Molecular Structure and Pasting Properties of Legume Starches.

Abstract

The molecular structures and pasting properties of four legume starches (white Dutch runner; WDR, adzuki bean, pea and common bean) were examined. The apparent amylose content (27 .0-30.0%) was 3.9-9.4% higher than the actual amylose content (17.6-25.5%) due to the high iodine affinity (IA) of the legume amylopectins. The crystalline type of pea starch was of Cb and those of the others were of the Cc. Adzuki bean starch had the highest maximum viscosity and breakdown. No breakdown was observed for pea starch. The legume amylopectins had IA of 1.32-2.28 g/100 g and number-average chain-length of 21-22. The phosphorus content of amylopectin varied be tween 13 and 820 ppm with WDR amylopectin having the highest content. All the legume amylo pectins had 1-4% of long-chain fraction, being consistent with their high IA. Compared with starches of cereal amylopectins, the legume amylopectins seemed to contain a relatively small amount of A-chain fraction. Distribution pattern for chains of degree of polymerization (DP) 6-8 was similar to those of potato and sweet potato amylopectins in which the amount of these chains decreased with an increase in DP. The legume amyloses had number-average DP of 820-1350 and comprised 2.4-4.7 chains per molecule, being similar to cereal amyloses. Among the legume amy loses, adzuki bean amylose was the largest and most branched molecule.

Starch characteristics of bean (Phaseolus vulgaris L.) grown in different localities

“…The first two peaks correspond to amylopectin and the 11.90 ± 0.16b 12.79 ± 1.09b 11.28 ± 0.11a 11.42 ± 0.17a third represents amylose (Grant et al, 2002). The amylose content in bean starches varied from 23.20 to 28.06% (Table 1) and was similar to values reported for common bean (Yoshimoto, Matsuda, Hanashiro, Takenouchi, & Takeda, 2001). Significant differences (P > 0.05) between varieties were observed in amylose content for varieties grown under irrigation, but not for varieties grown under rain fed conditions.…”

Composition, molecular structure, properties, and modification of pulse starches: A review

“…i Biliaderis et al (1979). j Sandhu and Lim (2008), Ratnayake et al (2001), Yoshimoto et al (2001), Biliaderis et al (1979), Colonna and Mercier (1979). k Biliaderis et al (1979), Colonna and Mercier (1984 molecule.…”

“…The thermal stability of cross-linked starches would be of value where increased thermal stability is required at low pH or under the high temperature conditions of pressure cooking and sterilization. Yoshimoto et al (2001). b Hoover and Ratnayake (2002) and Hoover and Sosulski (1985a).…”

“…The location of amylose in a starch granule is still in dispute. The possible locations are listed as follows: (1) amorphous growth ring, (2) amorphous lamellae, or (3) interspersed or co-crystallized with amylopectin molecules (Atkins, Cheng, Abeysekara, & Robards, Yoshimoto et al (2001), Tjahjadi and Breene (1984), and Biliaderis et al (1981). b Chavan et al (1999).…”

Relationship between ?-amylase degradation and the structure and physicochemical properties of legume starches

“…Extensive research has been done to study the chain length profile of amylopectin from different starch sources, such as maize (Takeda et al, 1988;Jane eta!., 1999), barley (Tang et al, 2001 a, b;Song and Jane, 2000;Jane et al, 1999;Yoshimoto et al, 2000Yoshimoto et al, , 2002MacGregor and Morgan, 1984), rice Hanashiro et al, 1996;Takeda et al, 1987b), wheat Shibanuma et al, 1994;Franco et al, 2002;Hizukuri and Maehara, 1990), tapioca , sweet potato (Hanashito et a!., 1996;McPherson and Jane, 1999) and legumes (Biliaderis, 1982b;Biliaderis et al, 1981;Ratnayake et al, 2001;Yoshimoto et al, 2001). The resulting chromatography showed that debranched amylopectin usually exhibits a trimodal or polymodal distribution pattern.…”