DRAGON FRUIT MACERATION USING ANTARCTIC PECTINASES

BEZUS, BRENDA; CAVALITTO, SEBASTIÁN; CONTRERAS ESQUIVEL, JUAN CARLOS; CAVELLO, IVANA

Congreso; LVII SAIB Meeting - XVI SAMIGE Meeting; 2021

Dragon fruit or pitaya is native to Mexico and Central and South America. The varieties Hylocereus monacanthus (red pitaya) and Hylocereus undatus (white pitaya) are grown commercially worldwide. In particular, red pitaya draws attention because of its intense red color. These fruits are low-calorie and high-fiber and vitamin content, and display antioxidant and prebiotic activity. Their texture makes them ideal for food products such as drinks, ice cream and jams. Pectinolytic enzymes can hydrolyze components of the vegetal cell wall, helping to tissue maceration and juice obtention. Enzymes of Antarctic origin act at medium and low temperatures, being of interest for reducing processes-temperatures.In the present work we obtained pitaya-juice after Antarctic-pectinase maceration at low temperature. The pectinolytic extract used was obtained from the psychrophilic yeast Mrakia sp. LP 7.1.2016. Red and white pitaya (Ø=1 cm x 1,5 cm long) where mixed with two parts of water and enzyme at 23 °C, pH 5.0, 8 h, 150 rpm. Control was performed with heat inactivated enzyme. Three enzymatic titles were tested on each pitaya: 0.1, 0.2 and 0.5 U polygalacturonase g-1 pitaya. After incubation, the solid was filtered by a cheesecloth, and manually pressed for juice obtention. Volume of each treatment was recorded and dry weight of the remained solid was determined after 48 h at 50 °C. °Brix, conductivity, neutral and reducing sugars, and color were determined in pitaya juices.After maceration, conductivity increased three times in average in all treatments and control, indicating the liberation of vegetal components. Final volumes obtained in control (17.6-18.6 ml) were significantly lower than those obtained in treatments (20.8-21.7 ml), but no differences were obtained between treatments. With regard to remained solid, those of red pitaya seems reduced in 19-24% respect to the control, and in the case of white pitaya, 22-35% of reduction was observed. °Brix liberated per gram of pitaya were 5.8-5.9 in controls, whereas 7.3-8.0 °Brix per initial gram of pitaya were liberated.Color was determined in red pitaya juices obtained using a colorimeter. A* axis (CIELAB scale) showed differences, with a 24% of increment when 0.1 U enzyme per gram of pitaya was used. Neutral sugars liberated from pitaya only were higher in the maximal enzymatic treatment on white pitaya (90 mg g-1 pitaya, 34% higher than control), whereas no differences were observed in red pitaya. Among 35-46% of increment in liberated reducing sugars per gram of pitaya were detected, compared to the control. Mrakia sp. LP 7.1.2016 pectinolytic extract was useful for pitaya maceration at mild temperature, with 15-19% of volume increment in comparison with the control. Color properties in the case of red pitaya were increased. This product can be used as a juice pitaya for its utilization in different food products.