Incorporation of gambir catechin crude extract in robusta instant coffee made from different coffee processing methods

Anotace: This research aimed to enhance the antioxidant properties of instant gambir coffee by adding gambir catechin crude extract during coffee processing using natural anaerobic, full wash, and honey methods. The experiment used a completely randomized non-factorial design (RALNF), with each treatment replicated five times. The treatments consisted of nine formulations (F), namely F1= natural anaerobic 87.5% (w/w): gambir catechin crude 5% (w/w), F2 = natural anaerobic 82.5% (w/w): gambir catechin crude 10% (w/w), F3 = natural anaerobic 77.5% (w/w), gambir catechin crude 15% (w/w), F4 = honey 87.5% (w/w): gambir catechin crude 5% (w/w), F5 = honey 82.5% (w/w): gambir catechin crude 10% (w/w); F6 = honey 77.5% (w/w): gambir catechin crude 15% (w/w) F7 = full wash 87.5% (w/w): gambir catechin crude 5% (w/w); F8 = honey 82.5% (w/w): gambir catechin crude 10% (w/w), and F9 = honey 77.5% (w/w): gambir catechin crude 15% (w/w). The results showed that the formulation treatments significantly affected the instant gambir coffee's water content, solubility percentage, acidity level (pH), total phenols, and IC50. The characteristics of the resulting instant gambir coffee included water content, solubility percentage, pH, total phenols, and IC50 with values of 6.56-7.02%, 94.35-96.55%, 5.25-5.75, 24.91-40.35 mgGAE/g, and 31.46-121.75 mg/mL, respectively.