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Cafestol and kahweol (C&K), two coffee diterpene alcohols with structural similarity which exhibit anticarcinogenic effects, were isolated from green coffee Arabica beans, followed by their lipase-catalysed esterification and purification by preparative high-performance liquid chromatography (HPLC). The isolation and enzymatic synthesis parameters of C&K esters were studied, with the latter optimised by a Central Composite Design; both procedures were monitored by gas chromatography. Scale up and improved isolation conditions resulted in 1.29 g of C&K, with 98% purity from 300 g of green Arabica beans. The highest C&K ester yields were observed using an alcohol:fatty acid molar ratio of 1:5, 73.3 mg mL -1 of CAL-B enzyme, 70 °C and 240 rpm for 3 days in toluene, leading to 85-88% conversion among a variety of tested C&K esters, including n-C 14:0 -C 20:0 , C 18:1 , C 18:2 and C 18:3 ., (Copyright © 2018. Published by Elsevier Ltd.)

The volatile fraction of murici, bacuri and sapodilla are here studied because of their increasing interest for consumers, abundance of production in Brazil, and the general demand for new flavors and aromas. Their volatile profiles were studied by two High Concentration Capacity Headspace techniques (HCC-HS), Headspace Solid Phase Microextraction (HS-SPME) and Headspace Sorptive Extraction (HSSE), in combination with GC-MS. Murici volatile fraction mainly contains esters (38%), carboxylic acids (19%), aldehydes (11%), alcohols (14%), others (13%) and sulfur compounds; bacuri is characterized by terpenes (41%), non-terpenic alcohols (24%), esters (15%), aldehydes (6%), and others (12%); sapodilla consists of esters (33%), alcohols (27%), terpenes (18%) and others (21%). The GC-MS component co-elution was overcome by GC×GC-qMS. The adoption of modern analysis technologies afforded to achieve a better knowledge of the volatile fraction composition of these fruit pulps by increasing substantially the number of compounds identified., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The microwave-assisted extraction (MAE) of 13 different green coffee beans (Coffea arabica L.) was compared to Soxhlet extraction for oil obtention. The full factorial design applied to the microwave-assisted extraction (MAE), related to time and temperature parameters, allowed to develop a powerful fast and smooth methodology (10 min at 45°C) compared to a 4h Soxhlet extraction. The quantification of cafestol and kahweol diterpenes present in the coffee oil was monitored by HPLC/UV and showed satisfactory linearity (R(2)=0.9979), precision (CV 3.7%), recovery (<93%), limit of detection (0.0130 mg/mL), and limit of quantification (0.0406 mg/mL). The space-time yield calculated on the diterpenes content for sample AT1 (Arabica green coffee) showed a six times higher value compared to the traditional Soxhlet method., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Optimisation of a microwave-assisted methanolysis was performed to obtain cafestol and kahweol directly from green coffee oil (Coffea arabica). A two-factor (the methanolysis period and temperature), three-level, factorial experimental design (3(2)) was adopted. The methanolysis procedure was performed under microwave irradiation, using closed vessel and accurate fast responding internal fibre-optic temperature probe. The effects on the responses were measured by HPLC. After 3 min of microwave irradiation (hold time) at 100°C, with 500 mg of green coffee oil, a yield higher than 99% was obtained. The yield of this reaction is 26% after 2h when working under conventional heating. The methods described in the literature lead to long reaction times, poor yields and formation of side products. The microwave-assisted technique proved to be faster, avoided undesired side products and gave better conversion, when compared to conventional heating process., (Copyright © 2012 Elsevier Ltd. All rights reserved.)