• Title/Summary/Keyword: 고온 안정성

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Quality Changes in Various Heat-treated Market Milks during Storage (열처리를 달리한 시유의 저장중 품질 변화)

  • Kwon, Soon-Ha;Ahn, Joung-Jwa;Kwak, Hae-Soo
    • Journal of Dairy Science and Biotechnology
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    • v.16 no.2
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    • pp.90-97
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    • 1998
  • This study was carried out to investigate changes of microbiological and sensory properties in various heat-treated market milks (LTLT, HTST, and UHT milks) stored at 10$^{\circ}C$ during 15d. Titratable acidity (TA) increased with storage, while pH tended to decrease. During the initial 9d, no difference was found in TA, however, after 9d, it was slightly higher in HTST and UHT milks than that in LTLT milk. In LTLT and HTST milks, total viable cells and psychrotrophs were dramatically increased during storage, In addition coliform and pathogenic bacteria were found at 12 and 15d. In UHT milk, total viable cells were found only at 15d. In sensory evaluation, LTLT and HTST milks developed a negligible off-flavor until 9d. At 12d, it became stronger in HTST milk than that in LTLT milk. In UHT milk, off-flavor was detected at 9d and increased rapidly there-after. The degree of off-flavor was little higher in HTST and UHT milks, compared with that of LTLT milk after 9d storage. These observations indicated that LTLT and HTST milks may not be microbiologically acceptable after 5d, while off-flavor was not detectable until 9d, In comparison, UHT milk keeps a good quality in microorganism until 15d, however, it may not be accepted in sensory aspect after 9d storage.

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Differences in Root Growth Characteristics of Creeping Bentgrass and Kentucky Bluegrass Sod (크리핑 벤트그래스와 켄터키 블루그래스 뗏장의 뿌리생육 특성 차이)

  • Woo, Jong-Goo;Lee, Dong-Ik;Lee, Song-Ho
    • Asian Journal of Turfgrass Science
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    • v.21 no.1
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    • pp.23-37
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    • 2007
  • This study was carried out to investigate the characteristics of root growth in Kentucky bluegrass sod(KBS) and creeping bentgrass sod(BGS) transplanted in summer(August 9) and fall(September 19), respectively. Hydroponic system was also used to observe rooting development in the study. Root development differed in KBS by transplanting time. It reached to more than 5 cm after 100 days In summer and 50 days in fall. However, BGS's root grew over 6cm after 40 days, regardless of the season. There was no significant differences in BGS, regardless of any cutting treatment. In the case of KBS, it was best with sod culled with 0.5cm deep and 1.5cm long. But it grew beyond 5 cm in root growth under any treatment after 40 days in transplanting. In a hydroponic study, BGS produced root over 100cm for 80 days through a summer season. However, the root of KBS did only grow in condition below $20^{\circ}C$. These results indicated that root growth characteristics were variable in BGS and KBS. It was considered that rooting development of BGS might be improved with sufficient irrigation in summer, and KBS grows well in lower temperature of $10{\sim}18^{\circ}C$, as compared with BGS. As to establishing the lawn with a sodding method, it should be careful in transplanting time, especially KBS.