title: Effect of different alkali treatments on the chemical composition, physical properties, and microstructure of pidan white.
abstract: Changes in chemical composition, physical property and microstructure of pidan white treated with 4.5 % NaOH or 5.5 % KOH were monitored during pickling up to 4 weeks, and followed by aging for another 2 weeks. As the pickling and ageing times increased, moisture content of pidan white decreased and salt content increased for both (4.5 % NaOH and 5.5 % KOH) treatments (P < 0.05). Free alkalinity and pH of pidan white treated with 4.5 % NaOH increased as pickling proceeded, but decreased during ageing for both pickling treatments (P < 0.05). At week 4 of pickling, pidan white treated with 5.5 % KOH had higher hardness, cohesiveness, gumminess and chewiness than those treated with 4.5 % NaOH. After ageing, higher springiness, elastic modulus (G') and viscous modulus (G") were generally found in pidan white treated with 5.5 % KOH (P < 0.05). As the pickling time increased, lower L*, b* values and higher a* value were observed in pidan white from both treatments (P < 0.05). As visualized by scanning electron microscope, the aggregation of egg proteins took place in pidan white gels, irrespective of pickling treatments used. Nevertheless, closer and more orderly protein aggregates with denser network were founded in pidan white treated with 5.5 % KOH.
authors.affiliation: College of Food Science, South China Agriculture University, Tianhe Road, Guangzhou, 510642 People's Republic of China.
authors.forename: Xianwei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Food Science, South China Agriculture University, Tianhe Road, Guangzhou, 510642 People's Republic of China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Jiang
authors.affiliation: Department of Bioindustry Technology, Da Yeh University, 168 University Rd. Dacum, Changhua, Taiwan.
authors.forename: Mingtsao
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Animal Science, The Ohio State University, Columbus, OH 43210 USA.
authors.forename: Herbert W
authors.initials: HW
authors.lastname: Ockerman
authors.affiliation: College of Food Science, South China Agriculture University, Tianhe Road, Guangzhou, 510642 People's Republic of China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Chen
keywords: Egg; Microstructure; Pickling treatment; Pidan white; Textural property
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