High pressure intensification of cassava resistant starch (RS3) yields

Cassava starch, typically, has resistant starch type 3 (RS3) content of 2.4%. This paper shows that the RS3 yields can be substantially enhanced by debranching cassava starch using pullulanase followed by high pressure or cyclic high-pressure annealing. RS3 yield of 41.3% was obtained when annealing was carried out at 400 MPa/60°C for 15 min, whereas it took nearly 8 h to obtain the same yield under conventional atmospheric annealing at 60°C. The yield of RS3 could be further significantly increased by annealing under 400MPa/60°C pressure for 15 min followed by resting at atmospheric pressure for 3 h 45 min, and repeating this cycle for up to six times. Microstructural surface analysis of the product under a scanning electron microscope showed an increasingly rigid density of the crystalline structure formed, confirming higher RS3 content

Unexpected High Digestion Rate of Cooked Starch by the Ct-Maltase-Glucoamylase Small Intestine Mucosal α-Glucosidase Subunit

For starch digestion to glucose, two luminal α-amylases and four gut mucosal α-glucosidase subunits are employed. The aim of this research was to investigate, for the first time, direct digestion capability of individual mucosal α-glucosidases on cooked (gelatinized) starch. Gelatinized normal maize starch was digested with N- and C-terminal subunits of recombinant mammalian maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) of varying amounts and digestion periods. Without the aid of α-amylase, Ct-MGAM demonstrated an unexpected rapid and high digestion degree near 80%, while other subunits showed 20 to 30% digestion. These findings suggest that Ct-MGAM assists α-amylase in digesting starch molecules and potentially may compensate for developmental or pathological amylase deficiencies

Prebiotics and Dietary Fibers from Food Processing By-Products

The abundance of agricultural wastes or by-products from industrial and domesti- Q1 cated food processing is the main cause of environment problems. These by-products are generally managed by disposal or even sold at a cheaper price. Disposal of these underutilized by-products are commonly done in inappropriate ways, i.e. discharge effluent into rivers or by burning in the open, which may cause air and water pollutions. Presently, scientific investigation on the benefits or functional properties of waste and by-products from industrial food processing, which produces a large amount of by-products, is necessary in the search for possible ways for their utilization (Vanesa et al., 2011). Three main groups of by-product from food processing, classified according to their main chemical compositions, are carbohydrate and dietary fibers, protein and lipids. The most common by-products are generated by the food industry, in particular the beverage, starch and flour industries. These items are classified under carbohydrate and dietary fiber groups. They are further divided into four sub-groups: monosaccharides, disaccharides, oligosaccharides and polysaccharides. Dietary fibers are a class of non-starch polysaccharides (i.e. cellulose, dextrins, chitins, pectins, β-glucans and waxes) and lignin, which are able to modulate the transit time through the gut. Thus, it provides similar beneficial effects to those of inulin-type fructans. These compounds are commonly found in many foods such as cereal, nuts etc. They are also partially susceptible to bacterial fermentation and may induce changes in bacterial populations, particularly in the numerous bifidobacteria and lactobacilli. These soluble dietary fibers have been shown to exert additional beneficial effects, for instance by improving gut barrier function in vitro and in vivo, which could be partially a consequence of their effect on the microflora composition (Laparra and Sanz, 2010)

Formation, Analysis, Structure and Properties of Type-III Enzyme Resistant Starch

During the retrogradation of starch a fraction becomes resistant to amylolytic enzymes. This undigestible fraction is described as enzyme resistant starch (RS) type III. RS type III is composed of short linear segments of alpha-(1-4)-glucans arranged in an A or B-type crystalline structure and is thermally very stable. Different factors have an impact on the formation (crystallisation) of these structures. Apart from the starch type, which defines the amylose/amylopectin ratio, polymer chain length and lipid content, process conditions following starch gelatinisation and the presence of other components, have an influence on the amount and on the quality of RS formed. Several in vitro and in vivo procedures to quantify RS have been used. However, RS levels may be affected by the analytical procedure. (C) 1995 Academic Press Limitedstatus: publishe

Enzyme-Resistant Starch .2. Influence of Amylose Chain-Length on Resistant Starch Formation

Potato starch amylose was hydrolyzed to varying degrees by incubation with barley beta-amylase for different periods. Determination of reducing sugars and gel-permeation chromatography showed that amylose fractions with different number average chain lengths (DP(n)BAR 40-610) were obtained. Enzyme-resistant starch (RS) was formed from the fractions in aqueous solutions (0.83%, w/v) at 4-degrees-C. Under the experimental conditions, the yield of RS increased with DP(n)BAR to plateau values of 23-28% within a region of DP(n)BAR of 100-610. X-ray diffraction showed a B-pattern for all RS samples obtained. The DP(n)BAR of the RS varied only between 19 and 26 and, thus, it is independent of the chain length of the amylose from which it was formed (DP(n)BAR 40-610). The results suggest that RS may be formed by aggregation of amylose helices in a crystalline B-type structure over a particular region of the chain (about 24 glucose units).status: publishe

Acid hydrolysis of native and annealed wheat, potato and pea starches - DSC melting features and chain length distributions of lintnerised starches

International audienceAnnealing (one and two step) slightly decreased the susceptibility of potato to acid hydrolysis (lintnerisation, 2.2 M HCl, 35° C)