In the paper studied the possibility of extending the validity term of bakery products(croissant) by slowing the aging process them. For this purpose investigate sorts were packed in impermeable materials to water and water vapor while were stored at temperatures ranging between 15-20°C and relative air humidity below 70 %. By preserving the croissants under proper conditions in special packing: PE, PP, PP sterilized, paraffin paper, ethylic alcohol treated paper and complex material, the validity term has been extended to 7 days at most, when the first depreciation signs of sensorial (taste, colour, smell),and physical (consistency-the core becomes brittle, humidity-the water quantity lowers significantly) properties become evident. The smooth and rigid crust becomes wrinkled, elastic and soft, the odour and the taste gradually disappear and the taste becomes flat or stuffy and sometimes even sour. The introduction of ethylic alcohol as well as the packing in proper materials determines the extension of croissant validity term to 30 days when the first signs of mould appear.

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The present work presents a packaging system that slows down the degrading and ageing processes of bakery products as well as mould appearance. There have been selected three packing methods: the packing in PE folio, PP folio, PP punched folio and the packing in a small bag specially designed to preserve bakery products. The selection has been done function of physical – mechanic and chemical properties of the packaging materials and according to the requirements of a good preservation of the packed product. The PE folio has a good mechanical resistance, a good permeability to gases and a high impermeability to water vapors. The PP folio has a greater contraction, a better transparency and better mechanical properties than the polyethylene. The permeability to water and gas vapors is lower than that of the polyethylene. The complex material based on textile / PE has superior physical and chemical properties and a high impermeability to moisture, gas and flavors. The experimental bread packaging methods prove a tight link among the permeability to water vapors, the duration of the product freshness and the mould appearance. The specially designed small bag made of two cotton lays and one polyethylene lay preserves the freshness of sliced bread, because the bread does not get dry or wet. After a 7-day storage period, the contamination degree with Penicillium frequetans of the sample packed in PP punched folio is of 5%. The contamination degree with Penicillium nigricans and frequetans of the sample packed in PP folio is of 85%. The sample packed in the cotton bag is 10% contaminated with Aspergillus fumigates, and the one packed in polyethylene folio is 20% contaminated with Aspergillus versicolor and Penicillium frequetans.

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This paper presents the experimental results for the packaging of tomato juice in bags that are made from complex plastic materials, through some preservation processes. The product is packaging in bags made from the complex plastic material PA / PVDC (polyamide / polyvinylidene chloride). In such a material, the products preserved their characteristics – sensorial, physic-chemical and microbiological up to three months.