Evaluación de la estabilidad de cápsulas de jugo de naranja obtenidas mediante gelificación iónica

Abstract

The ionic gelation method as an encapsulation technique is based on the interactions between hydrocolloids, which prevent the possibility of damage of bioactive compounds present in foods, such as citrus juice. Therefore, the objective of the present study was to evaluate the stability of the orange juice capsules obtained by ionic gelation using pectin and sodium alginate as encapsulating agents. The effects of the gelling agents on the stability were determined by the measurement of weight loss, diameter, color attributes, diameter, macroscopic morphology, density in elaborate capsules. In addition, a factor analysis design was used by modifying the concentration of high methoxyl pectin (1.5 %, 2 % and 2.5 % w/v), pH (2.5, 3.5 and 4.5) and total soluble solids (TSS) at 5 oBrix and 15 oBrix, maintaining the concentration of sodium alginate constant at 0.5 % (w/v). The capsules were stored at room temperature (26 oC) and refrigeration (4 oC) for 12 d. They mainly presented a spherical shape (> 45 %). The color attributes remained stable even after 12 d of storage. The initial TSS and pH influenced the stability of the capsules. At a concentration of 15 oBrix and pH 2.5, the capsules could not be adequately formed, capsules presenting greater syneresis and amorphous morphologies. However, the orange juice capsules remained stable for more than 2 weeks and with stable quality parameters when stored at refrigeration temperature (4 oC), pectin concentration 2 % (w/v), sodium alginate 0.5 % (w/v), TTS 15 oBrix and pH 2.5. The ionic gelation method through encapsulation offers an alternative to extend the shelf life of the juice and the development of new products made from this citrus.