutions, half (SFA 1 and SFS 1) or whole (SFA 2 and SFS 2) salt-water was replaced with SFF juices. Higher water activity (aw) was found in the beef jerky cured with SFFs than the control (C) (p< 0.05). The SFFs had the effect of causing a decrease in hardness and an increase in cohesiveness (p<0.05). Among the treatment samples, springiness was the highest in SFA2 and SFS2 (p<0.05) and the lowest values of Warner-Bratzler shear force were found in SFA1 and SFA2 (p<0.05). The SFFs also had the effect of increasing the flavor of the sensory properties; however, color measurements from both the instrumental surface color (L*, a*, b*, chroma, and hue angle) and color of sensory evaluation were decreased by addition of SFFs (p<0.05). Therefore, we conclude the SFFs can improve the texture and sensory properties of the beef jerky. In particular, the SFS is a good ingredient for the curing solution. However, studies are still needed on improving the aw, pH, and surface color of the beef jerky to apply the SFFs for making beef jerky.