TY - JOUR
T1 - Purification and biochemical characterization of polyphenol oxidase from soursop (Annona muricata L.) and its inactivation by microwave and ultrasound treatments
AU - Palma-Orozco, Gisela
AU - Marrufo-Hernández, Norma A.
AU - Tobías, Ileana
AU - Nájera, Hugo
N1 - Publisher Copyright:
© 2019 Wiley Periodicals, Inc.
PY - 2019/3
Y1 - 2019/3
N2 - The soursop (Annona muricata L.) is a climacteric fruit that may undergo enzymatic browning during ripening, mainly by the activity of polyphenol oxidase (PPO). Soursop PPO was purified 160-fold by hydrophobic interaction and ion-exchange chromatography. The native structure has a molecular weight of 112 kDa corresponding to a dimeric structure. The protein has an optimum pH and temperature of 6.5 and 25°C, respectively; and activation energy of 40.97 kJ·mol −1 . The lowest K m value was observed for caffeic acid (0.47 mM); the best substrate was 4-methyl-catechol (1,067 U·mM −1 min −1 ). Inactivation assays showed that PPO was completely inactivated by tropolone, Na 2 S 2 O 5 and ascorbic acid, and thermally at 55°C for <5 min, microwave exposure reduced activity to 57% at 70 W in 30 s and ultrasound treatment diminished activity to 43% at 120 W in 220 s. This study allows a better understanding of soursop PPO behavior and provides inactivation information. Practical applications: The conservation of fresh fruits is complicated due to the enzymatic reactions that are present in fruits, such as enzymatic browning. The enzymes responsible for these reactions can be inactivated by, different chemical compounds as well as by the use of emerging technologies, such as microwaves and sonication, which seek to satisfy the consumer needs to obtain fresh products with good nutritional characteristics and adequate safety.
AB - The soursop (Annona muricata L.) is a climacteric fruit that may undergo enzymatic browning during ripening, mainly by the activity of polyphenol oxidase (PPO). Soursop PPO was purified 160-fold by hydrophobic interaction and ion-exchange chromatography. The native structure has a molecular weight of 112 kDa corresponding to a dimeric structure. The protein has an optimum pH and temperature of 6.5 and 25°C, respectively; and activation energy of 40.97 kJ·mol −1 . The lowest K m value was observed for caffeic acid (0.47 mM); the best substrate was 4-methyl-catechol (1,067 U·mM −1 min −1 ). Inactivation assays showed that PPO was completely inactivated by tropolone, Na 2 S 2 O 5 and ascorbic acid, and thermally at 55°C for <5 min, microwave exposure reduced activity to 57% at 70 W in 30 s and ultrasound treatment diminished activity to 43% at 120 W in 220 s. This study allows a better understanding of soursop PPO behavior and provides inactivation information. Practical applications: The conservation of fresh fruits is complicated due to the enzymatic reactions that are present in fruits, such as enzymatic browning. The enzymes responsible for these reactions can be inactivated by, different chemical compounds as well as by the use of emerging technologies, such as microwaves and sonication, which seek to satisfy the consumer needs to obtain fresh products with good nutritional characteristics and adequate safety.
KW - Soursop (Annona muricata L.)
KW - enzymatic browning
KW - microwave
KW - polyphenol oxidase
KW - purification
KW - ultrasound
UR - http://www.scopus.com/inward/record.url?scp=85060231031&partnerID=8YFLogxK
U2 - 10.1111/jfbc.12770
DO - 10.1111/jfbc.12770
M3 - Artículo
C2 - 31353556
AN - SCOPUS:85060231031
SN - 0145-8884
VL - 43
JO - Journal of Food Biochemistry
JF - Journal of Food Biochemistry
IS - 3
M1 - e12770
ER -