High Amylose Research Articles

Editing of the soluble starch synthase gene MeSSIII-1 enhanced the amylose and resistant starch contents in cassava

Foods with high amylose and resistant starch (RS) contents have great potential to enhance human health. In this study, cassava soluble starch synthase MeSSIII-1 gene mutants were generated using CRISPR/Cas9 system. The results showed that the storage roots of messiii-1 mutants had higher contents of amylose, RS, and total starch than those in CK. The rates of small and large-sized starch granules were increased. Additionally, amylopectin starch in messiii-1 mutants had a higher proportion of medium- and long- chains, and a lower proportion of short-chains than those in CK. The onset, peak, and conclusion temperatures of starch gelatinization in messiii-1 mutants were significantly lower than those in CK, and the peak viscosity, trough viscosity and final viscosity all increased. MeSSIII-1 mutation could increase the contents of sucrose, glucose, and fructose in cassava storage roots. We hypothesize that these soluble sugars serve a dual role: they provide the necessary carbon source for starch synthesis and act as sugar signals to trigger the transcriptional reprogramming of genes involved in starch biosynthesis. This process results in a collective enhancement of amylose, RS, and total starch contents, accompanied by changes in starch granule morphology, fine structure, and physicochemical properties.

Glycemic response to high amylose, fibre rich red rice meals and in vitro antihyperglycemic properties of prebiotic enriched fermented red rice beverage

Glycemic response to high amylose, fibre rich red rice meals and in vitro antihyperglycemic properties of prebiotic enriched fermented red rice beverage

Fabrication and characterization of novel curcumin-loaded thermoreversible high amylose maize starch emulsion gel

This study developed a novel thermoreversible emulsion gel system based on high amylose maize starch (HAMS) and investigated the impact of the oil-to-water ratio on its physicochemical properties and encapsulation performance (using curcumin as model guest molecule). Electron microscopy showed a tightly porous network structure of the HAMS-based emulsion gels. Thermal results revealed a sol-gel transition occurring in the range of 59.41 to 67.64 °C for the prepared emulsion gels. Rheological analysis suggested that all samples displayed shear-thinning behavior and HAMS-based emulsion gels exhibited typical gel-like behavior with the gel strength bolstered by higher aqueous phases. Particle size analysis showed that droplet size of emulsion gel decreased from 245 to 184 nm with increased starch aqueous phase content. Texture profile analysis indicated enhanced strength, hardness, and chewiness of the emulsion gel with increased aqueous phases. Curcumin encapsulation efficiency in the HAMS-based emulsion gel also improved with higher aqueous phase content, reaching up to 93.82 %, which attributed to the smaller droplets caused increased interfacial area. The novel HAMS-based emulsion gel system showed considerable encapsulation capacity and desirable mechanical properties. It provided valuable insights into the application of starch-based emulsion gels in food and medical area.

Chemometrics analysis of the flow and thermal properties of cardaba banana starch.

Starch from a non-conventional source such as cardaba banana is relatively underexplored compared to conventional sources such as potato, maize or tapioca. Its high amylose content, however, suggests its suitability for specific industrial uses. Understanding the flowability, rheology and thermal properties of cardaba banana starch could lead to its novel application in food product formulation and pharmaceutical industry. Therefore, the present study aimed to examine the effect of modification on the bulk material characterization (powder flowability), granule size and shape (measured by light microscope), rheology and thermal properties of cardaba banana starch. The flowability of cross-linked starch was affected significantly by the granule size (105 892.7 μm), shape (circularity 0.78) and compressibility (0.20), making it a more free-flowing powder than other starch powders. The rheological behavior of the starch paste revealed that the Herschel-Bulkley model best predicts the rheological behavior with the highest coefficient of determinant (R2 > 0.9). Cross-linked Cardaba banana starch with an excellent characteristic will find good application in food products that require free-flowing behavior. © 2024 Society of Chemical Industry.

Exploring the health benefits of high amylose wheat phenolic extract in human endothelial cell model: Inhibitory effects on endothelial activation

Newly developed high amylose durum wheat genotypes, characterized by a high content of resistant starch, is gaining interest as a healthy ingredient for functional food. The objective of the present study was to investigate the effects of Svevo high amylose phenolic extracts (HAPE) on endothelial activation, the first obligatory step of the atherosclerotic process, investigating the underlying mechanisms of action. To this aim, human microvascular endothelial cells were treated with HAPE (1–10 μg/mL) and then challenged with the pro-inflammatory and pro-atherogenic cytokine TNF-α. Endothelium-leukocyte adhesion, the expression of endothelial inflammatory mediators, intracellular reactive oxygen species (ROS) levels and the activation of nuclear factor (NF)-κB were evaluated by multiple assays. The results showed that, HAPE, already at 5 μg/mL, suppressed the TNF-α stimulated expression of endothelial adhesion molecules as well as the adhesion of leukocytes to endothelial cells by more than 50% in comparison with TNF-α alone. These effects were associated with a significant (p < 0.05) reduction of intracellular ROS levels and NF-κB activation. In summary, our findings underscore the potential of Svevo high amylose as a functional food able to blunt endothelial activation, by inhibiting the concerted expression of endothelial markers involved in leukocyte recruitment and early atherogenesis.

The physicochemical, functional, and pasting properties of Moringa oleifera leaf powder from different leaf stalk colors

ABSTRACT Moringa oleifera (MO) leaf powder (MOLP) is functional, and its composition affects its use. The MO tree has different colors i.e. white, green, and red. This study aimed to evaluate MOLP physicochemical, functional, and pasting properties based on the leaf stalk color as the basis for their suitable use in food products. Leaf stalk color slightly affect characteristics, with typical high protein, dietary fiber, and ash, but low starch and fat. MOLP has high soluble dietary fiber, high amylose starch, and significant amounts of phenolics and flavonoids. Chlorophyll is the abundant pigment followed by β carotene. MOLP is rich in essential amino acids with methionine is a limiting essential amino acid. MOLP has almost equal saturated and unsaturated, and rich in essential fatty acids. Low starch and high fiber affect pasting properties, exhibiting low viscosity and gelatinization temperature, but high stability. Low solubility of MOLP is a challenge to improve.

Controlling high amylose corn starch modulates the structural features and digestive properties of rice noodles

Using traditional technology to prepare rice noodles with low starch digestibility and good edible quality is still a great challenge. Pretreated high amylose corn starch (P-HACS) was used to modulate the internal structure and digestive properties of rice noodles and maintain the texture properties of rice noodles. With the addition of P-HACS increased to 20%, the hardness, gumminess, and chewiness of the rice noodles decreased by 48.10%, 52.98%, and 67.02%, respectively. Notably, at an addition ratio of 20% P-HACS, the rice noodles were difficult to form, which may be attributed to their weakening network structure. X-ray diffraction and Fourier transform infrared spectroscopy revealed that replacing rice flour with P-HACS enhanced the B-type crystal and short-range ordered structure of rice noodles. With an addition ratio of 5%–20% P-HACS, the resistant starch (RS) content of rice noodles increased by 30.56%–79.17%, respectively, which mainly resulted from B-type crystals assembled by P-HACS starch chains. Interestingly, there was no significant (p > 0.05) difference in the RS content of rice noodles between 20% and 15% P-HACS. Therefore, the addition of 15% P-HACS was found to be the optimal approach for preparing rice noodles with low starch digestibility.

O88 REDUCTION IN SYSTOLIC BLOOD PRESSURE FOLLOWING DIETARY FIBRE INTERVENTION IS DEPENDENT ON BASELINE GUT MICROBIOTA COMPOSITION

Background/Objective: Dietary interventions high in fibre have been shown to lower blood pressure (BP). This effect is via the gut microbiota, via fermentation of fibre and production of metabolites called short-chain fatty acids (SCFAs). Not all patients respond to dietary fibre interventions for unclear reasons. We aimed to determine if we can identify fibre-responders based on their gut microbiota and production of SCFAs. Methods: We performed a phase II cross-over placebo-controlled randomised clinical trial in untreated hypertensive patients. Twenty treatment-naive participants with hypertension received 40 g per day of fermentable fibre delivered as acetylated and butyrylated high amylose maize starch (HAMSAB) or the placebo for 3 weeks. Blood pressure was monitored at baseline and endpoint by ambulatory BP monitoring, with those experiencing a reduction of ≥2 mmHg in systolic BP classified as responders. The microbiota was determined by sequencing the V4-V5 region of the 16S rRNA gene in baseline stool samples. The relationship between baseline gut microbiota and response to dietary intervention was assessed with the MaAsLin2 package. Plasma SCFAs levels were quantified by mass spectrometry. Results: We observed a placebo-subtracted mean 24-hour systolic BP of –6.1 mmHg (p=0.03, reported in Jama et al., 2023 Nature Cardiovascular Research), with 14 (70%) individuals classified as responders and 6 (30%) as non-responders. Genera significantly enriched in responders included Dialister (β=1.29, q=1.921x10-134), Coprococcus (β=1.26, q=3.282x10-121), Bifidobacterium (β=1.67, q=1.11x10-81), Ruminococcus (β=0.161, q=1.11x10-8), and Roseburia (β=0.82, q=4.275x10-2). Responders also produced higher levels of the SCFAs butyrate (mean±SEM, non-responders 4.95±2.4 vs responders 51.15±14.7, p=0.0096), but no difference in other SCFAs. Conclusions: Participants who experienced a decrease in systolic BP following a dietary fibre intervention had increased bacterial genera known to contain species that produce SCFAs (Bifidobacterium, Roseburia, Ruminococcus) at baseline, and were able to produce more butyrate. These data suggest that baseline microbiota composition contributes to the response to dietary fibre intervention trials in people with hypertension, likely via increased capacity to produce butyrate.

Multiomics of a rice population identifies genes and genomic regions that bestow low glycemic index and high protein content

To counter the rising incidence of diabetes and to meet the daily protein needs, we created low glycemic index (GI) rice varieties with protein content (PC) surpassing 14%. In the development of recombinant inbred lines using Samba Mahsuri and IR36 amylose extender (IR36ae) as parental lines, we identified quantitative trait loci and genes associated with low GI, high amylose content (AC), and high PC. By integrating genetic techniques with classification models, this comprehensive approach identified candidate genes on chromosome 2 (qGI2.1/qAC2.1 spanning the region from 18.62 Mb to 19.95 Mb), exerting influence on low GI and high amylose. Notably, the phenotypic variant with high value was associated with the recessive allele of the starch branching enzyme 2b (sbeIIb). The genome-edited sbeIIb line confirmed low GI phenotype in milled rice grains. Further, combinations of alleles created by the highly significant SNPs from the targeted associations and epistatically interacting genes showed ultralow GI phenotypes with high amylose and high protein. Metabolomics analysis of rice with varying AC, PC, and GI revealed that the superior lines of high AC and PC, and low GI were preferentially enriched in glycolytic and amino acid metabolisms, whereas the inferior lines of low AC and PC and high GI were enriched with fatty acid metabolism. The high amylose high protein recombinant inbred line (HAHP_101) was enriched in essential amino acids like lysine. Such lines may be highly relevant for food product development to address diabetes and malnutrition.

Impact of the degree of starch gelatinization on the texture, soaking, and cooking characteristics of high amylose rice: an experimental and numerical study

Impact of the degree of starch gelatinization on the texture, soaking, and cooking characteristics of high amylose rice: an experimental and numerical study

Upcycling of industrial pea starch by rapid spray nanoprecipitation to develop plant-derived oil encapsulated starch nanoparticles for potential agricultural applications

Starch is one of the natural encapsulant materials widely used in food, pharmaceutical and cosmetic industries. Starch with high amylose content (above 40 %, w/w) is prone to form single helices V-type allomorph with a hydrophilic outer surface and a hydrophobic inner cavity making them suitable for encapsulation of hydrophobic compounds such as essential oils, fatty acids, and vitamins. Pea starch obtained from pea protein processing industries have a high amylose content (40 %, w/w) rendering them unsuitable for direct food applications as ingredients. Therefore, in this study, an in-house spraying procedure was used to synthesize nanoparticles using pea starch, to encapsulate neem oil, a natural antimicrobial compound obtained from neem plant (Azadirachta indica) seed. The synthesis of the oil-encapsulated starch nanoparticles (OESNP) was optimized using a Box-Behnken experimental design to study the influence of the processing parameters such as the initial starch concentration, homogenization speed, duration of homogenization, sample injection rate, and quantity of antisolvent (ethanol). The optimized sample showed an 80–90 % encapsulation efficiency and particle size of <500 nm. The spherical OESNPs also demonstrated sustained release of the oil compared to free oil when dispersed in water. X-ray diffraction analysis revealed the coexistence of C-type and V-type polymorphs in the loaded and unloaded nanoparticles. It is concluded that the synthesized OESNPs with controlled release hold the potential to utilize industrial pea starch waste for the delivery of natural pesticides in agriculture.

Structural evolution of maize starches with different amylose content during pasting and gelation as evidenced by Rapid Visco Analyser

This study examined multi-scale structural alterations of maize starches varying in amylose content during pasting and gelation, using Rapid Visco Analyser (RVA). At 50 °C, starch granules maintained their morphology with low viscosity. As the temperature increased to 95 °C, helical and crystal structures were destroyed, leading to granule swelling, distortion and porosity, as identified by Wide Angle X-ray Scattering and Fourier Transforms Infrared measurements at 90% moisture. This resulted in increased viscosity and the formation of a loose gel network structure. Subsequently, maintaining the temperature at 95 °C caused a decrease in viscosity as most granules disappeared, forming a reorganized flaky gel structure with larger pores. As the temperature decreased, gel porosity reduced. In high amylose content starch, the viscosity remained low and granules were partially gelatinized since the heating temperature was below the gelatinization temperature. This study is the first to detail starch multilevel structural dynamics during RVA gelatinization.

Systematic evaluations and integration of Assam indigenous Joha rice starch in intelligent packaging films for monitoring food freshness using beetroot extract

It is becoming increasingly important to have starch sources with different physicochemical properties to meet the needs of new applications in food, packaging, bioplastic, and pharmaceutical industries. The first part of this study dealt with the isolation of starch from culturally, geographically, nutritionally esteemed, and high-yielding Assam Joha rice. Fine and uniform particle size (6.3 ± 0.09 μm), high amylose content (28 ± 1.03 %), swelling behavior, viscoelastic rheological behavior, moderate gelatinization temperature (66 ± 1.7 °C), thermostable nature, type A crystallographic pattern with high (45 ± 3.3 %) crystallinity, and suitable microbial quality make the Joha rice derived starch physico-chemically and functionally suitable for potential applications in diverse domains. The latter part of the study focuses on one of the applications of derived starch as a suitable matrix for intelligent packaging films with the incorporation of betanin-enriched beetroot extract (BRE) as a bio-based pH sensor. The addition of 1.0 % w/v BRE to the starch film (starch-BRE III) significantly increased its functionality by reducing UV–visible light transmittance and water vapor permeability, along with enhancing flexibility and hydrophobicity due to intermolecular bonding between BRE and the starch film matrix. Moreover, starch-BRE films with different BRE concentrations were successfully used to monitor the real-time freshness of white meat (chicken and fish) and Indian cottage cheese samples. Overall, the results indicated that starch-BRE III has great potential as an intelligent packaging material for monitoring food freshness.

Effect of ultrasound/CaCl2 co-treatment on the microstructure, gelatinization, and film-forming properties of high amylose corn starch

The effect of ultrasound/CaCl2 co-treatment on aggregation structure, thermal stability, rheological, and film properties of high amylose corn starch (HACS) was investigated. The scanning electron microscopy (SEM) images revealed the number of starch fragments and malformed starch granules increased after co-treatment. The differential scanning calorimetry (DSC) results showed the co-treated HACS got a lower gelatinization temperature (92.65 ± 0.495 °C) and enthalpy values (ΔH, 4.14 ± 0.192 J/g). The optical microscope images indicated that lesser Maltase crosses were observed in co-treated HACS. The results of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated ultrasound influenced the compactness of amorphous zone and CaCl2 damaged the crystalline region of HACS granules. Additionally, the rheology properties of HACS dispersion demonstrated the apparent viscosity of co-treated dispersion increased as the ultrasound time prolonged. The mechanical strength and structural compactness of HACS films were improved after ultrasound treatment. The mechanism of ultrasound/CaCl2 co-treatment improved the gelatinization and film-forming ability of HACS was that (i) ultrasound wave loosened the HACS granules shell, promoted the treatment of CaCl2 on HACS granules, and (ii) ultrasound wave improved the uniform distribution of HACS dispersion, increased the interaction between CaCl2 and starch chains during the process of film-forming.

Engineering high amylose and resistant starch in maize by CRISPR/Cas9-mediated editing of starch branching enzymes

To improve the amylose content (AC) and resistant starch content (RSC) of maize kernel starch, we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I (SBEI) and starch branching enzyme IIb (SBEIIb). A frameshift mutation in SBEI (E1, a nucleotide insertion in exon 6) led to plants with higher RSC (1.07%), lower hundred-kernel weight (HKW, 24.71 ± 0.14 g), and lower plant height (PH, 218.50 ± 9.42 cm) compared to the wild type (WT). Like the WT, E1 kernel starch had irregular, polygonal shapes with sharp edges. A frameshift mutation in SBEIIb (E2, a four-nucleotide deletion in exon 8) led to higher AC (53.48%) and higher RSC (26.93%) than that for the WT. E2 kernel starch was significantly different from the WT regarding granule morphology, chain length distribution pattern, X-ray diffraction pattern, and thermal characteristics; the starch granules were more irregular in shape and comprised typical B-type crystals. Mutating SBEI and SBEIIb (E12) had a synergistic effect on RSC, HKW, PH, starch properties, and starch biosynthesis-associated gene expression. SBEIIa, SS1, SSIIa, SSIIIa, and SSIIIb were upregulated in E12 endosperm compared to WT endosperm. This study lays the foundation for rapidly improving the starch properties of elite maize lines.

In situ starch and water modification using atmospheric plasma: Structure, functionality and in vitro digestibility

Starch modification has become necessary to develop functional foods. Sustainable technologies like plasma-activated water (PAW) have been combined with hydrothermal treatments; however, the scaling-up process is challenging. Therefore, a simultaneous treatment of starch and water in a plasma reactor and a 24 h soaking of starch-water after the treatment were compared. The effect of the treatments on the structural, functional, and digestibility properties of starches (normal (NS), waxy (WS), and high amylose (HAS)) with different amylose/amylopectin content was assessed. The results show that simultaneous treatment mainly affected the water properties. Nevertheless, the contact time (24 h) after treatment between starch and water promoted the alteration of amylose chains, branching amylopectin molecules and hydrated crystals of HAS, increasing its rapidly (RDS) and slowly (SDS) digestible starch content. Meanwhile, in NS, the contact time favored the high re-engagement of amylose-amylopectin chains inside starch granules, significantly improving the resistant starch (RS) fraction from 31 % to 75 %.

Effects of Binding between Ca in Hard Water and Phosphorus in Amylopectin on the Qualities of Boiled Rice and Rice Noodle Prepared by Soaking and Boiling in Hard Water.

Recently, global warming has led to an increase in chalky rice grains. This has consequently resulted in the deterioration in quality of rice products. Although we previously reported that hard water, rich in Ca, is useful for the quality improvement of high-temperature-damaged rice grains, the mechanism was not elucidated sufficiently. Therefore, we used various kinds of rice cultivars, from waxy to high-amylose ones, for soaking and boiling in hard water and compared physical and chemical properties of the products. It was shown that the degree of quality improvement, such as final viscosities in pasting property, and textural properties of boiled rice, was more remarkable for high-amylose rice than low-amylose rice. As we found that the phosphorus contents showed positive correlations with amylose and long chains of amylopectin, we estimate that the effects are mainly due to binding of calcium and phosphorus. Because that high-amylose or long-chain-rich amylopectin rice cultivars showed high calcium contents in rice products, these rice cultivars would be very useful to supply calcium through dietary intake via hard water cooking.

Physicochemical characteristics of tea seed starches from twenty-five cultivars

The physicochemical features of starches separated from tea seeds of 25 cultivars were analyzed. The distinct characteristic of tea seed starches was that they had high apparent amylose content (AAC, 28.94–39.91 %) and resistant starch contents (4.64–8.24 %), suggesting that tea starch can be used for production of low glycemic index food. One cultivar (T12) had smallest breakdown (74.2 RVU) and highest gel hardness, indicating it performed stably during shear thinning, resulting in a firm texture. Another cultivar (T25) had a peak viscosity of 417.6 RVU, a large breakdown and small setback, suggesting a low tendency for retrogradation. There was a range of 61.6 °C to 77.5 °C for the peak gelatinization temperature and 0.163 to 0.390 for the flow behavior index values. These parameters could serve for selecting suitable starches with minor differences in physicochemical properties for food use. Correlation analysis indicated that AAC is a key factor determining starch retrogradation properties. The broad genetic diversity in the tea seed starch physicochemical features provided potentially versatile applications in the food industry. The results gained from the present study contribute to a better understanding of tea seed starch quality, and encourage its application in many value-added food products.

Effect of nitrogen fertilizer on the quality traits of Indica rice with different amylose contents.

Nitrogen is a key factor affecting the quality of rice. Studying the impact of nitrogen fertilizer on the taste, physicochemical properties, and starch structure of Indica rice with different amylose contents is of great significance for scientifically fertilizing and cultivating high-quality rice varieties for consumption. The results indicate that increasing nitrogen fertilizer application reduces the amylose content and increases the protein content, resulting in a decrease in taste quality. Simultaneously, it reduces the intergranular porosity of starch particles, improving the appearance and milling quality of rice. Compared to the N1 treatment (nitrogen fertilizer application rate of 90 kg ha-1), the taste of low-amylose rice (Yixiangyou 2115) and high-amylose rice (Byou 268) decreased by 14.24% and 19.79%, respectively, under N4 treatment (nitrogen fertilizer application rate of 270 kg ha-1). The effect of nitrogen fertilizer on low-amylose rice is mainly reflected in increased rice hardness, enthalpy value, and setback viscosity, resulting in a decline in taste. The effect of nitrogen fertilizer on high-amylose rice is mainly reflected in a decrease in peak viscosity, an increase in gelatinization temperature, and crystallinity under high nitrogen levels. Increasing nitrogen fertilizer application can improve the appearance and milling quality of rice, but it also leads to an increase in protein content, hardness, gelatinization enthalpy, decrease in breakdown value, and a decline in palatability. In practical production, different production measures should be taken according to different production goals. © 2024 Society of Chemical Industry.

Amylopectin content rather than amylose or protein content is critical to determining the starch digestion rate in high-amylose rice

The starch digestion properties of cooked rice are associated with the chemical compositions of the rice grain. However, limited information is available on the chemical composition governing starch digestion properties in high-amylose rice. To overcome this knowledge gap, correlation plot analysis and partial correlation analysis were utilized to assess the correlations between active digestion duration, total glucose production, and glucose production rate of cooked rice to amylose, amylopectin, and protein content of rice grains throughout 17 high-amylose varieties. The correlation plot analysis identified significant positive or negative linkages between total glucose production and the glucose production rate of cooked rice with grain amylose, amylopectin, and protein content. Nevertheless, partial correlation analysis only characterized a significant positive correlation between glucose production rate and grain amylopectin content. The findings of this study indicate that grain amylopectin content rather than grain amylose or protein content is critical for the determination of the rate of starch digestion in high-amylose rice.