Bioactive compounds and antioxidant potential retention in thermally processed juice of GI tagged Mandarin fruits (Citrus reticulata Blanco)

In the present study, bioactive compounds and antioxidant potential of fresh and pasteurized juices of GI tagged mandarin cultivars were investigated. As observed after pasteurization, total soluble solids (TSS) (9.20–11.90^o Brix), pH (3.433.84), limonin (9.08–12.98ppm) and browning content (0.10–0.20O.D.) of fresh juices increased, however acidity (0.410.73%) and ascorbic acid content (20.67–30.42mg/100mL) decline considerably to 0.39–0.63% and 14.00–20.70mg/100mL. The sucrose content was found higher in fresh mandarin juices (3.78–5.06g/100mL), however glucose (1.96–2.26g/100mL) and fructose (1.89–2.41g/100mL) concentration enhanced in pasteurized juices respectively. The total carotenoid content (0.85–1.58mg/100mL) was decreased after thermal pasteurization (0.62–1.23mg/100mL) at 90–92°C for 30 sec. The antioxidant potential assessed by ABTS (2.54–3.43mML⁻¹Trolox), DPPH (3.35–7.26mML⁻¹Trolox), FRAP (1.24–1.95mML⁻¹Trolox) and TPC (8.30–11.98mg GAEL⁻¹) also dwindles after pasteurization. Decrease in a*, a/b* and increase in L*, b* values are the major changes observed after pasteurization. Among the varieties assessed, Coorg mandarin, Kinnow mandarin and Khasi mandarin retains the nutritional quality and found suitable for high end value added products to food industry.