Since little research has been conducted on cloud stability of low-acid juices, commercial carrot juice underwent one of two treatments: acidification over the range 3.5 to 6.1, or addition of pectin methylesterase (PME) from 0 to 1 U/g activity. Cloud stability, particle diameter, and zeta potential were measured for each treatment to quantify juice cloud stability and clarification for 3 (acidification) and 56 (PME) days of storage. Acidic pH values (< 4.5) created unstable cloud by making the zeta potential less negative, which increased particle size and led to clarification. Higher acidity caused clarification to occur more quickly and more completely. All PME additions resulted in clarification; higher amounts caused more rapid clarification due to a larger increase in particle size. The zeta potential of all samples was the same, suggesting that the mechanism of particle aggregation is different for PME- or acid-induced clarification.
|Advisor:||Barrett, Diane M.|
|Commitee:||Bamforth, Charles W., Dungan, Stephanie R.|
|School:||University of California, Davis|
|School Location:||United States -- California|
|Source:||MAI 51/05M(E), Masters Abstracts International|
|Keywords:||Carrot juice, Cloud, Flocculation, Particle size, Ph, Pme|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be