Thermal Transition Properties of Spaghetti Measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)

Abstract

Glass transition temperature (T g ) of spaghetti sample was measured by thermal and rheological methods as a function of water content from 0 to 70 kg/100 kg spaghetti. In the cases of sample containing un-freezable water (i.e., amount of water which did not form ice even at very low temperature), calorimetric measurements performed by differential scanning calorimetry showed that the T g values decreased from 142.8 to 42.7°C when water content increased from 0 to 13.95 kg/100 kg spaghetti, respectively. Glass transition temperature increased with the increase of heating rate (2-50°C/min) and reached to a nearly constant value above 30°C/min. Thermal mechanical compression test showed relatively lower T g values compared to the DSC values at low moisture contents, whereas at high moisture content T g showed higher values. In the cases of samples containing freezable water (27-70 kg/ 100 kg spaghetti), glass transition shifts were merged with the ice melting endotherm. The freezing point, measured from the endothermic peak, decreased with the decrease of water content. In the state diagram, maximal freezeconcentration condition was determined as X 0 s =0.81 kg/kg spaghetti from the intersection of the extended freezing curve and a horizontal line passing thru T 0 m =−10.3°C.

In situ analysis of cooking properties of rice by thermal mechanical compression test method

“…The TMCT has been used previously for analyzing the stickiness and glass-rubber transition temperature of various food materials, [21] including spray-dried orange juice powder, milk powders, spaghetti, and rice. [22][23][24][25] This method is based on the measurement of the displacement of a probe compressing the rice grain under a constant force while cooking in a temperature controlled TMCT device. During hydration and gelatinization, the softening of the grain will cause probe movement to maintain a set constant force.…”

Thermal Relaxation of Gelatin and Date Flesh Measured by Isothermal Condition in Differential Scanning Calorimetry (DSC) and its Relation to the Structural and Mechanical Glass Transition

“…Two types of behavior were usually observed: (1) glass transition increased exponentially and reached to a constant value at critical heating rate, and (2) glass transition increased linearly with the increase of heating rate. [11] However the linearity depends on the range of heating rate used for the experiments. melting (marked as B).…”

“…In addition, low displacement of the stiff sample could be another factor. [11] Rahman et al [12] used glass transition of spaghetti by mechanical (DMTA), thermal (linear-heating DSC and modulated DSC), water diffusion and density methods for a comparison.…”

Glass Transition in Rice Pasta as Observed by Combined Neutron Scattering and Time-Domain NMR

“…The glass transition concept, adapted from the science of polymer materials, has established itself very well to test the quality and stability of concentrated foods, i.e., low moisture content foods. It has been very useful to understand the structure-function relationship in many complex polysaccharide-based materials and the effect of plasticization by water on their thermal and mechanical properties [ 1 , 2 , 3 , 4 , 5 , 6 ]. The main parameter pertaining to the glass transition is the glass transition temperature .…”