Retention and distribution of polyphenols after pan-frying of French fries in oils enriched with olive leaf extract

ABSTRACT:  Palm oil, olive oil, and sunflower oil were supplemented with an extract rich in polyphenols obtained from olive tree ( Olea europaea ) leaves at levels of 120 and 240 mg total polyphenols per kilogram of oil. Pan-frying of potatoes was performed in both the enriched and the nonsupplemented oils under domestic frying conditions. Total polyphenol content was estimated by the Folin–Ciocalteau assay, oleuropein was determined by HPLC analysis, while other individual polyphenols by GC/MS analysis. Fourteen polyphenol species were identified in the olive leaf extract, among which oleuropein predominated (1.25 g/kg olive leaves). All the enriched oils contained oleuropein before and after frying. Oleuropein as well as other polyphenol species were detected in all French fries cooked in enriched oils. Polyphenol intake by consuming French fries pan-fried in the enriched oils was calculated to be 6 to 31 times higher than that in the case of French fries fried in commercial oils, being dependent on the frying oil type.     

大豆油和棕榈油煎炸薯条过程品质评价

为了对中包装的大豆油棕榈油煎炸专用调和油配方的开发和煎炸稳定性相关理化指标的选择提供参考,分别以一级大豆油、分提18℃棕榈油(一次精炼)及同批次的二次精炼18℃棕榈油为煎炸油,模拟薯条在180℃下高温煎炸32 h,对3种油品在煎炸过程中的酸值、过氧化值、p-茴香胺值、脂肪酸组成、极性组分含量、生育酚含量等理化指标进行了检测,并对18℃棕榈油中的风险因子,如PAH4、苯并(a)芘、3-氯丙醇酯(3-MCPDE)、反式脂肪酸含量进行了分析。结果表明：3种油品的酸值、过氧化值在煎炸过程中变化不明显,而p-茴香胺值、脂肪酸组成、极性组分含量在煎炸过程中变化比较明显;3种油品的生育酚氧化速度总体偏差不大;分提18℃棕榈油、二次精炼18℃棕榈油中的苯并(a)芘、反式脂肪酸含量均随煎炸时间延长呈缓慢升高的趋势;二次精炼18℃棕榈油的3-MCPDE在未煎炸时远高于分提18℃棕榈油的,3-MCPDE在煎炸初期降解剧烈,最终达到平衡;分提18℃棕榈油与二次精炼18℃棕榈油在煎炸稳定性方面没有明显区别,二次精炼不仅损失了部分有益的微量营养成分(如生育酚),还伴生出新的风险因子,如增加了3-MCPDE、反式脂...     

中国与法国规范桥梁桩长计算方法的对比分析

依托阿尔及利亚东西高速公路设计实践,重点介绍了法国规范桥梁桩长的计算方法,并与我国《规范》桥梁桩长计算方法进行了对比分析。由此结合法国规范就国内桥梁桩长计算提出了一些建议,供相关设计人员参考。     

Impact of the reducing sugars on the relationship between acrylamide and Maillard browning in French fries

The relationship between acrylamide content and Maillard browning in French fries was studied as a function of different glucose/fructose ratios in the raw product using several colour measurement methods. An exponential correlation was found between acrylamide formation and surface colour, as evaluated by the parameters a*, delta E and Agtron. As a consequence, small differences in product colour could result in more pronounced differences in acrylamide contamination. This relationship however appeared to be dependant upon the glucose/fructose ratio of the raw material. An excess of fructose compared to glucose stimulated acrylamide formation to a higher extent than Maillard browning. The opposite effect was established with an excess of glucose. In addition, a linear relationship was found between the absorbance of aqueous French fries extracts and acrylamide content, which moreover appeared to be less affected by the addition of extra reducing sugars prior to frying. To predict acrylamide formation, sugar analysis however remains an important instrument and is complementary to surface colour measurement.     

中法葡萄酒地理标志、质量等级、标签比较研究

为了更好地促进我国葡萄酒法规与国际接轨,加快我国葡萄酒产业升级,建立科学地产业规制法规,该文通过对中法葡萄酒地理标志、质量等级、标签法规等方面的法律法规进行比较研究,分析我国在葡萄酒产业的相关保护方面存在的不足,并针对我国的现状提出指导意见,以期全面提高我国葡萄酒产业规制。     

某型柴油机调喷器国产化研制

调喷器是某型号大功率柴油机保证燃油喷射系统,能够在特定的时间条件下准确、稳定地供油的关键件。前期装配一直采用进口件,周期长,成本高。通过针对产品结构与精度的分析,研究了适宜性工装,优化和改进了工艺方案及试验台的改造研究,并在工艺试验的基础上,突破了加工的关键技术,为某型号柴油机的国产化改进提高提供了可靠的技术保障。     

法麦Vanessa制麦特性的探讨

法麦Vanessa是优质的啤酒大麦,但该品种大麦不同于国麦和其它进口大麦,制成的麦芽通常粘度和葡聚糖较高,因此,制麦时要根据大麦特性适时制定相应工艺,才能获得优质麦芽。     

法语料库文本语义接受度评价研究

法文本语义接受度（SAS）研究属于基于语料库的SAS研究分支。以等距离系统随机抽样方法进行对比实验。抽取公式为A+BX≤C,A为起始页码,B为抽取间距,C为文本总页码,X为可取页数集。当以L’Assommoir（1953版）为语料,B∈（10;5;4;3;2;1）时,词句抽取率（SR）为9.55%,20.29%,25.13%,33.13%,50.36%和100％,SAS为0.089 7,0.084 1,0.085 4,0.084 7,0.084 8和0.085 4。依次攀升SR没有带来SAS显著变化。说明基于英日语料的SAS评价体系也适用于法文本,便于文学评论家对法文本进行量化评析。     

法国压水堆燃料元件新一代包壳材料的发展

概述了法国对核电站燃料元件包壳材料锆合金的开发与研究现状,着重介绍了所开发的新锆合金（Ｍ２,Ｍ３,Ｍ４,Ｍ５合金）在堆内外的性能。其中Ｍ４和Ｍ５合金包过央燃料棒燃耗达到５５ＧＷ．ｄ．ｔ＾－１的辐照考验结果表明,它们的堆内的腐蚀,蠕变和辐照伸长等性能优于改进型Ｚｒ－４合金包壳。