Increase In Amylose Content Research Articles

Structural characterization of starches from Chinese jackfruit seeds (Artocarpus heterophyllus Lam)

To investigate its molecular structure, starch was extracted from five jackfruit cultivars (M1, M5, M6, M11, and BD) and separated into amylose and amylopectin. The values for weight-average molar mass (Mw) and average radius of gyration (Rg) of the jackfruit starches (1.74 × 107 g/mol - 4.61 × 107 g/mol, 115.4 nm - 144.2 nm) were similar to those of rice and potato starch, higher than those of maize and waxy rice starches, but lower than those of barley starches. The jackfruit starches exhibited higher proportions of A and B1 chains, lower proportions of B2 and B3 + chains and shorter average chain lengths (38.33%–33.89%, 39.06%–39.58%, 17.13%–18.43%, 4.96%–8.62% and 18.27–19.71, respectively). Compared with the other cultivars, starch from the BD cultivar exhibited the lowest Mw and Rg of amylose (1.42 × 106 g/mol and 55.3 nm) and the highest Mw and Rg of amylopectin (6.99 × 107 g/mol and 132.8 nm). The amylose of the M1 cultivar and the amylopectin of the BD cultivar showed more compact structures than did the other starches identified. It was found that with increasing amylose content, the Mw and Rg of amylose and the proportions of B2 and B3 + chains showed an increased trend, whereas the Mw and Rg of amylopectin and proportions of A and B1 chains displayed the opposite trend. This study provides the theoretical basis for further research of starch structures.

Rheological properties of nanocomposite-forming solutions and film based on montmorillonite and corn starch with different amylose content

Nanoparticles (montmorillonite, MMT) can enhance biopolymer-based film properties. The structure–property relationship between polymers and nanoparticles may be explained by the rheological tests of nanocomposite forming solutions (NFS). The aim of this work was to study the effect of MMT concentration and amylose content on the rheological properties of NFS based on corn starch and glycerol following two preparation methods, through steady shear and dynamic tests. The organization level of NFS was influenced by the addition order of the components. Decreasing in flow index behavior when increasing amylose content was attributed to interactions between the starch components. In all NFS, G′ was higher than G″ indicating a gel-like behavior and suggesting that the MMT reinforced the starch matrix as observed by the increase in the storage modulus of films with MMT. Films obtained from method 2 have better mechanical properties probably due to the starch-MMT interactions.

KARAKTERISTIK TEPUNG TALAS VARIETAS BENTUL DAN SATOIMO HASIL FERMENTASI TERKENDALI DENGAN INOKULUM KOMERSIAL

Taro is one of non-rice carbohydrate sources which is rich in dietary fiber and minerals, mainly potassium, magnesium, calcium, dan phosphorus. The objectives of this research were to obtain taro flour with high amylose content and various pasting properties for different food ingredients through controlled fermentation technology using commercial inoculums. There are two taro varieties studied, namely Bentul and Satoimo. The fermentation time conducted were 12, 24, 36, and 48 hours. The commercial inoculums added were NKL, Bimo CF, and Fermipan. The results showed that fermentation of taro with Bimo CF for 48 hours increase the amylose content (66.82% for Bentul variety and 61.08% for Satoimo). The growth of mold contributed to the increase in amylose content. Longer fermentation time increase the breakdown and final viscosity of Bentul taro flour, but decrease the same characteristics in Satoimo flour. Fermented bentul taro flour has amylograph pattern similar to type A, while Satoimo has type C. Fermentation using Bimo CF for 48 hours produced the highest final viscosity in Bentul taro flour (3405 cP) thus it is potential to be used as a filler in products processed at low temperature. Meanwhile Satoimo taro produced flour with lowest breakdown viscosity (0.75 cP), therefore it is potential to be used as a filler in products processed at high temperature.

Hierarchical structure and thermal behavior of hydrophobic starch-based films with different amylose contents

This work discloses the multi-level structure and thermal behaviors of hydrophobic, propionylated starch-based films as affected by the amylose contents of starch materials used. Scanning electron microscopy results showed that amylose promoted the formation of more compact structure within the film matrices. Also, small and wide angle X-ray scattering analysis revealed that higher amylose content was preferable for the formation of new orders on nanoscale and crystallites. With these structural changes, the viscoelasticity of amorphous short chains was enhanced and the glass transition temperature was reduced by the increased amylose content; but the depolymerization of macromolecules and the decomposition of molecular bonds were postponed, since the increase in starch crystallites restricted the motion of adjacent amorphous regions. Hence, this work provides valuable information for rational design of hydrophobic starch-based films with desired thermal features by simply regulating the amylose content of starch raw materials.

Low glycaemic index foods from wild barley and amylose-only barley lines

In this study, we explored possibilities to develop low glycaemic-index foods from barley (Hordeum vulgare – Hv). Barley has a potential to suppress postprandial blood glucose levels, possibly because of its high content of β-glucan (BG). BG content is particularly high in Hordeum vulgare Subsp. spontaneum (Hs), which is the wild ancestor of cultivated barley. Increasing amylose content in starch is another way to decrease the glycaemic index of a starch-rich-food. Therefore, a recently developed Amylose-only barley grain (AO) containing a 99% amylose starch was included. Two in vitro gastro-intestinal models were used to predict glycaemic indices (pGIs). Grains and bread from Hs and AO showed lower pGIs as compared to Hv. The low pGI value of AO was due to the resistant starch. The low pGI of Hs barley grains was caused by increased viscosity of the digesta. A simulated colon was used to predict potential effects on microbiota.

Novel ssIIa Alleles Produce Specific Seed Amylose Levels in Hexaploid Wheat

Novel starch synthase II (ssIIa) alleles were created in a soft wheat (Triticum aestivum L.) via ethyl methanesulfonate mutagenesis and combined by crossing to create four unique ssIIa triple mutant haplotypes. A range of starch amylose content was obtained from the ssIIa triple mutant lines (35.6–46.8%), with moderate increases in amylose content found in lines carrying two ssIIa null alleles and one partially functional ssIIa allele. Seeds from all ssIIa triple mutants had significantly higher amylose and protein contents but also lower starch content, kernel weight, and flour swelling power compared with their wild‐type sister lines. Seed starch amylose content was negatively correlated with individual kernel weight (r = –0.54), starch content (r = –0.85), and flour swelling power (r = –0.91) but positively correlated with grain protein (r = 0.78), demonstrating that unique ssIIa triple mutant null combinations confer defined levels of seed starch amylose, protein content, and kernel size. The ssIIa mutant lines also had a hard grain texture (≈86 single kernel characterization system units), whereas all parental material and wild‐type sister lines had soft grain texture (≈35). This change in grain texture was independent of Ha locus genotype, because all lines carried a functional (soft type) Ha locus. The ssIIa alleles and allelic combinations reported here demonstrate the ability to create defined levels of seed starch, amylose, and protein.

Effect of Jackfruit Seed Starch (Artocarpus heterophyllus) Microstructure on Properties and Characteristics of Fried Battered Product

The objective of this research was to study the effect of the ratio between wheat flour (WF) and jackfruit seed starch (JS) on the physical, chemical quality and sensory characteristics of batter coating. The ratio of WF to JS used in the study to make batter coating were 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, 10:90 and 0:100. The WF and JS exhibited the “A-type” crystal form. Increasing JS content in the starch mixture was found to increase amylose content and relative crystallinity significantly. The amount of oil absorption in the battered product decreased significantly with increasing amylose content. The microstructure of the batter coating differed significantly depending on the ratio of WF to JS from 100: 0, 80: 20, 60: 40, 40: 60, 20: 80 and 0: 100. Higher JS content in the batter provided greater homogeneity with a fine starch network and less porosity. In terms of sensory descriptive analysis, adding JS resulted in increased hardness and crispness, but significantly decreased brittleness, puffiness, oiliness and oil coating (p ≤ 0.05). It was found that the highest acceptance levels of batter used the ratio of WF to JS of 50:50 which obtained the highest score in appearance, color, taste, flavor, texture and overall preference.

PENGARUH FOTOOKSIDASI UV-C TERHADAP SIFAT FISIKOKIMIA DAN BAKING EXPANSION PATI SAGU (Metroxylon sago)

Native Sago starch is difficult to used in industry because of the limitations of its phisycochemical properties. The aim of this research was to studied effect of UV-C photo-oxidation on physicochemical properties and baking expansion of sago starch. Five slurries ratio (starch : water ratio): 1:2; 1:4; 1:6; 1:8; and 1:10 were oxidized with UV-C irradiation for 20 minutes, and then compared with native sago starch. The results showed that UV-C photo-oxidation increasing amylose content and paste viscosity, but decreasing swelling power and solubility, and carbonyl and carboxyl content. Used of UV-C as a photooxidator effective to increasing baking expansion characteristic, and the best slurry ratio was 1:6, which has 6.97 ml/g specific volume or 33.7% increased from native sago starch (5.22 ml/g)

Alpha-Glucan, Water Dikinase 1 Affects Starch Metabolism and Storage Root Growth in Cassava (Manihot esculenta Crantz)

AbstarctRegulation of storage root development by source strength remains largely unknown. The cassava storage root delay (srd) T-DNA mutant postpones storage root development but manifests normal foliage growth as wild-type plants. The SRD gene was identified as an orthologue of α-glucan, water dikinase 1 (GWD1), whose expression is regulated under conditions of light/dark cycles in leaves and is associated with storage root development. The GWD1-RNAi cassava plants showed both retarded plant and storage root growth, as a result of starch excess phenotypes with reduced photosynthetic capacity and decreased levels of soluble saccharides in their leaves. These leaves contained starch granules having greatly increased amylose content and type C semi-crystalline structures with increased short chains that suggested storage starch. In storage roots of GWD1-RNAi lines, maltose content was dramatically decreased and starches with much lower phosphorylation levels showed a drastically reduced β-amylolytic rate. These results suggested that GWD1 regulates transient starch morphogenesis and storage root growth by decreasing photo-assimilation partitioning from the source to the sink and by starch mobilization in root crops.

Effect of pressure with shear stress on gelatinization of starches with different amylose/amylopectin ratios

Effect of pressure with shear stress on the gelatinization of cornstarch with different amylose/amylopectin ratios (waxy 0/100; maze 23/77; G50 50/50; G80 80/20) was systematically investigated using a high-pressure rheometer. Onset and peak temperature of starch gelatinization as well as the peak viscosity were used to discuss the influence of pressure together with shear stress on the gelatinization of starch granules. The results showed that without shear stress, pressure could resist the gelatinization process due to weak swelling of starch granules and lower quantity of amylose released. However, the shear stress can simply counteract the influence of the pressure since its impact is much high on gelatinization. Under certain pressure and shear stress, both onset and peak temperatures of gelatinization were increased with increasing amylose content, which is in correspondence with the results from differential scanning calorimeter measurement, while the overall viscosity was lower when starches with a higher amylose content was used because part of its granular was not fully dissolved during the measurement. SAXS measurements were used to study the gel structure and stability of starch suspensions. It was found that the scattering intensity of starches in the measured range (0.1–1.0 nm−1) is G80 > waxy, indicating the amount of ordered semi-crystalline structures in amylose is higher. Peak values, q = 0.4 nm−1 and q = 0.2 nm−1, detected for waxy starch under different shear rates, indicates that higher shear stress which plays a dominant role compared with pressure, resulted in more degradation in amylopectin, inhibiting the formation of aggregate structure.

Progress in High-Amylose Cereal Crops through Inactivation of Starch Branching Enzymes.

High-amylose cereal starches provide many health benefits for humans. The inhibition or mutation of starch branching enzyme (SBE) genes is an effective method to develop high-amylose cereal crops. This review summarizes the development of high-amylose cereal crops through the inactivation of one or more SBE isoforms or combination with other genes. This review also reveals the causes of increase in amylose content in high-amylose crops. A series of changes, including amylopectin structure, crystalline structure, thermal properties, and hydrolysis properties, occurs as amylose content increases. The different morphological starch granules nominated as heterogeneous starch granules or differently stained starch granules are detected in high-amylose cereal crops. Detailed studies on four heterogeneous starch granules in high-amylose rice, which is developed by antisense RNA inhibition of SBEI/IIb, indicate that granules with different morphologies possess various molecular structures and physicochemical and functional properties. This variation diversifies their applications in food and non-food industries. However, current knowledge regarding how these heterogeneous starch granules form and why they exhibit regional distribution in endosperm remain largely unknown.

Characterization of the endosperm starch and the pleiotropic effects of biosynthetic enzymes on their properties in novel mutant rice lines with high resistant starch and amylose content

Resistant starch (RS) is beneficial to human health. In order to reduce the current prevalence of diabetes and obesity, several transgenic and mutant crops containing high RS content are being developed. RS content of steamed rice with starch-branching enzyme (BE)IIb-deficient mutant endosperms is considerably high. To understand the mechanisms of RS synthesis and to increase RS content, we developed novel mutant rice lines by introducing the gene encoding starch synthase (SS)IIa and/or granule-bound starch synthase (GBSS)I from an indica rice cultivar into a japonica rice-based BEIIb-deficient mutant line, be2b. Introduction of SSIIa from an indica rice cultivar produced higher levels of amylopectin chains with degree of polymerization (DP) 11–18 than those in be2b; the extent of the change was slight due to the shortage of donor chains for SSIIa (DP 6–12) owing to BEIIb deficiency. The introduction of GBSSI from an indica rice cultivar significantly increased amylose content (by approximately 10%) in the endosperm starch. RS content of the new mutant lines was the same as or slightly higher than that of the be2b parent line. The relationship linking starch structure, RS content, and starch biosynthetic enzymes in the new mutant lines has also been discussed.

Influence of fatty chain length and starch composition on structure and properties of fully substituted fatty acid starch esters

A series of almost fully substituted Fatty Acid Starch Esters (FASEs) has been obtained in a homogeneous LiCl/DMAc medium by grafting octanoyl (C8), lauroyl (C12) and palmitoyl (C16) chlorides onto 3 starch species: Amylo-Maize, Potato and Waxy Maize. Structure-property relationships of FASEs are investigated as a function of both fatty acid chain length and amylose/amylopectin ratio of the starch. The structural study has revealed a layered type organization in which starch chain planes are separated by fatty chains. The latter are interpenetrated and/or tilted for FASE-C16 whatever the origin of the starch is, and fatty chains partially crystallizes into a structure with hexagonal symmetry. FASEs with C8 and C12 side chains are totally amorphous. The mechanical behavior of FASEs is shown to depend on both side chain length and amylose/amylopectin ratio, and an increase in material ductility is observed at increasing amylose content for C8 and C12 side chains.

Study of heat-moisture treatment of potato starch granules by chemical surface gelatinization.

Native potato starch was subjected to heat-moisture treatment (HMT) at 12%, 15%, 18%, 21%, and 24% of moisture content at 110 °C for 1 h, and the effects on morphology, structure, and thermal and physicochemical properties were investigated. To reveal the internal structure, 30% and 50% of the granular surface were removed by chemical surface gelatinization in concentrated LiCl solution. At moisture contents of 12% and 15%, HTM reduced the gelatinization temperatures and relative crystallinity of the starches, while at moisture contents of 21% and 24 % both increased. The alterations on morphology, X-ray pattern, physicochemical properties, and increase of amylose content were more intense with the increase of moisture content of HMT. The removal of granular layers showed that the changes promoted by HMT occur throughout the whole granule and were pronounced at the core or peripheral region, depending of the moisture content applied during HMT. © 2016 Society of Chemical Industry.

Structural features and thermal property of propionylated starches with different amylose/amylopectin ratio

This work concerned the effects of amylose/amylopectin ratio on the structure and thermal stability of propionylated starches with high degree of substitution (DS). Four starches with different amylose content were used to obtain propionylated starches. Acylation partly disrupted granule morphology of native starches, and the imperfection and porous structures of starch granule were intensified along with the increased amylose content. It was noted that the crystalline structure of starch was destroyed and thus intense acylation occurred in both amorphous and crystalline regions. The acylated starch with high-amylose content displayed more ordered region compared to low-amylose starch. Acylation enhanced the thermal stability of starch, and this effect became more evident as the amylose content increased. Thus, the amylose/amylopectin ratio has been confirmed capable of affecting the structure and thermal behaviors of hydrophobic propionylated starch, which is of value for the design of starchy materials with tailored thermal stability.

Impacts of nitrogen and zeolite managements on yield and physicochemical properties of rice grain

Zeolite (Z) can hold soil water and nutrient to obtain a higher yield on introduction into moist soil. However, the effects of Z and nitrogen (N) managements on rice grain quality is unclear. Therefore, the effects of different amounts of Z (Z0: 0 t/hm2; Z0.9 and Z0.22: 10 t/hm2 in different particle sizes of 0.45-0.9 mm and 0.17-0.22 mm in diameter) and N (N0, N52.5, N105, N157.5: 0 kg/hm2, 52.5 kg/hm2, 105 kg/hm2, 157.5 kg/hm2), and Z (Z0, Z10: 0 t/hm2, 10 t/hm2) and application frequencies of N on rice yield and grain quality were investigated in 2014 and 2015 in Northeast coastal region of China where Z10 was extended to use in large areas. Results showed that both N and Z applications significantly increased the yields of rough rice (RRY), brown rice, milled rice and head rice. However, there was no significant difference between Z0.9 and Z0.22. The chalkiness area, length-width ratio and head rice rate were not influenced by Z and N applications. However, Z application significantly decreased the chalk rate and slightly increased amylose content (AC) but mattered little to taste value (TV) of rice and rice cooking quality. N could significantly increase rice protein content (PC) but lessen the TV and breakdown value; the order of influence degree on rice yield increasing was as follows: CRF2 (third-split fertilization with Z10), CRF1 (basal fertilization one time with Z10), U2 (urea: third-split fertilization without Z) and U1 (basal fertilization one time without Z). Both CRF1 and CRF2 greatly enhanced the RRY. However, CRF1 was recommended for clear decrease in labor and fuel for growers. Compared with treatments of U1 and CRF1, CRF2 and U2 significantly decreased the AC. PC exhibited significant negative relation to TV and greatly determined the rice eating quality and cooking quality. Keywords: rice grain quality, rice yield, nitrogen, zeolite, physicochemical property DOI: 10.3965/j.ijabe.20160905.2535 Citation: Wu Q, Xia G M, Chen T T, Chi D C, Jin Y, Sun D H. Impacts of nitrogen and zeolite managements on yield and physicochemical properties of rice grain. Int J Agric & Biol Eng, 2016; 9(5): 93－100.

Thermal and rheological properties of brown flour from Indica rice

The thermal, paste and rheological properties of brown flours from four Indica rice subspecies with different amylose content were examined using Differential scanning calorimetry (DSC), Brabender Viscometer and rheometer. Peak, final and setback viscosities (p < 0.05) increased with increasing amylose content from Brabender micro Visco-Amylo-Graph (MVA), but the phase transition temperatures of brown rice flour from DSC (p < 0.05) decreased with increasing amylose content. Rheological properties were determined by steady shear, small amplitude oscillatory shear (SAOS) and thixotropic experiments. SAOS results showed a gel-like viscoelastic behavior with G′ higher than G″. Steady-shear results showed that the brown rice flour exhibited a non-Newtonian shear-thinning behavior and the flow curves can be well described by the Herschel-Bulkley model. The upward-downward rheograms showed that brown rice flour gel, except IR-1, had a hysteresis loop, indicating a strong thixotropic behavior.

Characterization of starch nanoparticles prepared by nanoprecipitation: Influence of amylose content and starch type

Starch nanoparticles (SNPs) were prepared by nanoprecipitation using seven native starches, including waxy corn, normal corn, high amylose corn, potato, tapioca, sweet potato, and pea starches (amylose content 0.8%–69.0%). The structural, morphological and physicochemical properties of SNPs were systematically investigated using dynamic light scattering, Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry and electron microscopy. Compared to micro-scale native starch (mean size of 15–49μm), the mean particle sizes of SNPs were mainly in the range of 30–75nm, which is much smaller than those reported in previous published literatures. Interestingly, the smaller the starch granules were, the smaller the corresponding SNPs were obtained. All SNPs exhibited a typical V-type crystalline structure, which were independent of the crystal type of the native starch. Moreover, the relative crystallinity of SNPs increased with the increasing amylose content in native starch, and a high correlation (R2=0.95) was observed. Compared with native starch, the gelatinization enthalpy of corresponding SNPs decreased, with the exception of high amylose corn starch.

Effect of maize type and extrusion‐cooking conditions on starch digestibility profiles

SummaryThis study aimed at evaluating the influence of screw speed (250–600 rpm), barrel temperature (100–160 °C) and water content (16.4–22.5%) on rapidly digestible (RDS), slowly digestible (SDS) and resistant (RS) starch levels of waxy, normal and high‐amylose maize starches. In native starches, an increase in amylose content was correlated with lower SDS content. After extrusion, this trend was reversed. Both waxy and normal maize starches became rapidly digested. However, for normal maize starch, some SDS fraction remained. In contrast, the high‐amylose maize starch showed a significant increase in digestibility and an increase in SDS content from 20.4% in the native starch up to 27.5% after extrusion. This high level of SDS may be attributed to the presence of some remaining granular structures and formation of crystalline orders, which have slow digestion properties.

Changes in physicochemical properties and in vitro digestibility of tartary buckwheat and sorghum starches induced by annealing

Annealing (ANN) was applied in this study to investigate its effects on the physicochemical properties and in vitro digestibility of tartary buckwheat starch (TBS) and sorghum starch (SS). In practice, ANN did not change the typical “A” type X‐ray diffraction pattern of TBS and SS. However, it induced increases in amylose content, relative crystallinity, water absorption capacity, gelatinization temperature, and the enthalpy of the two starches. Both solubility and swelling power were temperature dependent and progressively decreased after ANN. Meanwhile, marked reductions were observed in peak viscosity and oil absorption capacity of annealed TBS and SS. Except for these properties, both the slowly digested starch and resistant starch contents significantly increased. Decreases in rapidly digested starch content and total hydrolysis also occurred simultaneously. The results clearly indicate that ANN efficiently altered the properties of TBS and SS to improve their thermal stability and health benefits potential.