Innovated Food Design Visualized in the Nonlinear Analysis of Multi-functional Water Species Based on the Specified Physicochemical Parameters
Special Symposium - Innovations in Food Technology (LMC Congress)
Flexible Production, PAT & Modelling (Food-3b)
Keywords: Three water species, bacterial growth coefficient, effective moisture diffusivity (De), activation energy of De, correlation time of water molecule
An innovated food design was challengingly studied in the course of the nonlinear analysis of multi-functional water species by using a drying process of Japanese squid at 30~50°C. Optimal design of the drying process requested was effectively visualized by using six physicochemical parameters as a function of the three multi-functional water species. The three water species were clearly distinguished as species-A1 (mobile water species), species-A2 (relatively restricted-water species) and species-A2’ (unfrozen-water species), all of which were exactly characterized by six physicochemical parameters. The six parameters were individually evaluated as effective diffusivity (De), activation energy of De (ED), peak temperature of the temperature-programed-desorption profile (TP), correlation time (τC) derived by a proton NMR technique, bacterial growth coefficient (m), and color function (L*, a*, b*), characterizing the three water species expressed by a non-linear function of the moisture content (W0) of the squid as species-A1 given at W0 >120%-d.b. (designated W0I), species-A2 given at W0 <120%-d.b. (designated W0II), and species-A2’ given at -15>T(sample temperature)>-30°C.
On De, it was evaluated as 1.8×10-6 for the water species-A1 and 0.6~1.7×10-6 m2/h for -A2, on ED, 17 for -A1 and 25~35 kJ/mol for -A2, on TP, 110 for -A1 and 117~150°C for -A2, on τC, 4.8×10-9 for -A1 and 1.0×10-81.2×10-7 sec for -A2, on m, 0.35~0.55 for -A1 and 0 h-1 for -A2, and on the values of L*, a*, b*, it was recognized as milk white for -A1 and dark brown for -A2. On the water species-A2’, an unusual histerisis behavior for the value of τC was exactly appeared indicating two different locus’s depending on the temperature decrease from 30 to -15°C (at which an activation energy of water molecule rotation, EτC, was evaluated to be 3 kJ/mol for the water species-A1) or the temperature increase from -25 to -10°C (at which EτC was 40 kJ/mol for the water species-A2’).
All values of the six parameters can individually be chosen depending on the food quality requested as milk white colored at W0I or dark brown colored at W0II. The populations of species-A1, -A2, and -A2’ can easily be regulated by controlling W0, TD, and the relative humidity of supplied drying air (RH) as an operating parameter. The growth rates of staphylococcus and micrococcus for the squid sample were completely limited by the species-A2 or by an RH lower than 30% (designated as critical relative humidity, RH30) at less than 103 CFU/g without depending on W0. The RH30 was usefully employed as an optimal operation in the drying process.
See the full pdf manuscript of the abstract.
Presented Wednesday 19, 17:05 to 17:10, in session Flexible Production, PAT & Modelling (Food-3b).
