類別:http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/272026-10-05T09:45:08Z2026-10-05T09:45:08Z食品接觸包材中全氟和多氟烷基物質之高解析質譜鑑定策略林昀嬋Yun-Chan Linhttp://tdr.lib.ntu.edu.tw/jspui/handle/123456789/969112026-07-22T14:04:48Z2025-01-01T00:00:00Z標題: 食品接觸包材中全氟和多氟烷基物質之高解析質譜鑑定策略; Strategies for Identifying Per- and Polyfluoroalkyl Substances in Food Contact Materials with High-resolution Mass Spectrometry
作者: 林昀嬋; Yun-Chan Lin
摘要: 全氟和多氟烷基物質 (PFAS) 因為其化學結構，具有防油防水的功能，並廣泛的應用在食品接觸包材、消防泡沫、紡織品以及各種工業產品上。PFAS會生物累積並危害人體健康，像是造成癌症、肝損傷、生殖毒性以及嬰幼兒發育毒性等。而食品接觸包材為人們暴露PFAS常見的來源之一。雖然現在國際間開始針對部分PFAS進行規範，但仍然有幾千種未知PFAS在產業中使用，本研究將進行非目標物分析，來了解目前台灣的食品接觸包材中含有哪些PFAS。
本研究使用超高效能液相層析儀搭配Agilent 6450四極桿/飛行時間質譜儀 (UHPLC-Q-TOF MS) ，管柱為Premier BEH C18 AX column (100 × 2.1 mm, 1.7 µm)，在ESI負電模式下，水相和有機相為5mM醋酸銨(以氨水調整至pH 7.0) 和甲醇，起始有機相為10%，18分鐘內有機相上升至100%並維持0.5分鐘，之後返回起始梯度，總層析時間22分鐘檢測100 ng/mL 32種PFAS混合標準品，其中26種PFAS標準品能得到完整波峰，包含9種全氟烷基羧酸 (PFCAs)、4種全氟烷基磺酸鹽 (PFSAs)、3種氟調聚物飽和酸 (FTCAs)、3種氟調聚物不飽和酸 (FTUCAs)、2種雙多氟烷基磷酸酯 (diPAPs) 以及5種全氟醚 (Perfluoroethers)，但2種多氟烷基磷酸酯 (PAPs) 與4種氟調聚物醇類 (FTOHs) 化合物無法得到完整波峰。之後使用此層析條件分別進行數據依賴擷取 (DDA) 和非數據依賴擷取 (DIA) 兩種不同資料收集模式，得到的資料再利用MSDIAL和FluoroMatch軟體進行分析比較各自的資料庫鑑定結果。
初步鑑定使用32種PFAS混和標準品進行測試。MSDIAL設定鑑定參數cut off 70%，在DIA比對到化合物總共111個，包含較高匹配 (比對到MS1和MS2) 31個、與建議 (僅比對到MS1或較低MS2比對分數) 80個；26個已知PFAS化合物都有鑑定到，但其中18種已知PFAS標準品有比對到同分異構物問題，表示比對結果需要人工再次確認才會比較準確。而在DDA比對到化合物總共69個，包含較高匹配21個與建議48個，已知PFAS中僅有6:2 diPAP和8:2 diPAP有比對到MS1及MS2，可能因為DDA資料收集涵蓋範圍從m/z 150到m/z 1200對Q-TOF MS來說較廣，使得各個PFAS被檢測並引發碰撞獲得MS2資訊的機會降低。
FluoroMatch相較於DIA在DDA有較好的分析結果。在DDA中能比對到1個分數A、82個分數B及25個分數C，已知PFAS標準品PFUnDA為分數A比對結果，但其餘已知PFAS僅為分數D，表示可能為PFAS，但結構不確定。DIA結果則沒有比對到分數A，只有1個分數B和1個分數C，而已知PFAS則都是分數D。但在DIA和DDA中都無法對PFAS標準品有良好的比對結果，可能與儀器MS2資料收集不足和背景雜訊較多有關。
19項100 cm2真實食品接觸包材樣本經過磨碎，使用10 mL甲醇在70℃下透過自動加壓流體萃取系統 (EDGE) 進行5分鐘萃取，重複萃取一次合併萃取液後上機分析。以DIA模式得到的資料使用MSDIAL進行分析，和液相層析串聯式質譜儀 (LC-QqQ MS) 所檢測到PFBA、PFHxA、PFBS、6:2 FTCA、6:2 PAP及8:2 PAP結果比較，發現在12項一般防油紙袋中有比對到已知PFBA和PFBS以及非目標物 (E)-2:2 FTUCA、五氟丙酸 (PFPrA) 和全氟丁烷磺醯胺乙醇 (FBSE)，3項微波爆米花紙袋中有比對到非目標物2:2 Fluorotelomer thia propanoic acid，而2-((3,3,3-Trifluoropropyl) thio) acetic acid和PFSM-N-MeFSAA (C4H6F3NO4S) 非目標物則是在一般防油紙袋和微波爆米花紙袋中都有發現，1項雞蛋紙盒中有比對到非目標物3- (3,3,3-Trifluoropropylsulfanyl) propanoic acid。其中PFPrA可能為PFBA和PFHxA降解產物，而 (E)-2:2 FTUCA可能為PAPs與6:2 FTCA的降解產物。FBSE為PFBS的衍生物。
本研究使用MSDIAL在DIA模式下成功從19項真實食品接觸包材中鑑定到PFBA、PFBS以及7種非目標PFAS；非目標PFAS中包含PFCAs、FTUCAs、PFBS衍生物以及其他較不常見的PFAS種類FT-thioethers和PFSM-N-MeFSAA，表示目前台灣食品接觸包材中仍有新興PFAS的疑慮。目前針對食品包材的非目標物分析還尚未有很多研究，因此本研究的非目標物分析能更了解DDA和DIA的差異以及不同資料庫比對方法，未來也可以作為目標物分析的輔助方法，用來監測其他種類食品接觸包材中殘留或新興的PFAS化合物。; Per- and polyfluoroalkyl substances (PFAS) are widely used in food contact packaging materials (FCMs), firefighting foams, textiles, and other industrial products owing to their hydrophilic and hydrophobic properties. PFAS exhibit high bioaccumulative potential and may induce cancer, liver damage, reproductive toxicity, and developmental toxicity. FCMs are a common source of PFAS exposure. Although the international community has begun to regulate PFAS, thousands of unknown PFAS are still being used in the industry. Therefore, this study performed suspect non-target analysis to determine the unknown PFAS used in FCMs in Taiwan.
This study uses an ultra-high-performance liquid chromatograph coupled with an Agilent 6450 quadrupole/time-of-flight mass spectrometer (UHPLC-Q-TOF MS) with a Premier BEH C18 AX column (100 × 2.1 mm, 1.7 µm). In negative ESI mode, the mobile phases were 5 mM ammonium acetate (adjusted to pH 7.0 with ammonia) and methanol. The initial organic phase was 10%; after 18 min, the organic phase was increased to 100%, maintained for 0.5 minutes, and then returned to the initial gradient. The total chromatographic time was 22 min. Complete peaks were obtained for 26 of the 32 PFAS chemical standards at 100 ng/mL, including nine perfluoroalkyl carboxylic acids (PFCAs), four perfluoroalkyl sulfonates (PFSAs), three fluorotelomer saturated acids (FTCAs), three fluorotelomer unsaturated acids (FTUCAs), two di-polyfluoroalkyl phosphate esters (diPAPs), and five perfluoroethers, except for two polyfluoroalkyl phosphate esters (PAPs) and four fluorotelomer alcohols (FTOHs). Data-dependent acquisition (DDA) and data-independent acquisition (DIA) were performed, and the resultant data were processed using MSDIAL and FluoroMatch software to compare the respective database identification results.
Initial identification was conducted using a 100 ng/mL standard solution of 32 PFAS. MSDIAL identification score was set at 70%. In the DIA mode, 111 compounds were identified, comprising 31 reference-matched PFAS (corresponding to both MS1 and MS2) and 80 suggested PFAS (corresponding solely to MS1 or exhibiting a low MS2 score). 26 known PFAS were identified at the appropriate retention time, but 18 of the known PFAS standards matched the isomers, which means that the comparison results need to be manually confirmed again to be more accurate. Conversely, 69 compounds were identified in the DDA mode, including 21 reference-matched compounds and 48 suggested PFAS. However, only two known PFAS, 6:2 diPAP, and 8:2 diPAP, were identified in MS1 and MS2, respectively. The dynamic range for DDA spanned from m/z 150 to m/z 1200, which is comparatively extensive for the quadrupole and diminishes the probability of initiating collisions to obtain MS2.
For FluoroMatch, DDA has better analysis results than DIA. FluoroMatch annotated one at score A, 82 at score B, and 25 at score C with DDA; Perfluoroundecanoic acid (PFUnDA) among the known PFAS standards was identified at score A, while the others were only identified at score D, indicating potential PFAS with unconfirmed structures. For DIA, no chemicals were identified at score A, and only one each at scores B and C; all known PFAS were identified solely at score D. However, good comparison results could not be obtained for PFAS standards in both DIA and DDA, which may be related to insufficient MS2 data collection and high background noise.
Nineteen 100 cm2 samples of FCMs were ground and then extracted with 10 mL methanol at 70°C using an energized dispersive guided extraction (EDGE) automated system for 2 cycles of 5 minutes. The data obtained in DIA mode were analyzed using MSDIAL. Compared with the ultraperformance liquid chromatography-triple quadrupole mass spectrometer (LC-QqQ MS), which detects PFBA, PFHxA, PFBS, 6:2 FTCA, 6:2 PAP, and 8:2 PAP, 12 general oil-proof paper bags were identified as PFBA and PFBS, as well as the non-target compounds (E)-2:2 FTUCA, Perfluoropropionic acid (PFPrA), and perfluorobutane sulfonamidoethanol (FBSE). Non-target compound 2:2 Fluorotelomer thia propanoic acid were identified in three microwave popcorn paper. In addition, the non-target compounds 2-((3,3,3-Trifluoropropyl) thio) acetic acid and PFSM-N-MeFSAA (C4H6F3NO4S) appeared in the above two categories. A non-target compound, 3- (3,3,3-Trifluoropropylsulfanyl) propanoic acid, was identified in the egg carton. In addition, PFPrA is the degradation product of PFBA and PFHxA, while (E)-2:2 FTUCA may be the degradation product of PAPs and 6:2 FTCA. FBSE is a derivative of the PFBS.
In this study, MSDIAL in DIA mode successfully identified PFBA, PFBS, and seven non-targeted compounds from 19 FCMs. Non-targeted PFAS include PFCAs, FTUCAs, PFBS derivatives, and other less common PFAS types such as FT-thioethers and PFSM-N-MeFSAA, showing concerns about emerging PFAS in FCMs in Taiwan. Currently, there are few studies on non-target analysis of food packaging materials. Therefore, the non-targeted analysis of this study can better understand the differences between DDA and DIA, as well as the comparison methods of different databases. In the future, it can also serve as a complementary approach to targeted analysis for monitoring legacy and emerging PFAS in FCMs.2025-01-01T00:00:00Z長期暴露黃麴毒素B1影響秀麗隱桿線蟲的老化及先天免疫Tzu-Ting Chang張慈庭http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/741752026-07-22T12:40:53Z2019-01-01T00:00:00Z標題: 長期暴露黃麴毒素B1影響秀麗隱桿線蟲的老化及先天免疫; Chronic exposure to aflatoxin B1 adversely affects aging and innate immunity in Caenorhabditis elegans
作者: Tzu-Ting Chang; 張慈庭
摘要: 黃麴毒素B1 (aflatoxin B1) 是已知的人類一級致癌物，也是麴菌毒素中毒性最強的毒素。Aflatoxin B1常存在於保存不良的農作物產品，尤其常在米、花生和玉米中發現。Aflatoxin B1會造成肝臟毒性及和免疫毒性等不量反應，然而，鮮少研究探討長期暴露aflatoxin B1如何影響老化及先天免疫。本研究利用秀麗隱桿線蟲Caenorhabditis elegans以及綠膿桿菌 (Pseudomonas aeruginosa PA14) 之host-pathogen模式，探討長期暴露aflatoxin B1所造成之老化及先天免疫能力的影響；並利用C. elegans食物Escherichia coli OP50的活性和暴露aflatoxin B1對C. elegans老化相關指標的影響，探討aflatoxin B1對免疫老化的調節和其分子機制。研究結果指出C. elegans從幼蟲 (L1) 暴露5與10 µM aflatoxin B1到成蟲第0天會延遲C. elegans的成長，並在2.5與5 µM的暴露下會顯著降低C. elegans的繁殖能力；而在較高濃度 (2.5及5 µM) 暴露的情況下也會縮短C. elegans的壽命長度。在先天免疫方面，長期暴露2.5 μM aflatoxin B1後會顯著降低C. elegans在遭受P. aeruginosa PA14感染後的存活。結果亦顯示，長期曝露aflatoxin B1 2.5 µM至成蟲第4天及第6天，野生種N2 C. elegans腸道體內累積的live E. coli OP50顯著多於未暴露aflatoxin B1的野生種N2 C. elegans；然而並未在餵食以經UV去活性dead E. coli OP50 觀察到此現象。暴露aflatoxin B1並以live E. coli OP50餵養之C. elegans的老化指標 (body bends, head thrashes, defecation cycle, lipofuscin) 都受到影響，但以dead E. coli OP50餵養的C. elegans則沒有統計上顯著差異。進一步利用two-way AVONA進行統計分析，顯示E. coli OP50的活性和aflatoxin B1在C. elegans有交互作用。利用基因轉殖C. elegans LD1發現，暴露於aflatoxin B1 2.5 μM會抑制SKN-1轉移入細胞核的現象，而在skn-1突變種的實驗中，有無暴露aflatoxin B1和以live及dead E. coli OP50餵養之C. elegans之間皆無顯著差異，推論aflatoxin B1抑制先天免疫和老化與抑制SKN-1及其下游基因表達相關。最後，在基因表達量的結果顯示，aflatoxin B1會抑制gst-4、gcs-1、hsp-16.1、hsp-16.49及hsp-70的mRNA表達量。綜合本研究之實驗結果顯示，長期暴露2.5 µM aflatoxin B1會加速老化和抑制先天免疫能力，並和其食物E. coli OP50的病源性有交互作用。; Aflatoxin B1, a human carcinogen, is the most toxic secondary metabolite in aflatoxins. It is usually found in poor storage of agricultural products, especially in rice, peanut, and maize. Aflatoxin B1 exposure causes several adverse effects such as hepatotoxicity and immunotoxicity. However, studies regarding effects of aging and innate immunity by aflatoxin B1 are limited. This study used Caenorhabditis elegans and Pseudomonas aeruginosa PA14 as a host-pathogen model to study how aflatoxin B1 affects aging and innate immunity. Moreover, live Escherichia coli OP50 and UV-treated dead E. coli OP50 were used to test aging-related indicators by chronic aflatoxin B1 exposure in C. elegans and the underlying molecular mechanisms were investigated. The results showed that prolonged exposure to aflatoxin B1 from L1 larvae delayed the growth stage (5, 10 μM), decreased reproduction, and reduced longevity (2.5, 5 μM) of C. elegans. Moreover, exposure to 2.5 µM aflatoxin B1 also significantly reduced the survival of C. elegans against the infection of P. aeruginosa PA14. Furthermore, after chronic aflatoxin B1 exposure (2.5 µM), there was a significantly increased accumulation of E. coli OP50 in the intestine of wild-type N2 C. elegans in day-4 adulthood compared with the untreated ones while feeding with live E. coli OP50. In contrast, the phenomena was absent while feeding with dead E. coli OP50. In addition, an increased body bends and head thrashes as well as a decreased defecation cycle and lipofuscin were observed in wild-type N2 C. elegans fed with dead E. coli OP50 in day-4 and day-6 adulthood in the presence of aflatoxin B1. Moreover, two-way ANOVA analysis revealed that aflatoxin B1 and the pathogenic activity of E. coli OP50 interact together affecting aging indicators in C. elegans. By using the transgenic strain LD1, 2.5 µM aflatoxin B1 inhibited the nuclear translocation of SKN-1. In skn-1 mutant, chronic exposure to 2.5 µM aflatoxin B1 didn’t affect lipofuscin at day-4 adulthood fed with either live or dead E. coli OP50. This suggests that aflatoxin B1 suppresses innate immunity as well as adversely affect aging indicators mediated by SKN-1. Finally, chronic exposure to 2.5 µM aflatoxin B1 suppressed the mRNA levels of gst-4, gcs-1, hsp-16.1, hsp-16.49 and hsp-70. Taken togethetr, results from this study demonstrate that chronic aflatoxin B1 exposure enhances aging decline and suppresses innate immunity and has an interaction with the pathogenic activity of E. coli OP50.2019-01-01T00:00:00Z長期暴露棒麴毒素誘導秀麗隱桿線蟲神經毒性之評估：以血清素神經元調控做探討許祐寧Yu-Ning Hsuhttp://tdr.lib.ntu.edu.tw/jspui/handle/123456789/1050532026-09-07T16:41:18Z2026-01-01T00:00:00Z標題: 長期暴露棒麴毒素誘導秀麗隱桿線蟲神經毒性之評估：以血清素神經元調控做探討; Assessment of neurotoxicity induced by long-term patulin exposure in Caenorhabditis elegans: Focusing on the regulation of serotonergic neurons
作者: 許祐寧; Yu-Ning Hsu
摘要: 棒麴毒素 (Patulin, PAT) 是一種主要由Penicillium expansum產生的黴菌毒素，常見於發黴的水果、蔬菜與穀類中，尤其是在蘋果及其加工製品中。由於其具有耐熱及耐酸的特性，人類經常透過果汁與嬰兒食品而暴露於PAT。已知PAT會引起多種毒性效應，包括急性噁心、嘔吐及腸胃不適，長期暴露則可能損害腎臟、肝臟與免疫系統。然而，關於其潛在神經毒性的研究仍相對有限，其作用機制亦尚未明確。因此，本研究以Caenorhabditis elegans為模式生物，探討長期暴露PAT是否會誘發神經傳導物質調控相關之生理行為神經毒性，以及其可能的毒性機制。
本研究評估了C. elegans在不同PAT暴露濃度下的發育、運動及攝食行為相關指標。初步實驗結果顯示，PAT在50-90 μM時顯著抑制C. elegans生長；在運動行為方面，PAT暴露未明顯影響身體彎曲 (Body bending) 頻率，但在0.1-90 μM時顯著降低頭部擺動 (Head thrashing) 頻率，顯示PAT對運動行為之影響可能具有選擇性，而非單純造成整體運動能力下降。此外，暴露10-90 μM PAT時明顯降低咽喉收縮 (Pharyngeal pumping) 速率及產卵速率 (Egg-laying rate)，並呈現劑量依賴性影響，顯示其可能干擾攝食及生殖相關行為表現。在C. elegans中，由於頭部擺動、咽喉收縮及產卵行為皆與血清素神經調控密切相關，本研究進一步利用轉基因株 (GR1366) 觀察血清素生合成相關之tph-1::GFP螢光表現。結果顯示，PAT暴露後可顯著降低頭部區域tph-1::GFP螢光強度，顯示PAT可能影響tph-1啟動子活性或血清素合成相關神經訊號。此外，PAT亦顯著提升體內活性氧物質 (Reactive oxygen species, ROS) 含量與上調代謝ROS之相關基因sod-3、gst-4，並顯著影響C. elegans體內多個血清素調控相關基因之表達，包含tph-1、mod-1、ser-1、cat-1、cat-4及mod-5。
為進一步驗證血清素訊號於PAT誘發行為異常中之角色，本研究亦進行外源性血清素補充試驗及tph-1突變株 (MT15434) 分析。結果顯示，外源性血清素可顯著改善PAT造成之血清素相關行為缺陷，而在tph-1突變株中，PAT對頭部擺動、咽喉收縮及產卵行為所造成之毒性較野生型N2減緩，支持PAT誘發之行為毒性可能與tph-1及血清素神經調控路徑有關。
綜合上述結果，本研究顯示長期暴露PAT可誘發C. elegans生長發育毒性，並影響頭部擺動、咽喉收縮及產卵速率等血清素相關行為表現，並發現PAT可能透過誘導氧化壓力與干擾血清素神經調控系統，進而導致神經行為毒性。本研究提供PAT誘發體內神經毒性之實驗證據，並補足目前PAT於生物體神經傳導物質調控相關研究之不足，可作為後續探討PAT神經毒性作用機制之參考基礎。; Patulin (PAT) is a mycotoxin mainly produced by Penicillium expansum and is commonly found in mold-contaminated fruits, vegetables, and cereals, particularly apples and apple-derived products. Due to its heat- and acid-resistant properties, humans are frequently exposed to PAT through fruit juices and infant foods. PAT has been reported to induce various toxic effects, including acute nausea, vomiting, and gastrointestinal discomfort, while long-term exposure may cause damage to the kidney, liver, and immune system. However, studies regarding its potential neurotoxicity remain relatively limited, and the underlying mechanisms are still unclear. Therefore, this study used Caenorhabditis elegans as a model organism to investigate whether long-term PAT exposure induces physiological and behavioral neurotoxicity associated with neurotransmitter regulation, as well as its possible toxic mechanisms.
This study evaluated developmental, locomotor, and feeding-related behavioral endpoints in C. elegans exposed to different concentrations of PAT. Preliminary results showed that PAT significantly inhibited the growth of C. elegans at 50-90 μM. In terms of locomotor behavior, PAT exposure did not markedly affect the frequency of body bending, but significantly decreased the frequency of head thrashing at 0.1-90 μM, suggesting that the effects of PAT on locomotor behavior may be selective rather than simply causing an overall decline in motor ability. In addition, exposure to 10-90 μM PAT significantly reduced the pharyngeal pumping rate and egg-laying rate in a dose-dependent manner, indicating that PAT may interfere with feeding- and reproduction-related behavioral performance. Since head thrashing, pharyngeal pumping, and egg-laying behaviors in C. elegans are closely associated with serotonergic neuronal regulation, this study further used the transgenic strain GR1366 to observe the fluorescence expression of tph-1::GFP, which is related to serotonin biosynthesis. The results showed that PAT exposure significantly reduced tph-1::GFP fluorescence intensity in the head region, suggesting that PAT may affect tph-1 promoter activity or serotonin synthesis-related neuronal signaling. Furthermore, PAT significantly increased intracellular reactive oxygen species (ROS) levels and upregulated the ROS-metabolism-related genes sod-3 and gst-4. PAT also significantly altered the expression of multiple serotonin regulation-related genes in C. elegans, including tph-1, mod-1, ser-1, cat-1, cat-4, and mod-5.
To further verify the role of serotonin signaling in PAT-induced behavioral abnormalities, this study also performed exogenous serotonin supplementation experiments and analysis using the tph-1 mutant strain MT15434. The results showed that exogenous serotonin significantly improved PAT-induced defects in serotonin-related behaviors. In the tph-1 mutant strain, the toxic effects of PAT on head thrashing, pharyngeal pumping, and egg-laying behaviors were attenuated compared with those observed in wild-type N2 worms, supporting that PAT-induced behavioral toxicity may be associated with tph-1 and the serotonergic neuronal regulatory pathway.
Taken together, this study demonstrates that long-term PAT exposure induces developmental toxicity in C. elegans and affects serotonin-related behavioral performance, including head thrashing, pharyngeal pumping, and egg-laying rate. These findings further suggest that PAT may induce neurobehavioral toxicity by promoting oxidative stress and disrupting the serotonergic neuronal regulatory system. This study provides experimental evidence that PAT induces neurotoxicity in vivo and helps address the current lack of knowledge regarding the effects of PAT on the regulation of neurotransmitters in living organisms. These findings provide a valuable foundation for future investigations into the mechanisms underlying PAT-induced neurotoxicity.2026-01-01T00:00:00Z運用辛酸/幾丁聚醣/明膠之可食膜提升肉品安全性與架儲期俞沛恩Matthew Kang Herashttp://tdr.lib.ntu.edu.tw/jspui/handle/123456789/832752026-07-22T13:31:46Z2023-01-01T00:00:00Z標題: 運用辛酸/幾丁聚醣/明膠之可食膜提升肉品安全性與架儲期; Application of chitosan-gelatin-caprylic acid edible coating on fresh meat for enhancing the microbiological safety and shelf life
作者: 俞沛恩; Matthew Kang Heras
摘要: 長久以來，肉類產品一直是人們動物性蛋白質的主要來源，是飲食中不可或缺的食物之一。然而肉品在屠宰及儲藏過程中，可能因為品質下降 （如：脂質氧化、腐敗）和病原菌交叉汙染等問題，影響架儲期和安全性，對於消費者和零售商而言是一大隱憂。根據我國食藥署的食品中毒事件統計資料，肉類在各類食品中排名第三，且近年來肉品的人均攝食量逐年攀升，亦可能導致肉品引起的食源性疾病風險與發生率隨之上升，因此相關業者必須尋求更完善且有效的方法，以滿足大衆對肉品安全和架儲期的需求，亦是保障公共衛生與健康的重要課題。本研究旨在開發以幾丁聚糖 (CHI)、明膠 (GEL) 和辛酸 (CA) 為基礎之可食用複合塗膜，並測試其在LB培養基 和新鮮牛肉基質 (有氧包裝) 之抑菌、抗氧化和抗病原菌功效。此複合塗膜的保存特性測試，是將具有塗膜之新鮮牛肉儲存在冷藏溫度 (4 ℃) 下20天，評估其對於抑制鮮肉之微生物腐敗、脂質氧化和品質流失上的影響。而複合塗膜的抗病原菌性能，則是將新鮮牛肉接種病原菌之後再塗膜，然後將肉品置於冷藏 (4 ℃) 和 10 ℃ 低溫下儲存7天，藉以評估塗膜對於病原菌生長之影響。
在研究初始階段，先以培養基測定了CA對常見肉類病原菌 (即金黃色葡萄球菌、大腸桿菌O157:H7、鼠傷寒沙門氏桿菌和綠膿桿菌) 的最小抑菌濃度和最小殺菌濃度，以篩選最佳CA濃度加入幾丁聚糖-明膠 (CHI-GEL) 之複合膜中。培養基實驗表明1% CHI - 3% GEL複合膜對於所有病原菌的生長抑制超過3 log CFU/mL。若進一步添加0.25%或0.5% CA能夠大幅提升抑菌能力到4至9 log CFU/mL。在新鮮牛肉的塗膜試驗中也觀察到類似的結果，其中CHI-GEL複合膜對所有病原菌抑制功效隨著CA的添加而加强，達到超過3 log CFU/g。研究結果顯示出CA和CHI-GEL膜之間具有協同的抗菌活性。此外，CHI-GEL-CA複合膜在維持肉品品質方面的效果很顯著，包括：延遲腐敗菌的生長、減少過氧化物質的産生，降低pH和顔色的變化。最終結果顯示未塗膜的肉品對照組、CHI-GEL複合膜組和CHI-GEL-CA複合膜組對新鮮牛肉的保質期分別為：10天、15天和20天。另外，此複合膜也具有良好的穩定性和成本效益，以確保在肉品的適用性和實用性。綜上所述，本研究發現含有0.5% CA的CHI-GEL複合膜，是一種前瞻性且極具應用價值的可食性包膜，未來可用於確保新鮮肉品在有氧包裝下的安全性並延長其架儲期。; Meat products have long been a staple food in people’s diets as the primary source of animal protein. However, during processing and storage, the problems related to quality degradations (i.e., lipid oxidation, spoilage) and pathogen cross-contamination creates shelf life and safety concern for consumers and retailers alike. According to the Taiwan Food and Drug Administration, foodborne outbreaks related to meat products rank 3rd among all food types. Moreover, recently, there has been a continual increase in the average meat intake of the people in Taiwan, which can lead to higher rates of foodborne outbreaks. Therefore, finding effective treatments are important matters for food safety practitioners, to meet the public demand for safe and long shelf life meat products. The objective of this study was to determine the antimicrobial, antioxidant, and antipathogenic activities of a newly developed edible composite coating comprised of chitosan (CHI), gelatin (CHI-GEL), and caprylic acid (CA), under growth medium (Luria-Bertani broth) and aerobically packaged meat (fresh beef) matrix. The preservation properties of the coatings were evaluated based on the extent of microbial spoilage, lipid oxidation, and quality loss in fresh meat stored at refrigerated temperature (4 °C) for 20 days. The inhibitory properties of coatings were assessed based on pathogenic bacterial growth in inoculated meat stored at refrigerated (4 °C) or abusive temperature (10 °C) for seven days.
In the preliminary phase of the study, the minimum inhibitory concentration and minimum bactericidal concentration CA against common meat pathogens (i.e., Staphylococcus aureus, Escherichia coli O157:H7, Salmonella Typhimurium and Pseudomonas aeruginosa) were determined to select the ideal CA concentration to be incorporated in CHI-GEL composite coating. The growth medium experiments showed that 1% CHI-3% GEL composite coating effectively inhibited all pathogenic growth by > 3 log CFU/mL. Further addition of 0.25% or 0.5% CA was able to enhance the antipathogenic activities, inhibiting growth by 4 to 9 log CFU/mL. Similar results were observed in the fresh beef application, wherein the suppressive effects of CHI-GEL composite coating against all pathogen growth were increased with CA addition reaching > 3 log CFU/g. The results indicated synergistic antipathogenic activity between CA and CHI-GEL coating. Moreover, the CHI-GEL-CA composite coating also achieved satisfactory results in preserving meat quality, with indications of delayed spoilage, reduced thiobarbituric acid reactive substances (TBARS) production, less pH change, and lowered color loss. The overall meat shelf life was determined to be 10 days, 15 days, and 20 days for uncoated control, CHI-GEL coating, and CHI-GEL-CA coatings, respectively. Furthermore, the developed composite coating also had good stability and was very cost-effective, assuring their applicability and practicality in meat products. This study suggests that CHI-GEL composite coating containing 0.5% CA can be developed as a prospective and practical method for ensuring the safety and shelf life of aerobically packaged fresh meat products.2023-01-01T00:00:00Z