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Dissertation/Thesis Abstract

Effect of Pectin Methylesterase and pH on Carrot Juice Cloud Stability
by Schultz, Alison K., M.S., University of California, Davis, 2012, 107; 1534923
Abstract (Summary)

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.

Indexing (document details)
Advisor: Barrett, Diane M.
Commitee: Bamforth, Charles W., Dungan, Stephanie R.
School: University of California, Davis
Department: Food Science
School Location: United States -- California
Source: MAI 51/05M(E), Masters Abstracts International
Subjects: Food Science
Keywords: Carrot juice, Cloud, Flocculation, Particle size, Ph, Pme
Publication Number: 1534923
ISBN: 978-1-267-96963-7
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