Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Packaging Science

Committee Member

Dr. Kay Cooksey

Committee Member

Dr. Duncan Darby

Committee Member

Dr. James Rieck


Health foods and environmentally safe packaging are ongoing concerns for manufacturers and consumers. The purpose of this study was to compare the shelf life of an intermediate moisture chocolate health bar in its current package to the shelf life of the same health bar in two different bio-based packages. The renewable resources used to create bio-based packaging materials are more environmentally safe than conventional packages used today. This could ultimately reduce costs to manufacturers and lower prices of the health bar for consumers. The health bar in this study has an actual shelf life of six months. For this study, an accelerated storage of three months was used to observe the property changes of the health bar and its packages. The original packaging material (control) was metallized-oriented polypropylene (Met-OPP). The two bio-based packaging materials (variables) were polylactic acid (PLA) and sugarcane polyethylene (SPE). The two bio-based materials were each laminated to metallized cellophane (Met-Cell). Duplicating the original package, the bio-based packages were created using a double heated bar sealer. Samples were repackaged into these bio-based packages and stored in an environmental chamber at 35ºC, 75% relative humidity (% RH) for 10 weeks. Before all analyses, the seal integrity of all packages was checked. Product analyses included: (1) microbial, (2) percent moisture content, (3) sensory, (4) texture and (5) water activity. Film analyses included: (1) seal-peel, (2) tensile strength, (3) tater vapor transmission rate (WVTR) and (4) oxygen transmission rate (OTR). Before all film analyses, the thicknesses of the film samples were observed. All samples were analyzed on weeks 0, 2, 4, 6, 8 and 10 in triplicate for each treatment, except for sensory, tensile, seal-peel, WVTR and OTR analyses. Tensile and seal-peel analyses were performed with five replicates for each treatment. WVTR and OTR analyses were performed on weeks 0, 5 and 10 in duplicate for each treatment. Two statistical models were used to analyze the data collected: (1) film and product data were analyzed by Analysis of Variance (ANOVA). This analysis were performed at a 0.05 significance level. Based on these analyses, the PLA package compared best to the original package of the chocolate health bar.



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