Tags

Type your tag names separated by a space and hit enter

Characterization of polyphenol oxidase and peroxidase and influence on browning of cold stored strawberry fruit.
J Agric Food Chem 2007; 55(9):3469-76JA

Abstract

Polyphenol oxidase and peroxidase were extracted from two different varieties of strawberry fruit (Fragaria x ananassa D, cv. 'Elsanta' and Fragaria vesca L, cv. 'Madame Moutot') and characterized using reliable spectrophotometric methods. In all cases, the enzymes followed Michaelis-Menten kinetics, showing different values of peroxidase kinetics parameters between the two cultivars: Km = 50.68 +/- 2.42 mM ('Elsanta') and 18.18 +/- 8.79 mM ('Madame Moutot') mM and Vmax = 0.14 +/- 0.03 U/g ('Elsanta') and 0.05 +/- 0.01 U/g ('Madame Moutot'). The physiological pH of fruit at the red ripe stage negatively affected the expression of both oxidases, except polyphenol oxidase from 'Madame Moutot' that showed the highest residual activity (68% of the maximum). Peroxidase from both cultivars was much more thermolable as compared with PPO, losing over 60% of relative activity already after 60 min of incubation at 40 degrees C. The POD activation energy was much lower than the PPO activation energy (DeltaE = 97.5 and 57.8 kJ mol-1 for 'Elsanta' and 'Madame Moutot', respectively). Results obtained from d-glucose and d-fructose inhibition tests evidenced a decreasing course of PPO and POD activities from both cultivars as the sugar concentration in the assay medium increased. Changes in CIE L*, a*, b*, chroma, and hue angle values were taken as a browning index of the samples during storage at 4 degrees C. A decrease in L* was evident in both cultivars but more marked in 'Elsanta'. PPO and POD activities from cv. 'Elsanta' were very well-correlated with the parameter L* (r2=0.86 and 0.89, respectively) and hue angle (r2=0.85 and 0.93, respectively). According to these results, the browning of the fruit seemed to be in relation to both oxidase activities.

Authors+Show Affiliations

Dipartimento di OrtoFloroArboricoltura e Tecnologie Agroalimentari, DOFATA, Via Santa Sofia 98, 95100 Catania, Italy. mchisari@unict.itNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

17407312

Citation

Chisari, Marco, et al. "Characterization of Polyphenol Oxidase and Peroxidase and Influence On Browning of Cold Stored Strawberry Fruit." Journal of Agricultural and Food Chemistry, vol. 55, no. 9, 2007, pp. 3469-76.
Chisari M, Barbagallo RN, Spagna G. Characterization of polyphenol oxidase and peroxidase and influence on browning of cold stored strawberry fruit. J Agric Food Chem. 2007;55(9):3469-76.
Chisari, M., Barbagallo, R. N., & Spagna, G. (2007). Characterization of polyphenol oxidase and peroxidase and influence on browning of cold stored strawberry fruit. Journal of Agricultural and Food Chemistry, 55(9), pp. 3469-76.
Chisari M, Barbagallo RN, Spagna G. Characterization of Polyphenol Oxidase and Peroxidase and Influence On Browning of Cold Stored Strawberry Fruit. J Agric Food Chem. 2007 May 2;55(9):3469-76. PubMed PMID: 17407312.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of polyphenol oxidase and peroxidase and influence on browning of cold stored strawberry fruit. AU - Chisari,Marco, AU - Barbagallo,Riccardo N, AU - Spagna,Giovanni, Y1 - 2007/04/04/ PY - 2007/4/5/pubmed PY - 2007/7/25/medline PY - 2007/4/5/entrez SP - 3469 EP - 76 JF - Journal of agricultural and food chemistry JO - J. Agric. Food Chem. VL - 55 IS - 9 N2 - Polyphenol oxidase and peroxidase were extracted from two different varieties of strawberry fruit (Fragaria x ananassa D, cv. 'Elsanta' and Fragaria vesca L, cv. 'Madame Moutot') and characterized using reliable spectrophotometric methods. In all cases, the enzymes followed Michaelis-Menten kinetics, showing different values of peroxidase kinetics parameters between the two cultivars: Km = 50.68 +/- 2.42 mM ('Elsanta') and 18.18 +/- 8.79 mM ('Madame Moutot') mM and Vmax = 0.14 +/- 0.03 U/g ('Elsanta') and 0.05 +/- 0.01 U/g ('Madame Moutot'). The physiological pH of fruit at the red ripe stage negatively affected the expression of both oxidases, except polyphenol oxidase from 'Madame Moutot' that showed the highest residual activity (68% of the maximum). Peroxidase from both cultivars was much more thermolable as compared with PPO, losing over 60% of relative activity already after 60 min of incubation at 40 degrees C. The POD activation energy was much lower than the PPO activation energy (DeltaE = 97.5 and 57.8 kJ mol-1 for 'Elsanta' and 'Madame Moutot', respectively). Results obtained from d-glucose and d-fructose inhibition tests evidenced a decreasing course of PPO and POD activities from both cultivars as the sugar concentration in the assay medium increased. Changes in CIE L*, a*, b*, chroma, and hue angle values were taken as a browning index of the samples during storage at 4 degrees C. A decrease in L* was evident in both cultivars but more marked in 'Elsanta'. PPO and POD activities from cv. 'Elsanta' were very well-correlated with the parameter L* (r2=0.86 and 0.89, respectively) and hue angle (r2=0.85 and 0.93, respectively). According to these results, the browning of the fruit seemed to be in relation to both oxidase activities. SN - 0021-8561 UR - https://www.unboundmedicine.com/medline/citation/17407312/Characterization_of_polyphenol_oxidase_and_peroxidase_and_influence_on_browning_of_cold_stored_strawberry_fruit_ L2 - https://dx.doi.org/10.1021/jf063402k DB - PRIME DP - Unbound Medicine ER -