Hydrolytic stabilyty of L-(+)-ascorbic acid in low methoxy pectin films with potencial antioxidant activity at food interface

DE´NOBILI, M. DOLORES ; PEREZ, CAROLINA D.; NAVARRO, DIEGO A; STORTZ, CARLOS A; ROJAS, ANA M.

FOOD AND BIOPROCESS TECHNOLOGY

SPRINGER

Lugar: Nueva York; Año: 2012

1935-5130

l-(+)-Ascorbic acid (AA) was compartmentalized into a low methoxy l pectin (LMP) f ilm in v iew of localized antioxidant activ ity at f ood interf aces. The AA hy droly sis was specif ically studied in the present work in order to determine the ability of the f ormulated LMP f ilm to stabilize AA. Hence, f ilms were stored at controlled relativ e humidity (RH) in the absence of air. A commercial LMP characterized by a 40% degree of methy lesterif ication (DM) was used. Since sucrose is normally added f or its standardization, f ilms were also made with the dialy zed LMP in order to determine the sucrose ef f ect. Gly cerol was used f or plasticization. Kinetics of AA loss and subsequent browning dev elopment were determined, which are dependent on the RH. Considerable AA retention (t1/2 = 744, 727, and 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moisture t1/2 = 744, 727, and 185 day s) was achiev ed at 33.3%, 57.7%, or 75.2% RH, respectiv ely , at 25 °C. Browning rate constants decreased in one order of magnitude with respect to kinetic constants determined f rom f ilms prev iously dev eloped with high methoxy l pectin (HMP; DM of 73%). Absence of sucrose in the LMP network only af f ected the browning kinetics at 75.2% RH. The glass transition temperature (Tg) decreased with the increment of moistureTg) decreased with the increment of moisture