EFFECT OF SCION/ROOTSTOCKS, PACKAGING, AND STORAGE ON BIOACTIVE COMPOUNDS CONTENT OF ORANGE JUICE

Orange juice is one of the main juices consumed in the world. The combinations of scion/rootstocks cultivars have a major influence on the qualitative attributes of orange juice, primarily on the content of bioactive compounds. The shelf life of freshly squeezed orange juice can be maximized through packaging and storage. The profile of ascorbic acid (AA), dehydroascorbic acid (DHA) and phenolic compounds, in juices from eight combinations of scions and rootstocks, were analyzed in UHPLC (Ultra-High Performance Liquid Chromatography). The cultivars Sanguínea de Mombuca, Rubi, Lue Gin Gong and Valencia Delta Seedless grafted on ‘Rangpur’ lime and citrumelo 'Swingle' rootstock were grown at the São Manuel Experimental Farm of the São Paulo State University (UNESP), located in São Manuel, São Paulo, Brazil (22°44'28” S, 48°34'37” W, and 740 m a.s.l.). Harvesting was performed when the fruits reached a ripeness index or ratio between 8.5 and 10. Juices were extracted using a semi-industrial juicer and after pasteurized. Then, the pasteurization units (UPs) were calculated. Upon reaching 50 UPs, cooling took place using a serpentine heat exchanger (chiller). The juices were packaged in 300 ml clear and dark polyethylene terephthalate bottles, covered with aluminum foil and sealed by inverting the rotating cap. The samples were stored in a refrigerator at 4°C for 0, 7, 14, 21, 28 and 35 days. Calibration curves were prepared with commercial standards for the compounds quantification and the results were expressed as mg/L. All analyzes were performed in triplicate. Juices obtained from the combinations of 'Rubi' orange/'Rangpur' lime and 'Rubi' orange/'Swingle' citrumelo tree showed the highest levels of AA and DHA. However, all juice combinations evaluated showed optimal AA and DHA concentrations in their composition, and the highest AA concentrations were found in the juices at the time of extracting the fruit, without any storage, and were inversely proportional to the DHA concentrations. In all scion/rootstock combinations, the phenolic compounds hesperidin, naringerin, caffeic acid, p-coumaric and trans-ferulic acid had the highest concentrations in the juices at the time of fruit extraction, so they decreased during storage. Hesperidin was the main flavonoid, as chlorogenic and synaptic acids were the main hydroxycinnamic acids. For stored juices, chlorogenic acid and synaptic acid were higher for most scion/rootstock storage combinations. Regardless of the treatment, dark packaging provided a higher concentration of bioactive compounds in juices stored for longer periods. The data obtained from this study may make additional contributions to choosing the best scion/rootstock combinations for processing, orange juice with higher nutritional value, and how to pack and store orange juice.