• Food Science of Animal Resources
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• v.28 no.4
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• pp.415-421
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• 2008

This study evaluated the effects of thermal processing combined with high pressure on the properties of cooked pork. Pressurization followed by heating (PFH), heating followed by pressurization (HFP) and heating under pressurization (HUP) treatments were compared to a heated only control. Cooked meat without simultaneous pressurization showed little or no decrease in water binding properties relative to the control, regardless of the sequence of pressurization and heating. However, HUP treated pork had significantly higher water binding properties than the control (p<0.05). The pH values of all treatments were not significantly different with the exception of HUP at 300 MPa. The HUP treated pork showed the best tenderizing effects among all the treatments tested and the effect was more significant at increased pressure levels (p<0.05). In addition, increasing pressure levels significantly increased the L-values of pork (p<0.05). PFH and HFP treated pork had significantly lower a-values (p<0.05), while no significant differences were observed in HUP. HUP treated pork had the lowest b-values at 100 MPa. however, the differences were not significant at increasing pressure levels. These results indicate that heating under pressure is the best cooking condition for improving the quality characteristics of pork without adversely affecting its appearance.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.139-150
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• 2019

This study aimed to determine the suitable point of sale and consumption of different quality grade (QG) Hanwoo short loin during aging period, based on physicochemical, sensory, and microbiological quality. Short loins obtained from the carcasses of 13 Hanwoo steers and 2 bulls with 5 different QGs (1++, 1+, 1, 2, and 3) were analyzed over 28 d. QG and aging time had significant effect on water holding capacity, color, shear force, total volatile basic nitrogen (TVBN) content, and sensory traits. Higher QG groups generally exhibited a lower shear force, nucleotide content, and water holding capacity, and higher $L^*$, $a^*$, and $b^*$ values. Acceptable tenderness (shear force <5.4 kg) in QG 1++, 1+, 1, and 2 was achieved on days 7, 14, 16, and 18, respectively, and QG 3 showed a shear force of 6.8 kg, even after 28 d. Regardless of QG, TVBN content below threshold levels (20-30 mg%) was observed throughout the 28 d aging period, while total plate counts above 7 Log CFU/g were seen at 21 d. In conclusion, it is recommended that Hanwoo beef with QG 1++, 1+, and intermediate QG (1 and 2) should be sold or consumed between 7 and 21, 14 and 21, 16 and 21 d, respectively. Beef with QG 3 should be sold or consumed within 21 d, based on microbial growth, even though it has not achieved desirable tenderness. For this reason, an additional tenderizing process is recommended before this beef is ready for consumption.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.85-100
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• 2023

The present study aimed to evaluate the effects of high-intensity ultrasound (HIU) application on meat quality traits, sensory parameters, and the microstructure of semitendinosus muscle from Hanwoo cattle. The samples were treated in an ultrasonic bath (35 kHz) at an intensity of 800 W/cm² for 60 min, followed by aging at 1℃ for 0, 3, and 7 days. The application of ultrasound resulted in lower Warner-Bratzler shear force and higher myofibrillar fragmentation index values during the storage period. HIU also enhanced the tenderness, flavor, umami, and overall acceptability of cooked beef muscle. However, the electronic tongue evaluation results showed higher umami values in the control treatment on the seventh day of storage. The microstructure of sonicated meat showed disorganized myofibrillar architecture and swelling in the A-band region of sarcomeres during the storage period, which led to greater meat tenderness. The heatmap illustrated the high abundance of α-linolenic acid (C20:5n3) and eicosapentaenoic acid (C18:3n3) in sonicated meat samples on the third day of the storage. These results showed that HIU is a potential method for tenderizing and improving the sensory attributes of beef without compromising other quality aspects.

• Korean journal of food and cookery science
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• v.27 no.3
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• pp.29-37
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• 2011

Protease activity of fig (Ficus carica L.), cultivated in Korea was estimated. In particular, the proteolytic effect on myofibrilar protein was studied. A crude protease extract of fig was prepared in two ways; fig was homogenized in buffer followed by centrifugation, and the supernatant was precipitated by saturated ammonium sulfate followed by dialysis. The former method resulted in 41.15 mM/g fig protease activity, whereas the latter method resulted in 17.65 mM/g fig protease activity. The crude fig protease extract showed high specificity for casein as a substrate followed by egg white, bovine serum albumin, myofibrilar protein, collagen, and elastin. The extract had stable proteolytic activity in a pH range of 6.5~9.0 (optimal at pH 7-8) but lost activity, at pH 2-3. Proteolytic activity for myofibrilar protein was sensitive to pH. The proteolytic activity of the fig extract was steady up to $60^{\circ}C$ but declined at higher temperature. It also began to lose stability in salt concentrations >0.7 M NaCl. Fig has been used as a meat tenderizer for cooking, and these results support the tenderizing effectiveness of fig, particularly for Korean style meat marinating.

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.323-329
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• 2010

Studies on the tenderizing effect of fruits has been limited even though fig, kiwifruit, pear, and pineapple cultivated in Korea are utilized commonly during cooking for their proteolytic properties. Therefore, the characteristics of these fruits were investigated by treating beef with their crude protease extracts. The protease effects of crude protease extract from the fruits on casein and myofibrilar protein were in the following order : pineapple > kiwifruit > fig > pear. Electrophoretic analysis results found that pineapple, kiwifruit, and fig cleaved myosin heavy chain into smaller fragments. The myofibrilar fragmentation ratio of crude protease extracts was the highest for pineapple whileas the lowest for pear. Ground fruits (5% and 10%) increased amounts of soluble nitrogen and decreased shear force of beef. Pineapple was the most effective while pear was the least effective. Decrease in springiness and gumminess was observed by texture profile analysis of beef treated with fruits, especially pineapple and kiwifruit. Among the 5% treatments, pineapple and kiwifruit produced the highest tenderness. Additionally, 10% treatment was less preferable than the 5% treatment.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.554-558
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• 2010

In the study, the protease activity of kiwifruit (Actinidia deliciosa Planch) cultivated in Korea was estimated, with specific examination of proteolytic effects on myofibrilar protein. The crude protease extract of kiwifruit was prepared in two ways; one in which the kiwifruit was homogenized with buffer followed by centrifugation, and the other were the supernatant was precipitated by saturated ammonium sulfate followed by dialysis. The former had 21.23 mM/mL of protease activity, which corresponded to 112.28 mM/g kiwifruit utilized, and the latter had 11.58 mM/mL and 45.80 mM/g of kiwifruit. The crude protease extract of the kiwifruit showed high specificity for casein substrate followed by bovine serum albumin, egg white, collagen, and elastin, in order. The enzyme lost proteolytic activity in acidic conditions such as pH 2-3, and at high temperatures over $60^{\circ}C$. It showed optimal activity in both pH 3.0 and pH 7.5 as well as at $40^{\circ}C$ for casein substrate and at $50^{\circ}C$ for myofibrilar protein substrate. The proteolytic activity toward casein was high with up to 0.5M salt, followed by a sharp decrease beyond this concentration. On the other hand the proteolytic activity for myofibrilar protein decreased steadily with increasing of salt concentration. Kiwifruit has been used as a for meat tenderizer for in home cooking and these results support the its tenderizing effectiveness of kiwifruit especially for Korean style marinating of meat for cooking.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.193-199
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• 2003

In order to investigate the meat tenderizing effects of pear, pineapple and kiwifruit, crude protease was prepared from each fruit and treated with actomyosin in a single manner or mixed type in several combination. Actomyosin was incubated with various proteases for 24 hrs under three different pH condition, and its degrading performance was evaluated by the SDS-PAGE. Pear extract showed an active degrading activity for actomyosin at pH 5.3 and 7.0. But, little actomyosin degradation was observed at pH 8.0. Actomyosin was strongly degraded by the treatment of protease from pineapple at all different pHs(5.3, 7.0 and 8.0). Kiwifruit protease extract has shown actomyosin degradation activity 1hr after treatment at pH 5.3 and pH 7.0. Meanwhile, the mixture of pear and pineapple extracts(l:l, w/w) showed much more degradation than the results of singular manner treatment at pH 5.3 and 7.0. When the pear protease was mixed with kiwifruit protease(l:l, w/w), the performance of actomyosin degradation was similar to the results of each single protease treatment. When the mixture was made of pineapple and kiwifruit extracts, actomyosin degradation was almost the same as the result of treatment of pineapple protease only. When those three proteases were mixed together(l:l:l, w/w/w), actomyosin degrading activities was in time dependent manner at pH 5.3. In summary, pear protease can be used potentially as a meat tenderizer when it was mixed with pineapple or kiwifruit rendering proper tenderization of the meat.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.367-371
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• 2000

In order to study the tenderizing effect of proteolytic enzymes in fruits, beef(M. semimembranosus) was marinated with meat sauce containing each fruit juices. After cooking, the shear force was measured by Rheometer and evaluated the sensory properties of beef by quantitative descriptive analysis method. The results are as follows: 1. The combination ratio of meat sauce:water was 2:1 with pH 5.0∼5.5 showed the max. tenderness. 2. As a result of shear force test, the decrease of shear force was pineapple>papaya>fig>kiwifruit>pear: especially, pineapple, papaya and fig tendered the beef significantly comparing with pear and kiwifruit at p<0.001. 3. The tendering effect of pineapple and papaya on the meat showed significant difference (p<0.01) comparing with pear in tenderness and overall acceptability by sensory evaluation; and there was a significant difference between pear and papaya in taste (p<0.05). 4. There was highly significant correlation between mechanical tenderness and sensory properties: correlation of fruit and mechanical tenderness was -.877(p<0.01); between mechanical tenderness and overall acceptability, r = .532(p<0.01); between fruit and sensory tenderness, r = .495(p<0.01); between mechanical tenderness and sensory tenderness, r = .490(p<0.01). At p<0.05, between taste and juiciness, r = .208.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.11-20
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• 1987

The study was carried out to observe some fundamental effect of spices on tenderization of beef, particularly round muscle part. The study has been investigated analytically in terms of histological and sensory test to compare the tenderizing effect of the spices with respective effect of commercial meat tenderizer and mechanical tenderizer on beef. The results of formal titration assay using casein as a substrate were that garlic, radish and ginger were stronger in protein hydrolysis than the other spices. Beef with spice treatment produced partial degradation of muscle fiber and connective tissue. Connective tissues and muscle fiber were generally degraded conspicuously by the treatment of commercial meat tenderizer. A general disruption and severing of muscle fibers and severing of connective tissue were seen in the area of blade penetration. The results of sensory test on the texture were that F-value of 11.27 is significant at the 1% of the sample. Beef treated with spices was significantly tenderer than beef without treatment at 5% level.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.883-887
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• 1998

Protease activities were measured in vegetables used as cooking material or a side dish. Proteases of green pepper (Kwari and Chungyang), perilla leaves, soybean sprout and mungbean sprout were showed high activities. Especially, protease in soybean sprout was the highest activity among them. After dialysis, remaining activities in mungbean sprout, green pepper (Kwari and Chungyang) and perilla leaves were 12, 23, 45% and 37%. In the results of thawing after freezing the proteases, remaining activities in sprout of mungbean and soybean were 100% and 65%. Protease in soybean sprout was showed higher activity and stability than others. Proteolytic effects of soybean sprout on myofibrillar and sarcoplasmic protein were showed higher than stroma protein. In SDS-PAGE, myosin heavy chain, actin and tropomyosin were hydrolyzed with increasing time. Protease activity was rapidly increased with increasing meat concentration in a early proteolysis reaction, but was slightly increased in later.