Kinetic Study of Thermally Induced Inulin Gel

Abstract

Heated inulin solution undergoes a sol-gel transition during cooling and forms a white smooth gel under optimized conditions. The degree of gel formation is negatively related to hydrolysis of inulin during heating. Heating makes inulin soluble; overheating causes hydrolysis of dissolved inulin into smaller molecules. Using a 2-step model including a solubilization step and a hydrolysis of inulin step, we found that both steps follow pseudo first-order kinetics. Separate studies on initial rates of the solubilization and hydrolysis of inulin steps at constant temperatures show that the solubilization rate of inulin is much faster than that of the hydrolysis of inulin. Gel formation of inulin may be related to the average chain length of inulin after heating.

Effect of thermochemical treatment on the structure of inulin and its gelling properties

“…The analysis of the hardness and shear stress values is in agreement with the results of the previous findings (Kim & Wang, 2001; Kim et al. , 2001).…”

Sensory and Texture Properties of Mashed Potato Incorporated with Inulin and Olive Oil Blends

“…It is possible that in MPA samples, the structure of the MP was thickened due to the high INL concentration, because the system had enough particles and/or sufficient molecular INL chain density to reach a critical crowding effect. [4,30] This speculation is in agreement with the microstructure observed in INL-EVOO-based MP samples, [37] where amylose/amylopectin form a rigid matrix in which I particles are trapped. Guggisberg et al [38] showed that even though firmness and creaminess of low-fat set yogurt increased with both INL and fat content, the highest level of INL considered (4%) was not enough to imitate the whole-milk yogurt.…”

“…EVOO (Carbonell, Sevilla, Spain) was chosen for addition to the MP. Kappa-carrageenan (κ-C) ( 30). Additional samples without added ingredients (0:0 control), with 60 g/kg added I alone (60:0) and with 60 g/kg added EVOO alone (0:60) were also prepared for each type of MP and processing condition.…”

“…The INL long-chain structure resembles that of a network of fat crystals in oil, since this type of INL forms small microcrystal aggregates that occlude a considerable amount of water. [27] In fact, again in both MPA and MPB samples at a fixed EVOO concentration, moisture (1) [30] heating time probably induced INL hydrolysis, which in turn led to an increase in the reducing sugar concentration and probably caused a decrease in average polymer chain lengths. According to the latter authors, temperatures above 80 • C under neutral conditions caused some degree of hydrolysis of dissolved highlypolymerized INL molecules, and long INL chains were probably degraded into smaller ones, which were unable to form a gel.…”

An assessment of the texture of acidified sodium caseinate gels with added inulin using response surface methodology

“…Depending on the environmental conditions and fibre concentration, inulin can form gels, consequently modifying the rheological behaviour of the systems to which it is added (Kim and Wang 2001; Kim et al. 2001).…”