Gu Boo Park

Effects of dietary energy level and slaughter weight on growth performance and grades and quality traits of the carcass in finishing pigs.

Man Jong Park*, Jin Yeun Jeong*, Duck Min Ha**, Jeong Cheol Han**, Tae Geon Sim**, Byung Chul Park***,Gu Boo Park*, Seon Tea Joo* and Chul Young Lee**Division of Animal Science, Gyeongsang National University*,Regional Animal Industry Center, Jinju National University**, CJ Corp.***ABSTRACT(Y×L)×D-crossbred gilts and barrows weighing 80.2±0.2kg were fed a “medium-energy”(ME) or “low-energy”(LE) diet(3.2 vs 3.0M cal DE/kg) and slaughtered at 110, 125, or 138kg, after which physicochemical and sensory quality traits of major primal cuts of resulting carcasses were analyzed, under a 2(sex)×2(diet)×3(slaughter weight; SW) factorial arrangement of treatments. The ADG and ADFI were greater(P<0.01) in barrows than in gilts and also in 125- and 138-kg vs 110-kg SW. Moreover, ADG and gain:feed were greater in ME vs LE(P<0.01), whereas ADFI was greater in LE vs ME(P<0.01). Backfat thickness, which increased with increasing SW(P<0.01), was not affected by sex or diet. Carcass marbling score was greater (P<0.01) in gilts and LE than in barrows and ME, respectively. Carcass quality grade, which was superior in LE vs ME, was not affected by SW, whereas the yield grade decreased abruptly between 125- and 138-kg SW primarily due to the upper limit of carcass weight imposed on the A and B grades. Physicochemical characteristics including pH, drip loss, and variables pertaining to color of belly, ham, and loin were not affected significantly by any of the treatment factors, albeit statistically significant in some cases, in terms of quality criteria. In sensory evaluation, the acceptability of fresh belly was not influenced by any of the treatment factors. Marbling score of fresh ham was greater in LE vs ME(P<0.01) and tended to increase between 110- and 125-kg SW(P=0.10); in loin, the increase of this variable between the two SW was significant(P<0.01). Following cooking, LE was superior to ME in the acceptability in belly and ham, but the effect of SW was insignificant in any of the sensory quality traits evaluated in this study in any of the three major primal cuts. In conclusion, the present results suggest that SW can be increased to up to 138 kg without compromising carcass quality and that LE has some beneficial effects on quality of the whole carcass and the major primal cuts. (Key words :Finishing pig, Slaughter weight, Diet, Carcass, Meat quality)

The relationship between measurements of color and water-holding capacity in pork loin.

Sang Hun Moon*, Jin Yeon Jeong**, Gap Don Kim*, In Cheol Cho***, Jin Tae Jeon*, Seon Tea Joo* and Gu Boo Park*Division of Applied Life Science(BK21 program)*, Institute of Agriculture & Life Sciences**, Gyeongsang National University, National Institute of Animal Science, RDA***ABSTRACTThe objective of this study was to investigate the relationship between measurements of color and water-holding capacity (WHC) in pork loin. A total of 419 pork loins were sampled from crossbred(Landrace×Jeju native black pig) F2 pigs at a commercial slaughter house. Meat color measurements(CIE L*, a*, b*), chroma(C*) and hue angle(h) were measured with the Minolta Chromameter and WHC was measured by filter paper fluid, drip loss and cooking loss. Also pH, moisture content and crude fat content were measured at 24 hr postmortem. CIE L*, b* and h values had positive correlation with drip loss(r=0.52, 0.42), but CIE a* and C* values were not related to drip loss. Results showed that CIE L*, b*, and h color system was better than CIE L*, a*, b* color system to predict WHC, especially drip loss. pH was negatively correlated to drip loss(0.42) and CIE L* (0.67). Although CIE L* and pH were correlated to drip loss, the accuracy of their estimates for drip loss was 27% and 17%, respectively. Consequently, it was confirmed that meat color and WHC were not perfectly related and suggested that CIE L*, b*, and h color space should not be used independently to predict WHC of pork loin.(Key words :Meat color, Water-holding capacity, Pork loin)

Changes of Quality Characteristics of Manufactured Press Ham using Conjugated Linoleic Acid(CLA) Accumulated Pork during Storage Periods

To investigate the effects of conjugated linoleic acid added diet feeding on CLA accumulation and quality characteristics of manufactured press ham using CLA accumulated pork loin meat. The CLA used to add in diet was chemically synthesized by alkaline isomerization method with corn oil. Pigs were divided into 5 treatment groups(4 pigs / group) and subjected to one of five treatment diets(0, 1.25% CLA for 2weeks, 2.5% CLA for 2weeks, 1.25% CLA for 4weeks and 2.5% CLA for 4weeks, CLA diets; total fed diets) before slaughter. Pork loin were collected from the animals(110kg body weight) slaughtering at the commercial slaughter house. Manufacture press ham using CLA accumulated pork loin meat were vacuum packaged and then stored during 1, 7, 14, 21 and 28 days at 4 . Samples were analyzed for general compositions, physico-chemical properties(pH, color, shear force value), TBARS. pH value of CLA treatment(T4) was increased significantly than that of control(P < 0.05). pH of control and CLA treatments were increased significantly as the storage period passed(P < 0.05). Crude fat content of CLA treatment groups was significantly higher than the control pork (P < 0.05). Meat color(CIE L*, a*, b*) were no significant differences between the control and CLA treatment groups, and there were not changed by the passage of storage time. Shear force value were no significantly between the control and CLA treatment groups. All treatments were increased by the passage of storage time. All CLA treatment groups showed significantly(P < 0.05) lower TBARS value than the control. TBARS value was increased significantly during storage in all treatment. Summing up the a forementioned results, press ham manufacturing with CLA accumulated pork loin was not affected in physico-chemical properties. Also, it may be assumed that the high quality press ham can be manufactured with the extent of storage period.

Effect of Cooking and Packaging Methods on the Thiobarbituric Acid Reactive Substances and Cholesterol Oxidation Products of Turkey Thigh Meat Patties During Storage

Meat is a complex food with a highly struc-tured nutritional composition and major source ofcholesterol in the diet. It becomes edible andmore digestible when it is subjected to cooking.However, heat treatment can lead to undesirablemodifications, such as the loss of the nutritionalvalue of meats mainly due to lipid oxidation andchanges in some components of the cholesterol.The degree of oxide formation is related toprocessing temperature, heating time, storageconditions, level of activator present, packagingand most of the oxides found in foods weresubjected to processing conditions or exposure toheat(Paniangvait et al., 1995). cholesteroloxidation products(COPs) have been known to bemore injurious to arterial cells than pure

Bilolgical Activities of Conjugated Linoleic Acid (CLA) and Animal Products

이상의 연구 결과들을 요약해보면 CLA는 생체내외에서 다양한 생리활성 효과를 가지는 것을 알 수 있다. CLA의 주요 효과는 유방암, 췌장암, 피부암 및 대장암을 억제하는 효과, 동물체내에서의 면역력증강 효과, 동맥경화증에 대한 효과, 지방축적 억제효과, 체내 지방분해 촉진효과 및 식육에서의 항산화 효과와 육색안정 효과 등으로 요약된다. 그러므로 CLA는 건강보조식품으로 혹은 축산식품을 비롯한 다양한 식품의 기능성 첨가제로써의 충분한 가능성을 가지고 있는 것으로 사료된다. 그러나 이러한 CLA의 효과는 실험에 따라 다소간의 차이를 나타내고 또한 CLA의 생리활성 기작에 대한 정확한 이해가 부족한 실정이다. 따라서 향후 CLA와 관련하여 다음과 같은 연구가 필요할 것으로 사료된다. 1) 새로운 CLA 이성체의 발견 및 CLA 합성방법에 대한 연구 2) CLA가 가지는 각각의 생리활성 효과에 대한 정확한 기작을 밝히는 연구 3) CLA 이성체간의 생리활성 효과 차이에 대한 연구 4) CLA의 생리활성 효과를 극대화 할 수 있는 이성체간의 비율에 대한 연구 5) 기능성 식품첨가제로써의 CLA를 효과적으로 이용하는 방법 연구 6) CLA를 식용가축 및 축산물에 효과적으로 축적시키는 방법 연구 7) CLA를 이용한 육제품 및 유제품 개발 연구 8) 사람에 있어 CLA 효과에 대한 임상 연구. 【Conjugated linoleic acid(CLA) is a collective term for a group of positional (c8, c10; c9, c11; c10, c12, and c11, c13) and geometric(cis,cis; cis,trans; trans,cis; and trans,trans) isomers of octadecadienoic acid (linoleic acid) with conjugated double bond system. CLA has been shown to have a variety of biological effects. Major effects of CLA on health, such as anti-cancer, anti-oxidation, anti-atherosclerosis and improving immuno-responses, might be derived or partially derived from the alternated lipid metabolism after CLA feeding. Most of studies on the effect of CLA on fat metabolism are concentrated on rats, mice, pigs and other mammals. The CLA inhibited carcinogen-induced neoplasia in several animal models and inhibited the proliferation of human malignant melanoma, colorectal and breast cancer cells and CLA reduced the atherosclerosis. Several studies have determined the antioxidant property of CLA; however, the property still remains controversial. Some of the studies have shown that CLA acted as an antioxidant, whereas some other studies have demonstrated that CLA might be a prooxidant. Several studies suggested that CLA could reduce fat accumulation in mammals. CLA was suggested to promote muscle growth and reduce fat deposition in mouse, and improve feed efficiency in rats. CLA has been shown to inhibit the activity of stearoyl-CoA reductase. CLA also reduced the content of arachidonic acid. Since arachidonic acid, and eicosapentaenoic acid (EPA) and docosahexenoic acid (DHA) are synthesized by different pathways, reducing the synthesis of arachidonic acid may not mean reducing that of EPA and DHA. Many sutdies have been shown biological effects of CLA. Therefore, further research is needed to answer the following questions: 1) how to synthesize the new CLA by new methods, 2) why CLA has shown biological effects, 3) how to increase CLA effects in animal products.】

Effects of Dietary Glycine Betaine on the Growth Performance in Pigs

This study was conducted to investigate the effect of the addition of glycine betaine to the diet on growth performance in pigs. A total of 400 pigs were divided into 4 feeding stages(Growing I: 23.10 1.43, Growing II: 37.69 1.62, Finishing I: 66.51 3.44 and Finishing II: 90.42 2.17 kg of initial body weight) then each feeding stage was divided into 4 treatment groups(Control: 0 0/0, Tl : 0.2 0/0, T2: 0.4% and T3 : 0.6 % of glycine betaine, respectively). The average daily gain and feed efficiency of T2 and T3 were significantly increased(p

Effect of Irradiation and Packaging Methods on the Oxidation of Cholesterol in Raw and Cooked Chicken Leg Meat

Chicken thigh from a retail market were used as experimental samples. Some chicken samples of raw state were packaged with PVDC at an aerobic and vacuum condition. The other samples were cooked until core temperature arrived at 70 and then packaged immediately in the same way of raw samples. After samples were irradiated by electron beam at 6 kGy, they were stored in a refrigerator. Identification and quantity of cholesterol oxides were made at 0 and 7 days of storage, respectively. During the early stage of storage, 7β -hydroxycholesterol, , -epoxide, cholestanetriol and 7-ketocholesterol were produced from the raw meat αβ samples, and the production of these chemicals were significantly higher(P 0.05) from the samples with aerobic packaging than those with vacuum packaging. With storage time, 7 -hydroxycholesterol, α 6-ketocholesterol and some other chemicals, which were not found during the early stage of storage, were found. Also, the formation of these chemicals were significantly increased(P 0.05) with storage time. Cholesterol and lipid oxidation products of cooked meat after irradiation and irradiated meat after cooking were significantly increased(P 0.05) with storage time for all treatments, and vacuum packaging results in showed significantly lower value(P 0.05) than aerobic packaging. Summarizing the aforementioned results, it was found that the formation of cholesterol and lipid oxides and lipid oxidation was more easily affected by packaging condition than irradiation.

Effect of Dietary Glycine Betaine on Pork Qualities During Storage

ABSTRACT A total of 80 pigs were used to investigate the effect of dietary glycine betaine( N,N,N -trimethylglycine) onpork quality during cold storage. About 70 kg pigs were randomly alloted into one of four experimental dietgroups(0%, 0.2%, 0.4% and 0.6% glycine betaine). Pigs were slaughtered at approximately 110 kg liveweight, and pH, color(CIE L* a* b*), shear force, sarcomere length, lipid oxidation and composition of fat-ty acid were measured in pork loin for 13 days of cold storage. The concentration of glycine betaine inpork loin was significantly increased(P < 0.05) with incr easing of glycine betaine level in diet. Pork loinsfrom dietary betaine groups showed significantly higher muscle pH and lower CIE b* values compared tocontrol group after 13 days of storage. There were significant differences in shear force values among porkloins from diet groups at 24 hrs postmortem. However, pork loins from control diet showed longer sarco-mere length than those of dietary betaine groups. Dietar y glycine betaine increased the ratio of saturated fattyacids and decreased unsaturated fatty acids in pork loins. Especially the ratios of linoleic and myristic acid were de-creased with increasing dietary betaine level. However, d ietary glycine betaine did not affect lipid oxidation(TBARS) and sensory evaluation during cold storage.

Effect of Conjugated Linoleic Acid(CLA) Feeding Levels and Periods on Textural Property and Fatty Acid Composition of Pork

To investigate the effects of conjugated linoleic acid added diet feeding on CLA accumulation and quality characteristics of pork meat. The CLA used to add in diet was chemically synthesized by alkaline isomerization method with corn oil. Pigs were divided into 5 treatment groups(4 pigs/group) and subjected to one of five treatment diets(0, 1.25% CLA for 2 weeks, 2.5% CLA for 2 weeks, 1.25% CLA for 4 weeks and 2.5% CLA for 4 weeks, CLA diets; total fed diets) before slaughter. Pork loin were collected from the animals(110 kg body weight) slaughtering at the commercial slaughter house. Pork loin meat were aerobic packaged and then stored during 2, 5, 8, 11 and 14 days at 4 . Samples were analyzed for shear force value, texture, TBARS, fatty acid composition, cholesterol and CLA content. CLA treatment groups showed significantly(p 0.05) higher shear force value compared to those of control group at 11, 14 days of cold storage. All treatments were decreased significantly as the storage period passed. There was a not significantly difference in texture between control and CLA treatment groups. All CLA treatment groups showed significantly(p 0.05) lower TBARS value than the control. TBARS value was increased significantly during storage in all treatment. CLA treatment groups showed significantly(p 0.05) lower cholesterol content compared to those of control group. As dietary CLA was increased in feed, the content of CLA was increased, but the control was almost not detected. The contents of CLA were not significantly changed during chilled storage for 14 days. In the change of fatty acid composition, the contents of oleic, linoleic and arachidonic were decreased by dietary CLA-supplementation, whereas the increase level of CLA-supplementation resulted in the higher palmitic and stearic acid. In all results, CLA could be accumulated in pork meat and its antioxidant capability has been indicated. It