Effect of various dairy packaging materials on the headspace analysis of ultrapasteurized milk

Milk from three different dairies (each a separate trial: 1, 2, and 3) was standardized to 2% fat and processed at 140.6, 129.4, 118.3, and 107.2 degr eesC (temperatures 1, 2, 3, and 4, respectively) for 2 s and packaged into six different packaging boards [standard (A) milk boards with standard seam , juice boards with standard (B) and J-bottom (D) seams, barrier boards wit h standard (C) and J-bottom (E) seams, and foil (F) boards with J-bottom se am] resulting in 24 different treatments. A Shimadzu 15A series chromatogra ph equipped with a Porapak-P column was used to measure the headspace of th e milk stored at 6.7 degreesC for 1, 2, 3, 5, 10, and 15 wk of storage. Gas chromatographic headspace analysis for sulfur compounds showed that hyd rogen sulfide, methanethiol, and dimethyl sulfide were detected in milk pro cessed at 140.6, 129.4, 118.3, and 107.2 degreesC. In addition, dimethyl di sulfide was detected in milk processed at 140.6 and 129.4 degreesC, and dim ethyl trisulfide was detected at 140.6 degreesC. Milk processed at 140.6 de greesC contained the most sulfur compounds. Samples C1, E1, and F1 retained the most hydrogen sulfide and methanethiol at 6 d of storage. Methanethiol appeared to be heat-induced. At wk 6, a slightly hammy or cardboardy flavo r was detected for milk packaged in boards with standard seams (A, B, and C ), and a slightly cooked flavor was detected for milk packaged in barrier a nd foil boards with J-bottom (E and F) seams. The hammy or cardboardy flavo r intensified with storage time, and all of the cooked flavor dissipated at wk 10.