Degree Type

Thesis

Date of Award

1-1-2003

Degree Name

Master of Science

Department

Food Technology

Major

Food Science and Technology

Abstract

Flavor quality changes which occur during long-term storage of apple cider can be monitored by attributes such as analytical measurements (soluble solids, pH, acidity) and volatile flavor profiles. The objectives of this research were to evaluate the flavor quality of irradiated apple cider using two experimental designs. Experiment I studied the effects of irradiation, sorbate addition and three packaging materials (polystyrene, nylon-6 and low-density polyethylene) to maintain characteristic apple cider flavor during three weeks of refrigerated storage. Experiment II evaluated the effects of irradiation, sorbate addition and three gaseous environments (atmospheric air, oxygen-flush and nitrogen-flush) to maintain characteristic apple cider flavor during seven weeks of refrigerated storage. The control sample in both experiments was unirradiated apple cider. Quality attributes displayed general trends as a result of fermentation and other degradation reactions which take place in apple cider throughout storage. Generally, as a result of sugar conversion into acids and alcohols, soluble solids decreased while available acids increased with time. Volatile flavor compounds were evaluated by plotting rates of change using gas-chromatography peak areas versus time. The rates of change were determined on a logarithmic scale to quantify the effects of storage. Cider irradiated and stored in polystyrene and nylon-6 packaging materials had lower rates of volatile flavor loss than unirradiated cider and irradiated cider packaged in low-density polyethylene. Nitrogen-flush and atmospheric air conditions were better able to maintain characteristic apple cider flavors during storage than an oxygen-flush environment. Potassium sorbate was very effective in extending the shelf-life of apple cider. The rates of loss during storage for a majority of the volatile flavor compounds were significantly lower in the presence of 0.1% sorbate than in the absence of sorbate. Analytical measurements also supported the effect of sorbate to limit changes in soluble solids and acidity during refrigerated storage.

DOI

https://doi.org/10.31274/rtd-20200803-158

Copyright Owner

Loretta Rose Crook

Language

en

OCLC Number

54756957

File Format

application/pdf

File Size

111 pages

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