INTEGRATED GREEN TECHNOLOGIES AND MULTICRITERIA EVALUATION FOR ECOSCALE EXTRACTION OF PHENOLIC AND ANTIOXIDANT COMPOUNDS FROM Coffea arabica HUSK

Emerging technologies have been investigated as alternatives to conventional food processing methods, aiming to optimize efficiency, yield, and sustainability. This study investigated emerging green technologies for extracting phenolic compounds and antioxidants from Coffea arabica var. Catuaí Vermelho husks, with evaluation of process ecoscalability. Husks were mechanically processed, ground, and sieved (1.22 mm), then subjected to five treatments: ultrasonic bath (UB), ultrasonic probe sonicate (US), pulsed electric field (PEF), and mechanical agitation (MA, control). Process parameters were: (T1) PEF+UB (8 kV/cm, 6000 pulses + 45 kHz, 40 °C, 50 min), (T2) PEF+US (8 kV/cm, 6000 pulses + 20 kHz, 850 W, 40 °C, 10 min), (T3) UB (45 kHz, 40 °C, 50 min), (T4) US (20 kHz, 850 W, 40 °C, 10 min), and (T5) MA (150 rpm, 40 °C, 60 min). After extraction (1:10 w/v, H₂O), samples were centrifuged, vacuum-filtered, and stored at 4°C. Analyses included total phenolic compounds (TPC), total flavonoids (TF), antioxidant activity (ABTS and DPPH), color, pH and Ecoscale score. Data were analyzed using ANOVA and Tukey’s test (≤5% significance). Results showed stable pH across treatments, ranging from 4.88 ± 0.02 to 5.02 ± 0.02.  Compared to the control, significant differences were observed in color: lightness (L*) increased 4.7% in T3 (25.85 ± 0.01), a* parameter was 92.7% higher in T3 (7.21 ± 0.01), and b* showed 254% higher value in T3 (2.94 ± 0.06). TPC peaked in T1 (1802.57 ± 7.62 mg GAE/mL, p ≤ 0.05), a 2.8% increase over the control (1754.09 ± 0.00 mg GAE/mL). For flavonoids, the highest concentration was in T4 (60.95 ± 1.38 µg RE/mL, p ≤ 0.05), 12.6% above the control (54.14 ± 0.00 µg RE/mL). In quercetin equivalents, T4 also achieved higher values (15.76 ± 0.00 µg QE/mL), surpassing the control (12.14 ± 0.00 µg QE/mL) by 29.8%. In antioxidant capacity, ABTS results showed the control with the highest activity (1.05 ± 0.02 mg TE/mL), followed by T2 (1.01 ± 0.02 mg TE/mL), with no significant difference (p ≥ 0.05). In the DPPH assay, T2 stood out (1.02 ± 0.04 mg TE/mL), a 6.2% increase over the control (0.96 ± 0.03 mg TE/mL, p ≥ 0.05). Overall, T1 favored phenolic extraction, T4 excelled in flavonoid recovery, while the control and T2 showed greater antioxidant activity. Considering combined antioxidant and TPC yields, T1 was the most efficient, achieving superior sustainability, safety, and environmental performance, with a 93.62% Ecoscale score.