열처리에 의한 Yoghurt 의 보존성에 관한 연구

고준수 한국낙농학회 1983 韓國酪農學會誌 Vol.5 No.3

Yoghurt는 乳酸박테리아를 多量으로 含有하고 있기 때문에 低溫에서 貯藏하여야 하며 可能한 限 빨리 消費하여야 한다. 요구르트를 長期的 貯藏이 必要할 境遇 熱處理에 依하여 乳酸박테리아數를 減少시킴으로서 保存性을 增進시킬 수 있다. 本 試驗은 Starter culture를 3% 接種하여 3時間 培養製造한 요구르트와 3.5時間 培養 2種의 요구르트의 保存性을 試驗하였으며 그 結果는 다음과 같다. 1. 培養時間을 各各 3時間, 3.5時間으로 하여 製造한 요구르트는 pH가 4.32와 3.92, 滴定酸度는 1.03%과 1.37%, 總乳酸박테리아數는 9.6×10^7/㎖와 7.7×10^8/㎖ 그리고 Streptococci와 Lactobacilli比率은 1.1 : 1과 1.3 : 2로 優秀한 品質의 Set Yogurt를 生産할 수 있었다. 2. 요구르트를 加熱하였을 때 3.5時間 培養하여 製造한 요구르트가 乳酸박테리아의 死滅速度가 더 빨랐으며 60℃에서 30分 加熱하였을 때 3時間 培養製造한 요구르트에 8.5×10^6/㎖, 3.5時間 培養製造한 요구르트에는 2.1×10^5/㎖의 乳酸박테리아가 生存하여 있었으며 Streptococci의 死滅比率이 Lactobacilli보다 더 높았다. 3. 加熱하지 않은 요구르트와 60℃에서 30分 加熱한 요구르트를 各各 4℃, 20℃, 30℃에서 保存하였을 때 pH의 降下速度는 加熱하지 않은 요구르트에서 3.15時間 培養製造한 요구르트가, 加熱한 요구르트는 3時間 培養製造한 요구르트가 더 빨리 低下되었다. 4℃와 20℃에서 30日 保存하였을 때 3.5時間 培養하여 加熱한 요구르트의 pH는 3.8以上, 3時間 培養하여 加熱한 요구르트는 pH가 3.53以上으로 維持되었으며 保存性이 매우 優秀하였다. 4. 貯藏期間이 經過함에 따라 요구르트內의 乳酸박테리아數는 顯著히 減少하여 4℃에서 保存 30日, 30℃에서 保存 20日에 乳酸박테리아가 發見되지 않았다. 3時間 培養하여 加熱한 요구르트는 20℃에서 保存 30日에, 3.5時間 培養하여 加熱한 요구르트는 20℃에서 保存 20日에 乳酸박테리아가 모두 死滅하였으며 保存期間이 經過함에 따라 Lactobacilli의 比率이 增加하였다. 5. 熱處理한 Set yoghurt는 30℃에서 保存 20日까지, 4℃와 20℃에서 30日까지 貯藏이 可能하였으며 3.5時間 培養製造하여 加熱處理한 요구르트가 保存性이 가장 優秀하였다. Yoghurt containing large quantities of lactic acid bacteria has to be stored at refrigeration temperature. If the refrigeration system is not prepared, yoghurt has to be consumed immediately after produced, or heated so as to decrease the number of lactic acid bacteria involved for the preservation. Though the heat treated yoghurt loses the microbiological merits, it can hold nutritive value for a quite long. Set yoghurt was made by inoculating 3% starter culture and incubated for 3 and 3.5 hours at 42℃. The keeping quality of yoghurt by heat treatment was evaluated in this experiment, and the results are summarized as follows: 1. Titratable acidity, pH, total lactic acid bacteria and the ratio of streptococci and lactobacilli of yoghurt produced by incubating for 3 hours (Sample A) were 1.03%, 4.32, 9.6 × 10^7/㎖, 1.1 : 1 and those of yoghurt produced by incubating for 3.5 hours (Sample B) were 1.37%, 3.92, 7.7 × 10^8/㎖, 1.3 : 2. 2. Heating at 60℃ for 30 minutes decreased the number of viable lactic acid bacteria to 8.5 × 10^6/㎖ in sample A, and to 2.1 × 10^5/㎖ in sample B. Thermal death of lactic acid bacteria in Sample B was more serious than in Sample A, and lactobacilli survived heat treatment better than streptococci. 3. When yoghurts were stored at 4℃, 20℃ and 30℃, the change of pH of unheated sample B was faster than that of unheated sample A, and heated sample B was slower in change of pH than heated sample A. The pH of heated sample B stored at 4℃ and 20℃ for 30 days did not fall below 3.8 and showed good keeping quality. Heated sample A stored at 4℃ and 20℃ for 30 days maintained their pH value above 3.53. 4. As the storage time was extended the number of viable lactic acid bacteria was highly decreased. There was no viable lactic acid bacteria at 20th storage day at 30℃, 30th storage day at 4℃ and 20℃ except heated sample B. Heated sample B showed no viable lactic acid bacteria at 20th storage day at 20℃. Lactobacilli disappeared more slowly than streptococci. 5. Set yoghurt treated at 60℃ for 30 minutes could be stored at 30℃ for less than 20 days, however at 4℃ and 20℃ kept good quality for 30 days. Sample B treated at 60℃ for 30 minutes showed the best keeping quality.

선박자동화 발전방향

고준수,유병랑,이준호 한국마린엔지니어링학회 2003 한국마린엔지니어링학회지 Vol.27 No.5

공중모의 비행시험기 개조 개발 사례 연구

고준수,이용표,최섭,안종민 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

Lactobacillus acidophilus 와 Streptococcus thermophilus 에 의한 Ultrafiltration 처리우유의 발효 촉진 : I. 무기물과 L - cysteine 이 산생성 및 유산균 변화에 미치는 영향 I. Effect of Minerals and L - cysteine on Acid Production and Viable Lactic Acid Bacteria in Fermented Milk

고준수,김거용,제등선일 한국낙농학회 1990 韓國酪農學會誌 Vol.12 No.2

Lactobacillus acidophilus와 Streptococcus thermophilus에 의한 ultrafiltration處理 牛乳의 醱酵促進을 위해 利用된 無機物과 L-cysteine의 효과를 要約하면 다음과 같다. 1. L. acidophilus 單獨 培養時 酸生成은 全乳, UF-retentate 및 濃縮乳중 全乳에서 가장 높게 나타났으며, L. acidophilus와 S. thermophilus를 混合 培養할때의 젖산 濃度 증가는 UF-retentate에서 제일 높게 나타났다. 생존 젖산 균수는 L. acidophilus 단독 培養時에는 거의 유사하나, 混合 培養時에는 UF-retentate에서 제일 많았다. 2. L. acidophilus와 S. thermophilus 混合 培養時의 酸生成이 L. acidophilus 單獨培養時보다 더 높은 수준을 나타내었다. 생존 젖산 균수에 있어서는 L. acidophilus 單獨 培養時 더 높았으나 UF-retentate에서는 單獨 및 混合 培養時 生存 젖산 菌數가 유사하였다. 3. L. acidophilus 單獨 培養時 全乳, UF-retentate 및 濃縮乳에 無機物을 添加하면 酸生成이 促進되며, 微生物 數가 증가하였고, L. acidophilus와 S. thermophilus를 複合 培養시에는 濃縮乳에서만 徵生物 數가 증가하였다. 4. L. acidophilus 單獨 培養時 UF-retentate에 L-cysteine을 添加했을때 酸生成이 促進된다. The effects of minerals and L-cysteine on the fermentation of ultrafiltrated milk by Lactobacillus acidophilus and Streptococcus thermophilus are summerized as follows; 1. L. acidophilus inoculated solely produced more acid in whole milk than in UF-retentate and evaporated milk, mixed culture of L. acidophilus and S. thermophilus produced acid most in UF-retentate. The viable cells of lactic acid bacteria of the sole culture of L. acidophilus were similar in whole milk, UF-retentate and evaporated milk, whereas viable cells of the mixed cultures of L. acidophilus and S. thermophilus were highest in UF-retentate. 2. The mixed culture of L. acidophilus and S. thermophilus produced more acid than the sole culture of L. acidophilus. The viable cells of L. acidophilus inoculated independently usually showed the higher level, but those of the mixed and the sole cultures were similar in UFretentate. 3. Minerals added to whole milk, UF-retentate and evaporated milk, increased the acid production and viable cells of L. acidophilus. In the case of fermentation by the mixed culture of L. acidophilus and S. thermophilus, minerals only increased the viable cells in evaporated milk. 4. L-cysteine stimulated acid production in UF-retentate formented by the sole culture of L. acidophilus.

개조 항공기 감항성 설계연구

고준수,Ko, Joon Soo 한국항공운항학회 2013 한국항공운항학회지 Vol.21 No.4

Airworthiness certification is a repeatable process implemented to verify that a specific aircraft can be safely maintained and operated within its approved flight envelope. Airworthiness certification activity for the FA-50 aircraft has been performed according to the Airworthiness Certification Criteria, issued in 2011 by DAPA. It is a right time to study the application of those existing ACC process and tools to the hypothetical modification aircraft. This paper describes airworthiness engineers view of the integrated activities required to substantiate the modified aircraft performance. The compliance methods applicable to the airworthiness certification criteria is also suggested. It will be useful for the establishment of the future Korea modified military aircraft's ACC with the risk assessment and methods of compliances tailored to the legacy aircraft.

장기체공 무인항공기 기술기준 및 안전성 평가 연구

고준수,김경목,Ko, Joon Soo,Kim, Kyungmok 항공우주시스템공학회 2016 항공우주시스템공학회지 Vol.10 No.2

Multi disciplinary approach for aerodynamics, structure, propulsion, and flight control system is necessary to develop High Altitude Long Endurance Unmanned Aerial Vehicles (HALE UAV). Various HALE UAV development trends are surveyed to understand their operational requirements. Separating the UAV Take Off Weight by 150kg, Airworthiness implementation direction for HALE UAV is studied under the current Airworthiness regulations. NATO STANAG 4671 and STANAG 4703 Airworthiness certification criteria are analyzed, and their applicability was proposed for future HALE UAV development. In addition, minimization of the risk for UAV is studied by considering probability of cumulative catastrophic failure for HALE UAV. This Hazard Risk Index can support the future UAV Airworthiness Certification Criteria.

안정 특성치 민감도 분석 ( Sensitivity Analysis of the Stablity Characteristics )

고준수 대한전자공학회 1986 대한전자공학회 학술대회 Vol.1986 No.01

Lactobacillus acidophilus 와 Streptococcus thermophilus 에 의한 Ultrafiltration 처리우유의 발효 촉진 : II. 발효 및 저장중의 유성분 변화 II. Conversion of Milk Constituents during Fermentation and Storage

고준수,안종건,박재인,권일경,김거유 한국낙농학회 1992 韓國酪農學會誌 Vol.14 No.2

Lactobacillus acidophilus와 Streptococcus thermophilus를 사용하여 UF-retentate, 전유, 농축유를 발효하였을때 가용성질소화합물, 아미노산, 탄수화물 함량의 변화와 저장 중 산 및 젖산균 변화를 무기물(FeSO₄, MgSO₄, MnCL₂)과 L-cysteine의 영향과 함께 조사하였다. UF-Retentate와 농축유가 원료유일 경우 L. acidophilus와 S. thermophilus를 함께 사용한 복합균주로 발효했을 경우와 L. acidophilus 단독균주로 발효했을 경우 모두 가용성 질소함량의 증가는 매우 적었고, 전유의 경우 L. acidophilus 단독균주를 사용했을 때에만 가용성질소가 현저하게 증가하였다. L-Cysteine는 이와같은 양상에 영향을 미치지 않았고, UF-retentate와 농축유에 무기물을 첨가했을때 L. acidophilus단독균주에 의한 가용성질소의 생성량을 증가시킬 수 있었다. 발효후에 유당함량은 현저하게 감소했으며 L-cysteine은 유당함량 변화에 영향을 주지 않았으나 무기물은 UF-retentate를 L. acidophilus 단독균주로 발효한 경우와 전유를 L. acidophilus와 S. thermophilus 복합균주로 발효 시킨 경우를 제외하고는 유당함량의 감소를 촉진하였다. 발효후 대부분의 아미노산함량이 증가했으며 특히 glutamic acid의 함량이 많이 증가하였다. L-Cysteine은 L. acidophilus 와 S. thermophilus복합균주에 의해 제조된 발효유의 저장중 산 및 생존젖산균수의 변화에 영향을 미치지 않았다. This research was performed to study the effect of minerals(FeSO₄, MgSO₄, MnCl₂)and L-cysteine on the change of constituents of fermented ultrafiltration retentate(UF-retentate), whole milk and evaporated milk during fermentation by Lactobacillus acidophilus and Streptococcus thermophilus, and during stroage at 9℃ for 96 hours. The soluble nitrogen content increased a little in UF-retentate and evaporated milk fermented by mixed culture(L. acidophilus and S. thermophilus) and single culture(L. acidophilus), but whole milk fermented by single culture showed high increase in the soluble nitrogen value. L-Cysteine did not show any effect on the change of the soluble nitrogen content during fermentation, but minerals increased the soluble nitrogen content very much in UF-retentate and evaporated milk fermented by single culture during fermentation. Lactose content was decreased significantly by fermentation. L-Cysteine had no effect on the change of lactose content, and minerals stimulated the decrease of lactose content in fermented milks except UF-retentate fermented by single culture and whole milk fermented by mixed culture during fermentation. Fermentation increased the content of almost of amino acids especially that of glutamic acid. L-Cysteine added before fermentation had no effect on the change of acidity and number of viable lactic acid bacteria in fermented milks during storage at 9℃ for 96 hours.

粉末乳酸菌 스타터에 依한 요구르트의 試驗的 製造

高浚洙 江原大學校 1978 硏究論文集 Vol.12 No.2

醱酵乳 製造에 있어서 Starter의 효과(英文)

高浚洙 江原大學校 1980 硏究論文集 Vol.14 No.2