Peroxidase (POD) and polyphenoloxidase (PPO) in grape (Vitis vinifera L.)

Abstract

-The enzimatic activity of peroxidase (POD) and polyphenoloxidase (PPO) extracted from three grape cultivars (Vitis vinifera L.), cultivated in Marialva city, state of Paraná, was evaluated in this study. The enzymatic extracts were prepared starting from the Rubi, Borbon and Benitaka grape cultivars pulp and peel. The activity of the peroxidase was 53.00 units/100 g in the extract from the Rubi cultivar peel, and 327.00 units/100 g from the Benitaka cultivar, these values being superior to those observed in the same cultivars pulp extracts, which were 7.67 units/100 g and 44.00 units/100 g respectively. However, the result was opposite in the Borbon cultivar, with values of 141.11 units/100 g in the pulp and 11.50 units/100 g in the peel being found. The results of the polyphenoloxidase in the Borbon cultivar activity were 100.18 units/100 g in the pulp and 102.60 units/100 g in the peel, and in the Rubi and Benitaka cultivars were 60.40 units/100 g, 48.62 units/100 g in the pulp and 17.40 units/100 g, and 26.20 units/100 g in the peel, respectively. Protein determination was carried out in each extract, and the results found in the pulp and peel, respectively, were 0.56 and 0.64 mg/100 g for cultivar Benitaka, 1.38 and 6.45 mg/100 g for cultivar Rubi, and 21.38 and 5.68 mg/100 g for Borbon. The extracts were submitted to thermal treatments (60°C, 65°C, 70°C and 75°C for a 1 to 10 minutes period) to observe the behavior of the peroxidase and polyphenoloxidase enzymatic activity, being verified a continuous decrease of the peroxidase and polyphenoloxidase activities as a result of the thermal treatment. The extracts of the Rubi and Benitaka cultivars were more heat stable than the extract from the Borbon cultivar for both enzymes. However, the temperatures used were not enough for a total inactivation of the enzymes.

The Complexity of Modulating Anthocyanin Biosynthesis Pathway by Deficit Irrigation in Table Grapes

“…The resulting homogenate was centrifuged at 3,000 g for 30 min at 4 • C and the supernatant was utilized for subsequent measurement of polyphenol oxidase (PPO), peroxidase (POD), and superoxide dismutase (SOD) activities. The activity of PPO was determined as described by De Pieri Troiani et al (2003). The standard reaction mixture consisted of 3.4 mL of 100 mM sodium phosphate buffer (pH 6.0); 0.4 mL of catechol (Sigma, NY, United States); 0.2 mL of enzyme extract and the absorbance at 420 nm was measured after 10 min.…”

“…The activity of POD was assayed as described by Troiani et al (2003), one hundred microliter aliquot of tissue extracts was added to 3 mL of assay solution, consisting of 13 mM guaiacol (Amresco, OH, United States), 5 mM H 2 O 2 , and 50 mM sodium phosphate buffer (pH 7.0) (Cheng et al, 2013). Increases in optical density were then measured at 470 nm for 3 min at 25 • C. POD activity was expressed as the change in absorbance per minute per gram fresh skin weight.…”

Enzymatic degradation of azo dyes using three macrophyte species:Arundo donax,Typha angustifoliaandPhragmites australis

“…Also in another study [28], for Borbon grape cultivar, POD activity decreased about 58% at 60˚C for 6 min of heating. Cano et al [29] treated whole peeled bananas in boiling water for 11 min and observed 96-100% reduction in the activity of POD enzyme.…”

STUDY OF ENZYME INACTIVATION USING STEAM IN YACON (SMALLANTHUS SONCHIFOLIUS) ROOTS

“…Troiani et al . (2003) studied the inactivation of enzymes in three different grape cultivars submitted to heat treatments of 60, 65, 70 and 75C, for times varying from 1 to 10 min, and also failed to completely inactivate the enzymes.…”