The purpose of this study was to investigate the prevalence, toxin gene profiles, and enterotoxin producing ability of Bacillus cereus isolated from environment-friendly vegetables and good agricultural practices (GAP) vegetables. A total of 49 vegetables including 40 environment-friendly vegetables and 9 GAP vegetables were tested. The Vitek 2 system was used to identify B. cereus and the PCR was used to detect 6 toxin genes, respectively. B. cereus was detected in 34 (69.3%) of 49 vegetables and the prevalence of B. cereus in GAP vegetables (44.4%) was lower than in the environment-friendly vegetables (75.0%). The detection rates of entFM, nheA, hblC, and cytK enterotoxin genes, respectively, among all isolates were 100%, 97.0%, 88.2%, and 73.5%, respectively. All of the isolates had at least one or more enterotoxin gene and 20 isolates (58.8%) had hemolysin BL enterotoxin producing ability. The risk of food poisoning from the environment-friendly vegetables and the GAP vegetables has been shown as constant. Thus, it is necessary to expand the supply of GAP vegetables showing lower B. cereus contamination than the environment-friendly vegetables. The characteristics of the environment-friendly vegetables and the GAP vegetables that must be consumed after cleaning should be disseminated to consumers regarding food poisoning prevention.
Ptaquiloside는 고사리에 들어 있는 발암성 물질이다. 본 연구는 다양한 조리법에 따라 고사리에 함유된 ptaquiloside 을 측정해 보고자 하였다. 조리법은 가열, 물에 침지, 물 교환 횟수 등이었다. 알칼리 가수분해와 용매분획은 ptaquiloside를 화학적으로 안정한 물질인 pterosin B로 전환시켜 주었다. Pterosin B 함량은 이동상용매로 3 mM ammonium과 메탄올 용매를 사용하여 UPLC-MS/MS로 분 석하였다. 조리과정이 없는 생고사리의 H2O추출물에 함유 된 pterosin B함량은 81 mg/kg으로 검출되어 독성물질 ptaquiloside는 46.4 mg/kg이었다. 5분의 가열 시간 후 고사리의 pterosin B 함량은 약 60%정도 제거시켜주며, 이 중 2/3는 ptaquiloside에서 전환된 pterosin B가 아닌 고사리 고유의 ptersoin B 함량이었다. 12시간 침지를 추가한 고사리는 처리하지 않은 고사리에 비해 약 88%, 또한 매 시간 물교환 작업을 추가시 99.5%까지 제거됨을 알 수 있 었다. 따라서 독성물질 ptaquiloside의 제거는 가열시간과 더불어 침지와 물 교환 횟수도 동시에 이루어져야 함을 알 수 있었다.
In this study, we investigated the inhibition effect of various herbs on the rancidity of soybean oil. The antioxidant activity of herb-infused oils was evaluated by examining their total phenolic contents and DPPH radical scavenging abilities. The total phenolic contents were found to increase with addition of herbs to the soybean oil. Rosemary-infused oil (RO) exhibited the highest total phenolic contents (77.28 μg GE/mL), followed by the lemon-balm-infused oil (LO), green-tea-infused oil (GO), and soybean oil (SO) alone (36.82, 36.66, and 21.24 μg GE/mL, respectively). Similary, the DPPH radical scavenging activity of the herb infused oil also increased. Moreover, measurements on the total polar compound (TPC) contents, acid value, and p-anisidine value were carried out in order to confirm the changes in the rancidity of the oils during frying. The time for the TPC content to reach 25% was confirmed to be delayed from 62 h for SO to 68 h, 74 h, and 80 h for GO, RO, LO, respectively. Even though there were some differences between the p-anisidine and acid values, it was confirmed that the addition of herbs inhibited the rancidity of soybean oil. Therefore, the results in this study show that adding herbs to soybean oil could positively contribute to the inhibition of oxidation and rancidity.