본 실험에서는 냉동 새우(Litopenaeus vannamei)를 4oC에서 12일동안 저온 저장하며, 키토산 코팅과 천연보존제의 병행처리(0.05% carvacrol, 0.05% thymol)가 미생물(중 온균, 저온균, Pseudomonas spp., H2S 생성균)의 성장과 새우의 이화학적 특징(총 휘발성 질소화합물, pH) 및 관능적 품질(외관, 냄새, 전반적 수용도)에 미치는 영향을 살펴보았다. 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 모든 대상 미생물의 성장을 억제하였고 특히 중온균, 저온균, H2S 생성균의 경우 실험 의 마지막 날인 12일째까지 유의적인 항균효과(p < 0.05)를 보였다. 이 처리구들은 총 휘발성 질소화합물과 관능적 특성(외관, 냄새, 전반적 수용도)에서도 12일째까지 유의적인 차이(p < 0.05)를 보였으나 pH에서는 유의적 차이 가 없었다. 따라서 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 새우의 주요 부패 미생 물의 성장을 효과적으로 억제하는 것으로 보이며 냉장 새우의 유통기간 연장에 활용할 수 있을 것으로 보여진다.
The objective of this study was to investigate the antimicrobial effects of carvacrol (CV) against Staphylococcus aureus (S. aureus) and Escherichia coli O157:H7 (E. coli O157:H7) strains in milk. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of CV against S. aureus and E. coli O157:H7 were determined. In addition, bactericidal kinetics and antimicrobial activity of CV against the aforementioned pathogens in milk over a period of 2 weeks were investigated. CV exhibited antibacterial activity against both foodborne pathogens tested. The MIC and MBC of CV against S. aureus were 15.0 and 20 mg/mL, respectively, whereas those against E. coli O157:H7 were 16.0 and 32 mg/mL, respectively. In time-kill assays, CV at MBC reduced the number of S. aureus and E. coli O157:H7 in milk to undetectable levels within 24 hr. The antibacterial effects of CV persisted for 14 days without any loss of activity. Results of this study suggest that CV has a potential antibacterial activity against foodborne pathogens such as S. aureus and E. coli O157:H7 in milk.
The effects of essential oils on pH, pathogens, and volatile fatty acids (VFA) in two poultry litters were investigated through a lab study. Essential oil-added poultry litters were randomly divided to two groups: control (200 g poultry litter) and Treatment (50 g thymol/Briefly, 200 g broiler litter was treated with or without 50 g thymol (Control and T1, respectively; 1 groups) and 200 g duck litter was treated with or without 50 g carvacrol (Control and T2, respectively; 2 group). Adding thymol to broiler litter increased the pH, reduced pathogens, and did not affect VFA. Interestingly, adding carvacrol slightly reduced the pH of duck litter, but had no significant effect on reducing pathogens and VFA. This difference is probably because the essential oil used and the properties of the two litters are different. In addition, pH was thought to control the odor generated from the litter, but this has not been proven. Further field studies should focus on clarifying this point.
The relationship between environmental growth conditions of savory(Satureja hortensis) and Zn and vitamin B3 has been previously reported. Based on these results, HPLC and GC-MS were used to investigate the levels of phenolic compounds and perform metabolite analysis, respectively, in plants collected from different areas. Differences were observed in the levels of polyphenols and flavonoids depending on sampled areas and natural conditions. Next, HPLC and metabolite analyses confirmed the presence of bioactive substances. The results also showed that the longer the storage time, the higher was the content of carvacrol and of rosmarinic acid. Finally, the difference in the active ingredients was minimal when plants were cultivated under growth conditions similar to those in the place of origin.