Structural and physicochemical characterization of RS prepared using hydrolysis and heat treatments of chickpea starch

Abstract

The aim of this study was to evaluate the production and the structural and physicochemical properties of RS obtained by molecular mass reduction (enzyme or acid) and hydrothermal treatment of chickpea starch. Native and gelatinized starch were submitted to acid (2 M HCl for 2.5 h) or enzymatic hydrolysis (pullulanase, 40 U/g per 10 h), autoclaved (121°C/30 min), stored under refrigeration (4°C/24 h), and lyophilized. The hydrolysis of starch increased the RS content from 16% to values between 20 and 32%, and the enzymatic treatment of the gelatinized starch was the most efficient. RS showed an increase in water absorption and water solubility indexes due to hydrolytic and thermal process. The processes for obtaining RS changed the crystallinity pattern from C to B. Hydrolysis treatments caused an increase in relative crystallinity due to the greater retrogradation caused by the reduction in MW. RS obtained from hydrolysis showed a reduction in viscosity, indicating the rupture of molecules. The viscosity seemed to be inversely proportional to the RS content in the sample.

Pasting, textural and thermal properties of resistant starch prepared from potato (Solanum tuberosum) starch using pullulanase enzyme

“…The amylose content of V1 (25.17 %), was found to be increased in V2 (42.33 %) and V3 (51.44 %) which were the resulting retrograded starch of V1 after the treatment with pullulanase enzyme before and after gelatinization respectively. The increase in amylose and RS content of V3 followed by those of V2 could be attributed to the effect of pullulanase enzyme on debranching of α-(1-6) linkage of amylopectin (BeMiller and Whistler 2009; Leong et al 2007) which is converted into small chain linear polysaccharides like amylose molecules Polesi and Sarmento 2011.…”

“…Enzymatic hydrolysis of potato starch was carried out by the method of Polesi and Sarmento (2011). The potato starch suspension (10 % w/w db) was taken in sodium acetate buffer (0.1 M and pH 5.2).…”

“…The morphological studies of the V1, V2 and V3 were evaluated using the technique described by Polesi and Sarmento (2011) with scanning electron microscope (HITACHI Model S-3000H). The micrographs were obtained by assembly of the samples on aluminum stubs with double side adhesive tape to which the samples were fixed and covered with a thin gold layer.…”

“…The viscoamylographic property of samples (V1,V2 and V3) were performed using the method described by Polesi and Sarmento (2011) with Rapid visco analyser (RVA starch master 2, Newport Scientific, Warriewood, NSW, Australia) using 2 g of sample in 25 ml of distilled water. The following parameters are paste temperature, peak viscosity; breakdown viscosity, final viscosity and setback viscosity were examined from viscoamylograph.…”

“…Though recovery of RS using alcoholic alkaline methods dewed the significance and availability of RS as a functional ingredient in potato the need to have a increased yield in RS with the beneficial functionality of pasting, texture and better thermal stability and also increased crispness would improve the usage of RS in food product development (Nugent 2005), With this as the basis, the present study was focused to yield the RS present in potato using Pullulanase enzyme (Polesi and Sarmento 2011). Pullulanase enzyme has been used in recovery of RS in various legumes, vegetables and cereals along with many other enzymes including α-amylase (Zhang and Jin 2011).…”