3. Results and discussion
3.1. Comparison of extraction processes in terms of extraction yield
Extraction yields obtained by heat reflux extraction (HRE), maceration, ultrasound and microwave assisted extraction are presented in Fig. 3. Regarding HRE extractions, it can be identified that most of the extraction is achieved within 30 min. Increasing the duration of HRE up to 5 h does not lead to a drastic increase of the extraction yield (20% against 19% for 5 h and 30 min extraction duration respectively). Moreover, adding a preliminary step of homogenization prior to HRE does not improve significantly the yield (18.8 ± 0.2% and 19.0 ± 0.5% respectively). Maceration at 40 °C for 30 min results in a much lower extraction yield (10.0 ± 0.3%). These differences in yield between HRE and maceration are attributed to the temperature difference during extraction.