柵欄技術在真空包裝即食豆干產品之應用

Since tou-kan curd is high in nutrition and water activity, it's a very suitable environment for micro-organisms to grow in. Its vacuum packaging is particularly susceptible to contamination from Clostridium botulinum. In order to avoid this risk, this study reduced the dried bean curd's (both the large and small types) pH to under 4.60 or its water activity to under 0.85. The vacuum packaging was pasteurized in order to develop the contamination prevention hurdle technology. The study prepared a low-pH soaking liquid composed of polyphosphate (U, Tarisan U) or a low water-activity liquid composed of glycerol, propylene glycol, and salt. The bean curd was soaked in this, reducing the pH to below 4.6 and the water activity to below 0.85. The product storage study results showed that reducing the pH and water activity and then using vaccuum packaging and sterilization allowed the bean curd to be preserved for at least four weeks at below 7℃. At below 25℃, it could be preserved for at least 10 days. During the storage period, the total plate count, aerobic quality, and number of anaerobic spores were not tested. The study showed that hurdles such as pH value, water activity, low-temperature sterilization, and cold storage could be combined to produce sanitary vacuum-packaged tou-kan curd products.豆干具高水活性及營養的特色，是十分適合微生物生長的環境，其中肉毒桿菌的預防對真空包裝即食豆干的污染特別重要。為避免肉毒桿菌的危害，本試驗將豆干 (大豆干及小印干) pH 值降至 4.60 以下，或降低其水活性至 0.85 以下，並於豆干真空包裝後進行加熱殺菌，以開發防止微生物汙染之真空包裝即食豆干柵欄技術。本試驗利用多磷酸鹽 (特磷素 U，Tarisan U) 及乳酸調製低 pH 值浸漬液，或食用甘油、丙二醇 (propylene glycol) 及食鹽調製低水活性浸漬液，並將大豆干或小印干產品浸於其中，可降低產品 pH 值 (<4.6) 或水活性 (<0.85)。由產品貯存試驗結果顯示，殺菌前將豆干的 pH 值降至 4.6 以下，或降低水活性至 0.85 以下，再進行真空包裝及殺菌，可讓豆干在 7℃ 下至少保存 4 週，在 25℃ 下至少保存 10 天；於貯存期間，其總生菌數、好氣性及嫌氣性孢子數均未被檢出。試驗結果顯示，組合 pH 值、水活性、低溫殺菌及冷藏等柵欄，可用以生產衛生安全之真空包裝即食豆干產品。中文摘要 I 英文摘要 II 目次 III 表次 V 圖次 VII 壹、前言 1 貳、文獻整理 4 一、大豆製品簡介 4 二、pH質與微生物之關係 9 三、水活性與微生物之關係 12 四、溫度與微生物生長之關係 15 五、真空包裝定義 18 六、肉毒桿菌簡介 18 七、柵欄技術 24 參、研究架構 29 肆、材料與方法 30 一、實驗材料 30 二、儀器設備 30 三、實驗方法 31 (一) 利用潤濕劑降低大豆干或小印干產品之水活性 31 (二) 利用酸化浸漬液降低大豆干或小印干產品之 pH 值 31 (三) 真空包裝即食豆干製備 31 (四) 即食豆干真空包裝後殺菌試驗 32 (五) 樣品保存試驗 32 (六) pH 值測定 32 (七) 水活性測定 33 (八)官能品評分析 33 (九)總生菌數分析 33 (十)好氣性細菌孢子數分析 33 (十一)嫌氣性細菌孢子數分析 34 (十二)黴菌、酵母菌菌數分析 34 (十三)統計分析 34 伍、結果與討論 35 一、真空包裝即食豆干及小印干產品柵欄組合探討 35 二、官能品評分析 35 三、pH值調整探討 41 四、水活性調整探討 41 五、殺菌條件探討 46 六、包裝前殺菌及包裝後殺菌處理真空包裝即食豆干之微生物品質變化 .47 七、真空包裝即食豆干及小印干產品保存試驗 59 陸、結論 63 柒、參考文獻 6

Eradication and Control Strategies for Red Imported Fire Ants (Solenopsis invicta) in Taiwan

Invasive alien species are one of the major threats to biological diversity, public safety, agriculture, and economics. In recent years, a new wave of the red imported fire ant (RIFA) has been detected in new regions, including Kobe (Japan), Daegu (South Korea), Kaohsiung (Taiwan), and other locations in southeast Asia. Due to the increasing number of invasions, practitioners and scientists are seeking effective strategies to respond to RIFA invasions in Pacific regions, especially in countries that have had no presence of RIFA. This study aims to identify the strategies adopted to eradicate RIFA in Taiwan and to elucidate some of the assumptions about RIFA prevention and treatment in infested areas with diverse land patterns. Through a literature review and examination of eradication cases in Taiwan, five essential eradication lessons are discussed: (1) Immediate action through partnership with universities and the private sector; (2) engagement with the public and community with an interest in RIFA control through technology; (3) establishment of multi-level horizontal networks of response teams; (4) strategy implementation ranging from large-scale prevention to precise treatment; and (5) adoption of technology and social media. These strategies will have implications and applications for east and south Asian countries that are dealing with similar challenges

Rapid quantification of Salmonella Typhimurium inoculated to meat products by real-time PCR

The objective of this study was to use a 5′-nuclease (TaqMan) real-time PCR method with primers and probe specific to the spaQ gene as a rapid approach to quantitatively determine Salmonella Typhimurium. The result showed that the correlation coefficient between real-time PCR estimates and bovine serum albumin (BSA) plate counts of S . Typhimurium was 0.99, independently of 105-fold numbers of bystander Escherichia coli O157:H7 or total viable counts. The sensitivity of the real-time quantitative PCR assay was 10 CFU/mL for pure S . Typhimurium culture without enrichment. A known number of S . Typhimurium target cells were inoculated to dumpling fillings and chicken nuggets and DNA was extracted for real-time PCR analysis. The sensitivity was 60 CFU/g for S . Typhimurium inoculated to the food samples without any preceding procedure of enrichment. The duration of the entire experiment from DNA isolation and purification to PCR amplification was less than 12 h. This study demonstrated that realtime PCR is a rapid and reliable technique for quantifying S . Typhimurium possessing the spaQ gene in pure culture and in meat products

Supercritical Carbon Dioxide Decellularized Bone Matrix Seeded with Adipose-Derived Mesenchymal Stem Cells Accelerated Bone Regeneration

Large bone fractures with segmental defects are a vital phase to accelerate bone integration. The present study examined the role of supercritical carbon dioxide (scCO2) decellularized bone matrix (scDBM) seeded with allogeneic adipose-derived mesenchymal stem cells (ADSC) as bio-scaffold for bone regeneration. Bio-scaffold produced by seeding ADSC to scDBM was evaluated by scanning electron microscopy (SEM). Rat segmental femoral defect model was used as a non-union model to investigate the callus formation in vivo. Histological analysis and osteotomy gap closure in the defect area were analyzed at 12 and 24 weeks post-surgery. Immunohistochemical expression of Ki-67, BMP-2 and osteocalcin was evaluated to assess the ability of new bone formation scDBM. ADSC was found to attach firmly to scDBM bioscaffold as evidenced from SEM images in a dose-dependent manner. Callus formation was observed using X-ray bone imaging in the group with scDBM seeded with 2 &times; 106 and 5 &times; 106 ASCs group at the same time-periods. H&amp;E staining revealed ASCs accelerated bone formation. IHC staining depicted the expression of Ki-67, BMP-2, and osteocalcin was elevated in scDBM seeded with 5 &times; 106 ASCs group at 12 weeks after surgery, relative to other experimental groups. To conclude, scDBM is an excellent scaffold that enhanced the attachment and recruitment of mesenchymal stem cells. scDBM seeded with ASCs accelerated new bone formation

MicroRNAs regulating cluster of differentiation 46 (CD46) in cardioembolic and non-cardioembolic stroke.

Ischemic stroke is a major cause of mortality and morbidity globally. Among the ischemic stroke subtypes, cardioembolic stroke is with poor functional outcome (Modified Rankin score ≥ 2). Early diagnosis of cardioembolic stroke will prove beneficial. This study examined the microRNAs targeting cluster of differentiation 46 (CD46), a potential biomarker for cardioembolic stroke. CD46 mRNA level was shown to be differentially expressed (p < 0.001) between cardioembolic stroke (median = 1.32) and non-cardioembolic stroke subtypes (large artery stroke median = 5.05; small vessel stroke median = 6.45). Bioinformatic search showed that miR-19a, -20a, -185 and -374b were found to target CD46 mRNA and further verified by luciferase reporter assay. The levels of miRNAs targeting CD46 were significantly reduced (p < 0.05) in non-cardioembolic stroke patients (large artery stroke median: miR-19a = 0.63, miR-20a = 0.42, miR-185 = 0.32, miR-374b = 0.27; small artery stroke median: miR-19a = 0.07, miR-20a = 0.06, miR-185 = 0.07, miR-374b = 0.05) as compared to cardioembolic stroke patients (median: miR-19a = 2.69, miR-20a = 1.36, miR-185 = 1.05, miR-374b = 1.23). ROC curve showed that the miRNAs could distinguish cardioembolic stroke from non-cardioembolic stroke with better AUC value as compared to CD46. Endogenous expression of CD46 in Human Umbilical Vein Endothelial Cells (HUVECs) were found to be regulated by miR-19a and miR-20a. Thus implicating that miR-19a and -20a may play a role in pathogenesis of cardioembolic stroke, possibly via the endothelial cells

Tomatidine Represses Invasion and Migration of Human Osteosarcoma U2OS and HOS Cells by Suppression of Presenilin 1 and c-Raf–MEK–ERK Pathway

Osteosarcoma, which is the most prevalent malignant bone tumor, is responsible for the great majority of bone cancer-associated deaths because of its highly metastatic potential. Although tomatidine is suggested to serve as a chemosensitizer in multidrug-resistant tumors, the anti-metastatic effect of tomatidine in osteosarcoma is still unknown. Here, we tested the hypothesis that tomatidine suppresses migration and invasion, features that are associated with metastatic process in human osteosarcoma cells and also investigate its underlying pathway. Tomatidine, up to 100 &mu;M, without cytotoxicity, inhibited the invasion and migration capabilities of human osteosarcoma U2OS and HOS cells and repressed presenilin 1 (PS-1) expression of U2OS cells. After the knockdown of PS-1, U2OS and HOS cells&rsquo; biological behaviors of cellular invasion and migratory potential were significantly reduced. While tomatidine significantly decreased the phosphorylation of c-Raf, mitogen/extracellular signal-regulated kinase (MEK), and extracellular signal-regulated protein kinase (ERK)1/2 in U2OS cells, no obvious influences on p-Jun N-terminal kinase, p38, and Akt, including their phosphorylation, were observed. In ERK 1 silencing U2 OS cells, tomatidine further enhanced the decrease of their migratory potential and invasive activities. We conclude that both PS-1 derived from U2OS and HOS cells and the c-Raf&ndash;MEK&ndash;ERK pathway contribute to cellular invasion and migration and tomatidine could inhibit the phenomenons. These findings indicate that tomatidine might be a potential candidate for anti-metastasis treatment of human osteosarcoma

Development of a Broad-Spectrum Antiserum against Cobra Venoms Using Recombinant Three-Finger Toxins

Three-finger toxins (3FTXs) are the most clinically relevant components in cobra (genus Naja) venoms. Administration of the antivenom is the recommended treatment for the snakebite envenomings, while the efficacy to cross-neutralize the different cobra species is typically limited, which is presumably due to intra-specific variation of the 3FTXs composition in cobra venoms. Targeting the clinically relevant venom components has been considered as an important factor for novel antivenom design. Here, we used the recombinant type of long-chain α-neurotoxins (P01391), short-chain α-neurotoxins (P60770), and cardiotoxin A3 (P60301) to generate a new immunogen formulation and investigated the potency of the resulting antiserum against the venom lethality of three medially important cobras in Asia, including the Thai monocled cobra (Naja kaouthia), the Taiwan cobra (Naja atra), and the Thai spitting cobra (Naja Siamensis) snake species. With the fusion of protein disulfide isomerase and the low-temperature settings, the correct disulfide bonds were built on these recombinant 3FTXs (r3FTXs), which were confirmed by the circular dichroism spectra and tandem mass spectrometry. Immunization with r3FTX was able to induce the specific antibody response to the native 3FTXs in cobra venoms. Furthermore, the horse and rabbit antiserum raised by the r3FTX mixture is able to neutralize the venom lethality of the selected three medically important cobras. Thus, the study demonstrated that the r3FTXs are potential immunogens in the development of novel antivenom with broad neutralization activity for the therapeutic treatment of victims involving cobra snakes in countries

Identification of Immunoreactive Peptides of Toxins to Simultaneously Assess the Neutralization Potency of Antivenoms against Neurotoxicity and Cytotoxicity of Naja atra Venom

Assessing the neutralization capability of nonlethal but medically relevant toxins in venom has been a challenging task. Nowadays, neutralization efficacy is evaluated based simply on the survival rates of animals injected with antivenom together with a predefined dose of venom, which can determine potency against neurotoxicity but not validate the capability to neutralize cytotoxin-induced complications. In this study, a high correlation with in-vivo and in-vitro neutralization assays was established using the immunoreactive peptides identified from short-chain neurotoxin and cytotoxin A3. These peptides contain conserved residues associated with toxin activities and a competition assay indicated that these peptides could specifically block the antibody binding to toxin and affect the neutralization potency of antivenom. Moreover, the titers of peptide-specific antibody in antivenoms or mouse antisera were determined by enzyme-linked immunosorbent assay (ELISA) simultaneously, and the results indicated that Taiwanese bivalent antivenom (BAV) and Vietnamese snake antivenom-Naja (SAV-Naja) exhibited superior neutralization potency against the lethal effect of short-chain neurotoxin (sNTX) and cytotoxicity of cardiotoxin/cytotoxin (CTX), respectively. Thus, the reported peptide ELISA shows not only its potential for antivenom prequalification use, but also its capability of justifying the cross-neutralization potency of antivenoms against Naja atra venom toxicity