title: Effect of halide salts on development of surface browning on fresh-cut 'Granny Smith' (Malus × domestica Borkh) apple slices during storage at low temperature.
abstract: BACKGROUND
  The postharvest life of fresh-cut apple slices is limited by browning on cut surfaces. Dipping in halide salt solutions was examined for their inhibition of surface browning on 'Granny Smith' apple slices and the effects on biochemical factors associated with browning.
  
  
  RESULTS
  Delay in browning by salts was greatest with chloride = phosphate > sulfate > nitrate with no difference between sodium, potassium and calcium ions. The effectiveness of sodium halides on browning was fluoride > chloride = bromide > iodide = control. Polyphenol oxidase (PPO) activity of tissue extracted from chloride- and fluoride-treated slices was not different to control but when added into the assay solution, NaF > NaCl both showed lower PPO activity at pH 3-5 compared to control buffer. The level of polyphenols in treated slices was NaF > NaCl > control. Addition of chlorogenic acid to slices enhanced browning but NaCl and NaF counteracted this effect. There was no effect of either halide salt on respiration, ethylene production, ion leakage, and antioxidant activity.
  
  
  CONCLUSIONS
  Dipping apple slices in NaCl is a low cost treatment with few impediments to commercial use and could be a replacement for other anti-browning additives. The mode of action of NaCl and NaF is through decreasing PPO activity resulting in reduced oxidation of polyphenols.
authors.affiliation: School of Environmental & Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Li
authors.forename: Ron B H
authors.initials: RB
authors.lastname: Wills
authors.forename: John B
authors.initials: JB
authors.lastname: Golding
authors.forename: Roksana
authors.initials: R
authors.lastname: Huque
mesh_terms: D004156:Catechol Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D002726:Chlorogenic Acid / Q000009:adverse effects / Q000037:antagonists & inhibitors; D003080:Cold Temperature; D003433:Crosses, Genetic; D004791:Enzyme Inhibitors / Q000737:chemistry; D005511:Food Handling; D005520:Food Preservatives / Q000737:chemistry*; D063427:Food Quality; D061353:Food Storage; D005638:Fruit / Q000737:chemistry* / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D015416:Maillard Reaction / Q000187:drug effects; D027845:Malus / Q000737:chemistry* / Q000187:drug effects / Q000201:enzymology; D016877:Oxidants / Q000009:adverse effects / Q000037:antagonists & inhibitors; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D059808:Polyphenols / Q000032:analysis; D012677:Sensation; D012965:Sodium Chloride / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013499:Surface Properties
chemical_list: D004791:Enzyme Inhibitors; D005520:Food Preservatives; D016877:Oxidants; D010940:Plant Proteins; D059808:Polyphenols; D002726:Chlorogenic Acid; D012965:Sodium Chloride; D012969:Sodium Fluoride; D004156:Catechol Oxidase
keywords: apple slices; chloride; fluoride; halide salts; polyphenols; surface browning