Water dynamics of ready to eat shelf stable pasta meals during storage

This work reports for the first time a study of physico-chemical changes in cooked and sterilized pasta meals (pasta 25% and sauce 75%) during 34 days of storage. Water dynamics were studied with a multi-analytical and multidimensional approach: moisture content, water activity and H-1 mobility (H-1 T-2 and T-1 relaxation times and H-1 self diffusion coefficient [D]) have been considered. Macroscopic structure (hardness) of pasta meals became softer during storage. Moisture content and water activity changes did not highlight a macroscopic water migration between the pasta and sauce phases.H-1 T-2 was found to decrease in pasta and more markedly in sauce during storage while H-1 T-1 increased the mobility in pasta and decreased in sauce. H-1 translational mobility (D) was found to decrease more significantly in sauce than in pasta during storage. A water migration between the pasta and sauce phases observable at molecular level was therefore hypothesized. Industrial relevance: Ready to eat pasta meals are becoming an important segment of the global food market. Ready to eat pasta meals are subjected to quality loss and, in particular, textural degradation during storage. The complexity of these products (e.g. presence of multiple phases [pasta and sauce], high moisture content), makes a challenge for the food industry to understand the phenomena involved in their aging process. This is a first scientific report aiming at the description and comprehension of the phenomena involved in the aging process of ready to eat pasta meals and it might provide important information to intelligently intervene on formulation and/or processing to improve product's quality and shelf-stability.