Oxidation Activity in Ready-to-Eat Oranges

Ingallinera, Barbara; Spagna, G.; Barbagallo, Riccardo N.; Bognanni, R.; Rapisarda, Paolo

doi:10.17660/actahortic.2005.682.259

Cited by 3 publications

(3 citation statements)

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“…Enzymatic oxidation of phenols has been reported to be the more important reaction with respect to negative impacts on food processing (Coseteng and Lee, 1987), although following enzyme removal or inactivation, substantial auto‐oxidation can take place (Cilliers and Singleton, 1991; Ingellinera et al. , 2005).…”

Section: Discussionmentioning

confidence: 99%

Oxidation of ortho‐diphenols in red clover with and without polyphenol oxidase (PPO) activity and their role in PPO activation and inactivation

Lee

Tweed

Sullivan

2012

Grass and Forage Science

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Oxidation of phenol to quinone with its subsequent binding and complexing with protein in red clover (Trifolium pratense L.) when fed to ruminant livestock has been shown to improve nitrogen‐use efficiency and the deposition of polyunsaturated fats into animal products. This oxidation has, almost exclusively, been attributed to the activity of the enzyme group polyphenol oxidases (PPOs) and, specifically, catecholase during conservation. However, during conservation, temporal inactivation of PPO occurs and oxidation of phenolic substrate may occur through other mechanisms not associated with PPO. T1 progeny of a cross between a red clover clone having normal levels of foliar PPO activity and a transgenic PPO‐silenced red clover plant with undetectable levels of PPO activity were divided into two populations based on the presence of the silencing transgene and lack of measurable PPO activity (PPO−) or the absence of the silencing transgene and normal levels of PPO activity (PPO+). This material was subsequently used to determine the relevant extent of phenolic oxidation in the presence and absence of PPO activity under two damage regimes (heavy and light). PPO+ and PPO− material was passed through a garden shredder as the light‐damaged regime, or frozen at −20°C as the heavy damaged regime. Material was left at room temperature and sampled at regular intervals for the determination of PPO enzyme activity (active and total), PPO activation (conversion from latent to active forms) and formation of protein‐bound phenol (PBP) as a measure of oxidation. Experiments with red clover leaf extracts were carried out to determine the mechanism for the temporal activation and inactivation (loss of enzymatic activity) of PPO during wilting. PBP formation was evident in both PPO− and PPO+ treatments with the response further catalysed during the first 2 h by extent of damage that increased the activation of PPO, but which also resulted in a more rapid temporal inactivation of PPO. PBP formation, PPO activation and PPO inactivation were all shown to be mediated predominantly by quinone binding. A role of non‐PPO oxidation in PBP formation in wilted red clover is reported, showing the importance of o‐diphenolic substrate concentration and not just PPO activity to increase nitrogen use efficiency and the deposition of polyunsaturated fats into animal products.

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Section: Discussionmentioning

confidence: 99%

Oxidation of ortho‐diphenols in red clover with and without polyphenol oxidase (PPO) activity and their role in PPO activation and inactivation

Lee

Tweed

Sullivan

2012

Grass and Forage Science

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“…Thus, it could be said that this activity could be involved in ascorbic acid oxidation (Ingallinera et al. , 2005b).…”

Section: Resultsmentioning

confidence: 99%

“…PME is involved, with other pectinases, in the degradation of the pectic cell‐wall structures; this enzyme is specifically involved in the de‐esterification of pectin leading to the liberation of methanol and pectic acid (Schols et al. , 1995; Basak & Ramaswamy, 1997;Ingallinera et al. , 2005a,b).…”

Section: Introductionmentioning

confidence: 99%

Degradative enzymatic activities in fresh‐cut blood‐orange slices during chilled‐storage

Catalano

Ingallinera

Todaro

et al. 2009

Int J of Food Sci Tech

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Blood-orange fruits are suitable to fresh-cut fruit production because of their chemical compositions. Nevertheless, the main limitation of using freshly cut oranges is their susceptibility to juiciness loss and ascorbic acid degradation because of enzymatic alterations. The aim of this work is: to identify some of the enzymes causing the qualitative decay in blood-orange slices during 15 days of chilled storage (at 4 ± 0.5°C and 85% RH); to investigate the susceptibility to the previous alterations of five blood-orange clones (Moro nucellare, Sanguinello nucellare, Tarocco arcimusa, Tarocco gallo and Tarocco meli) to select the most suitable one for fresh-cut production. The enzymes studied were: pectinmethylesterase (PME) as index of juiciness loss, ascorbate oxidase (AAO) as index of ascorbic acid's degradation and polyphenol oxidase (PPO) as browning index. As far as we know, the changes of AAO activity during chilled storage of blood-orange freshcut slices has not previously reported and studied. Different clones showed different enzymatic activities and quality changes during chilled-storage. In particular a low juiciness loss in orange slices was correlated with a lower PME activity, as described in T. meli clone, while a high degradation of ascorbic acid was correlated with an higher AAO activity, as described in T. gallo clone; PPO activity seemed to have no significant action in quality degradation. Tarocco meli was the most suitable clone to the fresh-cut blood-orange production because it has the lowest enzymatic activity (PME, PPO and AAO) and the highest sensorial quality.

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Influence of postharvest processing and storage on the content of phenolic acids and flavonoids in foods

Amarowicz

Carle

Dongowski

et al. 2009

Molecular Nutrition Food Res

139

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The review is based on the evaluation of electronically collated data published between 2002 to June 2006. It is based on 325 references dealing with the following subclasses of phenolic compounds: hydroxycinnamic and hydroxybenzoic acids, chalcones, flavanones, flavones, flavonols, monomeric flavanols and anthocyanins. Only publications dealing directly with the effects of storage and postharvest processing on the phenolic acid and flavonoid contents of foods were considered. The expectation that the structural diversity even within each subgroup, and the number of different procedures and of different parameters would make finding homogenous tendencies unlikely, has, in most instances, been confirmed. By adding a database Excel table combined with a focused and unified evaluation, specific additional information was rendered accessible and concise. It holds true for most of the subclasses in question that the effect of storage and food processing on the polyphenol content is negligible in comparison to the differences between different varieties of plants. Variety dependence must always be considered, for all classes of compounds.

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Oxidation Activity in Ready-to-Eat Oranges

Cited by 3 publications

References 0 publications

Oxidation of ortho‐diphenols in red clover with and without polyphenol oxidase (PPO) activity and their role in PPO activation and inactivation

Oxidation of ortho‐diphenols in red clover with and without polyphenol oxidase (PPO) activity and their role in PPO activation and inactivation

Degradative enzymatic activities in fresh‐cut blood‐orange slices during chilled‐storage

Influence of postharvest processing and storage on the content of phenolic acids and flavonoids in foods

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