Articles liés à Physiological studies on reducing the deleterious effects:...

Physiological studies on reducing the deleterious effects: in some fresh-cut vegetables - Couverture souple

Atef, Mahmoud; Mahmoud El Gizawy, Ahmad; Mohamed Galal El-Din Ali, Hussein

 
9783639323351: Physiological studies on reducing the deleterious effects: in some fresh-cut vegetables
Couverture souple
ISBN 10 : 3639323351 ISBN 13 : 9783639323351
Editeur : VDM Verlag Dr. Müller, 2011

Synopsis

The effect of various compounds, (i.e., reducing agents (ascorbic, sodium sulfite, bisulfite and thiosulphate), thiol (L-cysteine), and organic acids (glycine, aspartic, glutamic, oxalic, succinic, phthalic, tartaric, citric, adipic, fumaric, and benzoic) on the browning process and polyphenol oxidase activity of fresh-cut of butterhead lettuce and two potato cultivars (Spunta and Desiree) were evaluated. Results indicated that slices slightly elevated enzyme activity and browning index (BI) in both cultivars more than those of sticks. Mechanistic study indicated that ascorbic acid reduced the quinone, resulted from PPO activity, back to the starting colorless catechol, where the quinone peak in the UV spectrum (435 nm) vanished completely upon addition of ascorbic acids. Cysteine did not reduce the formed quinone, but rather formed a cysteine-quinone adduct as a new peak appeared at the expenses of the quinone peak. Regarding the organic and amino acids, they worked as PPO inhibitor either as acidulants or metal chelators. Applications showed that compounds reacted with the resulted quinone were more efficient antibrowning agents than PPO inhibitors.

Les informations fournies dans la section « Synopsis » peuvent faire référence à une autre édition de ce titre.

Présentation de l'éditeur

The effect of various compounds, (i.e., reducing agents (ascorbic, sodium sulfite, bisulfite and thiosulphate), thiol (L-cysteine), and organic acids (glycine, aspartic, glutamic, oxalic, succinic, phthalic, tartaric, citric, adipic, fumaric, and benzoic) on the browning process and polyphenol oxidase activity of fresh-cut of butterhead lettuce and two potato cultivars (Spunta and Desiree) were evaluated. Results indicated that slices slightly elevated enzyme activity and browning index (BI) in both cultivars more than those of sticks. Mechanistic study indicated that ascorbic acid reduced the quinone, resulted from PPO activity, back to the starting colorless catechol, where the quinone peak in the UV spectrum (435 nm) vanished completely upon addition of ascorbic acids. Cysteine did not reduce the formed quinone, but rather formed a cysteine-quinone adduct as a new peak appeared at the expenses of the quinone peak. Regarding the organic and amino acids, they worked as PPO inhibitor either as acidulants or metal chelators. Applications showed that compounds reacted with the resulted quinone were more efficient antibrowning agents than PPO inhibitors.

Biographie de l'auteur

Mahmoud A.Saleh, M.Sc. studied Agricultural sciences from Ain Shams university, Egypt.

Les informations fournies dans la section « A propos du livre » peuvent faire référence à une autre édition de ce titre.

Éditeur
VDM Verlag Dr. Müller
Date d'édition
2011
Langue
anglais
ISBN 10 
3639323351
ISBN 13 
9783639323351
Reliure
Broché
Nombre de pages
96
Coordonnées du fabricant
non disponible
Personne responsable
non disponible