title: Effects of Ethephon on Fresh In-Husk Walnut Preservation and its Possible Relationship with Phenol Metabolism.
abstract: Fresh walnuts (Juglans regia L.) are in demand due to their high nutrition value and unique flavor of the kernel. In this study the effects of ethephon on decay control and kernel quality of fresh walnuts and its possible relationship with phenolic metabolism were investigated. Fresh in-husk walnuts treated with 0, 10, 500, and 800 mg/L ethephon were stored at 0 ± 0.5 °C for 42 d. Decay incidence, total phenolic (TP) compounds, phenylalanine ammonialyase (PAL), polyphenol-oxidase (PPO), and peroxidase (POD) activities of green husks, and acid values (AV) and peroxide values (PV) of kernels were assessed at 6-d intervals. The respiration rate of the whole walnut was assessed at 3-d intervals. Treatment with 500 mg/L ethephon enhanced respiration, reduced the decay index, and inhibited PPO and POD activity and browning of green husks, and also promoted PAL activity and TP content of green husks. This treatment also reduced the PV and AV of kernels. A concentration of 10 mg/L ethephonhad similar, but weaker, effects on walnuts. Treatment with 8000 mg/L ethephon, however, had opposite effects. These data indicate ethephon treatment at a proper concentration can extend storage life and maintain kernel quality of fresh in-husk walnuts through the manipulation of phenolic metabolism.
authors.affiliation: College of Life Science, Northwest Agriculture and Forestry Univ, Yangling, Shaanxi, 712100, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Life Science, Northwest Agriculture and Forestry Univ, Yangling, Shaanxi, 712100, China.
authors.forename: Shuangjie
authors.initials: S
authors.lastname: Liang
authors.affiliation: College of Life Science, Northwest Agriculture and Forestry Univ, Yangling, Shaanxi, 712100, China.
authors.forename: Huiling
authors.initials: H
authors.lastname: Ma
authors.affiliation: College of Life Science, Northwest Agriculture and Forestry Univ, Yangling, Shaanxi, 712100, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Zhang
authors.affiliation: College of Life Science, Northwest Agriculture and Forestry Univ, Yangling, Shaanxi, 712100, China.
authors.forename: Weina
authors.initials: W
authors.lastname: Shi
mesh_terms: D000642:Ammonia-Lyases / Q000378:metabolism; D004156:Catechol Oxidase / Q000378:metabolism; D005511:Food Handling / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D006801:Humans; D031324:Juglans; D009754:Nuts / Q000187:drug effects* / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism; D010636:Phenols / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*
chemical_list: D009943:Organophosphorus Compounds; D010636:Phenols; D010937:Plant Growth Regulators; D010649:Phenylalanine; D004156:Catechol Oxidase; D009195:Peroxidase; D000642:Ammonia-Lyases; C005073:ethephon
keywords: disease resistance; ethephon; fresh in-husk walnut; kernel traits; phenolic compounds