Aroma olive oils

Gutierrez N., Rodriguez-Mendez M. L., and de Saja J. A., Array of sensors based on lanthanide bisphtahlocyanine Langmuir-Blodgett films for the detection of olive oil aroma, Sens. Actuators B, 77, 437-442, 2001. 

Guadarrama, A., Rodriguez-Mendez, M.L.R., Sanz, C., Saja, J.A., and Ros, J.L. Electronic nose based on conducting polymers for the quality control of the olive oil aroma Discrimination of quality, variety of olive and geographic origin. Analytica Chimica Acta, 432, 283-292. 2001. 

Morales, M. T., Alonso, M. V., Rios, J. J. and Aparicio, R. (1995) Virgin olive oil aroma -relationship between volatile compounds and sensory attributes by chemometrics. Journal of Agricultural and Food Chemistry, 43, 2925-31. 

Supercritical fluid extraction combined with high-resolution GC MS proved to be a powerful tool for the analysis of the virgin olive oil aroma [15]. The volatiles identified were compared with those obtained by using the DHS method. Different aromatic profiles were obtained by applying the two extraction procedures. The profiles obtained by DHS-GC-MS corresponded to a genuine extra-virgin olive oil sample in accordance with previous findings [18]. The presence of off-flavors was not detected. In the SFE extracts, however, markers of oxidation processes were identified, since this technique is also suitable for the extraction of semivolatile compounds. These were volatile compounds related to oxidation of linoleic, linolenic, and oleic acids, and in particular aldehydes and acids, which had been previously found in oxidized olive oil samples [19],... 

S. Vichi, Extraction Techniques for the Analysis of Virgin Olive Oil Aroma in Olives and Olive Oil in Health and Disease Prevention, Elsevier, 2010. 

Hhong et ah (2009) described the sensory attributes of morama oil as fresh, thick, creamy, and smooth with a grassy and earthy aroma and raw nutty flavor and aftertaste. Compared to both sunflower and olive oils, potato chips fried in morama oil were rated as more acceptable by consumers (Tlhong et ah, 2009). Therefore, as a cooking oil, morama oil has great potential in terms of consumer acceptability. However, its acceptability as a salad oil remains imexplored. 

Since early antiquity, spices and resins from animal and plant sources have been used extensively for perfumery and flavor purposes, and to a lesser extent for their observed or presumed preservative properties. Fragrance and flavor materials vary from highly complex mixtures to single chemicals. Their history began when people discovered that components characteristic of the aroma of natural products could be enriched by simple methods. Recipes for extraction with olive oil and for distillation have survived from pre-Christian times to this day. 

Lipoxygenases play an important role in determining oil quality. The aromas typical of olive oil are due to complex mixtures of volatile compounds those especially abundant are saturated and unsaturated six carbon atom aldehydes, alcohols, and the esters of alcohols, the cited aldehydes and alcohols having sensory properties responsible for the so-called green odour (Hatanaka, 1996). 

Table 2.6 Median values of defects and fruity aroma, and their corresponding robust coefficients of variation, in relation to virgin olive oil categories...

Median of defects Robust coefficient of variation % Median of fruity aroma Robust coefficient of variation % Olive oil category... 

Olias, J.M., Perez, A.G., Rios, J.J. and Sanz, L.C. (1993) Aroma of virgin olive oil biogenesis of the green odor notes. J. Agric. Food Chem., 41, 2368-2373. 

The aroma compounds of olive oil have recently been reviewed by Kiritsakis (60). The most abundant aroma compounds in virgin olive oil are C-6 aliphatic compounds, frani-2-hexenal, frani-2-hexen-l-ol, hexan-l-ol, cw-3-hexen-l-ol, di-2-penten-l-ol, c/i-3-hexenal, hexyl acetate, and hexanal, accounting for about 80% of total volatile compounds with the prominence of tran -2-hexenal (61-64). These C-6 compounds provide the green perception and unique aroma of olive oil. Recently, 2,4-dimethylfuran has been found in olive oil with unpleasant sensory quality (65). As a result, the ratio of trani-2-hexenal/2,4-dimethylfuran has been proposed as a quality marker for olive oil and the ratio value of less than 1.5 indicates lower quality olive oil (65). 

Gas chromatography-olfactometery (GC-O) provides a sensory profile of odor active compounds present in an aroma extract by sniffing the GC effluent. Several techniques have been developed to collect and process GC-O data and to estimate the sensory contribution of individual odor active compounds, including dilution analysis (29, 30), time intensity (31), and detection frequency (32) methods. GC-O has successfully been used to evaluate the odor active compounds of olive oil (33), soybean oil (34), and fish oil enriched mayonnaise (35). 

Table 6.36 Odour profiles of virgin olive oils and their aroma models [64]...

Olive oil possesses a unique place among vegetable oils largely due to the mode of extraction and to the presence of volatile and non-volatile flavouring compounds. The most important constituents of the aroma of olive oil are C6 aldehydes and alcohols formed in the fruit from polyunsaturated fatty acids. This takes place on crushing, the first step of processing. The plant tissue... 

Rodriguez Mendez and coworkers did a series of researches in the development of new sensors able to detect the odors and aromas [32,58,75-78], They first used lutetium bisphthalocyanine (LuPc ) LB and evaporated films for the detection of the aroma of olive oil or wine (hexanol, hexanal, -buthyl acetate, and acetic acid) based on the changes in their conductivity [76], The kinetics and the intensity of the response of the films depend not only on the morphology and the thickness of the films but also on the nature of the reactant gas. They detected acetic acid down to 88 mmol/L, based on the refractive index changes in combination with an optical fiber... 

Delicious taste and aroma are synonyms to fresh and good quality of almost any foodstuff and, undoubtedly, affect the consumer s final opinion and choice. Sensory characteristics of olive oil, a major component in the Mediterranean diet, represent the sum of the sensory parameters that integrate its complex and specific qualitative profile including various intrinsic and extrinsic factors such as cultivar (genetic), weather conditions, stage of ripeness, methods and/or system of harvest and storage (Table 5.13). Regulations and standards related to olive oil sensory evaluation include... 

A. Guadarrama, M. L. Rodriguez-Mendez and J. A. de Saja (2000) Array of sensors based on conducting polymers for quality control of the aroma of the virgin olive oil , Sensors and Actuators, 69,276-82. 

Moss, M. and Oliver, L. 2012. Plasma 1,8-cineole correlates with cognitive performance following exposure to rosemary essential oil aroma. 2(3) 103-113. 

---