73D-24 |
Effects of package size and wall thickness increase on the shelf life of orange juice |
S. MIN and Q. H. Zhang. Dept. of Food Science & Technology, The Ohio State Univ., 2015 Fyffe Ct., Columbus, OH 43210 Higher barrier properties from a barrier layer would be achieved by increasing wall thickness of laminated containers. A shelf life study may elucidate the effect of increased wall thickness on the extension of food quality. The objective of this study was to determine effects of the package size and wall thickness on the shelf life of orange juice. A base material laminated with high impact polystyrene (HIPS), low density polyethylene (LDPE), and polyvinylidene chloride (PVDC, a barrier layer), was thermoformed into 4oz. and 6oz. containers by a thermoforming unit in a Benco aseptic packaging machine. The formed containers in two different sizes were sealed with a film laminated with LDPE, aluminum foil, and nylon after filling of orange juice at the same time. Orange juice was either pasteurized at 93°C for 30sec or not pasteurized. The obtained samples were stored at both 4°C and 22°C. Flavor compounds, a-pinene, myrcene, octanal, d-limonene, and decanal were analyzed by a headspace solid phase microextraction gas chromatography (SPME-GC). Color, pH, and browning index were measured at each sampling time to study the change of physical properties. Microbial stability was tested using total aerobic plate counts and yeast and mold counts. The initial results showed no significant differences between the levels of pH, browning index, and microbial counts for 14 days in both pasteurized and non-pasteurized orange juice in 4oz. and 6oz. containers. At 14 days of storage at 22°C, non-pasteurized orange juice in 4oz. containers showed significantly (p<0.05) higher levels of yellowness and concentrations of myrcene and octanal in the headspace, when compared to non-pasteurized orange juice in 6oz. containers. The increased wall thickness may influence the shelf life of orange juice at 4°C and 22°C
Session 73D, Food Packaging
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