DYNAMICS OF WATER ACTIVITY CHANGES IN PORTIONED MEAT PRODUCTS PACKED IN MULTILAYER FOILS

A b s t r a c t . Water activity ( aw) is one of the primary quality parameters basing o n which the storage stability of meat products can be determine d. Aw value undergoes fluctuations during product storage. The aim of the study was to determine and compare the dynamics of water activity changes (aw), pH value and selected chemical parameters in sau sages with different storage stability, vacuum packed in direct packagings and stored under coolin g conditions. Salami (beef, pork) as well as Lunch meat (pork) was the experimental material. Sausage portions were packed in two kinds of foil packagings: vacuum PA/PE bags and 4-layer bags with thermoshrinkable features, which gives a “strained skin” effect. Chemical composition, wat er activity and pH value were determined in samples, and the protein and water content quotient ( b/w ) was estimated. Basing on the results obtained, it was observed that examined sausages di ffer in basic chemical composition, pH value, water activity, as well as in protein content and w ater quotient (b/w) . Both sausages in each of five phases of storage in thermoshrinkable as well as in vacuum packagings, were characterized with higher water activity than before packaging, and each of t hese sausages showed different aw and its change dynamics. Analysis of variance, performed in this s tudy with the use of the Fisher-Snedecor test, showed statistically significant influence of sausa ge type and experiment phase on the water activity of the samples investigated, packed in multilayer foil s with different characteristics. K e y w o r d s : meat products, packaging units, water act ivity