Azhu Valappil Zareena, Fan Xuetong, Zhang Howard Q, Rouseff Russell L
Institute of Food and Agricultural Sciences, Citrus Research and Education Center, and Food Science and Human Nutrition, University of Florida, Lake Alfred, Florida 33850, USA.
J Agric Food Chem. 2009 Feb 11;57(3):924-9. doi: 10.1021/jf803142d.
Aroma composition and microbial quality of identical lots of apple cider treated by pulsed electric field (PEF), ultraviolet irradiation (UV), or thermal pasteurization stored at 4 degrees C were compared at 0 and 4 weeks. Conditions were optimized to achieve identical 5 log reductions in Escherichia coli K12 for each treatment. PEF and thermal pasteurization maintained acceptable microbial quality for 4 weeks, but UV samples fermented after 2 weeks. Twenty-eight volatiles were quantified using gas chromatography-mass spectrometry (GC-MS) and odor activity values (OAV) determined. OAVs of 69:hexyl acetate, 41:hexanal, 25:2-methylbutyl acetate, 23:2-methyl ethyl butyrate, and 14:2-(E)-hexenal were observed for the control cider. Significant differences (p < 0.05) in the levels of these odorants were observed between treated apple ciders only after 4 weeks of storage. Thermal samples lost 30% of the major ester and aldehyde volatiles during storage with significant decreases (p < 0.05) in butyl acetate, 2-methylbutyl acetate, hexanal, and 2-(E)-hexenal. In UV cider, hexanal and 2-(E)-hexenal were completely lost after 4 weeks of storage. Microbial spoilage in UV cider after 4 weeks of storage was chemically confirmed by the detection of the microbial metabolite 1,3-pentadiene. PEF cider lost <2% of its total ester and aldehydes after 4 weeks of storage and was preferred by 91% of the sensory panel over thermally treated cider.
比较了在4℃下储存的经脉冲电场（PEF）、紫外线照射（UV）或热巴氏杀菌处理的相同批次苹果酒在0周和4周时的香气成分和微生物质量。对条件进行了优化，以使每种处理的大肠杆菌K12均实现相同的5个对数级减少。PEF和热巴氏杀菌在4周内保持了可接受的微生物质量，但紫外线处理的样品在2周后发酵。使用气相色谱 - 质谱联用仪（GC-MS）对28种挥发性成分进行了定量，并测定了气味活性值（OAV）。对照苹果酒中观察到乙酸己酯的OAV为69、己醛为41、乙酸2-甲基丁酯为25、丁酸2-甲基乙酯为23和（E）-2-己烯醛为14。仅在储存4周后，处理过的苹果酒之间这些气味物质的含量才出现显著差异（p < 0.05）。热杀菌处理的样品在储存期间损失了30%的主要酯类和醛类挥发性成分，乙酸丁酯、乙酸2-甲基丁酯、己醛和（E）-2-己烯醛显著减少（p < 0.05）。在紫外线处理的苹果酒中，储存4周后己醛和（E）-2-己烯醛完全消失。储存4周后紫外线处理苹果酒中的微生物腐败通过检测微生物代谢产物1,3-戊二烯得到化学证实。脉冲电场处理的苹果酒在储存4周后其总酯类和醛类损失<2%，91%的感官评价小组认为其比热杀菌处理的苹果酒更受欢迎。
