Effects of Granular Structures on the Pasting Behaviors of Starches

Abstract

Japonica (Tainung 67 [TNu67]) and waxy (Taichung 70 [TCW70]) rice, normal and waxy corn, and cross‐linked waxy rice and corn starches were used in an investigation of the influence of the granular structure on the pasting behavior of starch, using small amplitude oscillatory rheometry. Both normal corn and normal rice (TNu67) starches had the highest storage moduli (G′), followed by their cross‐linked versions; native waxy corn and rice starches had the lowest. Native waxy starches showed paste characteristics (G′ < 500 Pa; tan δ > 0.2) at concentrations of up to 35%. However, cross‐linked waxy starches exhibited gel behavior at 10% concentration (cross‐linked TCW70) or higher (cross‐linked waxy corn starch). The degrees of swelling power were in the order: TCW70 > native waxy corn > TNu67 ≅ cross‐linked TCW70 ≅ normal corn ≅ cross‐linked waxy corn starches. Solubilities were in the order: normal corn > TNu67 > native waxy > cross‐linked waxy starches. The addition of 2% purified amylose from indica rice (Kaohsiung Sen 7) did not induce gelation of waxy corn starch. Swelling powers of normal corn, TNu67, and crosslinked waxy starches were similar, but normal corn and TNu67 had much higher G′ value. Such results implied that the formation of gel structure was governed by the rigidity of swollen granules and that the hot‐water soluble component could strengthen the elasticity of the starch gel or paste.

Correlation between grain nutritional content and pasting properties of pre-gelatinized red rice flour

“…According to Tsai et al, (1997), this phenomenon occurs when most of the starch granules are fully swollen and other granules and dissolved polymers remain molecularly non-aligned within the field of friction of the Rapid Visco Analyzer (RVA).…”

Correlation between wheat starch annealing conditions and retrogradation during storage

“…Reports have shown that the rigidity of swollen starch granules is the major factor determining the rheological properties of a starch paste or gel (Koo et al 2000). It is hypothesised that even though excess water causes leaching of amylose, which would increase the DR, annealing should increase the rigidity of the swollen granules, which would reduce the DR (Lii et al 1996;Tsai et al 1997 The average values ± standard deviation (n = 3); for each temperature set, values in the same column followed by different letters differed significantly (P < 0.05) Czech J. Food Sci., 34, 2016 (1): 79-86 doi: 10.17221/255/2015-CJFS annealing temperature and moisture content of the starch sample affected retrogradation behaviour.…”

Physicochemical Characteristics of Starches in Rice Cultivars of Diverse Amylose Contents

“…In particular, it is one of the most important rheological indicators of the cooking quality and processing characteristics of rice. The amylose content and branch chain length distribution have also been found to have a substantial impact on the swelling and pasting properties of rice starches (Tsai et al, 1997;Jane et al, 1999). To examine the gelatinization characteristics of the four rice cultivars under analysis in this study, the swelling and thermal properties of their starches were measured using method of Li and Yeh (2001) and a differential scanning calorimeter, respectively.…”