Means-end chains analysis of extra virgin olive oil purchase and consumption behavior

Consumption and purchase behavior towards extra virgin olive oil are not well understood in the US. Soft laddering interviews were conducted with 63 Northern California consumers and means-end chains analysis on the interview data revealed common grounds of consumption and buying motivations for three different a priori defined consumer segments. Consumption motivational structures were more similar across the different consumer segments than purchasing ones. Consumers who purchased only local extra virgin olive oil had simpler perceptual orientations than consumers who purchased imported extra virgin olive oils or both imported and local oils. Several different consumer values could be associated with consequences that were linked to just one attribute. On the other hand, one particular value could also be associated with a few different attributes. These findings provide opportunities for the olive oil industry to design products that will better satisfy consumer values and needs.     

Development and test of a new fuzzy-QFD approach for characterizing customers rating of extra virgin olive oil

This paper presents the development of an innovative fuzzy-QFD based methodology for characterizing customer rating of food products. The method has been tested on different samples of extra virgin olive oil to verify its suitability.The results demonstrated the effectiveness of such multi-criterion technique not only for the design and development of new products that meet customers’ requirements, but also for testing the quality of existing ones.The main innovation of the method, consists in the application of the fuzzy logic to address the issue, common in many decisional techniques, of dealing with data deriving from subjective verbally expressed evaluations that cannot be treated with mathematical models.The objective of this work was to test the combined assessment technique based on quality function deployment and fuzzy logic method for determining which characteristics of extra virgin olive oil influence most of the acceptance of the consumers toward the product. The relationship between consumer expectations, defined by a market survey, and main attributes of the examined products were assessed by means of the House of Quality (HOQ). The results obtained allowed to classify the quality of different brands of olive oil with respect to customer preferences.     

特级初榨橄榄油基本质量指标及要求

目的 介绍2022年5月1日起实施的GB/T 23347—2021《橄榄油、油橄榄果渣油》,对当前市售进口特级初榨橄榄油质量情况进行评估。方法 采购20种市售标称意大利、希腊、西班牙等国进口的特级初榨橄榄油,检验酸价、过氧化值、消光系数变异值、水分及挥发物和不溶性杂质5个基础项目,对所得数据进行分析。通过与国际橄榄理事会标准的对比,讨论限量及测定方法等方面的细微差异,并说明这些项目对于橄榄油质量评估的现实意义。结果 所测样品的酸价、过氧化值、不溶性杂质3个项目均符合我国标准对该产品等级的限量要求。对比GB/T 23347—2021和国际橄榄理事会贸易标准,发现对于优质初榨橄榄油的酸价限量,国内标准比国外标准更为严格,橄榄油进口贸易需要注意这一差异。结论 2021年新颁布的GB/T23347—2021在质量要求上有所提高,消费者购买橄榄油时应优先选择“特级初榨橄榄油”。橄榄油质量初步评估需要加快时间和减少成本,检验以上5个项目为最低要求。     

Diacylglycerol isomers in extra virgin olive oil: Effect of different storage conditions

An experimental investigation was carried out with the aim to investigate on the isomerisation of 1,2-diacylglycerols to 1,3-diacylglycerols as a function of the storage conditions, as well as to identify indices useful to evaluate the freshness of the oils. Two oils derived from two different cultivars (Coratina and Ogliarola barese) were stored for two years as follows: in bottles at dark; in clear glass bottles at light; in green glass bottles at light; in bottles at dark, the latter subjected to repeated opening and samplings to simulate domestic use. The obtained results evinced that during the storage period a significant increase in the 1,3-isomers was observed due to an isomerisation from the 1,2 to the 1,3 isomeric form, consequently the 1,3/1,2 ratio increased in both oils. The covariance analysis of the data showed that the isomerisation of diacylglycerols, taking place during time, was affected by the type of oil, probably due to the different initial hydrolysis level, but was not affected by the storage conditions. Among the parameters considered, the total diacylglycerols/1,3-diacylglycerols ratio could be used as freshness index of extra virgin olive oil, since it is not affected by either oil or storage conditions.     

基于PCA-SVM结合共聚焦拉曼光谱的特级 初榨橄榄油掺伪压榨菜籽油定量分析

为了促进国内橄榄油市场的健康发展，对掺伪同样存在天然类胡萝卜素的低温压榨菜籽油的特级初榨橄榄油进行了定量鉴别研究。采用共聚焦拉曼光谱技术对不同掺伪浓度油样进行测试，基于密度泛函理论对油样的拉曼光谱峰的归属进行了理论分析，并对拉曼光谱数据进行主成分分析（PCA），然后利用支持向量机（SVM）构建PCA-SVM模型。另外，对PCA-SVM模型的检出限进行了研究。结果表明：特级初榨橄榄油与低温压榨菜籽油的拉曼光谱存在一定差异，最明显的光谱差异主要集中在谱峰1 008、1 161、1 528 cm-1和谱段2 800～3 000 cm-1内，与密度泛函理论对不同油样拉曼光谱峰的分析一致；不考虑类胡萝卜素特征信号建立的PCA-SVM模型决定系数大于0.989，均方根误差小于2.990%，检出限为2%（低温压榨菜籽油体积分数）;在特级初榨橄榄油掺伪定量分析中，考虑类胡萝卜素的特征信号有助于提高模型预测精度，但仅限于掺伪低价植物油中无类胡萝卜素存在的情况;PCA-SVM模型在不考虑类胡萝卜素特征信号的情况下依然具有良好的定量预测效果。综上，所建立的PCA-SVM模型可以用于掺伪2%以上低温压榨菜籽油的特级初榨橄榄油的定量鉴别。     

Self-organizing maps based on chaotic parameters to detect adulterations of extra virgin olive oil with inferior edible oils

A nonlinear algorithm based on chaotic parameters (CPs) has been employed to determine the nature of different output signals obtained from UV–vis spectrophotometer (UV) measurements. These signals come from UV scans of adulterated samples of extra virgin olive oil (EVOO) with refined olive oil or refined olive pomace oil, or from pure samples of EVOO with white random or sinusoidal white random noises. The data collected from this equipment was used to calculate CP values. Then, a self-organizing map was used to detect different types of signals. Using this method, the signals can be identified and classified into five groups depending on their type, the percentage of noise added, and the concentration of adulterant agents, with a misclassification rate of less than 1.3%.     

鲜榨山茶油与特级初榨橄榄油营养价值的比较

以鲜榨山茶油和特级初榨橄榄油为研究对象,对其理化指标、脂肪酸组成和营养成分进行测定并比较。结果表明:鲜榨山茶油在理化指标上与特级初榨橄榄油相当,脂肪酸组成与特级初榨橄榄油相似,但油酸含量高于特级初榨橄榄油,棕榈酸和硬脂酸含量低于特级初榨橄榄油;在维生素E、角鲨烯、植物甾醇等天然生物活性物质方面媲美特级初榨橄榄油。     

西班牙和意大利进口特级初榨橄榄油品质比较

为了系统研究我国主要进口的特级初榨橄榄油性质,比较分析了我国主要进口的8种西班牙和意大利特级初榨橄榄油的脂肪酸组成、酸值、过氧化值及微量成分含量,并对其进行了挥发性成分分析及感官评价。结果表明：西班牙特级初榨橄榄油的C18∶1（77.22%）和C23∶0（0.94%）含量平均值高于意大利样品（分别为72.46%和0.64%）,西班牙特级初榨橄榄油的酸值、过氧化值低于意大利样品;西班牙特级初榨橄榄油中含有γ-生育酚和δ-生育三烯酚,而意大利样品中未检出这两种,且西班牙特级初榨橄榄油中α-生育酚含量平均值（189.58 mg/kg）高于意大利样品（161.26 mg/kg）,角鲨烯含量平均值（6 127.83 mg/kg）远高于意大利样品（4 083.50 mg/kg）,两者甾醇含量差异很小。虽然西班牙特级初榨橄榄油的醛类含量平均值低于意大利样品,但酯类含量更高。感官评价发现,西班牙特级初榨橄榄油的果味、苦味、辣味评分皆高于意大利样品。综上,西班牙特级初榨橄榄油的酸值、过氧化值较低,α-生育酚、角鲨烯含量高于意大利样品,且感官评分较高。     

NMR spectroscopy: a powerful tool for the analysis of polyphenols in extra virgin olive oil

Extra virgin olive oil (EVOO), a key component of the Mediterranean diet, has aroused interest in recent years due to its health properties. Nuclear magnetic resonance (NMR) spectroscopy is an appropriate tool for the accurate quantification of minor compounds in complex food matrices, such as polyphenols in olive oil. Flavonoids, lignans, secoiridoids and phenolic acids and alcohols in EVOO have been identified and quantified by NMR. This review provides an overview of the major developments in the structural elucidation of polyphenol compounds in EVOO. © 2019 Society of Chemical Industry     

Effect of extra virgin olive oil substitution for fat on quality of pork patty

BACKGROUND: Extra virgin olive oil (EVOO) is well known for its beneficial effects on human health. Thus, the purpose of this study was to investigate the effect of EVOO substitution for backfat on qualities of pork patty to avoid high consumption of animal‐originated fat, because it is closely related to development of cardiovascular disease and obesity. RESULT: Water‐holding capacity was higher in control (lean pork + 10% backfat) and T3 (lean pork + 5% backfat + 5% EVOO + 0.5% isolated soy protein + 0.5% carrageenan + 0.5% maltodextrin) than T1 (lean pork + 5% backfat + 5% EVOO + 0.5% isolated soy protein) and T2 (lean pork + 5% backfat + 5% EVOO + 0.5% isolated soy protein + 0.5% carrageenan). Hardness was higher in EVOO substitution for backfat patty samples than control. In sensory evaluation, the control was significantly higher in overall acceptability compared with EVOO substitution for backfat pork patty samples. CONCLUSION: The physical properties of pork patty made by EVOO substitution for backfat were stable as a commercial pork patty (control). However, sensory evaluation scores were higher in control compared to EVOO‐substituted pork patty samples. Copyright © 2008 Society of Chemical Industry     

Infrared spectroscopy for quantitative analysis and oil parameters of olive oil and virgin coconut oil: A review

Vegetable oils are major lipid sources with high nutritional and calorific values for human diet. Specifically, virgin coconut oil and extra virgin olive oil are the functional oils widely used in food and pharmaceutical products, either as vehicles or main components. The quality of edible oils is determined by its contents and parameters inherent in vegetable oils. Infrared spectroscopy is an ideal technique for quantitative analysis of vegetable oils as well as for determination of oils parameters as the changes in infrared spectra can be associated with the changes of oils parameters. Infrared spectra in complex samples are difficult to interpret, as a consequence, spectroscopist uses additional tools called with chemometrics to analyse edible oils qualitatively and quantitatively. This article reviews the use of infrared spectroscopy combined with chemometrics (multivariate analysis) for quantitative analysis and determination of oil parameters of virgin coconut oil and extra virgin olive oil. Although infrared spectra for edible oils are similar, they exhibit some differences which enable spectroscopist to differentiate due to the nature property of infrared spectroscopy spectra as fingerprint spectra which can be understood that there are no different edible oils having the same infrared spectroscopy spectra.     

Effect of the matrix volatile composition in the headspace solid-phase microextraction analysis of extra virgin olive oil

The effectiveness of headspace solid-phase microextraction (HS-SPME) for the quantitative analysis of extra virgin olive oil volatiles was investigated on 44 standard compounds, using an adsorbent polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber. The method’s sensitivity was satisfactory, as was its repeatability. However, when the extraction was carried out on mixtures containing all the standard analytes, phenomena of coating saturation and competition between components caused losses in linearity at lower levels of concentration, thus distorting the quantitative evaluation. Coating saturation or displacement between components was also found to be responsible for the bias in the quantitative determinations when extra virgin olive oil samples were analysed. These limitations were overcome by diluting the oil at concentrations not exceeding the total capacity of the fiber coating and until the quantity of displacing compounds was reduced to sufficiently low levels.     

Differential scanning calorimetry thermal properties and oxidative stability indices of microwave heated extra virgin olive oils

BACKGROUND: The use of differential scanning calorimetry (DSC) for assessing the deterioration effect of microwave heating on vegetable oils, and on olive oils in particular, has been partially explored in literature. The aim of this work was to evaluate the potential of DSC to discriminate among microwaved extra virgin olive oils (EvOo from different olive cultivar and origin), according to changes on thermal properties (upon cooling and heating) and traditional oxidative stability indices (peroxide, p‐anisidine and TOTOX values). RESULTS: An elevated value of lipid oxidation was reached by the most unsaturated EvOo sample (9.5% of linoleic acid) at 6 min of microwave treatment. Free acidity significantly increased (0.42%) only for the oil sample with the highest water content (874 mg kg^?1 oil) at the longest time of treatment. Crystallisation enthalpies significantly decreased and the major exothermic peak shifted towards lower temperature, leading to enlargement of the transition range in all samples due to the formation of weak and mixed crystals among triacylglycerols and lipid degradation products. On the contrary, thermal properties upon heating appeared to similarly vary among samples. CONCLUSIONS: The analysis of DSC thermal properties upon cooling seemed to clearly discriminate among different EvOo samples after microwaving. The relation between changes of thermal properties and oxidation parameters should be further studied using additional oxidative stability indices on a larger set of oil samples, due to the complexity of EvOo composition. Copyright © 2010 Society of Chemical Industry     

Dietary evaluation of Mediterranean fish and molluscs pan‐fried in virgin olive oil

The effect of domestic pan‐frying in virgin olive oil (VOO) on the proximate composition, energy content, cholesterol, squalene and fatty acids in the edible portion of six species of finfish, common squid and mussels just caught from several regions of the Aegean Sea (Mediterranean Sea) was investigated. The species selected are traditionally consumed pan‐fried in VOO by the Greeks. On a fresh weight basis, pan‐frying caused significant water loss and increase of total fat, crude protein and energy content. The amount of VOO absorbed during frying ranged from 4.5 to 14.2% of fresh matter, showing a non‐linear negative correlation with initial fat, fish length and fish weight. Cholesterol content increased from 25 to 106 mg 100 g^?1 fresh weight (fw) to 33–130 mg 100 g^?1 fw after frying. VOO absorbed during frying resulted in a 20–78 times increase of squalene content and in significant alteration of fatty acid composition, the major change being the increase of monounsaturated fatty acids which became predominant in all fried samples. The intakes of fat and major fatty acid classes by consuming the pan‐fried seafood were comparable with the respective average Greek values. Frying in VOO resulted in a two to three times decrease of the atherogenic index and a slightly less decrease of the thrombogenic index. Both indices remained lower than 0.45 in all fried samples. The cholesterol‐saturated fat index and the cholesterol index increased up to twice after frying, ranging between 3.4–9.9 and 2.9–9.3, respectively. From the results obtained it is concluded that fish and shellfish pan‐fried in VOO present a healthy lipid profile in terms of the n‐6/n‐3 ratio, major fatty acid classes and total fat content. Copyright © 2004 Society of Chemical Industry     

Potential use of extra virgin olive oil in bakery products rich in fats: a comparative study with refined oils

The lipid fraction of bakery products undergoes a significant degradation during baking, with an increase in undesirable oxidised substances, that can act as catalysts for further oxidative reactions during storage reducing the product shelf life. The use of extra virgin olive oil in bakery products rich in fat in place of refined oils was studied, assessing the evolution of the oxidative and hydrolytic degradation during storage. Two‐way analysis of variance, followed by Tukey's HSD test for multiple comparisons, covariance and principal component analyses were carried out to compare the effect of the type of oils. The data obtained showed that the evolution of the oxidation levels in the analysed samples during storage was related to the type of oil used in the production process. Particularly, the use of extra virgin olive oil led to significantly lower values of hydroperoxides, ultraviolet absorption constants, triacylglycerol oligopolymers and oxidised triacylglycerols.