The functional properties of cheese, such as texture and melt, are known to be controlled by several important parameters. Recently, the characteristics of Ca in cheeses, especially the form of Ca (insoluble (INSOL) or soluble) and the shift in Ca equilibrium (i.e., from INSOL to soluble Ca), during aging has received a lot of attention. The INSOL form of Ca, which is present as a structural form in casein, plays a critical role in determining the functional properties of cheese during the early period of ripening (~1 mon). It seems that there is always a reduction of INSOL Ca content in cheese during ripening and there are also factors that can affect the shift in Ca equilibrium. These factors may include the composition of cheese milk, cheese manufacturing pH, acid development during aging, adopting curd-washing in various methods, pre-acidification of milk, etc. There have been many studies showing that the rheological and melting properties of cheese during ripening were significantly (p<0.05) affected by the shift in Ca equilibrium. Therefore, for cheese makers, it is now possible to predict/manage the functional properties of cheese by monitoring and controlling Ca equilibrium in cheese during aging.

Two experiments were carried out to investigate the relationship of slaughter age and carcass traits of Hanwoo cattle. A total number of 11,284 heads of cattle (4,624 bulls, 6,120 steers, and 540 females) were used in the experiment (Exp.) 1. In the Exp. 2, 3,887 heads of steers slaughtered at age of 24-36 mon were used. After 24 h post-slaughter chilling, the carcasses were weighed and evaluated by an official grader of carcass traits according to the Korean carcass grading standard. Backfat thickness was the main variable in yield index and grade whereas marbling score was the main variable in carcass quality grade. Meat color was an important factor affecting carcass quality grade of bulls; fat color was an important factor affecting those of steers and females; and maturity was an important factor affecting that of females. After 24-mon-old, extension of slaughter age did not automatically increase the quantity and quality of meat. However, 29 mon of age can be regarded as the optimum time to slaughter steers to attain the highest take home money for farmers.

Effects of the addition of kimchi powder on the physico-chemical and sensory properties of semi-dried sausages were investigated at the following kimchi powder concentrations: control (0%), T1 (1%), T2 (2%), and T3 (3%). pH of the semi-dried sausages containing kimchi powder decreased with the addition of kimchi (p<0.05). Also, the addition of kimchi powder to the sausages significantly decreased the CIE $L^*$ and increased the CIE $a^*$ and CIE $b^*$ values (p<0.05). The T3 treatment resulted a higher mositure lose than other treatments. TBARS values of the T2 and T3 groups were significantly lower (p<0.05) than that of the control, while T3 had the highest VBN value among treatments at the end of the storage period. Addition of kimchi powder to semi-dried sausages improved the overall sensory properties of the sausages, and increased the softness and tenderness. These results suggest that addition of 2% kimchi powder to semi-dried sausage is helpful to improve the quality of sausages.

This study was designed to elucidate the quantities of milk nutrients entrapped during cholesterol removal from milk by crosslinked $\beta$-cyclodextrin ($\beta$-CD, 0.4~1.2%, w/v) and to evaluate the amounts of the residual $\beta$-CD in cholesterol-reduced milk treated by crosslinked $\beta$-CD. The content of lactose in the control milk (without treatment by crosslinked $\beta$-CD) was 4.86%, and the amounts of lactose entrapped by crosslinked $\beta$-CD ranged from 0.00 to 0.03%. The total amounts of the entrapped short-chain free fatty acid (FFA) and free amino acid (FAA) ranged from 0.03 to 0.09 ppm and from 0.28 to $0.71{\mu}mol/mL$, respectively. The amounts of the entrapped water-soluble vitamins (L-ascorbic acid, niacin, thiamine and riboflavin) ranged from 0.02 to 0.05 ppm, 0.01 to 0.06 ppm, 0.00 to 0.06 ppm and 0.01 to 0.06 ppm, respectively. The entrapped amounts of lactose, short-chain FFAs, FAAs and water-soluble vitamins were not remarkably affected by the concentrations of crosslinked $\beta$-CD (0.4~1.2%, w/v). Only very small amounts of residual $\beta$-CD in the cholesterol-removed milk were measured (1.22~3.00 ppm). Based on the data obtained from the present study, it was concluded that the amounts of entrapped nutrients were negligible during cholesterol removal from milk by crosslinked $\beta$-CD, and only trace amounts of residual $\beta$-CD were present in cholesterol-removed milk.

This study examined the effect of gamma irradiation on shelf-life extension and sensory characteristics of dak-galbi. Commercial dak-galbi sauce was gamma-irradiated at 0, 5, 10, 15, 20, 25, and 30 kGy. The dak-galbi sauce (200 g) was then added to diced chicken (800 g) for cooking, and the cooked dak-galbi samples in vacuum bags were stored at $35^{\circ}C$ for 5 d. Dak-galbi samples were analyzed on d 0, 1, 2, 3, 4, and 5 for microbial analysis (plate count agar), thiobarbituric acid (TBARS) and volatile basic nitrogen (VBN) measurements, and on d 0 for sensory evaluation. On d 0, total bacterial populations were below detection limit after dak-galbi marinated with the gamma-irradiated (${\geq}15\;kGy$) sauces were cooked, and the samples marinated with higher dose irradiated dak-galbi sauce had lower (p<0.05) bacterial populations during storage. TBARS values of the dak-galbi samples marinated with non-irradiated sauce were not different ($p{\geq}0.05$) with those marinated with irradiated sauces on d 0, and the TBARS values increased (p<0.05) during storage at $35^{\circ}C$, regardless of irradiation dose. In the VBN analysis, there was no difference ($p{\geq}0.05$) in VBN values among irradiation doses on d 0, but VBN values decreased (p<0.05) as irradiation dose increased during storage. Moreover, there were no significant differences ($p{\geq}0.05$) in sensory characteristics among irradiation doses. These results indicate that use of gamma irradiation on dak-galbi sauce may be useful in shelf-life extension without compromising the sensory characteristics of dak-galbi.

This study was conducted to investigate the effects of heating, fiber type used in solid-phase microextraction (SPME, two phase vs three phase) and storage time on the volatile compounds of porcine M. longissimus dorsi (LD). Volatile compounds were measured using a gas chromatography and mass spectrometry (GC/MS) with a quadrupole mass analyzer. Among the volatile compounds identified, aldehydes (49.33%), alcohols (24.63%) and ketones (9.85%) were higher in pre-heated loins ($100^{\circ}C$/30 min), whereas, alcohols (34.33%), hydrocarbons (22.84%) and ketones (16.88%) were higher in non-heated loins. Heating of loins induced the formation of various volatile compounds such as aldehydes (hexanal) and alcohols. The total contents of hydrocarbons, alcohols, and carboxylic acids were higher in two phase fibers, whereas those of esters tended to be higher in three-phase fibers (p<0.05). Most volatile compounds increased (p<0.05) with increased storage time. Thus, the analysis of volatile compounds were affected by the fiber type, while heating and refrigerated storage of pork M. longissimus dorsi increased the volatile compounds derived from lipid oxidation and amino acid catabolism, respectively.

The aim of this study was to model and optimize the calcium alginate (CA) and microbial transglutaminase (TG) systems to form a cold-set myofibrillar protein (MP) gel containing 0.1 M or 0.3 M NaCl using a response surface methodology. The gel strengths of cold-set and heat-induced MP gels, and cooking yields were measured. All measured parameters showed determination coefficients ($R^2$) above 0.7 without a lack-of-fit. The CA system had the best results with component ratios of 1.0:0.3:1.0 corresponding to sodium alginate, calcium carbonate and glucono-$\delta$-lactone, respectively, and was favourable at 0.1 M NaCl. In contrast, the TG system only had an effect on cold-set MP gelation at 0.3 M salt, and the optimal ratio of TG to sodium caseinate was 0.6:0.5. By combining the two systems at 0.3 M NaCl, an acceptable cold-set MP gel with an improved texture and high cooking yield could be formed. Therefore, these results indicated that the functionality of the cold-set MP gel could be enhanced by combining these two optimized gelling system.

This article concerns the labeling guideline for health benefits of livestock products. In recent years, livestock products with health benefits have emerged as a key market for livestock product industries. However, the current labeling regulation for functional foods severely prohibits livestock product industries from attaching most of the health benefits claims to the products. Also, manufacturers have some difficulties in labeling the health benefits of certain livestock products because of a lack of guidelines on health benefit claims for livestock products. Therefore, some livestock product industries and scientists have strongly demanded a revision of labeling regulation, Appended Chart No. 14 provided by Article 52 (2) of Enforcement Regulation of the Processing of Livestock Products Act, so they could mark the health benefits on their products. To support the 'revision of labeling regulation', the goals of this article were as follows; 1) to assess the current situation on nutrition labeling and nutrition claims on foods, 2) to determine the current situation on health claim regulatory systems used in foreign countries (CODEX, USA, Japan, EU, and Australia/New Zealand), 3) to assess the current situation on the health claim or health benefit claim regulations for functional foods, conventional foods, and livestock products in Korea, and 4) to determine the need for complement in health benefit claim for livestock products. In conclusion, guidelines for the use of health benefit claims on livestock products should be prepared as soon as possible and the guidelines should be viable and easy for manufacturers and control authorities to understand. Also, nutrient profiles should be developed to identify whether the livestock products are eligible to bear health benefit claims and to help consumers make the right choices.

유화형 소시지에 마늘즙과 양파즙을 각각 1%와 3%를 첨가하여 냉장온도($4{\pm}1^{\circ}C$)에서 21일간 저장하면서 pH, peroxide value, TBARS, 총 미생물수 및 아질산염 잔존량을 조사하였다. 실험구는 마늘즙과 양파즙을 첨가하지 않은 대조구, 마늘즙 1% 첨가구는 T1, 마늘즙 3% 첨가구는 T2, 양파즙 1% 첨가구는 T3 및 양파즙 3% 첨가구를 T4 등 5개 처리구로 나누어 0, 7, 14 및 21일간 저장하면서 실험하였다. pH는 저장기간이 경과하면서 모든 처리구에서 서서히 감소하였고, 마늘즙 첨가구는 양파즙 첨가구보다 낮았으며, 대조구의 pH가 가장 높았다. 과산화물가는 저장기간 동안 증가하였고, 마늘즙과 양파즙의 첨가구는 대조구보다 유의적으로 낮은 함량을 보였다(p<0.05). TBARS는 저장기간 동안 직선적으로 증가하였으며, 마늘과 양파를 첨가한 유화형소시지는 대조구보다 낮아 마늘과 양파즙이 지방산화를 지연시켰고, 마늘이 양파보다 효과적이었다. 그리고 마늘즙과 양파즙의 첨가량이 많을수록 TBARS값은 낮은 경향이었다(p<005). 총 미생물수는 저장기간이 지나면서 모든 첨가구에서 증가하였고, 저장 0일에는 처리구간 유의성이 없었으며, 처리구간에는 마늘즙 3% 첨가구인 T2에서 유의적으로 낮은 미생물수를 나타내었다. 아질산염 잔존량은 저장기간이 경과하면서 감소하였는데 T2에서 다른 시험구보다 많이 감소하였다. 이상의 결과를 종합적으로 고찰해보면 마늘즙 3% 첨가구는 산화 및 미생물 성장 억제 가능성이 있는 것으로 사료된다.

이 연구는 성인분변으로부터 발효유 제조에 이용되는 probiotic로서의 우수한 능력을 지닌 균주를 선발하는데 목적을 두었으며 선택배지에서의 성장, 그람 양성, 현미경 관찰을 통해서 간균인 총 204개의 sample 중에서 10% skim milk에서 24시간 배양 후 커드 형성 여부에 따라 19개를 선발하였고, 2차 계대하여 48시간 후에 커드 형성 여부를 통해 6개를 선발하였다. 그 중에서 산 생성 능력이 우수한 균주를 3개 선발하여 원유로부터 분리한 L. casei MCL과 L. casei YIT 9029의 특성을 비교하였다. 선발된 균주는 그람 양성이고, 간균이며, 당 발효 실험과 16S rDNA 분석결과 Lactobacillus casei로 판명되어 L. casei CU2604, L. casei CU3204, L. casei LC8로 명명하였다. 이중 L. casei YIT 9029과 동일한 당 발효패턴을 보인 L. casei CU2604는 pH 변화와 생균수의 변화가 L. casei YIT 9029와 비슷한 양상을 보이고 PFGE 패턴이 같았다. 그러나 세포벽 지방산조성 분석결과를 통하여 L. casei YIT 9029와는 다른 균주임을 알 수 있었으며, 담즙내성, pH내성은 더 우수한 결과를 보였고, 또한 L. casei CU2604는 병원성균에 대하여 우수한 생육억제 능력을 나타내었다. 이러한 결과를 토대로 L. casei CU2604는 상업용 균주에 못지 않은 스타터로서의 특징을 가지고 있는 것으로 판단되며, 이 균주의 probiotics 특성에 대한 추가적인 연구가 진행 중에 있다.

유기태 셀레늄 급여가 쇠고기의 육색의 안정성에 미치는 영향을 구명하기 위하여 유기태 셀레늄(효모, 미국 Sel-Plex)군, 유기태 셀레늄 강화버섯을 생산하고 폐기되는 셀레늄이 다량 함유되어 있는 폐배지(Se-SMC : Se-spent mushroom compost)를 급여한 쇠고기와 급여하지 않은 쇠고기의 육색 안정성을 비교한 결과는 다음과 같다. 육색(Hunter $L^*$, $a^*$, $b^*$), chroma(채도, 색도), hue(색조, 색상) 및 총색차(${\Delta}E$)값을 측정한 결과 처리구간에 차이가 없는 것을 볼 때 최대 홍화시점으로 알려진 절개 후 30분이 경과한 육색측정 값으로는 유기태 셀레늄의 급여효과를 구명하기 어려웠다. 반면 냉장($4{\pm}1^{\circ}C$) 14일 및 21일 저장한 시료를 분쇄한 후, $20^{\circ}C$의 항온기에서 48시간 산화시킨 후 육색소의 화학적 조성을 비교한 결과, OxyMb은 저장 14일차 대조구 26.04, 유기태 셀레늄 효모급여구 28.52, 셀레늄 강화 버섯폐배지 급여구 33.78이었고, 21일차는 대조구 12.65, 유기태 셀레늄 급여구 18.98, 셀레늄 강화 버섯폐배지 급여구 18.72로 대조구에 비하여 유기태 셀레늄 효모급여구와 셀레늄 강화 버섯폐배지 급여구가 높은(p<0.05) 결과를 보였다. MetMb의 함량에 있어서는 대조구가 유기태 셀레늄 효모급여구와 셀레늄 강화 버섯폐배지 급여구에 비하여 높은(p<0.05) 결과를 보여 셀레늄 급여 쇠고기는 Mb의 산화 및 갈변화를 억제하고 선홍색의 육색을 유지하는데 효과적인 것으로 판단된다.

본 연구는 유단백질에 단백질 분해효소를 처리하여 가수분해 후 저분자 peptide를 ABTS법을 이용하여 항산화 활성을 측정하여 유단백질 유래 저분자 peptide의 항산화력을 측정하고자 하였다. Chymotrypsin 처리한 유청단백질의 가수분해도가 가장 높았으며, 유청단백질의 락트알부민 및 락토글로브린이 분해되어 분자량 20 kDa 이하의 저분자 단백질이 생성된 것을 전기영동을 통하여 확인하였다. 유단백질의 농도에 따른 항산화 활성을 측정한 결과, 카제인의 항산화 활성이 유청단백질보다 높게 나타났다. 유단백질을 효소에 의하여 가수분해 시 항산화 활성이 증가하였으며, 카제인 가수분해물이 유청단백질 가수분해물과 비교하여 항산화 활성이 더 높았으나, 가수분해도와 항산화 활성도의 관계는 일치하지 않았다. Trypsin에 의한 카제인 가수분해 물의 항산화 활성이 80.7%로 가장 높았다. 본 연구에서는 chymotrypsin과 trypsin에 의한 분자량 3 kDa의 카제인 분획물의 항산화 활성이 가장 우수 하였으며, 유청단백질을 trypsin으로 분해하였을 때 항산화 활성이 증가하였다.

발효유제품, 김치, 및 신생아 분변 등에서 유산균을 분리하여 isoflavone 전환 능력을 평가하였다. 유산균 중 높은 수준의 $\beta$-glucosidase 활성을 보인 균주는 Enterococcus sp. 77, L. paracasei, Lactobacillus sp. 712, L. brevis ATCC 8287, Lactococcus sp. KU107, L. acidophilus KCNU, L. plantarum L155 등으로 나타났다. 이들 유산균에 대하여 유당 발효성을 평가하여 가장 우수한 유산균을 선발하여 API, 16S rDNA를 분석한 결과 Lactobacillus plantarum으로 동정되었으며 이 활성 유산균을 Lactobacillus plantarum YS712로 명명하였다. Lactobacillus plantarum YS712는 pH 2.5에서도 약 50% 이상의 강한 생존율을 보였으며 DPPH 라디칼 소거능도 95.8%로, 선발된 유산균 중 가장 높은 라디칼 소거능을 나타내었다. 이로써 Lactobacillus plantarum YS712는 발효식품 및 유제품에 다양하게 이용할 가치가 있다고 판단된다.

유제품에 들어 있는 우유와 산양유를 동정하기 위해 미토콘드리아의 12S rRNA 유전자를 목표로 하는 primer을 이용하는 duplex PCR 분석을 적용하였다. 소와 산양의 특이성 primer을 이용한 duplex PCR 분석은 우유와 산양유 DNA에 대해 각각 233 bp와 326 bp의 특이성 단편을 나타냈다. Duplex PCR 분석이 라벨에 표시된 성분을 확인하기위하여 시중마트에서 구입한 15개 유제품에 적용하였다. Duplex PCR 분석 결과 4개 시유, 3개 요구르트, 1개 전지분유는 표시된 성분과 완전히 일치하였다. 그러나 7개의 조제분유 중 5개만 표시성분과 일치하고 2개 조제분유제품은 산양유와 우유가 각각 오염되어 있는 것으로 나타났다. 제안된 duplex PCR 분석은 산양유에 들어있는 우유를 0.1%까지 측정할 수 있는 민감하고 신속한 방법이다. Duplex PCR 분석은 유제품 속에 들어있는 우유와 산양유를 one-step 방법으로 동시에 탐지할 수 있다.