Effect of Salts on the Water Sorption Kinetics of Dried Pasta

Abstract

The water sorption kinetics of dried pasta were measured in the 20-90 C range in 1.83 mol/L of NaCl and at 80 C in 1.83 mol/L of LiCl, KCl, NaBr and NaI solutions in order to elucidate the role of salt in the kinetics. At the temperatures higher than 70.8 C, the change in the enthalpy of sorption, ÁH, in the 1.83 mol/L NaCl solution was 33.1 kJ/mol, which was greater than the ÁH value in water, and the activation energy for the sorption, E, in the salt solution was 25.6 kJ/mol, which was slightly lower than the E value in water. The Hofmeister series of ions was an index for their effect on the equilibrium amount of the sorbed solution of pasta. The apparent diffusion coefficient of water into pasta was not correlated with the crystal radius of the salts, but was with the Stokes radius of the hydrated ions. Equations were formulated to predict the amount of sorbed solution under any condition of temperature and NaCl concentration.

Water Sorption Kinetics of Wheat Noodle with Different Diameters

“…5 to describe water sorption by dried spaghetti (Ogawa et al, 2011;Ogawa and Adachi, 2013;Aimoto et al, 2013;Yoshino et al, 2013) and the present results indicate that this equation also applies to water sorption by wheat noodle.…”

“…However, the kinetics of water sorption has not yet been sufficiently investigated, although moisture distribution in udon during and after boiling has been observed using magnetic resonance imaging (Kojima et al, 2001;Maeda et al, 2009). We previously reported the water sorption kinetics of spaghetti (Ogawa et al, 2011;Ogawa and Adachi, 2013;Aimoto et al, 2013;Yoshino et al, 2013). However, the diameter or thickness of udon is generally larger than that of spaghetti.…”

Effects of relaxation of gluten network on rehydration kinetics of pasta

“…The gradual increase in the moisture content may be due to the prevention of the swelling of starch granules, even though the rehydration capacity of the pasta at equilibrium was approximately 9 kg-H 2 O/kg-d.m. 19,20) Rehydration at the pasta surface may proceed along with the relaxation of the gluten network because of the rehydration of gluten and the swelling force of gelatinizing starch granules.…”

“…The rate of starch gelatinization, which is completed within a minute, 18) is much faster than that of water diffusion. 19,20) In this context, gluten was assumed to be the high-molecular-weight molecule that governed rehydration rates. The aim of this study was to investigate the effects of the relaxation of the gluten network on the rehydration kinetics of pasta in boiling water.…”

Effects of drying conditions on moisture distribution in rehydrated spaghetti

“…4,6,7) Culture tubes containing about 50 cm 3 of distilled water were equilibrated at 100°C in a stainless-steel tray on a digital hot plate (DP-1S, As One, Osaka, Japan). A sample of length 8 cm was immersed in a tube.…”