Squalene, extraction from olive

Supercritical CO2 column fractionation has also been investigated for the production of squalene concentrates from olive oil deodorizer distillates (56, 87). Bon-dioli et al. (87) used saponification and esterification steps to convert the FFA and fatty acid esters to triacylglycerols in order to improve squalene separation prior to countercurrent continuous fractionation. The highest squalene purity and extraction yield was achieved at 15 MPa and 313 K, using a temperature gradient of 303-323 K along the column to improve the squalene purity and yield. Ruivo et al. 

Other nonphenolic compounds have also been extracted from olive leaves such is the case with terpenic acids including oleanolic, ursolic, and maslinic acids, which were extracted by Albi et al. [259]. Both maceration and Soxhlet extraction using hexane as extractant were used to remove terpenic dialcohols, triglycerides, a-tocopherol, ester waxes, squalene, and (3-carotene, among other substances [260]. The extraction efficiency was similar, the differences between the two methods never exceeding 5%. 

Pressurized Fluid Extraction of Squalene from Olive... 

The aim of this work was to develop a simple, environmentally sound and fltst method for the extraction and determination of squalene in an olive biomass using the PFE technique, and investigate if this technique could be a viable processing technology for the extraction of squalene from olive oil pomace. The effects of different solvents and mixtures of solvent, extraction temperature and extraction time were also evaluated for their influence on yield of squalene. Squalene in the olive biomass extracts were quantified by liquid chromatography with UV absorbance and fluorescence detection. In addition, the proposed method was used to determine the content of a-tocopherol in the olive biomass. 

Table I. Extraction yield in g/g of squalene obtained with a central composite design from olive oil pomace, batch A.

Figure 2. Response surface plot of the extraction yield of squalene from olive oil pomace using 2 propanol as solvent, as a function of extraction time and...

Researchers interested in the properties and occurrence of natural antioxidants concentrate on vitamins E and C, carotenoids, phenolic acids, flavonoids, sesame lignins, phytosterols, extracts from the leaves of the plants belonging to the Lami-aceae family, oryzanols, tea leaf extracts, phosphatides, olive oil phenols, squalene, and propolis. Barrera-AreUano et al. (1999), Boskou (1999), Blekas and Boskou... 

In Section 20.4.2 it was established that the mixtures of ethyl lactate with lipid type substances usually present partial hquid-liquid miscibility with upper critical solution temperature (UCST) critical point. This property could be exploited to study and develop new separation processes for the edible oil industry. In this section two particular apphcations will be reviewed the recovery of squalene from olive oil deodorizer distillates and the extraction of tocopherol from olive oil. Both case studies are based in the liquid-hquid equilibria (LLE) data presented in Section 20.4.2. 

Another important application of ethyl lactate is related with the edible oil industry, taking advantage of the partial liquid-liquid miscibility that present the mixtures of ethyl lactate with different lipid type substances. This property could be exploited to develop new separation processes, similar to those mentioned in this chapter, namely the recovery of squalene from olive oil deodorized distillates and the extraction of tocopherols from olive oil. In both applications, the yield and separation factors obtained indicate good selectivity of using ethyl lactate as an extractive solvent, and demonstrate the viability of developing liquid-liquid countercurrent process using green ethyl lactate solvent in edible oil industrial applications. 

The official method of analysis of steradienes in olive oil (Commission regulation (EC) No. 656/95) involves saponification of the oil with an internal standard of cholesta-3,5-diene, followed by extraction of the unsaponifiable fraction into hexane. The steradiene fraction is then separated from other hydrocarbons, such as alkanes and squalene isomers, by column chromatography on silica gel. Quantitative analysis is then performed by GC. 

The olive biomass samples (olive oil pomace) were obtained from an olive oil processing ctory in Cdrdoba (Spain), which used a two phase centrifugation technique to extract the oil. The samples were kept frozen at -20°C. Two different samples (A and B) were used in all the experiments, which had been obtained using the same process, but at different time of the year. Sample A consisted of well grounded biomass, while sample B was crude and contained visual traces of kernels. The a-tocopherol and squalene standards were from Sigma Chemical (St. Lx>uis, USA). 

A confirmation experiment was performed using the optimized parameters found in this study, where a new sample was extracted at 190 °C, 2-propanol as solvent, a static extraction time of 10 min. x 3 cycles with 60 % flush. The average yield of squalene from batch A was 509 pg/g (RSD value 16%, n=4), and from batch B 219 pg/g (RSD value 3.2%, n=5). The discrepancy in yield between sample A and B might be referred to the ct that the samples were taken at different times of the year, and might origin from different kind of olives. 

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