Date of Award

8-2011

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Packaging Science

Advisor

Thomas, Ronald

Committee Member

Dawson , Paul

Committee Member

Whiteside , William

Committee Member

Rao , Anju

Abstract

A simulated food product sensitive to oxygen, which was a mixture of tomato paste, water, and corn oil (2:2:1), was filled into five different barrier coated pouches, a foil barrier and a low barrier pouch. These pouches were thermally processed at 250¡F for 30 minutes and stored in darkness under accelerated conditions (45±2¡C and 50±2%RH) for up to 180 days.
The simulant was analyzed for lipid oxidation by TBARS and lycopene degradation by colorimetry (L*,a*,b* values and Hue angle). The oxygen permeability (OP) in all the pouches increased by 5 to 500 fold after retort. TBARS values in all pouches increased throughout storage while the L*, a* and b* values decreased. The samples lost red color and luminosity and became darker. The TBARS and color results correlated well with the OP. Hue angle was significantly different among the pouches except for the low barrier pouch, indicating stability of lycopene in the barrier coated pouches and foil pouch.
The pouches were tested for surface morphology by SEM imaging. Some of the coated low barrier pouches showed a distinct web like cracking, indicating loss of barrier. All the barrier pouches had minor cracks and fractures on the coated surface after retort, explaining increases in OP and thereby higher lipid oxidation with color degradation. Shelf life analysis by the linear regression method showed a higher rate of lipid oxidation than loss of color in all the pouches. Shelf life of simulant also coincided well with TBARS and color data.

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