A Review of Textural Defects in Cooked Reconstituted Legumes ?The Influence of Structure and Composition

Abstract

Legumes provide an important part of the world's protein requirements, as well as other nutrients, but they are underutilized as food. A major factor limiting expanded consumption is storage induced textural defects that prolong cooking time and demand correspondingly higher energy requirements for preparation. These defects, including the hard-to-cook phenomenon and hardshell, are initiated by structural and compositional factors but can be at least partially controlled by storage and processing conditions. Structural components implicated include seed coat, cell walls, middle lamella, starch granules and membranes while, compositionally, proteins, carbohydrates, phytate, polyphenols and lignin may also be important. Methods of texture measurement of legumes, including mechanical, physical and sensory properties are reviewed. The most commonly held hypothesis for the mechanism of the hard-tocook defect states that beans fail to soften after exposure to high temperature and humidity storage because the increased water activity potentiates phytase which hydrolyzes phytate, rendering it no longer capable of chelating the Ca" and Mg++ ions of the middle lamella and, hence, undissoluble. More recent evidence, however, provides potential roles for lignification, starch gelatinization and perhaps other mechanisms depending upon conditions. The possibility of a nonenzymutic as well as an enzymatic route is raised and thoughts presented on a course of action for future research. Protein Lys in. Soybemns Dry bean. Pemnuts Legume. , totml Wheat Corn Rice C e r e m l s . totml 2 5 . 8 0 0 11,500 2,500 39.800 4 2 . 6 0 0 2 5 , 8 0 0 2 4 , 0 0 0 9 2 , 4 0 0 1.805 eo5 105 2.715 815 775 935 2 . 5 2 5

Nutrients and antinutrients in cowpea and horse gram flours in comparison to chickpea flour: Evaluation of their flour functionality

“…However, the phytic acid contents of all three legumes were higher than the levels reported for pigeon pea (2.2 mg/g) and bambara groundnut (2.9 mg/100 g) (Igbedioh, Olugbemi, & Akpapunam, 1994). Besides lowering the bioavailability of minerals and inhibiting the digestibility of proteins, phytic acid is also implicated in the ''hard-to-cook'' phenomenon of legumes (Stanley & Aguilera, 1985). However, its presence is also beneficial because it may have a positive nutritional role as an antioxidant and anticancer agent (Turner, Paphazy, Haygarth, & Mckelvie, 2002).…”

In vitro starch digestibility, pasting and textural properties of mung bean: effect of different processing methods

“…Softening of beans during cooking has been reported to be accompanied by structural changes in the seed (Rockland and Jones 1974;Sefa-Dedeh et al 1978). During cooking of legumes, the seeds undergo important physicochemical changes involving gelatinization and swelling of starch, denaturation of protein, solubilization of some of the polysaccharides, softening of the structure, and other physical and chemical changes, which result in a palatable texture (Stanley and Aguilera 1985). Cohesiveness (ratio of the positive force areas under the first and second compressions), gumminess and chewiness of the autoclaved mung bean were also found to be the lowest as compared to its soaked, germinated and cooked counterparts.…”

Stability and inheritance of storage-induced hardening in 20 common bean cultivars

“…bean lcommon) Michaels, T. E. et Stanley, D. W. 1991 Aguilera and Stanley (1985) reported that, based on combined data from four separate studies, beans stored for 10 mo at about 12% moisture and 25'C would require a 60% longer cooking time to soften. Antunes and Sgarbieri (1919) (Fig.…”