橄榄油中甾醇组成及总量测定方法的探讨

介绍了甾醇组成及总量测定在橄榄油评价中的意义,比较了3种甾醇测定方法优缺点,详细探讨了COI/T.20/Doc.no.10《气相色谱法测定甾醇组成及甾醇含量》测定方法中影响测定结果的操作要点等,以求通过对方法探讨和分析,提高COI/T.20/Doc.no.10方法的可操作性.通过对实例样品的分析可以看出,橄榄油理事会制定的COI/T.20/Doc.no.10方法是一种值得推荐的可行的分析方法.     

French Fries oleuropein content during the successive deep frying in oils enriched with an olive leaf extract

Olive oil, sunflower oil and soybean oil were enriched with an olive (Olea Europaea) leaf extract rich in oleuropein at a supplementation level of 100 mg total phenolics per kg oil. Supplemented oils were used for deep frying of potatoes for eight successive frying sessions without replenishment under domestic frying conditions. Supplemented oils contained oleuropein while deep frying resulted in a gradual decrease in oils oleuropein content. After the eighth successive frying, oleuropein was still detected in oils, its retention being 3.2–12.4%. Deep frying of potatoes in supplemented oils succeeded in preparing French fries containing oleuropein even after eight successive fryings. Contrary to the oil type, the number of frying sessions affected potatoes oleuropein content. Oleuropein intake by consuming French fries deep‐fried in enriched oils was approximately ten times higher in potatoes prepared in the first frying session as compared to the respective intake after the eighth frying.     

Effects of diets containing oils from repeated frying on magnesium absorption

Olive oil, sunflower oil and palm olein were used in repeated potato fryings until the oils reached the limit of 25% of polar compounds allowed by law. Six groups of rats, over 28 days, were fed diets containing 8% of: olive oil; olive oil from 69 fryings; sunflower oil; sunflower oil from 48 frying; palm olein, and palm olein from 80 fryings. Body weight and food intake were monitored weekly, during days 21–28 faeces and urine were collected and finally blood and carcasses were also collected and stored. No significant differences were observed in food intake and body weight among the six groups of animals. The type of oil did not modify magnesium intake, the urinary and faecal excretion of this mineral nor its apparent absorption or retention. The consumption of oils from frying, however, induced an increase in apparent magnesium absorption due to a decrease in faecal magnesium excretion, but magnesium retention did not vary owing to the increase in urinary losses. Serum magnesium and magnesium contents and concentrations in carcasses were unaffected. Therefore, it was concluded that the consumption of used frying oils enhances magnesium absorption, independently from the type of oil, although magnesium retention is not affected due to a an elevation of urinary excretion. © 1999 Society of Chemical Industry     

橄榄油与橄榄油基二酯油煎炸薯条 品质差异分析

甘油二酯(DAG)作为一种低热值的功能性脂质,因其特殊的理化性质和生理功能被广泛应用于食品体系中。为了考察DAG油作为煎炸油的可行性,以橄榄油基二酯油(ODO,82.3%)和橄榄油(OO,92.43%)煎炸薯条,对比研究两种油煎炸后的薯条在水分含量、质构、油含量、色泽、淀粉糊化度以及体外模拟消化淀粉水解率等方面的差异,并用扫描电子显微镜观察消化过程中薯条表面的微观形态变化,最后对两种油煎炸的薯条进行感官评价。结果表明：ODO煎炸薯条的水分含量(57.07%)、油含量(28.15%)、淀粉糊化度(90.7%)、体外模拟消化淀粉水解率(63.02%)分别高于OO煎炸薯条的水分含量(49.93%)、油含量(25.74%)、淀粉糊化度(88.3%)和体外模拟消化淀粉水解率(53.47%);在质构和色泽上,与OO煎炸薯条相比,ODO煎炸薯条具有更高的脆度、更低的硬度及更好的色泽;从微观形态看,ODO煎炸薯条外表面淀粉颗粒的收缩、分散和变形更明显,经体外模拟消化后,OO和ODO煎炸薯条均发生了较大的细胞破裂,其中ODO煎炸薯条显微结构破坏更严重;OO和ODO煎炸薯条在口感、外观、风味、油腻性、脆度...     

高油酸菜籽煎炸油的研究

研究开发以精炼高油酸菜籽油为基油的煎炸专用油,设计合理的煎炸油配方。根据棕榈油、棉籽油、高油酸菜籽油等常用煎炸油的煎炸特性、脂肪酸组成及最终产品的质量要求,得到了油酸含量高于45%、亚麻酸含量低于4%、多不饱和脂肪酸含量低于30%的配方油,并通过方程运算和预实验,得到最佳配方为高油酸菜籽油、24度棕榈油、棉籽油质量比范围50%～64%∶0%～36%∶0%～24%。通过计算机筛选出5种配方油,其中配方油5 (高油酸菜籽油与24度棕榈油质量比为64∶36)煎炸稳定性好,煎炸寿命长,油炸食品感官效果好,因而是煎炸配方油的最佳选择。     

Biological properties of olive oil phytochemicals

Olive oil is the principal source of fat in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Extra-virgin olive oil contains a considerable amount of phenolic compounds, for example, hydroxytyrosol and oleuropein, that are responsible for its peculiar taste and for its high stability. Evidence is accumulating to demonstrate that olive oil phenolics are powerful antioxidants, both in vitro and in vivo; also, they exert other potent biological activities that could partially account for the observed healthful effects of the Mediterranean diet.     

荤素分类煎炸对油脂品质的影响

为了延长煎炸油的使用寿命,有效降低成本,研究了荤素分类煎炸对油脂品质的影响。采用食材荤素分类及不分类煎炸并循环使用煎炸油,分析了两种煎炸方式下煎炸油的色泽、酸值、过氧化值、p-茴香胺值、极性组分含量的变化情况,并对比分析两种煎炸方式用油量。结果表明：采用荤素分类煎炸可以更好地抑制油脂色泽、酸值、p-茴香胺值及极性组分含量的增长速度;不分类煎炸油脂的色泽在煎炸2 d后无法用比色仪检测,分类煎炸7 d后油脂的色泽才接近不分类煎炸2 d的色泽;不分类煎炸的油脂酸值(KOH)在煎炸前3 d内急剧上升,由初始的0.09 mg/g增至1.30 mg/g,分类煎炸的油脂酸值(KOH)浮动较小,由初始的0.09 mg/g最高增加至0.62 mg/g;在煎炸7 d时,不分类煎炸的油脂p-茴香胺值由初始的4.0增加到38.0,分类煎炸的油脂p-茴香胺值由初始的4.0增加到15.0,不分类煎炸油脂的p-茴香胺值的增长速度是分类煎炸的近3倍;不分类煎炸,油脂极性组分含量在第1天内急剧上升,在第4天达到最高,为12.5%,后逐渐趋于平稳,分类煎炸,油脂极性组分含量在前3 d内均保持在8%左右,之后才有上升的趋势...     

Effect of potato presence on the degradation of extra virgin olive oil during frying

This work investigates the effect of potato presence on the degradation of extra virgin olive oil (EVOO) during repeated frying. For this reason the performance of EVOO during frying was compared with its performance during heating at frying temperatures. In order to make meaningful comparisons the temperature profiles obtained during the frying experiments were replicated during the heating experiments by means of a high energy exchange rate cooling/heating system. The effects of potato‐to‐oil ratio (1/7 and 1/35 kg_potatoes/L_oil) and number (N) of batches (N = 0, 1, 0, 20, 30, 40) were examined. EVOO was analysed using high performance size exclusion chromatography (HPSEC). It was found that polymerisation products increased linearly during frying and heating and that they were not affected by potatoes presence at low ratio. The effect of potato presence became statistically significant (yet not remarkable) at the high ratio. Decomposition products increased during frying whereas they decreased during heating.     

High performance size-exclusion chromatography analysis of polar compounds applied to refined, mild deodorized, extra virgin olive oils and their blends: An approach to their differentiation

An investigation was carried out to evaluate the use of High Performance Size-Exclusion Chromatography (HPSEC) of polar compounds of refined, mild deodorized, extra virgin olive oils as well as of their blends, in attempting to reveal significant differences in the amounts of the substance classes constituting polar compounds among these oils. Two sets of blends were prepared by mixing an extra virgin olive oil with both refined and mild deodorized olive oils in increasing amounts. The obtained data highlighted that the triacylglycerol oligopolymers were absent or present in traces in the extra virgin olive oil, while their mean amount was equal to 0.04 g/100 g and 0.72 g/100 g in mild deodorized and refined olive oils, respectively. Oxidized triacylglycerols and diacylglycerols were more abundant in mild deodorized oil and refined oil than in extra virgin olive oil. The Factorial Discriminant Analysis of the data showed that the HPSEC analysis could reveal the presence of refined/mild deodorized oils in extra virgin olive oils. In particular, the classification functions obtained allowed designation of mixtures containing at least 30 g/100 g of mild deodorized oil and all those containing refined olive oil as deodorized oil, therefore as oils subjected to at least a mild refining treatment.     

食用植物油煎炸过程中的品质变化

利用花生油、大豆油、调和油、棕榈油4种食用植物油作为煎炸油对豆腐、裹粉鸡柳、油条3种食材进行煎炸,研究煎炸时间对煎炸油极性组分含量及羰基值的影响,确定煎炸油时间预警点,同时研究了不同煎炸油品种、不同食材对煎炸油极性组分含量的影响。结果表明:极性组分含量、羰基值均与煎炸时间呈正相关(r_(极性组分)=0.809,r_(羰基值)=0.859,P=0.000);煎炸6~11 h煎炸油极性组分含量均值从初始的11.85%增至20.96%,最大值为34.10%,可作为煎炸油质量不达标的时间预警点;煎炸12 h,极性组分含量从低到高依次为花生油、棕榈油、调和油、大豆油,含量分别为21.1%、24.1%、26.8%、27.8%,豆腐、裹粉鸡柳、油条煎炸油中极性组分含量分别为17.7%、25.0%、32.2%;煎炸18 h,极性组分含量增大程度由低到高为棕榈油/调和油、大豆油、花生油,煎炸食材用油为豆腐煎炸油、裹粉鸡柳煎炸油、油条煎炸油。     

食用橄榄油贸易促进组织——国际橄榄理事会解析

《国际橄榄油和食用橄榄协定》是由联合国主持在橄榄油主要生产国与消费国之间签订的国际商品协定.从1959年到2015年历经五次改版,根据该协议成立的\"国际橄榄理事会\"(International Olive Council,IOC)总部驻地在橄榄油最大出口国西班牙首都马德里.国际橄榄理事会由成员理事会管理,下设执行秘书处...     

Development of Healthy Low-Fat Snacks: Understanding the Mechanisms of Quality Changes During Atmospheric and Vacuum Frying

Excess consumption of fat, a main component in fried food, is a key dietary contributor to coronary heart disease and perhaps some types of cancer. Although consumers are interested in healthier snacks, they are not willing to sacrifice organoleptic properties. Vacuum frying might be an alternative for the production of nutritious, healthy, palatable, and novel snacks. The objective of this review is to discuss the effect of atmospheric deep-fat frying on the main microstructural components and quality parameters of fried food, to understand how quality can be improved by lowering the operating pressure and, therefore, the processing temperature.