2026-07-20T01:17:06Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/81922023-12-13T01:05:23Zcom_10259.4_2516com_10259_5086com_10259_2604col_10259.4_2517

00925njm 22002777a 4500 dc Pilar Izquierdo, María Concepción author López Fouz, María author Ortega Santamaría, Natividad author Busto Núñez, Mª Dolores author 2023-08 Debittering of citrus by-products is required to obtain value-added compounds for application in the food industry (e.g., dietary fber, bioactive compounds). In this work, the immobilization of Rhodococcus fascians cells by encapsulation in Ca-alginate hollow beads and entrapment in poly(vinyl alcohol)/polyethylene glycol (PVA/PEG) cryogels was studied as an alternative to chemical treatments for degrading the bitter compound limonin. Previously, the Rhodococcus strain was adapted using orange peel extract to increase its tolerance to limonoids. The optimal conditions for the encapsulation of microbial cells were 2% Na-alginate, 4% CaCl2, 4% carboxymethylcellulose (CMC), and a microbial load of 0.6 OD600 (optical density at 600 nm). For immobilization by entrapment, the optimal conditions were 8% PVA, 8% PEG, and 0.6 OD600 microbial load. Immobilization by entrapment protected microbial cells better than encapsulation against the citrus medium stress conditions (acid pH and composition). Thus, under optimal immobilization conditions, limonin degradation was 32 and 28% for immobilization in PVA/PEG gels and in hollow beads, respectively, in synthetic juice (pH 3) after 72 h at 25 °C. Finally, the microbial cells entrapped in the cryogels showed a higher operational stability in orange juice than the encapsulated cells, with four consecutive cycles of reuse (runs of 24 h at 25 °C). 0175-7598 http://hdl.handle.net/10259/8192 10.1007/s00253-023-12724-9 1432-0614 Cell immobilization Ca-alginate hollow beads PVA/PEG cryogels Rhodococcus Debittering Citrus by-products Immobilization of Rhodococcus by encapsulation and entrapment: a green solution to bitter citrus by-products