利用鳕鱼皮蛋白制备热反应型肉香调味基料的研究

以复合酶深度水解鳕鱼皮蛋白为主要原料,通过与半胱氨酸和葡萄糖的美拉德反应制得肉香风味,并通过固相微萃取-气相-质谱联用技术检测鉴定出大量的肉香味物质.为鳕鱼皮蛋白水解物制备肉香调味基料提供理论依据.     

Occurrence of volatile organic compounds (VOCs) in Liverpool Bay, Irish Sea

Surface seawater samples were collected in the Irish Sea and Liverpool Bay area from the R.V. Prince Madog during the period of 25-31 of March 2006. VOCs were purged with nitrogen, pre-concentrated on a SPME fibre and analysed immediately on a GC-MS. Target compounds quantified were halogenated (0.2-1400 ng L(-1)), BTEXs and mono-aromatics (1.5-2900 ng L(-1)), aliphatic hydrocarbons and others (0.6-15,800 ng L(-1)). Day and night sampling was performed at a single station and suggested that factors such as sunlight and tide affect the presence of many of these compounds. Sample variability was high due to the variable weather conditions at the station. Poor correlations were found between marine phytopigments and selected VOCs. Principal component analysis (PCA) analysis showed that chlorinated compounds such as 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene, tetrachloroethene and carbon tetrachloride, predominantly from anthropogenic sources, originated from the River Mersey. Other brominated and iodinated compounds quantified were more likely to be from biogenic sources including novel marine compounds such as 2-chloropropane, 1-bromoethane and 1-chlorobutane.     

水体中痕量挥发性有机物单体碳同位素组成的固相微萃取-冷阱预富集GC-IRMS分析

单体碳同位素分析是进行污染物来源判识与过程示踪的有力工具 ,然而有机污染物浓度低、难以萃取富集 ,极大地限制了该技术的广泛应用 .采用固相微萃取 -冷阱富集GC -IRMS技术对水中痕量挥发性有机物进行了单体碳稳定同位素分析 ,样品经SPME萃取富集后在色谱进样口冷冻成形 ,样品多次进样得以累积从而满足了检测限的要求 .本方法检出限较目前文献所报道的SPME方法提高了 1个数量级 .在优化的条件下 ,对低浓度的三氯乙烯、四氯乙烯、苯以及甲苯的水溶液进行了单体碳同位素组成测定 ,测定结果与纯液相中的同位素值相比 ,同位素分析误差不超过 0 .5× 10 -3 ,而分析的精度达到± 0 .3× 10 -3 .固相微萃取 -冷阱富集可以提供高效准确的单体碳同位素分析 ,该方法适用于水体中痕量挥发性有机污染物的同位素组成测定 .