Extraction of Oil and Minor Compounds from Oil Palm Fruit with Supercritical Carbon Dioxide

Extraction of oil, carotenes and tocochromanols from oil palm (Elaeis guineensis) fruit with subcritical propane

This work aims to screen the extraction of oil and bioactive compounds including carotenes and tocochromanols from oil palm fruit with subcritical propane and without using a cosolvent. The overall extraction curves of palm oil with subcritical propane were studied and compared to those extracted with supercritical carbon dioxide. Carotenes and tocochromanols were evaluated not only in the extracted oil, but also in the oil of residual fiber in order to calculate the efficiency to recover these valuable compounds. The experimental results showed that oil yield of up to 70 % could be obtained within 120 minutes with subcritical propane at 50 bar and a flow rate of 35 kg·h−1·kg−1. It was also shown that compressed propane is an excellent solvent for the extraction of oil enriched in carotenes and tocochromanols. Subcritical propane extraction can be used as an alternative process for the simultaneous recovery of these valuable minor components from palm fruit.

Chemical characterization of Echium plantagineum seed oil obtained by three methods of extraction

Echium seed oil has been considered an important alternative source of omega 3 fatty acids (n-3 FA) for human consumption. Considering the oxidative instability of n-3 FA richer oils, the objective of this study was to determine the chemical and sensory parameters of the oil obtained from Echium plantagineum seeds obtained by three extraction methods (hydraulic press: HYD; continuous screw press: PRESS; and solvent technique: SOLV). Stearidonic acid (C18:4, n3), the most important n-3 FA present in the oil, changed from 12.5% to 12.7%. Regarding the minor compounds, PRESS sample showed the highest concentration of gamma-tocopherol (782.24 mg/kg oil), while SOLV samples presented the highest amount of β-sitosterol (73.46 mg/100 g) with no difference of campesterol concentration (159.56 mg/100 g) among the samples. Higher values of total phenolics (19.65 mg GAE/kg oil) and β-carotene (34.83 mg/kg oil) were also found in the SOLV samples, suggesting the influence of hexane in the extraction of these bioactive compounds. High resolution mass spectrometry identified caffeic acid and its derivatives as the main phenolic compounds present in the echium oil. PRESS sample showed the best oxidative stability as measured by PV (0.61 mmol/kg oil) and malondialdehyde (173.13 µmol), probably due to faster time of processing compared to HYD and SOLV samples. Our data showed that the extraction method changed the chemical composition of the minor compounds in the echium oil, but these alterations did not reduce its nutritional quality or sensory acceptability. PRACTICAL APPLICATION: Echium oil represents a great potential source of omega 3 fatty acids, but there is not enough information about its oxidative stability and chemical composition, especially toward minor compounds. Our study characterizes echium oil composition obtained from three extraction methods, contributing to amplify the technical information about this important alternative oil for human consumption.

Guidelines on reporting treatment conditions for emerging technologies in food processing

In the last decades, different non-thermal and thermal technologies have been developed for food processing. However, in many cases, it is not clear which experimental parameters must be reported to guarantee the experiments' reproducibility and provide the food industry a straightforward way to scale-up these technologies. Since reproducibility is one of the most important science features, the current work aims to improve the reproducibility of studies on emerging technologies for food processing by providing guidelines on reporting treatment conditions of thermal and non-thermal technologies. Infrared heating, microwave heating, ohmic heating and radiofrequency heating are addressed as advanced thermal technologies and isostatic high pressure, ultra-high-pressure homogenization sterilization, high-pressure homogenization, microfluidization, irradiation, plasma technologies, power ultrasound, pressure change technology, pulsed electric fields, pulsed light and supercritical CO₂ are approached as non-thermal technologies. Finally, growing points and perspectives are highlighted.

Extraction of carotenoid-rich palm pressed fiber oil using mixtures of hydrocarbons and short chain alcohols

Solvent extraction is the most efficient method for recovering residual oil from palm pressed fiber (PPFO), which may contain up to eight times the carotenoid content of that found in crude palm oil. The objective of the present study is the use of binary mixtures of hydrocarbons (HC), hexane (Hex), cyclohexane (CHex) or heptane (Hep), and alcohols (ALC), ethanol (Eth) or isopropanol (IPA), in order to promote the highest recovery of a carotenoid-rich PPFO, in which the compositions of the mixtures are defined based on the calculation of solute-solvent distance (Ra) considering β-carotene as the solute. The extraction experiments were conducted in batch, at 60 ± 2 °C, or in a fixed-bed packed column, at 55 ± 3 °C. Hex and Hep:IPA provided 80% of batch PPFO extraction yield, while in column, the highest yields were obtained with Eth and Hex:IPA (66%). The total carotenoid content obtained was the same independent of the solvent and extraction configuration (from 1790 ± 230 up to 2539 ± 78 mg β-carotene/kg PPFO). In terms of the carotenoid profile, β-carotene was mostly extracted by Hex, Hex:Eth stood out in the extraction of α-carotene, and Eth extracted the highest content of lycopene. It is possible to infer that mixtures of HC and ALC with compositions defined based on Hansen Solubility Parameters (HSPs) demonstrated good ability to extract carotenoid-rich PPFO, maintaining their relatively stable fatty acids composition and free acidity, showing that partial substitution of HC by ALC is technically possible.

Supercritical Fluid Extraction of Fat and Caffeine with Theobromine Retention in the Cocoa Shell

The cocoa shell is a residue of low commercial value, which represents an alternative for obtaining substances of added value for the food and pharmaceutical industry. Substances of interest in the shell include fat and methylxanthines (theobromine and caffeine). In order to obtain the extraction behavior with supercritical CO2, a 23 factorial design was proposed with six central points, taking dynamic extraction into consideration. The following factors were involved: pressure (2,000–6,000 psi), temperature (313–333 K), and time (30–90 min). The obtained yield was between 3.66% and 15.30%. Fat was the substance that was extracted most effectively (94.73%). Caffeine demonstrated variability in the residue, with at least six treatments that exceeded a removal rate of more than 90%, while it was practically impossible to extract theobromine. The difference with regard to the extraction of theobromine may be attributed to its low solubility. Characterization using FT–IR showed the modifications before and after the process, providing clear evidence of the changes corresponding to the fat at 2,924, 2,854 and 1,745 cm−1. The results presented establish the basis for the extraction of substances such as fats and methylxanthines from a cocoa shell with the use of CO2.