Search

Gadung starch has limitations in several functional properties and thermal stability. Modifying starch through temperature treatments such as Freeze Moisture Treatment (FMT) and Heat Moisture Treatment (HMT) potentially improves these weaknesses. This research aimed to determine the effects of FMT and HMT on the functional, pasting, and physicochemical properties of gadung starch. This study consisted of a variety of treatments, namely native starch, FMT, HMT 100°C, HMT 110°C, FMT + HMT 100°C, and FMT + HMT 110°C. The results showed that FMT and HMT treatments significantly affected the functional, pasting, and physicochemical properties of gadung starch. The combination modification treatment of FMT + HMT 110°C increased swelling volume by 1.44 times, and water absorption capacity increased by 1.37 times. This was confirmed by the formation of porous and amorphous starch granules. Modified starch also had the best heat stability, as indicated by a low breakdown viscosity of 31.00 ± 9.90 cP. FMT+HMT110°C modified treatment was the best treatment because it had more pores, cracks, and higher swelling volume. The starch crystallinity index of modified starch decreased from 35.75 to 31.58 and changed the crystallinity type from B-type to A-type. The starch modification did not cause changes in functional groups but reduced crystallinity as indicated by the smaller ratio of the bands at 1045/1022 and the higher ratio at 1022/995 from FTIR spectra. Thus, FMT and HMT could effectively improve the characteristics of gadung starch by forming heat-stable amorphous starch.

In this study, the addition of potato soluble dietary fiber (PSDF) in 0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% during concentration freeze-thawing (FT, at − 20 °C for 22 h and then at 30 °C for 2 h) on the structural and physicochemical properties of potato starch was investigated. During FT, the potato starch granules break, which increases the leaching of amylose, However, the addition of PSDF during FT could inhibit the leach of amylose than without PSDF. Besides, addition of PSDF during FT increases the short-range ordered structures, and relative crystallinity reduces the value of G′, G″, and peak viscosity of potato starch treated by FT. Furthermore, PSDF could inhibit the swelling of FT-treated potato starch granules during heating and improve the shear resistance of FT-treated potato starch gel. And the degree of effect is closely related to the concentration of PSDF. These findings indicated that PSDF could be used to adjust the quality of raw starch products during freeze-thawing and thus improve the applications of PSDF in starch-based foods. [ABSTRACT FROM AUTHOR]

BACKGROUND: Roots, tubers and bananas (RTB) play an essential role as staple foods, particularly in Africa. Consumer acceptance for RTB products relies strongly on the functional properties of, which may be affected by the size and shape of its granules. Classically, these are characterized either using manual measurements on microscopic photographs of starch colored with iodine, or using a laser light‐scattering granulometer (LLSG). While the former is tedious and only allows the analysis of a small number of granules, the latter only provides limited information on the shape of the starch granule. RESULTS: In this study, an open‐source solution was developed allowing the automated measurement of the characteristic parameters of the size and shape of yam starch granules by applying thresholding and object identification on microscopic photographs. A random forest (RF) model was used to predict the starch granule shape class. This analysis pipeline was successfully applied to a yam diversity panel of 47 genotypes, leading to the characterization of more than 205 000 starch granules. Comparison between the classical and automated method shows a very strong correlation (R2 = 0.99) and an absence of bias for granule size. The RF model predicted shape class with an accuracy of 83%. With heritability equal to 0.85, the median projected area of the granules varied from 381 to 1115 μm2 and their observed shapes were ellipsoidal, polyhedral, round and triangular. CONCLUSION: The results obtained in this study show that the proposed open‐source pipeline offers an accurate, robust and discriminating solution for medium‐throughput phenotyping of yam starch granule size distribution and shape classification. © 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]

Noodles are popular staple foods globally, and dried noodle products (DNPs) have gained increasing attention due to recent changes in consumer diet behavior. Rapid rehydration and excellent texture quality are the two major demands consumers make of dried noodle products. Unfortunately, these two qualities conflict with each other: the rapid rehydration of DNPs generally requires a loose structure, which is disadvantageous for good texture qualities. This contradiction limits further development of the noodle industry, and overcoming this limitation remains challenging. Starch is the major component of noodles, and it has two main roles in DNPs. It serves as a skeleton for the noodle in gel networks form or acts as a noodle network filler in granule form. In this review, we comprehensively investigate the different roles of starch in DNPs, and propose strategies for balancing the conflicts between texture and rehydration qualities of DNPs by regulating the gel network and granule structure of starch. Current strategies in regulating the gel network mainly focused on the hydrogen bond strength, the orientation degree, and the porosity; while regulating granule structure was generally performed by adjusting the integrity and the gelatinization degree of starch. This review assists in the production of instant dried noodle products with desired qualities, and provides insights into promising enhancements in the quality of starch-based products by manipulating starch structure. [ABSTRACT FROM AUTHOR]

This study aims to investigate grain quality and nutritional values of rice (Pokkali, a salt-tolerant cultivar; RD73, a new cultivar improved from KDML105 introgressed with Saltol QTL from Pokkali, and KDML105, a moderately salt-susceptible cultivar) grown under non-saline (0.04–0.87 dS/m) and slightly saline (1.08–4.83 dS/m) field conditions. The results revealed that salinity caused significant reduction in grain size but significant increments in reducing sugar and total protein contents in the grains. Nevertheless, the amounts of starch in the grains of KDML105 and Pokkali rice genotypes were unaffected by the stress. The starch granule size distribution was also unaffected by salinity. Interestingly, only starch from Pokkali was significantly diminished in amylose content, from 19.18% to 16.99%. Accordingly, parameters relating to starch gelatinization, retrogradation, and pasting properties of KDML105 and RD73 were unaffected by salinity; only Pokkali showed a significant increase in percentage of retrogradation along with a significant reduction in gelatinization enthalpy. In the saline field, total phenolic content and antioxidant capacity in the grains of all rice cultivars tended to increase, particularly in Pokkali. On average, essential element contents in grains from the saline-treated plants showed a 33%, 32%, 32%, 22%, 20%, 11%, and 10% increase in total P, N, K, Mg, Zn, Fe, and Ca content, respectively. Interestingly, total Fe content exhibited the greatest percentage of increments in KDML105 (187%). Taken together, cultivation of rice in the slightly saline field did not alter its eating and cooking qualities, while enhanced some nutritional properties such as proteins, minerals, and secondary metabolites like phenolic compounds. [ABSTRACT FROM AUTHOR]

The functional properties of Andean grain starches of two species, amaranth (Amaranthus caudatus) and canihua (Chenopodium pallidicaule), three cultivars each, were studied. The study focused on chemical composition, pasting properties, thermal properties, water solubility index (WSI), swelling power (SP), and granule morphology. All amaranth starches were waxy starches, with amylose content less than 5 %, which had some differences in chemical composition (p

Most tuberous crops, for instance, the yam, whose scientific name is Dioscorea alata, have food reserves in the form of starch in tubers. Characterization of starch grains of a plant species is pertinent to uncover information on plant taxonomic traits and identify their potential use as food and industrial raw materials. The study aimed to determine the characteristics of starch grains of water yam from Lermatang village, Tanimbar Islands Regency. This study isolated and submitted six accessions of water yam in Lermatang Village. The morphological inspection of the plants used the Descriptor for Yam from IPGRI, and sample preparation for observing starch grains employed the fresh section method. The six accessions of D. alata found in Lermatang village, Tanimbar Islands, were Uwi Merah, Uwi Gula, Uwi Pingingsian, Uwi Babulu, Uwi Akiakab, and Uwi Petatas. These yam varieties show differences in their tubers' shape and colors. The study found that starch granules of D. alata in each accession varied in terms of granule shape and hilus type. The starch granules revealed dominant triangular, oval, and elliptical shapes and eccentric and concentric hilus types. The starch grain diameter in the six accessions of Uwi was categorically large (44.88 – 57.5 µm), with Uwi Petatas being the largest. Previous reports have shown that accessions having large starch granule types could be further developed into an array of foods, thus conveying the promising use of the Uwi Petatas for such a purpose.

Abstract In rice, grain filling is a crucial stage where asynchronous filling of the pollinated spikelet’s of the panicle occurs. It can influence both grain quality and yield. In rice grain, starch is the dominant component and contains amylose and amylopectin. Amylose content is the chief cooking quality parameter, however, rice varieties having similar amylose content varied in other parameters. Hence, in this study, a set of varieties varying in yield (04) and another set (12) of varieties that are similar in amylose content with variation in gel consistency and alkali spreading value were used. Panicles were collected at various intervals and analysed for individual grain weight and quantities of amylose and amylopectin. Gas exchange parameters were measured in varieties varying in yield. Upper branches of the panicles were collected from rice varieties having similar amylose content and were subjected to gene expression analysis with fourteen gene specific primers of starch synthesis. Results indicate that grain filling was initiated simultaneously in multiple branches. Amylose and amylopectin quantities increased with the increase in individual grain weight. However, the pattern of regression lines of amylose and amylopectin percentages with increase in individual grain weight varied among the varieties. Gas exchange parameters like photosynthetic rate, stomatal conductance, intercellular CO2 and transpiration rate decreased with the increase in grain filling period in both good and poor yielding varieties. However, they decreased more in poor yielders. Expression of fourteen genes varied among the varieties and absence of SBE2b can be responsible for medium or soft gel consistency.

In rice, grain filling is a crucial stage where asynchronous filling of the pollinated spikelet's of the panicle occurs. It can influence both grain quality and yield. In rice grain, starch is the dominant component and contains amylose and amylopectin. Amylose content is the chief cooking quality parameter, however, rice varieties having similar amylose content varied in other parameters. Hence, in this study, a set of varieties varying in yield (04) and another set (12) of varieties that are similar in amylose content with variation in gel consistency and alkali spreading value were used. Panicles were collected at various intervals and analysed for individual grain weight and quantities of amylose and amylopectin. Gas exchange parameters were measured in varieties varying in yield. Upper branches of the panicles were collected from rice varieties having similar amylose content and were subjected to gene expression analysis with fourteen gene specific primers of starch synthesis. Results indicate that grain filling was initiated simultaneously in multiple branches. Amylose and amylopectin quantities increased with the increase in individual grain weight. However, the pattern of regression lines of amylose and amylopectin percentages with increase in individual grain weight varied among the varieties. Gas exchange parameters like photosynthetic rate, stomatal conductance, intercellular CO2 and transpiration rate decreased with the increase in grain filling period in both good and poor yielding varieties. However, they decreased more in poor yielders. Expression of fourteen genes varied among the varieties and absence of SBE2b can be responsible for medium or soft gel consistency. [ABSTRACT FROM AUTHOR]

Introduction: Given that rice serves as a crucial staple food for a significant portion of the global population and with the increasing number of individuals being diagnosed with diabetes, a primary objective in genetic improvement is to identify and cultivate low Glycemic Index (GI) varieties. This must be done while ensuring the preservation of grain quality. Methods: 25 Italian rice genotypes were characterized calculating their GI "in vivo" and, together with other 29 Italian and non-Italian genotypes they were studied to evaluate the grain inner structure through Field Emission Scanning Electron Microscopy (FESEM) technique. Using an ad-hoc developed algorithm, morphological features were extracted from the FESEM images, to be then inspected by means of multivariate data analysis methods. Results and Discussion: Large variability was observed in GI values (49 to 92 with respect to glucose), as well as in endosperm morphological features. According to the percentage of porosity is possible to distinguish approximately among rice varieties having a crystalline grain (< 1.7%), those intended for the preparation of risotto (> 5%), and a third group having intermediate characteristics. Waxy rice varieties were not united by a certain porosity level, but they shared a low starch granules eccentricity. With reference to morphological features, rice varieties with low GI (<55) seem to be characterized by large starch granules and low porosity values. Our data testify the wide variability of Italian rice cultivation giving interesting information for future breeding programs, finding that the structure of the endosperm can be regarded as a specific characteristic of each variety. [ABSTRACT FROM AUTHOR]

The objective of this study was to characterize the endosperm starch in rice that ectopically overexpressed the α-amylase. Transgenic rice plants, transformed with cauliflower mosaic virus 35S promoter driven AmyI-1 (35S::AmyI-1) and AmyII-4 (35S::AmyII-4), and 10 kDa prolamin promoter driven AmyI-1 (P10::AmyI-1), were cultivated under standard conditions (23 °C, 12 h in the dark/ 26 °C, 12 h in the light), and brown grains were subsequently harvested. Each grain displayed characteristic chalkiness, while electron microanalyzer (EPMA)-SEM images disclosed numerous small pits on the surface of the starch granules, attributable to α-amylase activity. Fluorescence labeling and capillary electrophoresis analysis of starch chain length distribution revealed no significant alterations in the starches of 35S::AmyI-1 and 35S::AmyII-4 transgenic rice compared to the wild-type. Conversely, the extremely short α-glucan chains (DP 2-8) exhibited a dramatic increase in the P10::AmyI-1 starch. Rapid visco-analyzer analysis also identified variations in the chain length distribution of P10::AmyI-1 starch, manifesting as changes in viscosity. Moreover, ¹H-NMR analysis uncovered dynamic modifications in the molecular structure of starch in rice grain transformed with P10::AmyI-1, which was found to possess unprecedented structural characteristics. [ABSTRACT FROM AUTHOR]

Non-structural carbohydrates (NSCs) required for bamboo shoot development, the critical stage that determines the yield of a bamboo stand, originate from the parent bamboo with the complex underground system. However, the metabolic mechanism of NSCs in the rhizome–culm system during bamboo shoot development remains unclear. In this study, we focused on the changes of NSCs in the rhizome–culm system and used anatomical, physiological, and biochemical methods to investigate the metabolism of NSCs in bamboo shoots of Phyllostachys edulis and the role of NSCs supply in the parent bamboo at different ages. The results showed that NSCs were accumulated and consumed from the bottom to the top in a bamboo shoot, which was consistent with the developmental pattern. The starch granules were stored in advance. The bamboo sheath stored starch from the dormant stage of shoot buds. The functions of culms and rhizomes showed age-dependent differences. Adult culms showed the highest capacity to provide NSCs, with more stored NSCs and higher β-amylase activity. Conversely, young culms seemed to prefer their growth, while old culms tended to store starch. Accordingly, adult rhizomes preferred sugar transport due to the lowest starch storage, lower ADP-glucose pyrophosphorylase (AGPase) activity, and higher β-amylase activity, while young and old rhizomes tended to prefer starch storage. These results provide a basis for further understanding of nutrient metabolism in bamboo stands. [ABSTRACT FROM AUTHOR]

As a traditional and popular dietary supplement, lotus rhizome starch (LRS) has health benefits for its many nutritional components and is especially suitable for teenagers and seniors. In this paper, the approximate composition, apparent amylose content (AAC), and structural characteristics of five LRS samples from different regions were investigated, and their correlations with the physicochemical properties of granular and gelatinized LRS were revealed. LRS exhibited rod-shaped and ellipsoidal starch granules, with AAC ranging from 26.6% to 31.7%. LRS-3, from Fuzhou, Jiangxi Province, exhibited a deeper hydrogel color and contained more ash, with 302.6 mg/kg iron, and it could reach the pasting temperature of 62.6 °C. In comparison, LRS-5, from Baoshan, Yunnan Province, exhibited smoother granule surface, less fragmentation, and higher AAC, resulting in better swelling power and freeze-thaw stability. The resistant starch contents of LRS-3 and LRS-5 were the lowest (15.3%) and highest (69.7%), respectively. The enzymatic digestion performance of LRS was positively correlated with ash content and short- and long-term ordered structures but negatively correlated with AAC. Furthermore, the color and network firmness of gelatinized LRS was negatively correlated with its ash content, and the retrograde trend and freeze-thaw stability were more closely correlated with AAC and structural characteristics. These results revealed the physicochemical properties of LRS from different regions and suggested their advantages in appropriate applications as a hydrogel matrix. [ABSTRACT FROM AUTHOR]

This review included resistant starch and its health aspects due to its importance in our diet as it has enormous benefits, especially for people who suffer from chronic diseases such as diabetes, cholesterol, and high blood pressure. Moreover, resistant starch is an important component in the meals of people who follow a diet to lose weight as it has complex carbohydrates which are difficult to digest. Resistant starch is used in the prevention of intestinal inflammation and some cancerous diseases due to its ability to enhance the work of beneficial bacteria in the intestine and thus prevent colon and rectal cancer. This reviewprovides a comprehensive overview of the physical properties of resistant starch, which include odour, colour and viscosity, in addition to its chemical composition including amylose and amylopectin, and to identify the structure and shape of the starch granule. Some methods of forming resistant starch of its five types from some plant sources such as wheat, oats, corn, rice, potatoes, legumes, etc. were also reviewed, and the possibility of increasing its percentage in these sources through a series of sequential processes such as cooking, then cooling and freezing.

ABSTRACT The aim of this study was to evaluate the effect of exogenous amylase on gas production, in vitro dry matter digestibility (IVDMD), and in vitro digestion kinetics of sorghum (Sorghum vulgaris) and two corn hybrids of different grain textures. Ruminal fluid was collected from two rumen-fistulated cows receiving or not exogenous amylase (0.7g kg-1 of dry matter (DM basis)), provided to achieve 396 kilo Novo units kg-1 for amylase activity (DM basis). Gas production was measured after 1, 3, 6, 9, 12, 15, 18, 21, 24, 30, 36, 42 e 48 hours of incubation. Amylase increased gas production (mL) by 5.4%. Corn hybrids have higher in vitro dry matter digestibility than sorghum. Exogenous amylase increased the potential of gas production (A) (P=0.01). There was an effect of hybrid for IVDMD (P

IntroductionGiven that rice serves as a crucial staple food for a significant portion of the global population and with the increasing number of individuals being diagnosed with diabetes, a primary objective in genetic improvement is to identify and cultivate low Glycemic Index (GI) varieties. This must be done while ensuring the preservation of grain quality.Methods25 Italian rice genotypes were characterized calculating their GI “in vivo” and, together with other 29 Italian and non-Italian genotypes they were studied to evaluate the grain inner structure through Field Emission Scanning Electron Microscopy (FESEM) technique. Using an ad-hoc developed algorithm, morphological features were extracted from the FESEM images, to be then inspected by means of multivariate data analysis methods.Results and DiscussionLarge variability was observed in GI values (49 to 92 with respect to glucose), as well as in endosperm morphological features. According to the percentage of porosity is possible to distinguish approximately among rice varieties having a crystalline grain (< 1.7%), those intended for the preparation of risotto (> 5%), and a third group having intermediate characteristics. Waxy rice varieties were not united by a certain porosity level, but they shared a low starch granules eccentricity. With reference to morphological features, rice varieties with low GI (

Summary: The determination of starch granule morphology in plants is poorly understood. The amyloplasts of wheat endosperm contain large discoid A‐type granules and small spherical B‐type granules.To study the influence of amyloplast structure on these distinct morphological types, we isolated a mutant in durum wheat (Triticum turgidum) defective in the plastid division protein PARC6, which had giant plastids in both leaves and endosperm.Endosperm amyloplasts of the mutant contained more A‐ and B‐type granules than those of the wild‐type. The mutant had increased A‐ and B‐type granule size in mature grains, and its A‐type granules had a highly aberrant, lobed surface. This morphological defect was already evident at early stages of grain development and occurred without alterations in polymer structure and composition. Plant growth and grain size, number and starch content were not affected in the mutants despite the large plastid size. Interestingly, mutation of the PARC6 paralog, ARC6, did not increase plastid or starch granule size. We suggest TtPARC6 can complement disrupted TtARC6 function by interacting with PDV2, the outer plastid envelope protein that typically interacts with ARC6 to promote plastid division.We therefore reveal an important role of amyloplast structure in starch granule morphogenesis in wheat. [ABSTRACT FROM AUTHOR]

Reserve starch from seeds and tubers is a crucial plant product for human survival. Much research has been devoted to quantitative and qualitative aspects of starch synthesis and its relation to abiotic factors of importance in agriculture. Certain aspects of genetic factors and enzymes influencing carbon assimilation into starch granules remain elusive after many decades of research. Starch phosphorylase (Pho) can operate, depending on metabolic conditions, in a synthetic and degradative pathway. The plastidial form of the enzyme is one of the most highly expressed genes in potato tubers, and the encoded product is imported into starch-synthesizing amyloplasts. We identified that the genomic locus of a Pho1a-type starch phosphorylase is duplicated in potato. Our study further shows that the enzyme is of importance for a normal starch granule phenotype in tubers. Null mutants created by genome editing display rounded starch granules in an increased number that contained a reduced ratio of apparent amylose in the starch. [ABSTRACT FROM AUTHOR]

Summary: Plants perceive the direction of gravity during skotomorphogenic growth, and of gravity and light during photomorphogenic growth. Gravity perception occurs through the sedimentation of starch granules in shoot endodermal and root columella cells. In this study, we demonstrate that the Arabidopsis thaliana GATA factors GNC (GATA, NITRATE‐INDUCIBLE, CARBON METABOLISM‐INVOLVED) and GNL/CGA1 (GNC‐LIKE/CYTOKININ‐RESPONSIVE GATA1) repress starch granule growth and amyloplast differentiation in endodermal cells.In our comprehensive study, we analysed gravitropic responses in the shoot, root and hypocotyl. We performed an RNA‐seq analysis, used advanced microscopy techniques to examine starch granule size, number and morphology and quantified transitory starch degradation patterns. Using transmission electron microscopy, we examined amyloplast development.Our results indicate that the altered gravitropic responses in hypocotyls, shoots and roots of gnc gnl mutants and GNL overexpressors are due to the differential accumulation of starch granules observed in the GATA genotypes. At the whole‐plant level, GNC and GNL play a more complex role in starch synthesis, degradation and starch granule initiation.Our findings suggest that the light‐regulated GNC and GNL help balance phototropic and gravitropic growth responses after the transition from skotomorphogenesis to photomorphogenesis by repressing the growth of starch granules. [ABSTRACT FROM AUTHOR]

Reserve starch from seeds and tubers is a crucial plant product for human survival. Much research has been devoted to quantitative and qualitative aspects of starch synthesis and its relation to abiotic factors of importance in agriculture. Certain aspects of genetic factors and enzymes influencing carbon assimilation into starch granules remain elusive after many decades of research. Starch phosphorylase (Pho) can operate, depending on metabolic conditions, in a synthetic and degradative pathway. The plastidial form of the enzyme is one of the most highly expressed genes in potato tubers, and the encoded product is imported into starch-synthesizing amyloplasts. We identified that the genomic locus of a Pho1a-type starch phosphorylase is duplicated in potato. Our study further shows that the enzyme is of importance for a normal starch granule phenotype in tubers. Null mutants created by genome editing display rounded starch granules in an increased number that contained a reduced ratio of apparent amylose in the starch.

Copyright of Journal of University of Anbar for Pure Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mung bean starch (MBS) has a strong potential to be used as food packages. However, preparing tough and uniform MBS films via industrial casting remains challenging due to the high viscosity of MBS slurry. Herein, MBS was modified by using dielectric barrier discharge cold plasma (CP) in an attempt to decrease its viscosity and improve the film‐forming properties. Results indicated that CP with an applied power of 120 W for 5 min decreased the peaking viscosity of MBS slurry from 2936.5 to 466.3 cP. Moreover, CP treatment simultaneously modified the crystallinity (20.2%–16.7%), amylose content (30.5%–44.3%), and short‐range orders (1.04–0.85). CP also broke the protective envelope of MBS granules. Further, the film‐forming properties of MBS were investigated. It was observed that CP‐modified MBS film casts exhibited uniform morphology, higher tensile strength (6.6–9.6 MPa), and improved thermal stability (89.0–100.8°C) compared with the untreated MBS film. The study indicates that the CP can be used as a green and facile technology to improve the properties of MBS films resulting in an efficient food packing material. [ABSTRACT FROM AUTHOR]

Fusarium wilt of banana, especially Tropical Race 4 (TR4) is a major factor restricting banana production. Developing a resistant cultivar and inducing plant defenses by elicitor application are currently two of the best options to control this disease. Isotianil is a monocarboxylic acid amide that has been used as a fungicide to control rice blast and could potentially induce systemic acquired resistance in plants. To determine the control effect of elicitor isotianil on TR4 in different resistant cultivars, a greenhouse pot experiment was conducted and its results showed that isotianil could significantly alleviate the symptoms of TR4, provide enhanced disease control on the cultivars 'Baxi' and 'Yunjiao No.1' with control effect 50.14% and 56.14%, respectively. We compared the infection processes in 'Baxi' (susceptible cultivars) and 'Yunjiao No.1' (resistant cultivars) two cultivars inoculated with pathogen TR4. The results showed that TR4 hyphae could rapidly penetrate the cortex into the root vascular bundle for colonization, and the colonization capacity in 'Baxi' was significantly higher than that in 'Yunjiao No.1'. The accumulation of a large number of starch grains was observed in corms cells, and further analysis showed that the starch content in 'Yunjiao No. 1' as resistant cultivar was significantly higher than that in 'Baxi' as susceptible cultivar, and isotianil application could significantly increase the starch content in 'Baxi'. Besides, a mass of tyloses were observed in the roots and corms and these tyloses increased after application with isotianil. Furthermore, the total starch and tyloses contents and the control effect in the corms of 'Yunjiao No.1' was higher than that in the 'Baxi'. Moreover, the expression levels of key genes for plant resistance induction and starch synthesis were analyzed, and the results suggested that these genes were significantly upregulated at different time points after the application of isotianil. These results suggest that there are significant differences between cultivars in response to TR4 invasion and plant reactions with respect to starch accumulation, tyloses formation and the expression of plant resistance induction and starch synthesis related genes. Results also indicate that isotianil application may contribute to disease control by inducing host plant defense against TR4 infection and could be potentially used together with resistant cultivar as integrated approach to manage this destructive disease. Further research under field conditions should be included in the next phases of study. [ABSTRACT FROM AUTHOR]

Brassica napus is the most important oilseed crop in the world, and the lipid was stored in the oil body (OB) in the form of triacylglycerol. At present, most of studies on the relationship between oil body morphology and seed oil content in B. napus was focused on mature seeds. In the present study, the OBs in different developing seeds of B. napus with relatively high oil content (HOC) of about 50% and low oil content (LOC) of about 39% were analyzed. It was revealed that the size of OBs was first increased and then decreased in both materials. And in late seed developmental stages, the average OB size of rapeseed with HOC was higher than that of LOC, while it was reversed in the early seed developmental stages. No significant difference was observed on starch granule (SG) size in HOC and LOC rapeseed. Further results indicated that the expression of genes that involved in malonyl-CoA metabolism, fatty acid carbon chain extension, lipid metabolism, and starch synthesis in the rapeseed with HOC was higher than that of rapeseed with LOC. These results give some new insight for understanding the dynamics of OBs and SGs in embryos of B. napus. [ABSTRACT FROM AUTHOR]

As a traditional and popular dietary supplement, lotus rhizome starch (LRS) has health benefits for its many nutritional components and is especially suitable for teenagers and seniors. In this paper, the approximate composition, apparent amylose content (AAC), and structural characteristics of five LRS samples from different regions were investigated, and their correlations with the physicochemical properties of granular and gelatinized LRS were revealed. LRS exhibited rod-shaped and ellipsoidal starch granules, with AAC ranging from 26.6% to 31.7%. LRS-3, from Fuzhou, Jiangxi Province, exhibited a deeper hydrogel color and contained more ash, with 302.6 mg/kg iron, and it could reach the pasting temperature of 62.6 °C. In comparison, LRS-5, from Baoshan, Yunnan Province, exhibited smoother granule surface, less fragmentation, and higher AAC, resulting in better swelling power and freeze-thaw stability. The resistant starch contents of LRS-3 and LRS-5 were the lowest (15.3%) and highest (69.7%), respectively. The enzymatic digestion performance of LRS was positively correlated with ash content and short- and long-term ordered structures but negatively correlated with AAC. Furthermore, the color and network firmness of gelatinized LRS was negatively correlated with its ash content, and the retrograde trend and freeze-thaw stability were more closely correlated with AAC and structural characteristics. These results revealed the physicochemical properties of LRS from different regions and suggested their advantages in appropriate applications as a hydrogel matrix.

Main conclusion: We discovered that the internodal swellings of Phryma (eudicots) stems were same as the internodal pulvini of Poaceae (monocots) from the viewpoints of internal structures and functions. The stems of eudicots are usually rod-shaped and are composed of nodes, attached by leaves, and internodes. The internodes of some species, belonging to the clade ‘asterids’ and its sister clade ‘Caryophyllales’ of eudicots, have swellings, which have negative tropism, at the basal or apical part of each internode. To know the internal features of the swollen internodes, we performed outer morphological and anatomical studies on the swollen internodes of Phryma, eudicots, one of the genera having swollen internodes, from the winter bud stage to the flowering stage. The results revealed the following: (i) the swollen regions of the internodes were composed of less lignified tissues (e.g., endodermis without Casparian strips, and xylem having less lignified xylem fibers); (ii) the internodal less lignified parts were supported by collenchyma; (iii) the endodermis includes amyloplasts, having accumulated starch granules, which would function as statoliths for negative gravitropism. Consequently, we determined that the swollen parts of the Phryma internodes are same as the internodal pulvini of Poaceae of monocots from the viewpoints of internal structures and functions. [ABSTRACT FROM AUTHOR]

The ovary-to-grain transition process is crucial for individual grain weight potential, but the but the physiological regulation of this highly dynamic and complex developmental process remains largely unknown unknown. Here, we performed a high temporal-resolution analysis of the proximal (large) and distal (small) ovaries/grains collected at an interval of 3 days from the booting stage to maturity stage. During grain-filling process, proximal grains always maintained a greater dry matter (0–36 days after anthesis, DAA), water (0–33 DAA), sugar (3–33 DAA), protein (6–36 DAA), and starch (amylose and amylopectin, 18–36 DAA) content, and larger volume (-15–36 DAA) than distal grains, but their partition or concentration did not differ between the proximal and distal grains. This result suggested that the capability of proximal and distal grains to produce water, sugar, protein, and starch within the same volume was similar; thus, grain sink (i.e. volume) was the cause in determinant of grain weight potential. In fact, the proximal ovary had a larger volume and related parameters (length, width and thickness) than the distal ovary before anthesis stage. in addition, the correlation coefficients of length and width with volume are higher than the correlation coefficients of thickness with volume. Clearly, we discovered a dynamic physiological mechanism for high proximal grain weight: the rapid elongation and widening of the proximal ovary improved its size, which passed to the proximal grain a volume advantage in the following ovary-grain transition, which allowed it to took up more sucrose and then converted into more starch and protein, improving dry matter accumulation and increasing proximal grain weight. Our findings provide a precise strategy for breeding and cultivation to increase individual grain weight potential by improving ovary volume. • Ovary morphology and volume are closely linked to grain volume potential. • Ovary length and width determines ovary volume potential. • Grain-filling rate and duration is limited by grain volume. • Increasing the proportion of fast-growing duration improves grain-filling potential. [ABSTRACT FROM AUTHOR]

Heterogeneous (interfacial) enzyme catalyzed hydrolysis of starch granules occurs in various biological systems, including plants, animal/human digestion, and microorganisms. Factors such as granular size, surface area, pores, and smoothness play crucial roles in influencing this process. However, limited understanding persists regarding the high enzymatic resistance of starch granules with smooth surfaces. In this study, we investigated the hydrolysis mechanism of glucoamylase (GA) on three different types of starch granules with smooth surfaces, extracted from Curcuma zedoaria (zedoary) rhizomes, Solanum tuberosum (potato) tubers, and Manihot esculenta (tapioca or cassava) roots. We compared the Langmuir adsorption, interfacial kinetics, and the multi-level structure of the three starches. Our data demonstrate that the lower enzymatic resistance observed in tapioca starch stems from the higher density of enzymatic attack sites (kinΓ max) recognized by GA on tapioca starch (1.0 nmol/g) compared to potato (0.6 nmol/g) and zedoary (0.3 nmol/g) starch granules. The high kinΓ max for tapioca starch was significantly influenced by its relatively lower B-type crystallinity, which is disrupted by the presence of short fa chains (degree of polymerization (DP) < 12) and long amylose chains. Furthermore, the relatively higher proportion of longer chains (fb 1 and fb 2 chains) on the surface of tapioca starch also contributed to higher kinΓ max for GA, resulting in lower enzymatic resistance. These findings enhance our understanding of how the structure of starch granules affects enzymatic catalysis, particularly in granular starches with smooth surfaces devoid of pores. Such insights are crucial for elucidating the digestion and utilization of starch granules. [ABSTRACT FROM AUTHOR]

Nut fruits likely played a significant role before and during the origin of agriculture; however, relatively little research conducted on the morphological characteristics and statistical comparisons of nut fruit starch granule hinders the progress of paleodietary analysis of prehistorical society. For better species identification of starch granule remaining on tools discovered at archaeological sites, it is desirable to develop a more abundant morphology database of modern nut fruit starch granules as well as the establishment of relevant identification standards. Therefore, nuts from 40 species in four genera (Quercus, Lithocarpus, Castanea, and Castanopsis) of Fagaceae were collected from South China for statistical measurement and comparative analysis. Starch granules are highly accumulated in 34 species except for 6 species, whose shapes involve oval, subcircular, drop-shaped, rounded triangle, polygonal, spherical caps, and bell-shaped types, or a combination of several types, and the average length is between 10 and 20 μm. According to research on Quercus phylogeny relationships, it was found that the species in the same infragenious section produce similar morphological characteristics of starch granules. The result was applied in the identification of starch granules extracted from stone tools from the 20 to 10 ka cultural layer of Xiaodong Rockshelter, and some starch granules can be recognized to species level, revealing that nuts from Quercus and Lithocarpus were gathered and exploited by ancient people. This expansion of modern starch presentation and comparison of nuts helps to improve the accuracy of the identification of ancient starch and deepen the understanding of plant utilization of ancient humans.

Lily scale-explants cultured in vitro regenerate adventitious bulblets at their base. Large scale-explants (6 × 18 mm; the basal side is 6 mm) yielded more (26%) bulblet growth than small ones (6 × 6 mm). The beneficial effect of the scale was also clear when bulblets excised from scale explants were transferred to fresh medium for additional growth. When a small piece of the original scale was left attached to these bulblets, growth increased by 33%. The growth of bulblets was highest in explants cut from the middle of a scale as opposed to the edge, and in explants cut from the basal half as opposed to the apical half. We examined the development of the scale-explants during the period of bulblet regeneration in vitro and the scale explants were physiologically very active as judged by the decrease in the amount of polysaccharides in the explant (ca.70%) and the increase in total amount of soluble sugars in the explant (ca. 40%). In the basal scale explants, the number of starch granules was far higher than in apical scale explants. During culture, the number of vascular bundles increased in basal and apical scale explants from 6 to 3.3 to 8 and 4 bundles, respectively. Key Message: Explants excised from different parts of lily bulb scales exhibit a different growth in vitro dependent on their amount of storage starch and vascular bundle intensity. [ABSTRACT FROM AUTHOR]

Starch is the primary form of reserve carbohydrate storage in plants. Rice (Oryza sativa L.) is a monocot whose reserve starch is organized into compounded structures within the amyloplast, rather than a simple starch grain (SG). The mechanism governing the assembly of the compound SG from polyhedral granules in apposition, however, remains unknown. To further characterize the proteome associated with these compounded structures, three distinct methods of starch granule preparation (dispersion, microsieve, and flotation) were performed. Phase separation of peptides (aqueous trypsin-shaving and isopropanol solubilization of residual peptides) isolated starch granule-associated proteins (SGAPs) from the distal proteome of the amyloplast and the proximal 'amylome' (the amyloplastic proteome), respectively. The term 'distal proteome' refers to SGAPs loosely tethered to the amyloplast, ones that can be rapidly proteolyzed, while proximal SGAPs are those found closer to the remnant amyloplast membrane fragments, perhaps embedded therein—ones that need isopropanol solvent to be removed from the mature organelle surface. These two rice starch-associated peptide samples were analyzed using nano-liquid chromatography–tandem mass spectrometry (Nano-HPLC-MS/MS). Known and novel proteins, as well as septum-like structure (SLS) proteins, in the mature rice SG were found. Data mining and gene ontology software were used to categorize these putative plastoskeletal components as a variety of structural elements, including actins, tubulins, tubulin-like proteins, and cementitious elements such as reticulata related-like (RER) proteins, tegument proteins, and lectins. Delineating the plastoskeletal proteome begins by understanding how each starch granule isolation procedure affects observed cytoplasmic and plastid proteins. The three methods described herein show how the technique used to isolate SGs differentially impacts the subsequent proteomic analysis and results obtained. It can thus be concluded that future investigations must make judicious decisions regarding the methodology used in extracting proteomic information from the compound starch granules being assessed, since different methods are shown to yield contrasting results herein. Data are available via ProteomeXchange with identifier PXD032314. [ABSTRACT FROM AUTHOR]

In vitro digestibility of starch is a common analysis in human nutrition research, and generally consists of performing the hydrolysis of starch by α-amylase in specific conditions. Similar in vitro assays are also used in other research fields, where different methods can be used. Overall, the in vitro hydrolysis of native starch is a bridge between all of these methods. In this literature review, we examine the use of amylolysis assays in recent publications investigating the complex starch structure-amylolysis relation. This review is divided in two parts: (1) a brief review of the factors influencing the hydrolysis of starch and (2) a systematic review of the experimental designs and methods used in publications for the period 2016–2020. The latter reports on starch materials, factors investigated, characterization of the starch hydrolysis kinetics and data analysis techniques. This review shows that the dominant research strategy favors the comparison between a few starch samples most frequently described through crystallinity, granule type, amylose and chain length distribution with marked characteristics. This strategy aims at circumventing the multifactorial aspect of the starch digestion mechanism by focusing on specific features. An alternative strategy relies on computational approaches such as multivariate statistical analysis and machine learning techniques to decipher the role of each factor on amylolysis. While promising to address complexity, the limited use of a computational approach can be explained by the small size of the experimental datasets in most publications. This review shows that key steps towards the production of larger datasets are already available, in particular the generalization of rapid hydrolysis assays and the development of quantification approaches for most analytical results. [ABSTRACT FROM AUTHOR]

Heat stress (HS) is a major environmental constraint in sustaining global waxy maize production under future climate condition. Starch physicochemical properties under 5‐day (HS5) and 10‐day (HS10) postsilking HS were investigated using two waxy maize hybrids (Suyunuo5 and Yunuo7) as materials. Ambient and high temperatures were 28°C/20℃ and 35°C/27℃, respectively. Starch granules were enlarged and exhibited additional pitting or cellular structures, increased amylopectin chain length, increased relative crystallinity, and increased 1047/1022 cm−1 ratio under HS. This finding indicated the stable and ordered structure of starch granules, especially under HS10. Pasting viscosities of Yunuo7 reduced by HS, and the change was the same under both HS5 and HS10. Peak viscosity of Suyunuo5 was unaffected and breakdown viscosity increased with HS5 although both characteristics decreased with HS10. HS increased gelatinization temperatures and retrogradation percentage. Results showed that HS enlarges starch granules with stable structure, reduces starch viscosities, and increases retrograde tendency, with severe detrimental effect under long HS durations. [ABSTRACT FROM AUTHOR]

Abstract Heat stress (HS) is a major environmental constraint in sustaining global waxy maize production under future climate condition. Starch physicochemical properties under 5‐day (HS5) and 10‐day (HS10) postsilking HS were investigated using two waxy maize hybrids (Suyunuo5 and Yunuo7) as materials. Ambient and high temperatures were 28°C/20℃ and 35°C/27℃, respectively. Starch granules were enlarged and exhibited additional pitting or cellular structures, increased amylopectin chain length, increased relative crystallinity, and increased 1047/1022 cm−1 ratio under HS. This finding indicated the stable and ordered structure of starch granules, especially under HS10. Pasting viscosities of Yunuo7 reduced by HS, and the change was the same under both HS5 and HS10. Peak viscosity of Suyunuo5 was unaffected and breakdown viscosity increased with HS5 although both characteristics decreased with HS10. HS increased gelatinization temperatures and retrogradation percentage. Results showed that HS enlarges starch granules with stable structure, reduces starch viscosities, and increases retrograde tendency, with severe detrimental effect under long HS durations.

Starch modification is vital for tailoring properties, involving changes in amylose/amylopectin ratio, chain lengths, and types of glucosidic linkages. Enzymatic modification, occurring on raw granular starch or post-gelatinization, offers mild, safe, and eco-friendly approaches. Although gelatinized starch allows more efficient modification, retaining the granular form is desirable for reduced energy consumption and hindering of retrogradation. Transglycosylases (TGases), such as branching enzyme, cyclodextrin glucanotransferase and 4-α-glucanotransferase, have gained attention for improving physiochemical attributes of starches by altering the structures of the α-glucan molecules. The TGases have been applied alone as well as in combination with chemical and/or physical treatments, manifesting the broad diversity in starch modification. However, understanding the relationship between the structures of TGases and their reaction products from granular starch is lagging behind. The present mini review aims to provide and discuss: i) structural features of different TGases applied in granular starch modification; ii) effects of enzymatic modification of starch granules, including use of single or multiple enzymes; iii) obtained modifications from the perspective of enzyme structures having an open, a loop-blocked or a tunnel-shaped active site. [ABSTRACT FROM AUTHOR]

Brassica napus is the most important oilseed crop in the world, and the lipid was stored in the oil body (OB) in the form of triacylglycerol. At present, most of studies on the relationship between oil body morphology and seed oil content in B. napus was focused on mature seeds. In the present study, the OBs in different developing seeds of B. napus with relatively high oil content (HOC) of about 50% and low oil content (LOC) of about 39% were analyzed. It was revealed that the size of OBs was first increased and then decreased in both materials. And in late seed developmental stages, the average OB size of rapeseed with HOC was higher than that of LOC, while it was reversed in the early seed developmental stages. No significant difference was observed on starch granule (SG) size in HOC and LOC rapeseed. Further results indicated that the expression of genes that involved in malonyl-CoA metabolism, fatty acid carbon chain extension, lipid metabolism, and starch synthesis in the rapeseed with HOC was higher than that of rapeseed with LOC. These results give some new insight for understanding the dynamics of OBs and SGs in embryos of B. napus.

Catalases (CATs) are important self-originating enzymes and are involved in many of the biological functions of plants. Multiple forms of CATs suggest their versatile role in lesion mimic mutants (LMMs), H2O2 homeostasis and abiotic and biotic stress tolerance. In the current study, we identified a large lesion mimic mutant9428 (llm9428) from Ethyl-methane-sulfonate (EMS) mutagenized population. The llm9428 showed a typical phenotype of LMMs including decreased agronomic yield traits. The histochemical assays showed decreased cell viability and increased reactive oxygen species (ROS) in the leaves of llm9428 compared to its wild type (WT). The llm9428 showed enhanced blast disease resistance and increased relative expression of pathogenesis-related (PR) genes. Studies of the sub-cellular structure of the leaf and quantification of starch contents revealed a significant decrease in starch granule formation in llm9428. Genetic analysis revealed a single nucleotide change (C > T) that altered an amino acid (Ala > Val) in the candidate gene (Os03g0131200) encoding a CATALASE C in llm9428. CRISPR-Cas9 targetted knockout lines of LLM9428/OsCATC showed the phenotype of LMMs and reduced starch metabolism. Taken together, the current study results revealed a novel role of OsCATC in starch metabolism in addition to validating previously studied functions of CATs. [ABSTRACT FROM AUTHOR]

Resistant starch (RS) in the diet reaches the large intestine and is fermented by the gut microbiota, providing beneficial effects on human health. The human gut bacterium FMB-CY1 was isolated and identified as a new species closest to Ruminococcus bromii. Ruminococcus sp. FMB-CY1 completely degraded RS including commercial RS types 2, 3, and 4, and generated glucose and maltose; however, it did not assimilate glucose. Genome analysis revealed 15 amylolytic enzymes (Amy) present in FMB-CY1. The evolutionary trees revealed that the Amys were well divided each other. All Amys (4, 9, 10, 12, and 16) containing cohesin and/or dockerin and scaffolding proteins known to be involved in constituting the amylosome, were identified. A new species of Ruminococcus, strain FMB-CY1, was considered to have the ability to form amylosomes for the degradation of RS. This new RS-degrading Ruminococcus species provides insights into the mechanism(s) underlying RS degradation in the human gut. [ABSTRACT FROM AUTHOR]

The physical, chemical, and cooking qualities of pumpkin are important qualitative variables to consumers and food processors. Pumpkin is typically stored in ambient conditions in the supply chain. The objectives of this study were to monitor the changes in freshly harvested and ambient stored pumpkin quality and to determine the key quality parameters for classifying fresh and stored fruit. Physical properties such as fruit weight, firmness, and dimension as well as chemical properties declined after storage, especially for starch content (from 8.3 to 5.8% w/w), starch granule size (from 7.2 × 10−5 to 6.9 × 10−5 μm2), and pectin content (from 17.0 to 5.0 g kg−1 fresh weight). Amounts of soluble solids, lipids, and β-carotene in pumpkin flesh, on the other hand, escalated with storage time. Nonetheless, great diminutions were observed in cooking quality in terms of hardness (from 32.6 to 9.9 N), gumminess (from 3.4 to 1.4 N), and chewiness (from 1.5 to 0.4 J) in texture profiles of cooked pumpkin as well as peak viscosity (from 618.1 to 290.3 cP), final viscosity (from 979.5 to 434.1 cP), and setback (from 387.9 to 161.0 cP) values of the pasting properties of pumpkin starch. Principal component analysis (PCA) performed with texture profile data revealed the variations among fresh and stored pumpkin, and this was considered the effective quality trait for classifying both pumpkin types. [ABSTRACT FROM AUTHOR]

The functional properties of Andean grain starches of two species, amaranth ( Amaranthus caudatus ) and canihua ( Chenopodium pallidicaule ), three cultivars each, were studied. The study focused on chemical composition, pasting properties, thermal properties, water solubility index (WSI), swelling power (SP), and granule morphology. All amaranth starches were waxy starches, with amylose content less than 5 %, which had some differences in chemical composition (p < 0.05). The pasting properties differed between the species, canihua showed more resistance, than amaranth, to heat and shear stress (higher cool paste (CPV) and lower breakdown (BD), ranged between 1250 and 1600 cP and -30 - 10 cP respectively. The amaranth starches presented only similar CPV with 800-1000 cP, while canihua cultivars presented similar PT and BD, and both species presented similar PV, around 1000 cP. Thermal properties (T o , T p , T c , ΔH, and ΔT) differed among cultivars and species. These differences could be related to the homogeneity molecular structure and content of amylose in canihua cultivars and possibly to genotype factor. Polygonal shapes were the predominant shape of starch granules, ranged 1.0-1.4 μm and 0.8-0.9 μm, for amaranth and canihua starches respectively. Amaranth starches swelled quickly to disintegrate partially at the end, contrary to canihua starches. The thermal and pasting properties were correlated between them. SB, CPV, HPV, CS, were correlated to the content of amylose in canihua starches. One amaranth cultivar was significantly different from the others. Thus, according the functional properties differenced both species and some cultivars in each species. Additionally, the amaranth starch has the potential to be used in the food industry where heat and stress are applied such as extrusion, while canihua starches can be used in desserts or in cosmetic uses, based on their functional properties., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Jenny Merida Lopez reports financial support, article publishing charges, equipment, drugs, or supplies, statistical analysis, and travel were provided by Swedish International Development Cooperation Agency. Cinthia Carola Rojas reports a relationship with Universidad Mayor de San Simon that includes: employment. Bjorn Bergenstahl reports a relationship with Lund University that includes: employment. Jeanette K. Purhagen reports a relationship with 10.13039/501100003252Lund University that includes: employment. None has patent pending to None. None If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The microwave heating has become widely popular in potato processing because of its high heating rate, short processing time, and for controlling undesirable changes in starch. In the experiment potato columns of TPS potato ‘BARI TPS-1’ and local potatoes ‘Diamant’, ‘Tel Pakri’ and ‘Romana’ were heated with 50 mL of water for 0, 20, 40, 60, 90, 120, 240, and 300 sec by a microwave oven; and the changes in potato columns were analyzed physiologically and histologically to investigate how potato tuber and starch condition changes in local potato and TPS tubers after microwave heating. The ‘BARI TPS-1’ potato columns resulted comparatively higher rate of weight loss and firmness loss percentage than the other seed potato varieties, indicating that temperature rapidly increased in TPS tuber columns than that of the others. Among local varieties ‘Tel Pakri’ gave a relatively higher weight loss and firmness loss percentage than the others. This study also showed comparatively higher solubility percentage in ‘BARI TPS-1’ tuber than the other local varieties, suggesting rapid disruption of swollen starch granule and faster starch degradation in TPS than the other local potato starches. Scanning Electron Microscope (SEM) images of starch granule showed rapidly ruptured and clumped starch granules in ‘BARI-TPS-1’ than the others, indicating TPS starch might obtain gelatinization temperature within a shorter period of microwave heating than that of the other varieties. [ABSTRACT FROM AUTHOR]

Background and objectives: Variation in composition and functionality of glutinous rice starch greatly affects their industrial application. This study examined the starch compositional, structural, and functional variability among five Thai glutinous rice cultivars, and the effect of molecular structure and composition on starch functionality was pinpointed. Findings: Amylose content, amylopectin chain‐length distribution (CLD), and relative crystallinity were not different among the cultivars (p ≤.05), whereas RD14 possessed largest mean granule diameter. Conclusion temperature of gelatinization and peak viscosity (PV) were lowest in RD6 and RD10, respectively, while RD6, RD10, and RD14 had lower breakdown (BD) compared to others. Despite small variation within each parameter, multivariate analysis revealed the distinct characteristic of waxy donor, RD6, and RD10 compared to others. Proportion of amylopectin B1 chains and granule size showed negative correlation (r > 0.5) with PV and BD, respectively, whereas proportion of amylopectin B2 chains positively correlated (r > 0.5) with PV and final viscosity (FV). Conclusion: Amylopectin CLD and starch granule size were the key factors determining starch pasting properties among these waxy rice genotypes. Significance and novelty: Variations in composition, structure, and properties of Thai glutinous rice starches were observed, which could be adopted for a diverse array of end uses. [ABSTRACT FROM AUTHOR]

High hydrostatic pressure (HHP) treatment has been widely used to achieve the desired safety and quality of food products during the past two decades. In this work, effects of HHP (100–600 MPa) pretreatments on physicochemical properties, bioactive components and antioxidant activities of dehydrated yam slices were studied. The results indicated that HHP pretreatments dramatically improved the hardness, crispness, integrity ratio, and total color change of the dehydrated yam slices, while significantly inhibited their rehydration ratio when the pressure was ≥200 MPa. According to the results of scanning electron microscopy (SEM), optical microscopy (OM), and polarized optical microscopy (POM), HHP could induce the indentations and cracks of partly starch granules surface, but without any starch gelatinization. Compared with the control sample, higher total polyphenols compounds (TPC) and allantoin content were observed in the HHP pretreated samples, and the 200 MPa pretreated sample had the highest TPC and allantoin which reached 0.45 mg GAE/g and 5.47 mg/g dry weight, respectively. Furthermore, the antioxidant analysis showed that 100 and 200 MPa pretreatment could effectively enhance the antioxidant capacity of the yam slices. The above results suggested that HHP pretreatment, especially under 200 MPa, could be an appropriate assist for preparation of high-quality dehydrated yam slices. • High hydrostatic pressure (HHP) pretreatment was used to improve dried yam slices quality. • Integrity ratio and hardness were increased effectively by HHP ≥200 MPa. • No effects on the gelatinization of yam starch induced by HHP. • HHP remarkably enhanced total phenolic compounds and allantoin. [ABSTRACT FROM AUTHOR]

[Display omitted] • Storage temperature of maize significantly affects carotenoid degradation rate. • Hybrids with higher grain hardness ensure better carotenoid retention. • Elevated contents of zeins, free and bound lipids in grain stabilize carotenoids. Carotenoids in maize grain degrade during storage, but the relationship between their stability and the physicochemical properties of the grain is unclear. Therefore, the carotenoid degradation rate in milled grain of three dent hybrids differing in grain hardness was evaluated at various temperatures (-20, 4 and 22 °C). The carotenoid degradation rate was calculated using first-order kinetics based on the content in the samples after 7, 14, 21, 28, 42, 56, 70 and 90 days of storage and related to the physicochemical properties of the grain. The highest grain hardness was found in the hybrid with the highest zein and endosperm lipid concentration, while the lowest grain hardness was found in the hybrid with the highest amylose content and the specific surface area of starch granule (SSA). As expected, carotenoids in milled maize grain were most stable at −20 °C, followed by storage at 4 and 22 °C. Tested hybrids differed in the degradation rate of zeaxanthin, α-cryptoxanthin and β-carotene, and these responses were also temperature-dependent. In contrast, all hybrids showed similar degradation rate for lutein and β-cryptoxanthin regardless of the storage temperature. Averaged over the hybrids, the degradation rate for individual carotenoids ranked as follows: lutein < zeaxanthin < α-cryptoxanthin < β-cryptoxanthin < β-carotene. The lower degradation rate for most carotenoids was mainly associated with a higher content of zein and specific endosperm lipids, with the exception of zeaxanthin, which showed an opposite pattern of response. Degradation rate for lutein and zeaxanthin negatively correlated with SSA, but interestingly, small starch granules were positively associated with higher degradation rate for most carotenoids. Dent-type hybrids may differ significantly in carotenoid degradation rate, which was associated with specific physicochemical properties of the maize grain. [ABSTRACT FROM AUTHOR]

Starch is the primary form of reserve carbohydrate storage in plants. Rice (Oryza sativa L.) is a monocot whose reserve starch is organized into compounded structures within the amyloplast, rather than a simple starch grain (SG). The mechanism governing the assembly of the compound SG from polyhedral granules in apposition, however, remains unknown. To further characterize the proteome associated with these compounded structures, three distinct methods of starch granule preparation (dispersion, microsieve, and flotation) were performed. Phase separation of peptides (aqueous trypsin-shaving and isopropanol solubilization of residual peptides) isolated starch granule-associated proteins (SGAPs) from the distal proteome of the amyloplast and the proximal ‘amylome’ (the amyloplastic proteome), respectively. The term ‘distal proteome’ refers to SGAPs loosely tethered to the amyloplast, ones that can be rapidly proteolyzed, while proximal SGAPs are those found closer to the remnant amyloplast membrane fragments, perhaps embedded therein—ones that need isopropanol solvent to be removed from the mature organelle surface. These two rice starch-associated peptide samples were analyzed using nano-liquid chromatography–tandem mass spectrometry (Nano-HPLC-MS/MS). Known and novel proteins, as well as septum-like structure (SLS) proteins, in the mature rice SG were found. Data mining and gene ontology software were used to categorize these putative plastoskeletal components as a variety of structural elements, including actins, tubulins, tubulin-like proteins, and cementitious elements such as reticulata related-like (RER) proteins, tegument proteins, and lectins. Delineating the plastoskeletal proteome begins by understanding how each starch granule isolation procedure affects observed cytoplasmic and plastid proteins. The three methods described herein show how the technique used to isolate SGs differentially impacts the subsequent proteomic analysis and results obtained. It can thus be concluded that future investigations must make judicious decisions regarding the methodology used in extracting proteomic information from the compound starch granules being assessed, since different methods are shown to yield contrasting results herein. Data are available via ProteomeXchange with identifier PXD032314.