4.4. Comparison between non-conventional HPTE and conventional Soxhlet extraction
HPTE (particle size 0.125–1 mm; amount of dry peels loaded 10 g; time 30 min; temperature 150 °C; pressure 6 bar; M 1:4) resulted in higher yield in D-limonene (214% of increase!) with respect to classical Soxhlet extraction (particle size 0.125–1 mm; amount of dry peels loaded 2 g; time 4 h; temperature 68 °C; pressure 1 bar; M 1:25), as shown in Fig. 6.