Amylose Content Research Articles

Detailed analysis of amylose content of rice grains and its relation to the physical properties of cooked rice.

Amylose content is a critical factor in the physical characteristics of cooked rice. This study analyzed the relationship between amylose content in grain and the physical characteristics of cooked rice by analyzing amylose content in stratified layers of rice grains. Amylose content in grain differed among cultivars and showed annual change in every analyzed cultivar. Regarding amylose content and cooked rice, "surface hardness" was related to amylose content localized on the surface part of grain and in the central part; "overall hardness" was related to overall amylose content, including the central part; "surface stickiness" was partly related to amylose content localized on the surface part; "surface balance degree" was partly associated with amylose content of the surface part; and "overall balance degree" was correlated with amylose content of the overall part. These results provide a basis for understanding the contribution of amylose to the properties of cooked rice.

Extraction, Physicochemical Properties, and Potential Applications of Starches Isolated From Cooking Plantains

ABSTRACTContrary to dessert plantains and bananas, most cooking plantain varieties are consumed cooked and can be considered an unconventional starch source with industrial applications that remain largely unexplored. Several plantain varieties (e.g., Macho, Hembra, Criollo, Dominico Hartón, and Manzano) can be used for starch extraction. Generally, conventional extraction processes are employed to isolate starch granules. Plantain starch exhibits high purity, a notable amylose content (∼40%), resistant starch (RS) levels exceeding 90 g/100 g, lenticular granule morphology (∼65 µm), gelatinization temperatures below ∼75°C, and a C‐type crystalline structure. Starches derived from plantain sources demonstrate physicochemical properties similar to those of conventional starches, such as corn, cassava, potato, and wheat, including high amylose content and RS—both desirable for producing functional products. Moreover, plantain starch shows superior resistance to enzymatic hydrolysis and greater structural stability than dessert plantains and bananas, making it a promising candidate for low‐glycemic formulations and eco‐friendly materials. Additionally, modifications such as oxidation and acetylation enhance its functional properties, including water absorption, swelling capacity, and thermal stability, thereby broadening its industrial applications. Future research should focus on the utilization of plantain starches in both food and nonfood systems and on identifying the most suitable plantain varieties for starch extraction. This review systematically analyzes the literature on the extraction of starch granules from plantain varieties, their physicochemical properties, and the physical and chemical modifications of these starches.

Extraction and Characterization of Starches from the Pulp and Peel of Native Plantain (Musa AAB Simmonds) from Two Colombian Departments

Plantain (Musa AAB Simmonds) of the Dominico hartón variety from two Colombian territories (Cauca and Risaralda) with differences in altitude was used to extract the flour and starch from the pulp and peel. The plantain of Cauca origin presented the highest yield in flour extraction. Starch extraction was based on the use of an aqueous solution of sodium metabisulfite, achieving the highest yield in starch extraction (above 80% d.b.) when using a concentration of 1.2% of sodium metabisulfite, highlighting the best performance in the plantain of Risaralda origin. In the characterization of the starches, the granules from the pulp showed a larger size, higher amylose content, lower ash content, lower water absorption and solubility capacity, higher melting enthalpy, and higher crystallinity than those obtained with the starches from the banana peel. The starch from Cauca pulp presented properties characteristic of a structure with higher hardness.

Creating a Superior Wx Allele with Temperature-Responsive Amylose Regulation and a Novel Transcriptional Pattern in Rice via CRISPR/Cas9-Mediated Promoter Editing

High quality stands as a pivotal competitive edge in the rice industry. Optimizing amylose content (AC) and the physicochemical properties of endosperm starch by regulating the Wx gene is crucial for enhancing rice grain quality. In this study, we created a novel Wxb-d25 allele by deleting a 25 bp segment (−26 to −2) within the Wx core promoter using CRISPR/Cas9. Compared with the wild type and the previously reported Wxb-i1, Wxb-d25 exhibited no significant changes in agronomic traits. However, its grains displayed temperature-dependent variations in AC and altered transparency and viscosity characteristics, holding the potential to synergistically improve both the eating and cooking quality (ECQ) and appearance quality (AQ) of rice. Further studies demonstrated that this promoter modification, by partially disrupting the transcription initiator, significantly downregulated the original Wx-01 transcript and generated a novel Wx transcript (ONT.7395.1) in Wxb-d25 grains. Despite its low expression abundance, the ONT.7395.1 transcript could be completely processed into mature Wx mRNA. The combined effects of the dual transcripts resulted in significantly increased Wx gene expression and AC in Wxb-d25 grains under conventional cultivation conditions. These findings provide a genetic resource and a theoretical foundation for utilizing the Wxb-d25 allele to improve rice grain quality.

Changes in Physicochemical Properties and In Vitro Digestibility of Broken Rice Starch by Ultrasound and Quercetin Dual Treatment

Applying physical modification methods to raise the resistant starch content is a feasible strategy for developing foods with a low glycemic index (GI) and regulating postprandial hyperglycemia. Here, broken rice starch (C) was modified via ultrasound and quercetin complexation (US-Q). The structure, physicochemical properties, and in vitro digestibility of the US-Q product were subsequently determined. Scanning electron microscopy (SEM) images showed that the modification changed the starch granules’ morphology, forming a more compact and stable structure. Fourier transform infrared (FTIR) spectroscopy images revealed the interaction between the starch and quercetin. An X-ray diffraction (XRD) analysis demonstrated that the crystallinity of the US-Q was lower than that of the C, indicating that the combined modification with ultrasound and quercetin disrupted the long-range ordered structure of the starch and facilitated the formation of a short-range ordered structure from amylose. Size exclusion chromatography (SEC) images showed that both the molecular weight (from 72,080.96 kDa to 85,141.95 kDa) and amylose content (from 15.94% to 26.76%) increased significantly, while the branching degree and average degree of polymerization of amylopectin decreased, suggesting that the ultrasonic treatment processing method had a significant impact on the formation of the quercetin–starch complexes. In terms of in vitro digestion, the resistant starch content of the US-Q was significantly increased from 6.57% to 20.23%, whereas the hydrolysis rate was decreased from 92.6% to 78.35%, indicating that the presence of quercetin reduced the digestibility of the starch complexes by inhibiting the starch-hydrolyzing enzyme activity. Overall, this study improves the understanding of ultrasound and quercetin dual treatment of broken rice starch, providing a theoretical basis for the development of low-GI starch foods for industrial applications.

Antioxidant capacities and in vitro anti-microbial activities of rice (Oryza sativa var Bajong) from Borneo

Rice contains antioxidants and phenolic components that exert anti-inflammatory and anticancer properties. Different geographical areas produce rice with various chemical constituents and phytochemicals, in turn these confer differential protective effects including antimicrobial and anticancer properties. Sarawak rice, Oryza sativa var Bajong (Bajong), a fragrant dark purple rice grain harvested from two locations in Sarawak, namely interior Lubok Nibong (LN) and coastal Sri Aman (SA), was assessed for their antioxidant properties and antimicrobial activities. The rice was extracted using methanol solvent and evaluated for total phenolic content (TPC), total flavonoid contents (TFC), as well as their antioxidant and antimicrobial activities based on the Folin–Ciocalteu assay, the aluminium calorimetric method, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and disk diffusion assay, respectively. Using dual-wavelength measurement, Bajong LN showed 2.16% higher amylose content than Bajong SA. Furthermore, 24-h extract of Bajong LN and 48-h extract of Bajong SA exhibited high antioxidant properties (34–70 µg/mL) and were rich in phenolic (46.54 ± 2.62 mg GAE/g; 25.28 ± 3.91 mg GAE/g) and flavonoid contents (5.53 ± 0.36 mg QCE/g; 7.7 ± 2.19 mg QCE/g) respectively. It is interesting to note that 72-h Bajong extract exhibited the largest zone of inhibition (9–9.3 mm) against Gram-negative Pseudomonas aeruginosa (Ps. aeruginosa), which correlated to the high TPC and TFC despite a reduction of antioxidant activity due to prolonged extraction hours. These significant results conferred added value to a staple, health-promoting Bajong had warranted it to be further investigated as a nutraceutical and pharmaceutical crop.

Molecular signatures of selection for amylose and protein content in Northeast Asian rice (Oryza sativa L.)

Abstract Grain quality of rice (Oryza sativa L.) holds significant cultural value for Northeast Asian consumers, with low levels of amylose and protein content preferred for their contribution to the soft and sticky texture of cooked rice. Understanding the genetic diversity at the subpopulation level, in conjunction with local adaptation as identified by the signatures of selection for amylose and protein content, forms the basis for precise calibration of phenotypes in local breeding programs. This study investigated the genetic and phenotypic variations, as well as selective sweeps for amylose and protein content, in rice accessions from China, Japan, and Korea to reveal how their genomic landscapes have been shaped. The Northeast Asian rice accessions were identified as temperate japonica with distinct country-specific population structures. Phenotypic analysis revealed overlapping but distinct distributions of amylose and protein contents, with the Japanese panel exhibiting the lowest mean protein content, the Korean panel showing narrower trait distributions reflecting uniform selection, and the Chinese panel displaying broader variations. Genome-wide scans identified loci under selection for low amylose and protein contents, with major peaks on chromosomes 3, 6, 10, and 11 shared across countries, suggesting conserved loci critical for grain quality improvement. Country-specific selection signals, such as OsAGPS2 on chromosome 8 in Japan, chromosome 6 in Korea, and OsAAP11 on the short arm of chromosome 11 in China, highlight local adaptation and breeding strategies. These findings provide valuable insights into the genetic architecture of grain quality traits and suggest candidate loci for applications in marker-assisted selection or genome editing. By addressing both regional preferences and shared targets, this study lays the foundation for developing rice cultivars that align with consumer demands while promoting agricultural sustainability and food security.

A large‐scale gene regulatory network for rice endosperm starch biosynthesis and its application in genetic improvement of rice quality

SummaryRice (Oryza sativa L.) is one of the most important food crops. Starch is the main substance of rice endosperm and largely determines the grain quality and yield. Starch biosynthesis in endosperm is very complex, requiring a series of enzymes which are also regulated by many transcription factors (TFs). But until now, the large‐scale regulatory network for rice endosperm starch biosynthesis has not been established. Here, we constructed a rice endosperm starch biosynthesis regulatory network comprised of 277 TFs and 15 starch synthesis enzyme‐encoding genes (SSEGs) using DNA affinity chromatography/pull‐down combined with liquid chromatography‐mass spectrometry (DNA pull‐down and LC–MS). In this regulatory network, each SSEG is directly regulated by 7–46 TFs. Based on this network, we found a new pathway ‘ABA‐OsABI5‐OsERF44‐SSEGs’ that regulates rice endosperm starch biosynthesis. We also knocked out five TFs targeting the key amylose synthesis enzyme gene OsGBSSI in japonica rice ‘Nipponbare’ background and found that all mutants had moderately decreased amylose content (AC) in endosperm and improved eating and cooking quality (ECQ). Notably, the knockout of OsSPL7 and OsB3 improves the ECQ without compromising the rice appearance quality, which was further validated in the indica rice ‘Zhongjiazao17’ background. In summary, this gene regulatory network for rice endosperm starch biosynthesis established here will provide important theoretical and practical guidance for the genetic improvement of rice quality.

Synergistic Amylase and Debranching Enzyme Catalysis to Improve the Stability of Oat Milk.

Oat starch plays a crucial role in the stability of oat milk. Enzyme-hydrolyzed oat starch has been demonstrated to be an effective means of improving the stability of oat milk. The effects of different enzyme combinations on the stability of oat milk and the properties of starch in oats were investigated by adding α-amylase, amyloglucosidase, and different ratios of pullulanase and isoamylase. The results showed that as the degree of hydrolysis increased, the molecular weight, amylose content, and side chain length distribution of the starch decreased significantly. Moreover, compared with oat starch, the rheological and emulsifying properties of the starch hydrolysates were improved, and the characterization of emulsion stability showed that a 1:2 ratio of pullulanase to isoamylase promoted effective debranching and thus improved the stability of oat milk. This study demonstrated that debranching enzymes enhance the enzymatic hydrolysis of beverages and improve the physicochemical properties and stability of oat milk.

Physicochemical, functional, pasting and thermal properties of resistant starch type III from banana (Musa acuminata X balbisiana cv. Awak) pseudostem

In Malaysia, banana is the second most widely cultivated fruit. The banana pseudostem (BP) is cut and dumped as waste after harvesting. Unfortunately, pseudostem is currently underutilised as a functional food ingredient due to its high-quality starch content. Therefore, this study aimed to determine the proximate compositions, physical attributes, and functional characteristics of starches produced from BP, in comparison with commercial starches, such as potato starch (PS) and corn starch (CS). Native starch from banana pseudostem (BPNS) was isolated. Then, resistant starch type III (RS3) was prepared from native starch (RS3BP) by an autoclaving process. The starches were subjected to physicochemical (i.e., proximate composition, water activity, bulk density, and colour), functional (i.e., amylose, amylopectin, water holding, and oil holding capacities), pasting (by using rapid visco analyser), and thermal properties determination (by using differential scanning calorimetry). The results showed that there were significant (p<0.05) increases in the amylose content of RS3BP after the autoclaving process. The water and oil holding capacities of BPNS did not change after autoclaving. The results of pasting and thermal properties indicated that BPNS contained a stronger starch granule and greater thermal stability than commercial starches (PS and CS). In addition, the autoclaving process decreased significantly (p<0.05) the content of moisture, crude protein, crude fat, and ash but increased significantly (p<0.05) the total carbohydrate and energy values in BPNS. The autoclaving process also resulted in a significant (p<0.05) darker and red-yellowish colour of RS3BP than other starches. In conclusion, the findings of this study demonstrated that the isolated BPNS has good starch granule stability and retains its functional properties after autoclaving during the production of RS3BP, even with an increased energy source. Therefore, BP can be considered a viable alternative raw material for producing native starch or resistant starch type III.

Effect of Low Temperature and Nitrogen Modified Atmosphere Treatments on the Storage of High Moisture Indica Rice: Quality, Microstructure, and Metabolome Characteristics

Effects of low temperature (LT, 20 °C) combined with nitrogen-modified atmosphere (MA, 95% N2) storage (LT + MA) on quality, microstructure, and metabolome characteristics of high moisture content (15.5%) during 180 days of storage were investigated to explore a potential preservation technique for high moisture rice. The results showed that after 180 days of storage, the fatty acid value, malondialdehyde content, and amylose content of rice under LT + MA storage were 53.33%, 72.93%, and 91.85% of those under conventional storage (CS, conventional atmosphere, 30 °C, RH 65%), respectively. The color, pasting properties, and scanning electron microscopy (SEM) of the LT + MA treatment were found to be markedly superior to those of the CS treatment. In addition, the differential metabolites sucrose, trehalose-6P, trehalose, 3,7-Di-O-methylquercetin (DMQ), rutin, and vitexin 2″-O-rhamnoside (VOR) were screened to assess for sensitivity to changes in storage conditions. The study demonstrated that the LT + MA effectively suppressed the escalation of FAV, MDA content, and amylose content. In addition, it was observed to inhibit the deterioration of color and pasting properties while concurrently maintaining the polygonal shape of rice starch granules. Furthermore, the differential metabolites of non-targeted metabolomics indicated that the LT + MA group exhibited superior efficacy in retarding rice aging.

The impact of starch composition and gluten content on noodle texture and starch digestibility.

The impact of starch composition and gluten content on noodle texture and starch digestibility.

The relationship between fine structure and physicochemical properties of starches from wheat (<i>Triticum aestivum</i> L.) varieties

Considering the impact of geographic location on starch properties, this research investigates the relationship between fine structure and physicochemical properties of starch isolated from three wheat varieties (Pw1, Sw2, and Hw3) cultivated in Pakistan. The starch granules displayed a range of morphologies, including large lenticular and irregularly disk-like forms as well as smaller oval shapes. Among the starches, Sw2 exhibited the lowest amylose content, while Pw1 showed the longest average amylopectin chain length and the highest molecular weight. X-ray diffractometer and 13C solid-state nuclear magnetic resonance analyses revealed typical A-type diffraction patterns in all three starches, with Pw1 having the highest relative crystallinity. FT-IR results indicated that Pw1 possessed the most ordered structure, as reflected by the highest R1047–R1022 ratio. Findings of differential scanning calorimetry showed that Pw1 had an elevated gelatinization temperature, resulting from its high proportion of long amylopectin chains (degree of polymerization [DP] > 37). In contrast, Hw3 displayed the highest peak and setback viscosities because of its substantial proportion of amylopectin short chains. Hw3 also demonstrated the highest water solubility and swelling power because of its high amylose content. All starches exhibited shear-thinning behavior, with Sw2 having the lowest storage modulus in frequency sweep tests. Additionally, Sw2 showed the greatest oil- and water-absorption capacities, which is associated with its low amylose content. Variations in the fine structure of starch account for the distinct physicochemical properties observed among the wheat varieties, playing an essential role in the tailored selection of wheat products based on their characteristics.

Impact of TaFtsZ2 overexpression and mutation on wheat starch granule characteristics and quality.

Impact of TaFtsZ2 overexpression and mutation on wheat starch granule characteristics and quality.

Efficient preparation of starch-lipid complexes: A review.

Efficient preparation of starch-lipid complexes: A review.

Investigating the influence of the molecular structure and physiochemical properties of starches from glutinous and japonica sorghum on light-flavor liquor fermentation.

Investigating the influence of the molecular structure and physiochemical properties of starches from glutinous and japonica sorghum on light-flavor liquor fermentation.

Effect of sowing date on physicochemical properties of waxy and non-waxy proso millet (Panicum miliaceum L.) starches.

Effect of sowing date on physicochemical properties of waxy and non-waxy proso millet (Panicum miliaceum L.) starches.

Effect of atmospheric cold plasma pretreatment on the formation of ternary complexes among wheat starch, β-lactoglobulin and fatty acids with different chain lengths.

Effect of atmospheric cold plasma pretreatment on the formation of ternary complexes among wheat starch, β-lactoglobulin and fatty acids with different chain lengths.

Modification of browntop millet (Brachiaria ramosa) starch: Effects of pulse electric field and gamma-irradiation on morphological, thermal, rheological, and powder flow properties.

Modification of browntop millet (Brachiaria ramosa) starch: Effects of pulse electric field and gamma-irradiation on morphological, thermal, rheological, and powder flow properties.

Unveiling lotus root processing under vacuum microwave: starch-malic acid interactions based on moisture, structure, and in vitro digestibility.

Unveiling lotus root processing under vacuum microwave: starch-malic acid interactions based on moisture, structure, and in vitro digestibility.