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BACKGROUND RESULTS CONCLUSION Amylose has a major influence over starch properties and end‐use quality in wheat. The granule‐bound starch synthase I, encoded by Wx‐1, is the single enzyme responsible for amylose synthesis. Natural null mutants of Wx‐1 appear at extremely low frequencies, particularly in the Wx‐D1 locus, where only four spontaneous null variants have been identified, with different geographic origins. The current study identified an induced Wx‐D1 null mutant (M4‐9484) from the M4 generation of an ethyl methanesulfonate‐mutagenized population of wheat cv. ‘SM126’.The sequencing showed that the complete Wx‐D1 ORF sequences of ‘SM126’ and M4‐9484 were 2862 bp long and that there was one SNP mutation between them. The mutation was located at the RNA splice site within the junction of exon 8 and intron 8, which led to abnormal transcription of Wx‐D1, with five different aberrant transcripts being identified in the mutant. The Wx‐D1 null allele resulted in amylose and total starch content being decreased in M4‐9484 in comparison with the wild‐type ‘SM126’, with higher swelling capacity and being fully pasted at higher temperatures than the wild‐type parent.The mutation of the Wx‐D1 null gene affects the formation of amylose directly, resulting in significantly altered starch properties. This discovery offers valuable insights for enhancing wheat starch quality and contributes to the diversification of starch characteristics. It also deepens our understanding of the genetic and molecular mechanisms underlying amylose synthesis, thereby supporting breeding programs. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Summary: The inherent poor cooking quality and poor texture of mixed‐grain pasta limit consumer acceptance. This study systematically investigated the effect of curdlan in the processing of sweet potato puree oat mixed‐grain noodles, and comprehensively analysed a number of key indicators such as cooking characteristics, moisture state, texture properties, microstructure, starch crystallinity characteristics, short‐range ordered structure and thermal properties. At the production practice level, the study clearly indicated that the 0.6% curdlan addition ratio was the best solution in sweet potato puree oat mixed‐grain noodles processing. This finding not only significantly reduces the fracture rate, water absorption rate and cooking loss rate during the cooking process, but also significantly improves the quality and yield of the product, and brings significant improvement in the taste and texture of the noodles, which is of great significance for industrial production. In the microstructural and molecular studies, we revealed how curdlan could enhance the structural stability and mechanical strength of noodles by promoting the uniform distribution of starch granules in the gluten protein network. Further, through X‐ray diffraction, ordered structure and thermal property analyses, we have found that colchicine can effectively regulate the interactions of hydrogen bonding between starch and the content of straight‐chain and branched‐chain starch, which significantly reduces the crystallinity, ordered short‐chain structure and enthalpy of pasting of starch in the pasta. These in‐depth research results not only help us to understand more comprehensively the formation mechanism of the modification of pasta quality by curdlan, but also provide a solid theoretical foundation and practical guidance for the improvement of pasta quality in mixed grains. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bananas and plantains are important food sources for many people in the world. Their high starch content places them among the highest energy providers. This study aimed to determine the effects of altitude on banana starch properties in Cameroon. A dessert banana, a cooking banana, a plantain cultivar, and a plantain‐like hybrid were grown at low and high altitudes (respectively at 80 m and 1300 m above sea level). RESULTS: Starch analyses showed an increase in moisture and pH values against a drop in total titratable acidity and dry matter content with respect to altitude. Amylose content, as well as water absorption capacity, oil absorption capacity and syneresis of high‐altitude plantain and plantain‐like hybrid, were significantly higher. Starch digestibility was low and ranged between 13.4% and 37.9% after 2 h of incubation. High‐altitude plantain starches contained more amylose and were more resistant to enzymatic hydrolysis. CONCLUSION: Starches from CARBAP K74 and Kelong mekintu, grown at high altitude, showed good water and oil absorption capacities, low digestibility, and high resistance. The adequate properties of these banana starches predispose them for use as thickeners and gelling agents as well as ingredients for the formulation of low‐calorie foods. This study highlights the importance of altitude when discussing banana and plantain starch properties. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nitrogen has a critical influence on the yield and quality of proso millet. However, the exact impact of nitrogen on the cooking quality of proso millet is not clear. In this study, the cooking quality and starch properties of two proso millet varieties (waxy‐Shaanxi millet [wSM] variety and non‐waxy‐Shaanxi millet [nSM] variety) were compared and analyzed under nitrogen fertilizer treatment (N150, 150 kg/hm2) and a control group without nitrogen application (N0, 0 kg/hm2). Compared with the N0 group, the N150 treatment significantly increased protein content, amylose levels, and total yield. Employing rapid visco analyser and differential scanning calorimetry analyses, we observed that under the N150 treatment, the peak viscosity and breakdown viscosity of proso millet powder were diminished, while the setback viscosity and enthalpy values (ΔH) increased. In addition, nitrogen treatment increased the solids content in the obtained rice soup and significantly hardened the texture of the rice. At the same time, we noticed that the absorption capacity of starch in water and oil was enhanced. These results showed that nitrogen fertilizer had significant effects on the cooking quality and starch properties of proso millet. [ABSTRACT FROM AUTHOR]

Summary: Although dried noodles have been industrialised for many years, some technical bottlenecks, such as dense cross‐section structure, poor rehydration ability and the lack of nutritional and flavour substances, still need to be addressed. Fermentation has been used to produce dried noodles to impart a porous structure and microbial metabolites, improving their rehydration properties and the nutritional and flavour quality of dried noodles. However, the current commercially fermented dried noodles exhibit some issues, such as high breakage rate, rough surface and sticky texture that need to be solved. Drying at high (HT) and ultra‐high temperatures (UT) has been shown to improve the quality of dried pasta or noodles. However, HT and UT drying are not currently used to produce fermented dried noodles. This article investigates the changes in the quality and starch physicochemical properties of fermented dried noodles with high (HM), medium (MM) or low moisture (LM) content dried at HT or UT. The results showed that the UT‐LM condition most prominently improved the noodle quality, significantly reduced the cooking loss rate (5.19%) and significantly increased the water absorption rate (191.41%) of the noodles, and improved the rehydration of noodles. In addition, the cross‐linking of the gluten network was analysed using confocal laser scanning microscopy and the AngioTool software. It was found that the UT treatment promoted the cross‐linking of the gluten network, and the highest number of cross‐linking points (976) was achieved under the UT‐LM condition. The tight gluten network reduces the amylose leaching from the noodles, giving the noodles a denser surface structure and lower adhesiveness. In conclusion, UT‐LM drying could be used as an effective drying condition to improve the quality of fermented dried noodles. [ABSTRACT FROM AUTHOR]

Summary: Considering the high interest in using pulses in the production of staple foods, including pasta, this study aimed at investigating the effect of pre‐gelatinisation on the overall quality of pasta from red lentils. Pre‐gelatinized flours showed a lower gelatinisation temperature (up to about 57 °C vs. about 65 °C) and higher retrogradation tendency than native flour. Such changes resulted in higher water absorption capacity (up to 1.23 vs. 0.98 g g−1) and higher farinographic torque, but did not impact the cooking quality. Conversely, the resistant starch content of cooked pasta decreased (from 14.79 to 10.4 g/100 g total starch) and the starch hydrolysis index increased (from 48.28 to 67.71) when pre‐gelatinised flours were used. In conclusion, pre‐gelatinisation impacted starch, hydration and the mixing properties of red lentils flours, without compromising the cooking behaviour of the related pasta. [ABSTRACT FROM AUTHOR]

The microwave is widely applied to process cereals and grains. However, its effects on their chemical components are still not explored clearly. In this study, millet kernels are treated by microwave. The physical and chemical properties of starch in microwave‐treated millet kernels (SMM) are investigated and compared to those in untreated millet kernels (SUM). The experimental results indicate that the peak viscosity of SMM reduces with the increase of microwave time and initial moisture content of millet kernels (IMM). The peak viscosity of SUM is 831.00 BU. Compared with that of SUM, the peak viscosity of SMM decreases after microwave treatment (MT). When the IMM is 35%, the peak viscosity of SMM decreases by 66.23%. MT significantly increases (p < 0.05) the rapidly digestible starch (RDS) and slowly digestible starch (SDS) content of SMM, which reduces its resistant starch (RS) content. Under MT time of 150 s, the SDS of SMM is up to 35.92%. When the IMM is 35%, after MT, the RDS content of SMM reaches 52.10%. Additionally, the relative crystallinity and short‐range order of SMM are both decreased after MT. Therefore, the microwave is a useful tool for improving the properties of the starch in millet. [ABSTRACT FROM AUTHOR]

Summary: To investigate the effects of seven starches made from different crop sources on noodle quality, Chinese dried noodles made from various reconstituted flours were prepared and analysed. Potato starch had better solubility and swelling power than the other starches, leading to higher water absorption, cooking loss and breakage ratio of the potato starch noodles. The correlation results unravelled that the cooking breakage ratio of noodles presented positive correlations with solubility, swelling power, peak viscosity (PV), trough viscosity (TV) and final viscosity (FV) values of starches. Besides, the adhesiveness of noodles showed a positive correlation with conclusion temperature (Tc) and setback viscosity (SV) values of starches. Moreover, the peak temperature (Tp) value of starches was negatively correlated with cooking loss; the granule size of starches had a positive correlation with noodles water absorption; and the peak time (PkT) value of starches represented positive relationships with noodles chewiness, shearing force and breaking strength. [ABSTRACT FROM AUTHOR]

Nitrogen is an important factor that influences the yield and quality of wheat grain. However, little is known about its effect on the different positions of the grain in spikelets. Compared with the control group, nitrogen application increased the weight, starch content, and protein content of grains in each position considerably. In particular, the protein content in high grain positions of Yangmai 13 (YM 13) under nitrogen treatment are similar to those positions in Yannong 19 (YN 19) under normal levels. Nitrogen application substantially increased the volume proportion of small starch granules and the average degree of polymerization (DP) but reduced the apparent amylose content (AAC), and the breakdown values (BV) of the first grain (G1) and the second grain (G2) in YN19. Nitrogen application considerably increased AAC, the volume proportion of small starch granules, and the ordered structure of starch surface of G1 and AAC, BV, and DP of G2 in YM13. These results demonstrated that a medium nitrogen level is conducive to increase the agronomic traits in high‐position grains and a better pasting properties of starch in low‐position grains. [ABSTRACT FROM AUTHOR]

Background and objectives: In this study, the characteristics of A‐ and B‐type starch granules from three wheat cultivars exhibiting weak, medium, and strong gluten forces were investigated. It was analyzed the wheat flour chemical composition and gluten content, wet starch extraction yield, and the physicochemical, morphological, and digestion properties of isolated A‐ and B‐type starch granules. The starches were characterized for swelling power, solubility, pasting properties, gel texture profile, thermal properties, relative crystallinity, morphology, and in vitro starch digestibility. Findings: The starch extraction yield was higher for the wheat sample exhibiting weak gluten force, followed by the samples with medium and strong gluten. There was no difference between the A‐ and B‐type starch granules regarding starch extraction yield. The wheat starch physicochemical properties varied depending on gluten force and starch granule size, specified as A‐type or B‐type. Weak gluten‐containing wheat starch displayed a slower glucose release compared with the medium‐ and strong gluten‐containing samples. A‐type granules exhibited slower in vitro starch digestibility and digestion rate in the small intestine in all cultivars. Conclusions: The obtained results allow a great application diversity of wheat starch granules through their separation based either on the genotype or on the granule size. Significance and novelty: Starch extraction from wheat with different gluten forces could be an alternative to obtain starch with different characteristics as well as the separation of A‐ and B‐type granules that would fulfill the needs of specific markets. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of the time of heat-moisture treatment (HMT) of oat grains in husk on lipase activity, pasting properties of flour, and properties of starch isolated from grains. Oat grains with 13% moisture were subjected to 15, 30, 45, and 60 min of HMTat 110°C. Starches of heat-moisture-treated oat grains were isolated with the alkaline method. The 60-min HMT suppressed more than 60% of the lipase activity of oat grains and increased the extraction yield of oat starch. HMT also reduced swelling power, solubility, gelatinisation enthalpy, and relative crystallinity of starches isolated from oat grains. The reduction of breakdown and retrogradation of oat flour promoted by 60 min of HMT provides better paste stability, and thus can be used for canned and frozen foods. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of freezing rate and storage time on the properties of frozen wheat dough starch. The dough was frozen at either slow (−0.14°C/min) or fast (−1.75°C/min) rates and stored at −20°C for 8 weeks. Every 2 weeks, the frozen dough was sampled and freeze-dried. Analyses of the dried dough included damaged starch, paste properties, and thermal, morphological, and structural properties. Damaged starch increased significantly during storage, and it was higher in the dough frozen at a slow rate than in the dough frozen at a fast rate. The peak viscosity during storage gradually but significantly decreased. During this period, the peak viscosity was higher for the dough frozen at a slow rate than the dough frozen at a fast rate. The enthalpy of starch crystallite fusion gradually but significantly increased during storage, and it was lower in the dough frozen at a slow rate than in the dough frozen at a fast rate. The structural properties show a decrease in the crystalline percent as a result of the freezing and storage time. SEM images show that starch granules were separated from the gluten matrix after storage, and separation was greater for the dough frozen at a fast rate than that frozen at a slow rate. The freezing rate and storage time increased starch damage and changed the microstructure of the dough. [ABSTRACT FROM AUTHOR]

The aim of this study, was to evaluate the effect of extrusion conditions and particle size index on the starch properties of expanded nixtamalized snacks elaborated with whole blue corn. Whole grains were ground to achieve two different particle size indexes (PSI), 83.9 and 94.1, and were extruded at three feed moistures (14, 16.5, and 20.5%). The data suggested that the severity of milling and the extrusion process resulted in higher starch degradation, specifically in the snacks obtained with a feed moisture of 20.5%, which showed the higher values of starch damage. Nixtamalization by extrusion produced minimum amounts of resistant starch, mainly as retrograded starch and amylose-lipid complex, as demonstrated by thermal and structural analyses. Snacks produced with feed moisture of 16.5-20.5% and a PSI of 94.1 showed the highest values of resistant starch. The rheological properties of snacks with PSI of 83.9 indicated lower starch degradation and presented lower amounts of resistant starch than snacks with higher PSI. The feed moisture affected all the parameters evaluated in the snacks more than the PSI. [ABSTRACT FROM AUTHOR]

Starch continues to be an important renewable biopolymer in both the food and non-food industries. Its properties, which vary depending on the plant source, stem directly from its structure. The recent substantial increase in knowledge of the molecular structure of starch components and the architecture of starch granules has contributed significantly to an enhanced understanding of the structural base of starch functionality. This résumé provides an overview of the present views of the starch structure-function relationships with an emphasis on industrially important starch sources. [ABSTRACT FROM AUTHOR]

ABSTRACT The grain quality of rice has recently attracted a lot of attention around the world, including Africa. Rice germplasm in African gene banks has not been adequately characterized for its cooking and eating qualities which are mainly controlled by starch physicochemical properties. The aim of this study was to characterize two groups of rice germplasm from Africa and the U.S. for starch properties including gelatinization temperature (GT), apparent amylose content (AAC), and paste viscosity (RVA), and to determine molecular marker associations with these traits. Wide diversity was found for all traits studied. Variation in these traits was significantly associated with molecular markers for the alk and waxy genes which encodes soluble SS II ( SSIIa) and granule bound synthase ( GBSS) enzymes, respectively. Based on four previously reported waxy SNP haplotypes, 93.1 and 75.9% of the variation in AAC was explained for the U.S. and African germplasm, respectively. The classification of the genotypes by their SNP haplotypes helped to clarify the relationship between AAC and peak viscosity. The characterization of individual lines using physicochemical properties and functional markers, and the determination of marker-trait associations will facilitate the breeding of rice for grain quality in Africa and elsewhere. [ABSTRACT FROM AUTHOR]

Amala is a traditional thick paste consumed in West Africa (Nigeria, Bénin, Togo). It is prepared from blanched dried yam flour and has a particular texture. The texture attributes of amala pastes obtained from market and prepared in laboratory were sensorily evaluated. Both compression and extrusion tests were done from which maxima force and slope were calculated. The physical (particle size), starch characteristics and functional properties (solubility, swelling power [Sp], viscosity) of yam flours were also determined to establish a predictive model for amala sensory texture attributes. The main amala sensory attributes were stickiness, firmness and smoothness. Stickiness and firmness could be assessed by uniaxial extrusion test: These attributes were highly correlated with the maximum extrusion slope (r = − 0.60 and r = 0.53, respectively). Stickiness was associated with yam flour Sp, which in turn was related to gelatinization temperature and enthalpy changes. In addition, soluble matter and soluble amylose were found to be indicators of amala sensory stickiness. No clear relationships were observed between sensory firmness and yam flour physicochemical characteristics or functional properties. [ABSTRACT FROM AUTHOR]