New Researches in Biotechnology - Facultatea de Biotehnologii ...

Proceeding of the 4 rd International Symposium“NEW RESEARCH IN BIOTECHNOLOGY” USAMV Bucharest, Romania, 2011we analyzed the permeability for gases and water vapors for the bread packagings for theinner-outer and viceversa oxygene transfer and water vapors is linked to the apearance ofseveral alterations of the packed product.The packing layers permeability is the determinant parameter for evaluating theirbarrier properties in the mass transfer (Journal of Food Engineering 89, 2008). For toappreciate a material’s innocuity in direct contact with the food stuff there was determinedthe ceding degree for the different compounds of a package in an extraction liquid.1982. MATERIALS AND METHODSIn order to obtain some available experimental data, wheat flour obtaining fromFLAMURA wheat variety grinding in Chopin Laboratory Mill was used like controlsample. The technological characteristics of flour are shown in Table 1.Moisture%Ash%Table 1. Analytical parameters of Control flourWet gluten%Protein%Hydrationcapacity%FallingNumbersec13.42 0.68 31.1 13,3 62.6 329Buckwheat flour was provided by local producers.The analytical flour quality was determined according to the international standardmethods (ash content – ICC104/1, wet gluten – ICC105/2, protein content – ICC106/2,hydration capacity with Pharinograph - ICC115/1 and Zeleny index – ICC116/1).Like raw material I used also compacted fresh yeast (Saccharomyces cerevisiae)from S.C. ROMPAK, Pascani, with 32.5% dry matter and 46.54% protein content (N x6.25).Dough was prepared using a straight dough method. After baking, the samples werecooling 6-8 hours in controlled atmosphere (UV lamps).In order to be scoring (after 24 hours), and to be examined from microbiologicalpoint of view (after 72 hours), the samples were sliced for packed in plastic bagsMicrobiological quality of bread with buckwheat, over 3 days at room temperaturewas evaluated according with SR EN ISO 4832/2006 quality standard.The mineral substances were evaluated using EDX-900.For the bread packing there were used polypropylene bags (PP), high densitypolyethylene (HDPE), low density polyethylene (LDPE), multilayer foil (PE/ adhesive /PA/ adhesive/ PE) supplied by Sudpack.The determination of the permeability at gases was led according to the BS EN ISO2556/2003 standard, using the Dansensor 1 L 100-5000 device. The determination of thepermeability at water vapors was led according to the SR EN ISO 15106-1/2005 standard,using the Dansensor 1 L 80-5000 device.For the components global determination we used as food simulants distilled water,3% acetic acid and isooctane according to STAS 1186-1/2003. The working method fordetermining the Pb and Cd migration from the plastic materials is similar to the one in SRISO 1: 19997, the exception being made by the acetic acid solution that in our case had a