45D-22 |
Irradiation, packaging material and sorbate addition to maintain characteristic apple cider flavor during storage |
L. R. CROOK, Department of Food Science and Human Nutrition, Iowa State University, 2555 Food Sciences Bldg., Ames, IA 50011 and T. D. Boylston, Dept. of Food Science & Human Nutrition, Iowa State Univ., 2547 Food Sciences Bldg., Ames, IA 50011-1061. Pasteurization, the current process used to reduce microbial load and deem apple cider safe to consume, can cause undesirable changes to color, flavor and texture attributes. Electron beam irradiation has been studied as an alternative to pasteurization. Packaging materials and sorbate addition may help maintain the characteristic apple cider flavor during storage of irradiated apple cider. The objective of this study was to evaluate the effects of irradiation, package type, sorbate addition, and storage time on the volatile flavor compounds of apple cider. Freshly processed apple cider, with (0.1%) and without potassium sorbate, was purchased from a local producer. The untreated cider was placed in glass jars. The cider to be irradiated was placed into three different package materials: high-density polyethylene (HDPE), low-density polyethylene (LDPE), and Nylon-6 (N6) plastic polymers, and exposed to a 2kGy dose of electron beam irradiation. Samples were evaluated weekly for four weeks. Volatile flavor analysis was completed using solid phase microextraction (SPME), gas chromatography, and mass spectrometry. Six of the major ester compounds that contribute to characteristic apple flavor were among the volatile flavor compounds. In order of intensity, they were: hexyl acetate, butyl acetate, ethyl-2-methyl butyrate, 2-methylbutyl acetate, ethyl hexanoate, and propyl butyrate. Irradiation treatment and storage contributed to a decrease in the intensity of these esters. Irradiation and/or the addition of sorbate, however, resulted in greater retention of esters than in untreated cider or cider without sorbate. The major flavor compounds were not significantly affected by packaging material, although the cider packaged in HDPE tended to provide higher contents of the esters compared to that in LDPE and N6. Overall, packaging material did not have a significant impact on the characteristic flavor profile of apple cider. Irradiation treatment and potassium sorbate addition, however, minimized the degradation of the esters during extended storage.
Session 45D, Food Packaging: General
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