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標題: | 銅葉綠素摻假油品快速篩檢法之開發 Development of a rapid screening method for identifying the color adulteration of edible oil with copper chlorophylls |
作者: | Hung-Cheng Wang 王鴻誠 |
指導教授: | 謝博全(Po-Chuan Hsieh) |
關鍵字: | 銅葉綠素,紫外/可見光分光光譜儀,摻假油品,快篩,光降解, Copper chlorophyll,UV-Vis,Adulterated oil,Rapid Screening,Photo-degradation, |
出版年 : | 2017 |
學位: | 碩士 |
摘要: | 吸收光譜法為具有定性定量功能的即時檢測工具,相當適合用來檢驗色素,但由於油品中所含天然葉綠素及其衍生物與目標分析物銅葉綠素之吸收特性十分類似,因此必須透過前處理的方式將葉綠素類干擾物去除,才能夠對銅葉綠素進行定量。本研究利用葉綠素和銅葉綠素的抗光能力差異,使用光鋐科技製造波長365 nm功率5 W之LED提供光量子數480 mmol/m2s對義大利生產的Colavita冷壓初榨橄欖油樣品進行照光前處理,葉綠素類干擾物之光降解反應係數為0.319 s-1,而銅葉綠素主要衍生物Cu-pyropheophytin a (Cu-py a)與Cu-pheophytin a (Cu-pheo a) (Frontier Scientific, Inc.)之光降解反應係數都僅有0.001 s-1,因此證明銅葉綠素在照光前處理過程中的損失是可忽略的。去除葉綠素類干擾物後,將樣品放入紫外/可見光分光光度計測量570、652、700 nm的吸光值,代入銅葉綠素定量公式數據處理,即可對摻假油品中的銅葉綠素做定量分析。銅葉綠素定量公式的回收率在91—97%之間,線性檢量區間範圍為0.5—10 ppm (RSD < 4%,n = 3),檢測極限為0.1 ppm (S/N > 3),此濃度下銅葉綠素摻假樣品的綠色外觀已難以藉由肉眼分辨,證明此方法足以檢測市面上銅葉綠素摻假油品的可能濃度範圍。單次檢測所需樣品量為1 mL。本實驗測試了51個不同來源的橄欖油及葡萄籽油和4個食用級銅葉綠素混合物(取自日本葉緑素株式会社)摻假的沙拉油標準品(SIGMA-ALDRICH),16分鐘照光可以完成93%的樣品前處理;而24分鐘照光則可以完成所有55個樣品的前處理。此外可藉由增加光源強度或是光源數目縮短照光前處理時間。 UV/Vis spectroscopy is a low cost and quick analytical method, suitable for the analysis of colorants. However, the measurement of copper chlorophylls by visible spectroscopy is seriously interfered by natural chlorophylls. In this study, based on different photo-stability between chlorophylls and copper chlorophylls, the 5W power, 365 nm wavelength LED (EPILEDS) was chosen as the light source and providing light quantum number 480 mmol/m2s to remove the interference from chlorophylls by photo-degradation pretreatment. The first-order photo-degradation kinetic coefficient of chlorophylls in Colavita Italian extra virgin olive oil was 0.319 s-1, but Cu-pyropheophytin (Cu-py a) and Cu-pheophytin a (Cu-pheo a) (Frontier Scientific, Inc.), the major derivatives of Cu-Chls, whose first-order photo-degradation coefficient were both only 0.001 s-1. It showed that the loss of Cu-Chls in light pretreatment process was too little to be neglected. After the UV/Vis measurement, absorbance of 570, 652, 700 nm was substituted into Cu-Chls quantification formula to calculate the concentration of adulterated Cu-Chls, and good recovery results (91─97%) were achieved for spiked Cu-Chls concentrations in edible oil samples. Linear dynamic range for Cu-Chls was tested to be 0.5─10 ppm and the limit of detection (LOD) was 0.1 ppm (RSD < 4%, S/N > 3). At concentration of only 0.1 ppm, the green color appearance of oil was near imperceptible, which proved the limit of detection of this method was able to achieve the possible concentration of added copper chlorophyll. In addition, sample consumption was only 1 mL for single test. Fifty-one different sources of olive oil, grapeseed oil and 4 Cu-Chls mixture (from JAPAN CHLOROPHYLL Co. Ltd) adulterated soybean oil have been tested in this research, pretreatment of 93 % samples can be completed by light irradiation for 16 min, and pretreatment of all 55 samples can be completed by light irradiation for 24 min. It is possible to shorten the light pretreatment time by increasing light intensity or the number of light sources. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/78032 |
DOI: | 10.6342/NTU201700108 |
全文授權: | 有償授權 |
顯示於系所單位: | 生物機電工程學系 |
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