Date of Award
Master of Science (MS)
Food Science and Human Nutrition
William S Whiteside
Ronald L Thomas
Curtis H Stowe
The effect of pouch films with oxygen scavengers (OSs) and modified atmosphere on hot-filled Freestone Peach puree quality indices, such as colorimetric parameters (L*, a*, b*, ΔE*, Chroma, and hue angle), browning index (absorbance at 420 nm), soluble solids content (SSC, degrees Brix), pH, and titratable acidity (TA, % acid as Malic), were evaluated throughout 21-week accelerated storage at 35C/50% RH. Three multilayer pouch films, ultra-high-barrier with an OS (UHB-OS), ultra-high-barrier without an OS (UHB), and inorganic-barrier with OSs (IB-OS); and two internal atmospheric conditions (ambient air and nitrogen) were combined to produce six variable samples. Significant differences (p < 0.05) in color values, L* (lightness), a* (redness), b* (yellowness) and Chroma (saturation) were only found between films, but not atmospheres. By the end of storage, ΔE* (total color difference) showed significant differences between films where Film UHB-OS showed the relative lowest color change (ΔE*=3.35c) followed by Film IB-OS (ΔE*=3.88b) and then Film UHB (ΔE*=6.73a). Although, based on trend line slopes of ΔL*, prediction of shelf life determined the most effective film as Film IB-OS (92 weeks), followed by Film UHB-OS (79 weeks) and Film UHB (53 weeks). Nitrogen had a lower ΔE* for the first 5 weeks, after which, color protection was based on film type, and nitrogen resulted in a lower hue angle and browning index throughout storage compared to ambient air demonstrating a protective effect. Suggested sucrose hydrolysis contributed reducing sugars for browning and increased SSC. Inconclusive results were found among pH and titratable acidity. This study demonstrated that OS films significantly extended peach puree shelf life were comparable to each other as well as nitrogen showed beneficial results over ambient air indicating prevention of oxygen-based degradative reactions.
Skrypec, Steven, "Effect of Oxygen Scavenging Films and Modified Atmosphere on the Quality of Hot-Filled Freestone Peach Puree" (2020). All Theses. 3266.