Abstract
As a new scientific method to overcome the difficulties in designing requested food products in the food engineering field, a hybrid method combining the chemical engineering-proton NMR technique was examined by using 18 different kinds of foods. The hybrid method proposed clearly distinguished water species-A1 and -A2, which were divided at the correlation time of τC = 1 × 10−8 s evaluated by the proton NMR technique. Water species-A1 was recognized as a weakly restricted water species, such as free water, whereas water species-A2 was recognized as a strongly restricted water species, such as bound water formed by strong adsorption. It was clearly demonstrated that the two water species were reproduced during repeated cycles of dehydration and re-hydration. All the parameters, such as effective diffusivity of water (De), activation energy of De (ED), pre-exponential factor of De (δD0) and hardness (NP) of food, were evaluated individually for the two water species.
