Low Amylose Content Research Articles

“Development and characterization of edible films based on starch isolated from different Colombian potato varieties”

This work reports on the extraction and characterization of the behavior of starch from residues of several potato varieties (Criolla, Sabanera and Pastusa) of Colombian origin from the Andean region using different techniques and the evaluation of the effect of citric acid (CA) on the grain morphology. Additionally, films were produced with each one of the extracted starches and glycerol. Pastusa variety starch shows a higher granule size than the other varieties and Pastusa starch shows lower amylose content compared to Sabanera and Criolla. Criolla and Pastusa starches exhibit more thermal stability than Sabanera starch. Starch-glycerol films were also produced using the cast solving method. The films were mechanically analyzed by tensile test and the barrier properties were assessed by water vapor permeability (WVP). The tensile strength of the films varied in the 2.0–2.4 MPa range, while the elongation at break was comprised between 25 and 32 %. With regard to water vapor permeability, the obtained values fall within the 4–7 × 10–10 g m-1 s-1 Pa-1 range. It was observed that the thickness of the films and the protein content affected water vapor permeability, increasing this value at higher levels of thickness.

Effect of starch and protein on eating quality of japonica rice in Yangtze River Delta

This study examined four types of japonica rice from Yangtze River Delta, categorized based on amylose content (AC) and protein content (PC): high AC with high PC, high AC with low PC, low AC with high PC, and low AC with low PC. It systematically explored the effect of starch, protein and their interactions on eating quality of japonica rice. Rheological analysis revealed that increased amylose, long chains amylopectin or protein levels during cooking strengthen starch-protein interactions (hydrogen bonding), forming a firm gel network. Scanning electron microscopy showed that increased amylose, long chains amylopectin or protein levels made protein and starch more stable in combination during cooking, limiting starch structure cleavage. Therefore, the eating quality of high AC in similar PC japonica rice and high PC in similar AC japonica rice were poor. Further, correlation and random-forest analysis (RFA) identified amylose as the most influential factor in starch-protein interactions affecting rice eating quality, followed by amylopectin and protein. RFA also revealed that in high AC japonica rice, the interactions of Fb3 and albumin with amylose were more conducive to forming good eating quality. In low AC japonica rice, the interactions of Fb2 and prolamin with amylose were more beneficial.

Natural fermentation of potato (Solanum tuberosum L.) starch: Effect of cultivar, amylose content, and drying method on expansion, chemical and morphological properties

Natural fermentation with sun-drying is a modification that promotes the expansion capacity of starch, and its effects on potato starch have not been reported so far. The aim of this study was to evaluate the effects of the amylose content of potato (Solanum tuberosum L.) starches and natural fermentation followed by oven or sun drying on its properties. Cassava starch was also used a control. Native and fermented starches were evaluated based on their chemical composition, amylose, carboxyl and carbonyl content as well as their thermal, pasty, and morphological properties. The fermentation water was evaluated by pH and titratable acidity to control the process. Puffed balls were prepared to evaluate expandability, mass loss, porosity and texture. The fermentation intensity was greater for potato and cassava starch with low-amylose content than for potato starch with higher amylose content. In addition, the acidity of the fermentation water increased faster with cassava starch than with potato starches. The fermented potato starches with the highest amylose content had low acidity and low expansion capacity compared to the fermented potato and cassava starches with low-amylose content. Fermentation and sun-drying of low-amylose potato and cassava starches increased the expansion and reduced the hardness of the puffed balls.

Rice storage under controlled conditions: Changes in its physicochemical and functional properties

Rice storage is necessary to improve cooked rice's textural and functional characteristics. Storage conditions affect the quality of rice. Fresh rice samples with low amylose content (≈10%) were stored for 6 months at different temperatures (2) and air availability (3) to evaluate their individual and synergic effect on rice quality. Chemical composition, rice texture, cooking, thermal properties, water uptake, and texture after cooking were analyzed at 2-month intervals. The results showed that storage temperature, time, and the interaction between them significantly affected stored rice's hardness, water uptake, solid loss, and gelatinization temperatures. Higher air availability resulted in an increase in hardness and Amylose-Lipid (A-L) complexing index. The A-L complexing index increased with storage time, predominately when the rice samples were kept at higher temperatures. Also, this complex was positively correlated with the hardness of the cooked grain (r = 0.81) and its water absorption capacity (r = 0.90), suggesting that the A-L complex formation improves rice quality characteristics. A better rice quality was found at 23 °C with air restriction and 180 storage days.

QTL Detection and Candidate Gene Identification for Eating and Cooking Quality Traits in Rice (Oryza sativa L.) via a Genome-Wide Association Study.

The eating and cooking quality (ECQ) directly affects the taste of rice, being closely related to factors such as gelatinization temperature (GT), gel consistency (GC) and amylose content (AC). Mining the quantitative trait loci (QTLs), and gene loci controlling ECQ-related traits is vital. A genome-wide association study on ECQ-related traits was conducted, combining 1.2 million single nucleotide polymorphisms (SNPs) with the phenotypic data of 173 rice accessions. Two QTLs for GT, one for GC and five for AC were identified, of which two were found in previously reported genes, and six were newly found. There were 28 positional candidate genes in the region of qAC11. Based on a linkage disequilibrium (LD) analysis, three candidate genes were screened within the LD region associated with AC. There were significant differences between the haplotypes of LOC_Os11g10170, but no significant differences were found for the other two genes. The qRT-PCR results showed that the gene expression levels in the accessions with high ACs were significantly larger than those in the accessions with low ACs at 35d and 42d after flowering. Hap 2 and Hap 3 of LOC_Os11g10170 reduced the AC by 13.09% and 10.77%, respectively. These results provide a theoretical and material basis for improving the ECQ of rice.

Creation of rice doubled haploids with low amylose content using in vitro anther culture.

In vitro androgenesis is a unique model for producing homozygous doubled haploid plants. The use of haploid biotechnology accelerates to obtain of doubled haploid plants, which is very important in rice breeding. The purpose of this work is to improve the production of doubled haploids in rice anther culture in vitro and selection of doubled haploid plants with valuable traits. The study the influence of nutrient media on the production of calli and plant regeneration processes in anther culture of 35 rice genotypes was revealed a significant influence of nutrient media on callus production. It was shown that the addition to culture medium phytohormones ratio with high level of cytokinin (5.0 mg/L BAP) and a low level of auxin (0.5 mg/L NAA), supplemented with amino acid composition promotes high production of green regenerated plants (68.75%) compared to albino plants (31.25%). As a result, doubled haploid lines of the glutinous variety Violetta were selected, which characterized by a low amylose content variation (from 1.86 to 2.80%). These doubled haploids are superior to the original variety in some yield traits and represent valuable breeding material.

Interaction between genetic regions responsible for the starch properties in non-glutinous rice varieties in Hokkaido, Japan.

Starch properties are the major determinants of grain quality and food characteristics in rice (Oryza sativa L.). Understanding the interactions between genetic regions responsible for starch properties will lead to the development of rice cultivars with desirable characteristics. This study investigated the genetic effect and interaction between qAC9.3, a low-amylose quantitative trait locus (QTL), and the genetic region around Starch branching enzyme IIb (SbeIIb). Both these factors are responsible for the starch properties of the Hokkaido breeding population. The amylose content, pasting temperature, and amylopectin chain-length distribution were compared using F5 lines derived from the cross between the lower amylose content and lower pasting temperature strain 'Hokkai332 (qAC9.3, SbeIIb)' and the higher amylose content and higher pasting temperature variety 'Kitagenki (-, SbeIIbsr )'. The qAC9.3 genotype exhibited low amylose content and reduced the hardness of boiled rice but increased the ratio of amylopectin long chains and did not alter the pasting temperature. In contrast, the SbeIIb genotype was associated with pasting temperature but did not affect the amylose content and hardness of boiled rice. It was suggested that appropriately selecting genotypes of these genetic regions and QTL would allow the fine-tuning of starch properties of cooked rice suitable for future demand.

Effect of addition of pullulan on the properties of native/waxy corn starch‐based films

AbstractThis article reports on the preparation of native/waxy corn starch (NCS/WCS)‐based films with the addition of pullulan (PUL). Our study investigated the effects of varying amounts of PUL and amylose contents on the structure, mechanical and physicochemical properties of corn starch films. Notably, it was observed that WCS films with low amylose content exhibited superior transparency, while NCS films with high amylose content demonstrated enhanced tensile strength (up to 7.35 ± 0.18 MPa). Fourier transform infrared spectroscopy (FTIR) analysis indicated that the addition of PUL did not change the molecular interactions within the corn starch films. The X‐ray diffraction (XRD) results supported that the WCS films were amorphous, while the NCS film exhibited B‐type and V‐type crystals. Moreover, an increase in PUL content led to a gradual reduction in the crystallinity of both WCS films and NCS films. The addition of PUL improved the mechanical properties and oxygen barrier characteristics of these films but had an adverse impact on their water vapor barrier properties. These findings offer valuable insights for the selection of additives for corn starch film, which can further enhance the practical application potential of corn starch films in food and other industries.

Structure and in vitro digestibility of amylose–lipid complexes formed by an extrusion-debranching-complexing strategy

The formation of amylose–lipid complexes, known as resistant starch type Ⅴ (RS5), is limited by the low content of amylose in natural starch, increasing the amylose content is an effective approach to improve the yield of RS5. In this paper, an extrusion-debranching-complexing strategy with two extrusions was proposed to increase the formation of amylose–lipid complexes. A combination of corn starch (CS), pullulanase (60 U/g, w/w), and lauric acid (LA) with different contents of 4 %, 6 % and 8 % (w/w) generated enzymatically debranched extruded corn starch-lauric acid (EECS-LA) complexes after the second extrusion. The EECS-LA complexes were ordered form II complexes, with a significantly improved short-range molecular order. The melting temperature was in the range of 105–145℃. The enthalpy change increased with the increase of LA content and the value was 9.42 J/g for EECS-8 %LA complexes; these complexes could reform after dissociation. Scanning electron microscopy examination of the EECS-LA complexes revealed an irregular lamellar structure. The RS content of EECS-LA complexes increased significantly, achieving a value of 38.34 % for EECS-8 %LA complexes. This extrusion-debranching-complexing strategy is effective for preparing RS5 and could be useful in industry for the continuous production of RS5.

Comparative Effect of Amylose Concentration in Brown and White Rice on Hepatocellular Insufficiency Using Rat Bioassay

Background: The scientific name of rice is Oryza sativa. It is one of the important staple human foods. There are more than 110,000 cultivated varieties of rice, most widely known and grown. Nutrient concentration may vary depending on production, environment, pre- and post-harvesting treatment, and processing. Cooked rice with high amylose content effectively controls metabolic disorders, serum blood glucose levels, and lipid profile and is also effective in weight loss. Objectives: This study aimed to determine the comparative effect of amylose concentration in brown and white rice on hepatocellular insufficiency in healthy rat models. Methods: We divided 25 rats into 5 groups (G0, G1, G2, G3, and G4). There were 5 rats in each group. Group 0 was the control group on a normal diet. Group 1 was fed white rice flour, G2 was fed cooked white rice, G3 was fed brown rice flour, and G4 was fed cooked brown rice. Free access to food and water was secured. Weight changes, blood glucose, and lipid profiles were analyzed pre and post-treatment. Results: Rats on white rice feed showed weight gain, increased blood glucose, cholesterol, triglycerides, and low HDL levels. However, rats on brown rice feed showed less weight gain (P < 0.05), a lower increase in blood glucose (P < 0.05), high HDL, lower LDL cholesterol, and triglycerides. The pancreas and liver histopathology showed no major changes due to the short trial duration. Conclusions: Rats fed white rice showed ineffective results disturbing biological parameters as compared to those rats which were fed brown rice. Due to low amylose content and the presence of antioxidants, flavonoids, and high fiber content, brown rice shows beneficial effects in controlling and maintaining relevant biological parameters.

Characterization of the physicochemical properties of Lipu Colocasia esculenta (L.) Schott starch: A potential new food ingredient

The physicochemical properties of Lipu taro starch (LTS), cassava starch (CS) and wheat starch (WS) were analyzed. These starches exhibited a comparable starch content (86 %). However, LTS had a significantly lower amylose content (15.93 %) compared to CS (26.62 %) and WS (33.53 %). Moreover, LTS demonstrated an irregular polygonal cubic morphology with a smaller particle size of 2.55 μm while possessed an A-type crystal structure with high crystallinity at 25.07 %. In contrast, CS and WS had larger particle sizes of 13.33 μm and 16.68 μm, respectively, with lower crystallinities of 22.52 % and 20.33 %. Due to these physicochemical properties, LTS exhibited superior emulsification properties with a higher emulsifying activity index of 8.63 m2/g and an emulsion stability index of 69.18 min, whereas CS and WS had values of 2.35 m2/g and 25.15 min, and 0.37 m2/g and 11.48 min, respectively. LTS also demonstrated enhanced thermal stability, characterized by higher gelatinization temperature (indicated by To, Tp, Tc, and ΔT) and reduced paste viscosity (indicated by PV, TV, FV, SBV, and BDV) compared to CS. However, the mechanical strength of the gel made from LTS (indicated by hardness, adhesiveness, springiness, gumminess, and chewiness) was comparatively inferior to those from CS and WS.

Impact of molecular structure of starch on the glutinous taste quality of cooked chestnut kernels

Chestnuts are a starchy food with a characteristic glutinous taste that is often used to assess their quality. In this study, our findings indicated that chestnuts with higher glutinous taste quality had lower amylose content and microcrystalline structures, as well as higher subcrystalline structures and relative crystallinity in both the raw and steamed starches. In the leached starch, chestnuts with higher glutinous taste quality had lower amylopectin B1 chains and microcrystalline structure, but higher amylopectin B2 chains, subcrystalline structure and relative crystallinity. These results suggest that amylose content, relative crystallinity, and amylopectin chain length distribution are important factors determining the glutinous taste quality of chestnuts. To further enhance our understanding of these factors, an sensory evaluation model was developed based on textural profile analysis parameters. This study provides valuable insights into the relationship between molecular structure of starch and the glutinous taste quality of starchy foods.

Exploration of unique starch physicochemical properties of novel buckwheat lines created by crossing Golden buckwheat and Tatary buckwheat

Buckwheat is considered as a healthy cereal food, and it is essential to cultivate new buckwheat lines with good starch physicochemical properties for both consumers and food producers. Six novel buckwheat (Duoku, Dk) were generated by crossing of Golden buckwheat and Tatary buckwheat, and their kernel appearance properties and starch physicochemical properties were analyzed together with one domestic line (Cimiqiao) and one wild line (Yeku). The results showed that Dk samples had better appearance properties than two control samples. The Dk samples showed lower amylose content, similar amylopectin molecular structure and chain length distributions, and larger starch granules compared with Cimiqiao. The digestion results showed that two Dk samples: Dk6 & Dk9 had high resistant starch content; while the other two Dk samples: Dk37 & Dk38 had a steady glucose releasing rate. The Dk samples also showed high gelatinization temperature, indicating they were good raw materials for producing glass noodle. This study proved that Dk buckwheat had unique starch physicochemical properties, and could be used as new food materials in the future.

New Source of Rice with a Low Amylose Content and Slow In Vitro Digestion for Improved Health Benefits

Rice provides 70% of dietary carbohydrates and other essential nutrients. Breeding for consumer preferences and health benefits are the main considerations. Rice with a low amylose content offers a good cooking quality with its soft and sticky texture but fast starch digestibility with a high sugar release. Therefore, to provide health benefits, it is important to identify rice varieties with slow starch digestibility and a low amylose content. A total of 167 indigenous upland rice germplasms were analysed for amylose content (AC) and in vitro starch digestibility. The results showed that 167 upland rice genotypes were mostly low in AC, which was related to a soft and sticky texture during cooking. Based on the glutinous and non-glutinous types, thirteen and nine indigenous upland rice germplasms were selected with a lower AC than RD6 and KDML105 (check varieties). The in vitro starch digestibility and the hydrolysis were different at each time point and different in each variety. In the glutinous group, ULR155, ULR138, ULR308, and ULR241 released less sugar and had slower starch digestibility than RD6. In the non-glutinous group, ULR219 and ULR264 showed lower AC, slower digestion, and lower sugar release than KDML105. The results suggest that six indigenous upland rice varieties will provide a rice source to accommodate consumer preferences while also offering health benefits.

Improving of noodle quality caused by starch-protein interaction of waxy and strong-gluten wheat flour

Waxy wheat flour (WWF) has good processing properties and can be used to enhance the quality of noodles because of its high amylopectin or low amylose content. The aim of this study was to investigate the correlation between changes in the structural characteristics of waxy wheat starch (WS) and gluten (WG) and changes in noodle quality following molecular interactions with strong-gluten wheat starch (NS) and gluten (NG) by separation and reconstitution methods. The results showed that the noodle quality was better when WWF was added at 15% (w/w). WS promoted the formation of strong crystalline structure of amylopectin, and WG promoted the formation of double-helical short-range molecular structure of starch, and its degree of order was positively correlated with the cohesiveness and water absorption of cooked noodles, and negatively correlated with chewiness. The interaction of WS and WG with NS and NG could improve noodle quality through the change of intermolecular interactions.

Compositional characterization of starch, proteins and lipids of long bean, dwarf long bean, mung bean and French bean seed flours

Four underutilized legumes comprised of mung bean, long bean, dwarf long bean and French bean were investigated for their total starch, dietary fibre, amylose, amylopectin and resistant contents along with proteins and lipids profiles employing standard methods in order to explore appropriate end uses. Results showed significant variations (p<0.05) in the fat, protein, moisture, ash, total dietary fibre, carbohydrate, starch, amylose and amylopectin contents of all the four legume seeds Flours. Mung bean, long bean, dwarf long bean, and French bean showed carbohydrates contents of 55.24, 49.63, 48.12 and 45.56 g/100 g, respectively. Dwarf long bean, long bean and mung bean recorded total starch of 38.39, 49.78 and 57.68 g/100 g, respectively. Whereas French bean had the highest total dietary fibre of 16.91 g/100 g and dwarf long bean the highest amylopectin (86.67 g/100 g), both dwarf long bean and long bean recorded insoluble dietary fibre and soluble dietary fibre in the range of 7.25 to 14.58 g/100 g and 0.05 to 1.25 g/100 g, respectively, however, all the seed flours showed higher content of insoluble dietary fibre than soluble dietary fibre. Significant differences (p<0.05) observed in the total starch, resistant starch and non-resistant starch content of all the 4 samples. Non-resistant starch was the predominant constituents of the total of all the seed flours with mung bean showing the highest value (54.16 g/100 g) followed by long bean, dwarf long bean and French bean with 48.74, 37.73 and 16.88 g/100 g, respectively. Though the beans had low amylose contents, their amino acids score and patterns surpassed the FAO reference proteins and their saturated and unsaturated fatty acids ratio falls within FAO allowed limits. This study highlights the hidden potentials of these non-conventional legumes as sources of quality proteins, functional foods, healthy fats and dietary fibres.

Understanding the Relationship between the Molecular Structure and Physicochemical Properties of Soft Rice Starch.

The relationship between the molecular structure and physicochemical properties of soft rice starch (SRS) has been investigated in this research. The amylose content of SRS ranged from 10.76% to 11.85%, classified as the very low amylose type. Compared to waxy and japonica rice starch, the largest amount of small starch granules and the highest viscosity were shown in the SRS. The results of X-ray diffraction and Fourier transform infrared proved that the SRS depicted a typical A-type pattern with a low short-range ordered structure. Additionally, SRS had a great deal of A and B1 chains. Molecular weights and density of starch from soft rice were lower than those from waxy rice but higher than those from japonica rice. Furthermore, SRS possessed a higher amount of resistant starch. Correlation analysis indicated that the amylose content and the chain-length distributions of amylopectin play a major role in influencing the molecular structure and physicochemical properties of rice starch. In conclusion, the low amylose content, highest viscosity, and other excellent properties of soft rice starch make it have bright application prospects in instant rice and rice cakes.

Effects of Starch Molecular Structure and Physicochemical Properties on Eating Quality of Indica Rice with Similar Apparent Amylose and Protein Contents.

It is important to clarify the effects of starch fine structure and protein components on the eating quality of indica rice. In this study, seven indica rice varieties with similar apparent amylose content (AAC) and protein content (PC) but different sensory taste values were selected and compared systematically. It was found that except for AAC and PC, these varieties showed significant differences in starch molecular structure and protein components. Compared with rice varieties with a low sensory taste value, varieties with a higher sensory taste value showed significantly lower amylose and higher amylopectin short chains (degree of polymerization 6-12) content; the protein component showed that the varieties with good taste value had higher albumin and lower globulin and glutelin content (p < 0.05). Rice varieties with lower AC, globulin, and glutelin content, as well as a higher content of albumin and amylopectin short chains, resulted in a higher swelling factor, peak viscosity, breakdown value, and ratio of hardness to stickiness, in which condition cooked rice showed a higher sensory taste value. Moreover, this study indicated that rice varieties with a higher content of albumin and amylopectin short chains were conducive to the good appearance of cooked rice. This study lays the foundation for the taste evaluation of good-tasting indica rice.

Effect of the addition of mung bean, corn, and sweet potato starch on the properties of konjac gel.

Konjac gel (KG) food is a popular choice among consumers due to its delicious taste, low-calorie content, and ability to provide satiety. The aim of the study was to evaluate the effects of the addition of mung bean starch (MBS), corn starch (CS), and sweet potato starch (SPS) on the water solubility, gel strength, microstructure, and viscosity of KG. The experimental results showed that MBS exhibited the largest amylose content (47.07 ± 1.71%), and SPS had the lowest amylose content (27.92 ± 1.24%). With the increase of starch concentration, the gel strength and viscosity of KG increased, the KG with 3% MBS had higher water solubility and stronger gel strength, and the KG with 3% SPS had better viscosity. In addition, according to the scanning electron microscope, the microstructure of KG without starch was a porous honeycomb, and the network structure of CS/KG was more orderly and uniform. The microstructure of MBS/KG was tightly wrinkled, while the honeycomb structure of SPS/KG was more orderly and the network outline was clearer. The addition of starch could improve the quality of KG, the type of starch used had different effects.

Comparison of the fine structure and physicochemical properties of proso millet (Panicum miliaceum L.) starch from different ecological regions

Field experiments were conducted to evaluate the morphology, granule size, fine structure, thermal properties, and pasting properties of starch from a waxy (139) and a non-waxy (297) varieties of proso millet grown in Yulin (YY) and Yangling (YL). Compared with the starches from the two varieties grown in YY, the starches from the two varieties grown in YL exhibited higher relative crystallinities, 1045/1022 cm−1 ratio, and amounts of amylopectin long branch chains (APL) but lower 1022/995 cm −1 ratio, amounts of amylopectin short branch chains (APs), and APs/APL ratios. Starches from YL also synthesized long branch-chain amylopectin to enhance intermolecular interactions and form a stable granular structure, which resulted in increased starch gelatinization temperature, enhanced shear resistance, and reduced setback viscosity. Starch from the waxy (139) variety has good application prospects in the food industry because of its high gelatinization temperature and light transmittance and low setback value, which can be ascribed to its extremely low amylose content, polydispersity index, high molecular weight, and dispersed molecular density. It may serve as a reference for applying proso millet starches in the food industry and developing breeding programs to improve starch quality.