The combined application of Arabic gum coating and γ-aminobutyric acid mitigates chilling injury and maintains eating quality of 'Kinnow' mandarin fruits.

Abstract

Low temperature storage of citrus generally extends the storage potential but leads to chilling injury appearance on the rind of fruits. The said physiological disorder has been found associated with changes in the metabolism of cell walls and other attributes. In this work, the influence of Arabic gum [AG (10 %)] and γ-amminobutyric acid [GABA (10 mmol L-1)] either alone or in combined form was studied on fruits of 'Kinnow' mandarin during storage at 5 ± 1 °C for 60 days. The results exhibited that the combined AG + GABA treatment significantly suppressed weight loss (5.13 %), chilling injury (CI) symptoms (2.41 score), incidence of disease (13.33 %), respiration rate [(4.81 μmol kg-1 h-1) RPR] and ethylene production [(0.86 nmol kg-1 h-1) EPR]. In addition, AG + GABA application reduced relative electrolyte (37.89 %) leakage (REL), malondialdehyde [(25.99 nmol kg-1) MDA], superoxide anion [(15.23 nmol min-1 kg-1) O2•-] and hydrogen peroxide [(27.08 nmol kg-1) H2O2] along with lower lipoxygenase [(23.81 U mg-1 protein) LOX] and phospholipase D [(14.07 U mg-1 protein) PLD] enzyme activities compared with control. The AG + GABA treated 'Kinnow' group showed higher glutamate decarboxylase [(43.18 U mg-1 protein) GAD] and lower GABA transaminase [(15.93 U mg-1 protein) GABA-T] activity having higher endogenous GABA (42.02 mg kg-1) content. The fruits treated with AG + GABA exhibited higher cell walls (CW) components such as Na2CO3-soluble pectin [(6.55 g kg-1) NCSP], chelate-soluble pectin [(7.13 g kg-1) CSP] and protopectin [(11.03 g kg-1) PRP] concentrations along with lower water-soluble pectin [(10.64 g kg-1) WSP] compared to control. In addition, 'Kinnow' fruits treated with AG + GABA showed higher firmness (8.63 N) and lower activities of CW degrading such as cellulase [(11.23 U mg-1 protein) CX], polygalacturonase [(22.59 U mg-1 protein) PG], pectin methylesterase [(15.61 U mg-1 protein) PME] and β-galactosidase [(20.64 U mg-1 protein) β-Gal] enzymes. The activity of catalase [(41.56 U mg-1 protein) CAT], ascorbate peroxidase [(55.57 U mg-1 protein) APX], superoxide dismutase [(52.93 U mg-1 protein) SOD] and peroxidase [(31.02 U mg-1 protein) POD] was also higher in combined treatment. In addition, AG + GABA treated fruits showed better biochemical and sensory attributes than the control. So, combined AG + GABA could be used for CI mitigation and storage life prolongation of 'Kinnow' fruits.

• Authors: Sajid Ali, Ahmad Sattar Khan, Aamir Nawaz, Safina Naz, Shaghef Ejaz, Anis Ali Shah, Muhammad Wasim Haider
• Journal: International journal of biological macromolecules (Int J Biol Macromol) Vol. 236 Pg. 123966 (May 01 2023) ISSN: 1879-0003 [Electronic] Netherlands
• PMID: 36898459 (Publication Type: Journal Article)
• Copyright: Copyright © 2023 Elsevier B.V. All rights reserved.

Chemical References

• Hydrogen Peroxide
• gamma-Aminobutyric Acid
• Pectins

Topics

• Food Preservation
• Fruit (chemistry)
• Hydrogen Peroxide (metabolism)
• gamma-Aminobutyric Acid
• Pectins (metabolism)