The effect of xanthan on short and long‐term retrogradation of rice starch

Abstract

The short‐term retrogradation of the rice starch (RS)/xanthan (Xan) mixtures was investigated by Brabender‐E viscograph and dynamic rheometer while the long‐term retrogradation was investigated by DSC and pulsed NMR (PNMR), respectively. RS and 0, 2.5, 5, and 10% Xan (based on RS weight) were prepared into RS/Xan mixtures at the ratios of 100:0, 40:1, 20:1, and 10:1 w/w, respectively. With increasing Xan concentration, the reduced setback (SB) value suggests the decrease of short‐term retrogradation. The gelation rate constant (k) of the mixtures increased during the storage at 4°C for 5 h due to phase separation. The endothermic enthalpy of the pastes of RS/Xan mixture after being stored at 4°C for 1, 3, 5, 7, 14, and 21 days were lower than the native starch stored for the same days. The spin–spin relaxation time (T2) indicating the water mobility of starch gels was detected. T2 decreased gradually with extending storage time, which may be attributed to the retrogradation of RS. T2 of the system with xanthan was apparently higher than that without. The overall results demonstrate the remarkable inhibitory effects of Xan on the retrogradation of RS.

Effect of sodium alginate on the gelatinization and retrogradation properties of two tuber starches

“…Krystyjan et al (2015) reported that the PT value of PS was increased by the presence of inulin. The previous studies also found a similar trend in the decrease in SB value with the addition of polysaccharide (Chaisawang & Suphantharika, 2006;Kaur et al, 2015;Tang et al, 2013;Varela et al, 2016). Chaisawang and Suphantharika (2006) found that the PT value of anionic tapioca starch was obviously increased by the addition of xanthan gum and guar gum.…”

“…The increase in PT value is probably due to the synergistic effect between the hydrocolloids and starch granules (Xu et al, 2012). Chen, Tong et al (2014) and Tang et al (2013) found that the presence of xanthan gum or pullulan significantly reduced the SB value of rice starch. Moreover, the increased PT value for PS may be attributed to the strong electrostatic repulsions between the phosphate group of PS and the carboxyl group of AG (Chen, Wang, et al, 2014).…”

“…Chen, Ren, et al (2015) reported that both the short-term retrogradation of amylose and the long-term retrogradation of amylopectin could be affected by the addition of pullulan. Tang et al (2013) observed that the retrogradation of rice starch could be remarkably retarded with the addition of xanthan gum. Xu et al (2013) reported that the addition of spring dextrin could obviously retard the retrogradation of wheat starch or cornstarch.…”

“…The addition of suitable hydrocolloid (including the different type and concentration) into the starch could decrease the gel firmness, retrogradation enthalpy, the relative crystallinity, and retard the retrogradation of starch (Li, Wang, Chen, Liu, & Li, 2017;Zhou et al, 2008). The uses of hydrocolloids to modify the starch properties have been extensively studied in the previous literatures (Chen, Ren, Zhang, Tong, & Rashed, 2015;Li, Wang, Chen, Liu, et al, 2017;Tang, Hong, Gu, Zhang, & Cai, 2013;Zhou et al, 2008). Zhou et al (2008) also found that the retrogradation ratio (RR i ) of wheat starch reduced with the addition level of polysaccharide, while increased with prolonging storage time.…”

Pasting investigation, SEM observation and the possible interaction study on rice starch–pullulan combination

“…Starch-hydrocolloid combinations have been extensively used in food industry [1] with the hope of modifying various characteristics of starch, such as pasting and rheological properties [2,3], retrogradation behaviors [4][5][6], and texture [7]. Taking the pasting properties for example, the addition of hydrocolloids in starch can modify the paste viscosity and overcome the shortcomings of native starch.…”