ORCID Profile
0000-0002-2337-6962
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.FOODCHEM.2019.125258
Abstract: Starch is the abundant component in rice endosperm, and its microstructure determines the quality and functional properties of rice grain. It is well known that the starch fine structure is markedly influenced by high temperature during grain filling. However, it is poorly understood on the competition among starch synthesis related enzymes as well as the interaction between amylose and amylopectin biosynthesis under increased growing temperature. In this study, the non-waxy and waxy rice were planted under normal and high temperatures. Parameterizing analysis of the starch microstructure using mathematical models proved that amylose synthesis competed with the elongation of long amylopectin chains (DP>60) Short chains of amylopectin can be used as the substrate for elongation of longer amylopectin chains High temperature eliminated the consistency and regularity of the synthesis of amylose and amylopectin. In addition, enzyme assay proved the validity of fitting results from mathematical modeling analysis of starch.
Publisher: MDPI AG
Date: 14-01-2023
Abstract: In vitro digestion methods that can accurately predict the estimated GI (eGI) values of complex carbohydrate foods, including biscuits, are worth exploring. In the current study, standard commercial biscuits with varied clinical GI values between 9~30 were digested using both the INFOGEST and single-enzyme digestion protocols. The digestion kinetic parameters were acquired through mathematical fitting by mathematical kinetics models. The results showed that compared with the INFOGEST protocol, the AUR180 deduced from digesting using either porcine pancreatin or α-amylase showed the best potential in predicting the eGI values. Accordingly, mathematical equations were established based on the relations between the AUR180 and the GI values. When digesting using porcine pancreatin, GI= 1.834 + 0.009 ×AUCR180 (R2= 0.952), and when digesting using only α-amylase, GI= 6.101 + 0.009 ×AUCR180 (R2=0.902). The AUR180 represents the area under the curve of the reducing-sugar content normalized to the total carbohydrates versus the digestion time in 180 min. The in vitro method presented enabled the rapid and accurate prediction of the eGI values of biscuits, and the validity of the formula was verified by another batch of biscuits with a known GI, and the error rate of most s les was less than 30%.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.CARBPOL.2016.08.078
Abstract: Correlations among barley protein, starch molecular structure and grain size were determined using 30 barley s les with variable protein contents. Starch molecular structure was characterized by fluorophore-assisted carbohydrate electrophoresis and by size-exclusion chromatography (SEC, also termed GPC). The chain-length distributions of amylopectin were fitted using a mathematical model reflecting the relative activities of starch branching enzymes and starch synthase enzymes. Increased protein content significantly and negatively correlated with higher amounts of amylose with longer chains (degree of polymerization, DP 1600-40000) while barley grain sizes positively associated with starch contents. Protein content also positively correlated with the proportion of longer chains of amylopectin (DP 34-100). These results showed that the enzyme activities of starch synthases change with protein content, leading to altered starch contents, structures and grain sizes. From this perspective, selecting for large grain size (or low protein content) does not necessarily relate to starch structure, although may suggest long chains of amylopectin. Measuring starch structure could give a good indication of process performance in human food, animal feed and brewing, as all these structural features contribute to significant functional properties.
Publisher: Tsinghua University Press
Date: 06-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2FO03737H
Abstract: Effects of storage temperatures on the retrogradation and digestion property of cooked whole rice.
Publisher: MDPI AG
Date: 16-12-2018
DOI: 10.3390/FERMENTATION4040103
Abstract: Background: Achieving optimal fermentation is challenging when the variation within malt starch structure and enzyme activities are not part of the standard malting specifications. This study explores how the variation of starch and starch amylolytic enzymes in both malts and rice adjuncts affect the mashing and the subsequent yeast fermentation in the laboratory-scale production of beer. Results: The addition of rice adjuncts significantly increased the maltose content whilst reducing the glucose content during mashing. The maltotriose content, released during mashing, was significantly negatively correlated with the total amylose content (r = −0.64, p 0.05), and significantly negatively correlated with the number of amylopectin longer chains (degree of polymerization 37–100) (r = −0.75, p 0.01). During fermentation, while the content of maltotriose significantly and positively correlated with both the rate and amount of ethanol production (r = 0.70, p 0.05 r = 0.70, p 0.05, respectively), the content of soluble nitrogen in the wort was significantly and positively correlated with both the rate and the amount of ethanol production (r = 0.63, p 0.05 r = 0.62, p 0.05, respectively). The amount of amylopectin with longer chains was however, significantly negatively correlated with the ethanol production (r = −0.06, p 0.05). Small variations among the ethanol concentration and the rate of ethanol production during fermentation were found with the addition of different rice varieties. Conclusions: The effects of the rice adjuncts on the performance of fermentation depends on the properties of the malt, including the protein modification and malt enzyme activities. This study provides data to improve standard malt specifications in order for brewers to acquire more efficient fermentation, and includes useful molecular structural characterisation.
Publisher: Springer Science and Business Media LLC
Date: 10-05-2023
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 02-2023
DOI: 10.1016/J.JAD.2022.11.021
Abstract: Insomnia is a risk factor for affective disorders. This study examined whether in iduals with insomnia symptoms early in the pandemic, either pre-existing or new-onset, were more vulnerable to anxiety and depressive symptoms over time than those who maintained normal sleep. Additionally, sleep-related factors such as pre-sleep arousal were assessed for their influence on clinically significant anxiety and depression risk. Using a global online survey with 3-, 6-, and 12-month follow-ups between April 2020 and May 2021, data from 2069 participants (M = 46.16 ± 13.42 years 75.3 % female) with pre-existing, new-onset, or no insomnia symptoms was examined using mixed-effects and logistic regression models. New-onset and pre-existing insomnia predicted persistent anxiety and depressive symptoms longitudinally (p's < 0.001), over other known risk factors, including age, sex, and previous psychiatric diagnoses. Anxiety and depressive symptoms in both insomnia groups remained above clinically significant thresholds at most time points, whereas normal sleepers remained subclinical. Pre-sleep arousal was found to increase the risk of clinically significant anxiety (OR = 1.05) and depressive symptoms (OR = 1.09) at 12-months. Sleep effort contributed to anxiety (OR = 1.06), whereas dysfunctional sleep-related beliefs and attitudes predicted clinically significant depression (OR = 1.22). Insomnia group categorization was based on self-report at baseline supported by a validated measure. High participant attrition was observed at 3-months (53 % n = 971), but retention remained steady till 12-months (63 %, n = 779). Insomnia is a modifiable risk factor for persistent anxiety and depressive symptoms that needs to be addressed in mental healthcare. Additionally, pre-sleep arousal may be an important transdiagnostic process linking insomnia with affective disorders.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.CARBPOL.2018.09.078
Abstract: Starch molecular fine structure can have significant effects on pasting and thermal properties of rice flour. This study investigates the mechanistic explanation of these effects, by obtaining data for rice flour with different starch fine structures. Starch structural parameters for both amylose and amylopectin were obtained using size-exclusion chromatography (SEC, a type of gel-permeation chromatography, GPC), and the data fitted with methodologies (one of which is new) based on the underlying biosynthetic processes. It is found that the setback viscosity of rice starch measured by the rapid viscosity analyzer (RVA) depends not only on amylose content but also on the amount of long amylose chains and the size of whole amylopectin molecules. Conversely, long amylose chains and large amylopectin molecules are found to be responsible for the lower peak and trough viscosities. Other results for the effects of amylopectin chains are consistent with the literature. Mechanistic explanations for all observations are put forward. The novel findings about the influence of the distribution of amylose chain lengths and whole amylopectin size, in addition to amylose content alone, can provide guidance for rice breeders and food scientists in the selection of rices with improved functional properties.
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 11-2020
Publisher: MDPI AG
Date: 11-12-2022
Abstract: Whole white rice is a major staple food for human consumption, with its starch digestion rate and location in the gastrointestinal tract having a critical role for human health. Starch has a multi-scale structure, which undergoes order-disorder transitions during rice cooking, and this structure is a major determinant of its digestibility. The length distributions of amylose and amylopectin chains are important determinants of rice starch gelatinization properties. Starch chain-length and molecular-size distributions are important determinants of nucleation and crystal growth rates, as well as of intra- and intermolecular interactions during retrogradation. A number of first-order kinetics models have been developed to fit starch digestograms, producing new information on the structural basis for starch digestive characteristics of cooked whole rice. Different starch digestible fractions with distinct digestion patterns have been found for the digestion of rice starch in fully gelatinized and retrograded states, the digestion kinetics of which are largely determined by starch fine molecular structures. Current insights and future directions to better understand digestibility of starch in whole cooked rice are summarized, pointing to ways of developing whole rice into a healthier food by way of having slower starch digestibility.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1FO00450F
Abstract: A more general approach for fitting in vitro starch digestograms by first-order kinetics models is proposed.
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.CARBPOL.2018.08.089
Abstract: Arabinoxylan (AX) and xyloglucan (XG) are important components of primary cell walls of cereal grains and vegetables/fruits, respectively. Despite the established health benefits of these non-starch polysaccharides, the mechanisms of their utilisation by the gut microbiota are poorly understood. In this study, the mechanisms of solubilised wheat AX and tamarind XG degradation were investigated under in vitro fermentation conditions using a porcine faecal inoculum. Through structural analysis of the polymers, we demonstrate that depolymerisation by microbial surface accessible endo-degrading enzymes occurs prior to active fermentation of AX or XG. Breakdown products are released into the medium and potentially utilised cooperatively by other microbes. Acetate and propionate are the main fermentation products and are produced concurrently with polysaccharide depletion. Butyrate, however, is produced more slowly consistent with it being a secondary metabolite.
Publisher: Springer Science and Business Media LLC
Date: 14-03-2018
DOI: 10.1038/S41598-018-22818-4
Abstract: Recent studies show that a single or small number of intestinal microbes can completely degrade complex carbohydrates. This suggests a drive towards competitive utilisation of dietary complex carbohydrates resulting in limited microbial ersity, at odds with the health benefits associated with a erse microbiome. This study investigates the enzymatic metabolism of wheat and rye arabinoxylans (AX) using in vitro fermentation, with a porcine faecal inoculum. Through studying the activity of AX-degrading enzymes and the structural changes of residual AX during fermentation, we show that the AX-degrading enzymes are mainly cell-associated, which enables the microbes to utilise the AX competitively. However, potential for cross-feeding is also demonstrated to occur by two distinct mechanisms: (1) release of AX after partial degradation by cell-associated enzymes, and (2) release of enzymes during biomass turnover, indicative of co-operative AX degradation. This study provides a model for the combined competitive-co-operative utilisation of complex dietary carbohydrates by gut microorganisms.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 11-2020
Publisher: Wiley
Date: 02-09-2021
DOI: 10.1111/JTXS.12626
Abstract: The reversibility of gel property of alcohol (methanol, ethanol)‐pretreated fish gelatin (FG) were investigated through removing alcohol solutions by freeze drying. Results showed that the gel strength and the hardness of FG could be retained (1%, 40%) or even improved (1% methanol) using low or high concentration alcohol solutions, while decreased in medium concentration alcohol solutions. Compared with untreated FG, rheology results showed that, all alcohol solutions pretreated FG had lower apparent viscosity, while higher alcohol solutions pretreated ones decreased the gel and melt points and shorten the gelation time. Sodium dodecyl‐sulfate polyacrylamide gel electrophoresis showed that methanol pretreated FG had the higher α contents than those of ethanol pretreated. Circular dichroism spectra results indicated that β‐sheet could be decreased after removing ethanol solutions, whereas the β‐sheet increased after removing the methanol solutions. Moreover, low field nuclear magnetic resonance relaxation test showed that pretreated FG had lower transverse relaxation times of internal water ( T 21 and T 22 ) compared to that of the untreated FG. Overall, FG still retains higher gel properties after removing the low or high alcohol concentrations.
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.CARBPOL.2017.05.046
Abstract: Australian wild rices have significant genetic differences from domesticated rices, which might provide rices with different starch molecular structure and thus different functional properties. Molecular structure, gelatinization properties, and pasting behaviours of starch of three Australian wild rices (Oryza australiensis, taxa A (O. rufipogon like) and taxa B (O. meridionalis like)) were determined and compared to domesticated indica and japonica rice. These had higher amylose content, more shorter amylose chains and fewer short amylopectin chains, resulted in a high gelatinization temperature in these wild rices. Compared to domesticated japonica rice, taxa A had a lower pasting viscosity taxa B had a similar pasting viscosity but lower final viscosity. The significantly different starch molecular structure from that of normal domesticated rices, and concomitantly different properties, suggest advantageous uses in products such as rice crackers or rice pudding, and a source of nutritionally-desirable slowly digestible starch.
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.IJBIOMAC.2019.06.149
Abstract: Two varieties of barley s les were subjected to germination conditions to investigate the underlying mechanisms underpinning changes in molecular structure, chemical compositions and thermal properties of starch during this process. Starch thermal transitions were examined using differential scanning calorimetry, and the molecular fine structure of amylose and amylopectin were determined using size-exclusion chromatography and fluorophore-assisted carbohydrate electrophoresis, respectively. Both amylose and amylopectin chains were hydrolyzed during germination, but a preferential attack of amylopectin chains was observed with concomitant increases of relative amylose content, resulting in increased gelatinization temperatures (onset, peak, conclusion) and reduction in enthalpy change. Amylolytic enzyme activities increased during germination, resulting in decreased starch content. After malting, significant degradation of amylose chains followed by the reduction of gelatinization temperatures was seen. Roasting of pale malts was found to degrade starch and protein whilst completely stopping enzyme activities. The resulting coloured malts had extremely low starch enthalpy change due to the loss of amylopectin crystallinity at high temperature. This study provides insights into starch structural changes of barley throughout malting and roasting, which are determining factors for fermentable sugar production during mashing.
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.CARBPOL.2022.119745
Abstract: The addition of amino acids (AAs) including glycine (Gly), lysine (Lys) and glutamic acid (Glu) with different concentrations on starch morphological, physicochemical and in vitro digestion properties were studied. While AAs showed no effects on neither morphology nor crystalline characters, they all significantly influenced the starch relative crystallinity and swelling capacity in an order of Glu > Lys > Gly. For all s les, both fastly- and slowly- digestible starch fractions (S
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.FOODCHEM.2019.125276
Abstract: Gelatinization properties of physically modified starch-gluten matrices are often exclusively traced back to starch constitution without considering the state of gluten. Thus, gelatinization of model dough, combining reference (rS)/modified starch (mS) with reference (rG)/modified gluten (mG), was investigated using nuclear magnetic resonance and differential scanning calorimetry to relate structural alterations of biopolymers to their hydration properties. No differences were found in gelatinization onsets of model dough consisting of rS and mS combined with mG (starch: gluten = 50:50 (m/m)), although gelatinization enthalpy of mS mG (1.7 ± 0.4 J/g dm) was significantly lowered in comparison to rS mG (2.2 ± 0.2 J/g dm). Relaxation time T
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.FOODCHEM.2019.01.030
Abstract: Autoclave cooking is used to produce "convenience" rice. In this study, autoclaving effects on sensory properties are investigated, and mechanistic explanations in terms of the underlying molecular structure are explored by analyzing this structure by size-exclusion chromatography and fitting the results with models based on biosynthetic processes. Compared to steam cooking, autoclaving produces stickier texture, and slightly affects hardness. It is found that molecular sizes of leached starch of both autoclaved and steam cooked rice are similar, but significantly smaller than that of the parent grain starch model fitting parameters of leached amylopectin and amylose structures between autoclaved rice and steam cooked rice display no large variations. The amount of leached amylopectin (an important texture-controlling parameter) of autoclaved rice is higher than that of steam cooked rice. Correlation analysis indicates that, compared to steam-cooked rice, the stickier texture of autoclaved rice is caused by more amylopectin leaching during autoclaving.
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.FOODCHEM.2018.05.049
Abstract: A new combined methodology for obtaining relations between starch molecular structure and digestion kinetics of starch-based foods is illustrated using published data on cooked rice. Digestibility data are treated with the logarithm of slopes method, giving region(s) where first-order loss kinetics are applicable accurate values for the rate parameters are obtained by non-linear least-squares. A new method is developed to find independent structural variables for whole and enzymatically-debranched starches. Chain-length distributions of amylose and amylopectin are fitted with models using biologically-meaningful parameters, including accounting for SEC band broadening. While slower digestion rate usually means higher residual starch, this is not always so both digestion parameters must be considered separately. The treatment shows that digestion kinetics depend on amylose content and also amylose molecular fine structure: the amount of shorter amylose chains and total amylose molecular size. The new combined data-treatment methodology is applicable to a wide range of food systems.
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.FOODCHEM.2022.133471
Abstract: Chalky rice has an undesirable appearance and reduced commercial value. To understand the relationship between starch structural characteristics and chalkiness, a comprehensive investigation was conducted of molecular structural differences between starch in chalky and translucent parts of the same chalky grains (three Japonica and two Indica rices), this strategy being such as to minimize genetic and environmental effects. Compared to translucent parts, chalky parts had a larger ratio of large to small branched molecules and more short amylopectin chains (degree of polymerization < 35), but fewer longer chains, which affect higher-level starch structures, such as crystallinity. No significant differences in amylose structure were observed. White-belly and white-core chalky grains showed distinguishable starch characteristics, suggesting studying different chalkiness types separately. These findings extend understanding of chalkiness from the perspective of starch structure, and control of this structure can in the future help breeders to develop strategies against the formation of chalkiness.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 03-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1FO04256D
Abstract: Amyloglucosidase (AMG) and α-amylase (AMY) are both involved in starch digestion in human small intestine, whereas their mutual interactions with starch molecules of distinct structures are still unknown.
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.CARBPOL.2019.115185
Abstract: Starch branching enzymes (SBEs) play a major role in determining starch molecular structure in cereal endosperm. This study investigates how SBEIIs contribute to the chain-length distributions (CLDs) of both amylopectin and amylose, obtained by enzymatic debranching of native starch. Wheat starches with low (37%) to high (93%) amylose content were obtained through altering SBEII in planta. Multiple components were detected in both amylose and amylopectin CLDs. Model fitting of these CLDs reveals a quantitative association between the enzyme activities in amylopectin and amylose. SBEIIa modifies shorter branches (degree of polymerization DP ≲ 12) in amylopectin and longer amylose chains with a CLD peak at ˜3000 DP. SBEIIb acts on longer branches (DP≲ 32) in amylopectin, while its effect on amylose fine structure is not significant. Using both the amylose and amylopectin models to analyze the CLD reveals connections between amylose and amylopectin in wheat starch biosynthesis.
Publisher: Informa UK Limited
Date: 24-01-2023
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 04-2018
Publisher: MDPI AG
Date: 27-06-2023
Abstract: In the current study, the production of microparticles released from fifteen commercial sugarcane pulp (SCP) take-out containers into different food simulants under different conditions was investigated, where deionized water (DI water), 4% acetic acid (4% HAc), and 95% ethanol (95% EtOH) were used to simulate aqueous, acidic, and fatty foods, respectively. Results showed that compared with DI water and 95% EtOH, 4% HAc caused the degradation of sugarcane fibers, thereby releasing the highest number of microparticles. The overall migration values of the sugarcane pulp take-out containers in 4% HAc were above the prescribed limit of 10 mg/dm2. Furthermore, it was estimated that consumers may intake 36,400–231,700 microparticles in a take-out container at one time, of which the proportion of particles with a particle size between 10 and 500 μm was the highest, ranging from 26,470 to 216,060 items. Moreover, the Al and Fe are the main metals in these take-out containers, ranging between 35.16 and 1244.04 and 44.71 and 398.52 mg/kg, respectively, followed by Pb, Ti, and Sr. This study provides important information that the safety of both the production of microparticles and the metallic elements should be considered for SCP take-out containers when in contact with food.
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.JHAZMAT.2022.129516
Abstract: The rapid development of online-to-offline food delivery service has necessitated the replacement of plastic lunchbox using biodegradable ones. In current study, a total number of fourteen panelists were firstly recruited and trained to investigate how different commercial disposable lunchboxes affect the freshly cooked rice sensory properties during heat preservation (60 °C, 60 min). The lunchboxes were made of pure polypropylene (PP), polypropylene-starch (PP-S), pure wheat-straw and sugarcane-straw (WS & SS) and Paper. The discrepancy of volatile aromatic substances was then analyzed using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) to study the possible mechanism beneath the variations of the influences of different lunchboxes on the aromatic properties of rice. Results showed that, compared with the textural attributes, the aroma was significantly and positively correlated with panelist's acceptability, among which, the aroma of starchy, sulfur and smoky are the most important ones. The moisture absorption plays an important role in affecting the aromatic characteristics of the packaged rice. While all lunchboxes have inhibitory effects on the production of volatile flavor substances including 2,6-Dimethylpyrazine, 2-Acetylpyrazine and γ-Octalactone, pure PP and PP-S lunchboxes generated undesirable flavor substances including 2-Ethyl-1-hexanl and C hene, and thus reduced panelist's preferences. It was also found that the panelist liked the rice packaged by Paper lunchbox the best because of its better performance in maintaining the aroma of starchy and sulfur, the two substances that are associated with the higher concentration of ethereal and fruity volatile flavor substances. This study provides important information for manufacturers to understand how different disposable lunchboxes may impact the textural and aromatic properties of packaged foods.
Publisher: Elsevier BV
Date: 06-2023
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.FOODCHEM.2019.05.168
Abstract: The eating and cooking quality (ECQ) of stored rice grains is significantly affected by ageing, but the molecular mechanisms for this are not well understood. In the present study, changes of starch hierarchical structures and thermal properties of starch were investigated for rices with up to 12 months storage. For the first time, it was seen that storage resulted in molecular degradation of starch. This mainly involved shorter amylose chains and around (1 → 6)-α glycosidic branching points of amylopectin, which altered the crystalline structure. This resulted in lower gelatinization temperatures and enthalpy but higher crystalline heterogeneity. The ageing effect was varietally-dependent. The information obtained from this study offers improved molecular-level understanding of the effects of ageing process on rice cooking and eating qualities.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.FOODCHEM.2017.09.021
Abstract: The conversion of barley starch to sugars is a complex enzymic process. Most previous work concerned the biotechnical aspect of in situ barley enzymes. However, the interactions among the macromolecular substrates and their effects on enzymic catalysis has been little examined. Here, we explore the mechanisms whereby interactions of protein and starch in barley flour affect the kinetics of enzymatic hydrolysis of starch in an in vitro system, using digestion rate data and structural analysis by confocal microscopy. The degradation kinetics of both uncooked barley flour and of purified starches are found to be two-step sequential processes. Barley proteins, especially the water-soluble component, are found to retard the digestion of starch degraded by α-amylase: the enzyme binds with water-insoluble protein and with starch granules, leading to reduced starch hydrolysis. These findings are of potential industrial value in both the brewing and food industries.
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.CARBPOL.2019.05.031
Abstract: Cooked high-amylose rices have slower digestibility, giving nutritional benefits, but inferior eating qualities. Molecular structural mechanisms for this inferior eating quality are found here using structural analysis by size-exclusion chromatography of both the parent starch and starch leached during cooking. All commonly-accepted sensory attributes of cooked rice were characterized by a trained human panel. Hardness, with the strongest negative correlation with panelist preference, was the dominant but not sole factor determining palatability. Hardness was controlled by the amounts of medium and long amylopectin chains and amylose in the starch, and by amylose content and amount of longer amylopectin chains in the leachate. This gives knowledge and understanding of the molecular structural characteristics of starch controlling cooked-rice preference: not just high amylose but also other aspects of molecular structure. This can help rice breeders to target starch-synthesis genes to select slowly digested (healthier) rices with acceptable palatability.
Publisher: Tsinghua University Press
Date: 03-2023
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.CARBPOL.2019.115656
Abstract: How various isoforms of rice-starch biosynthesis enzymes interact during amylose and amylopectin synthesis is explored. The chain-length distributions of amylopectin and amylose from 95 varieties with different environmental and genetic backgrounds were obtained using size- exclusion chromatography, and fitted with biosynthesis-derived models based on isoforms of starch synthase (SSI-SSIV), starch branching enzyme (SBE, including SBEI and SBEII) and granule-bound starch synthase (GBSS) that are involved in amylose and amylopectin synthesis. It is usually thought that these are synthesized by separate enzymes. However, the amount of longer amylopectin chains correlated with that of shorter amylose chains, indicating that GBSS, SBE and SS affect both amylose and amylopectin synthesis. Further, the activity of GBSS in amylose correlated with that of SS in amylopectin. This new understanding of which enzymes are suggested by the statistics to be involved in both amylose and amylopectin synthesis could help rice breeders develop cereals with targeted properties.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.IJBIOMAC.2019.07.206
Abstract: Starch molecular structural effects in duckweed (Lemna minor and Landoltia punctata) controlling in vitro enzymatic degradation kinetics was studied. The molecular size distributions of fully-branched starches and the chain length distributions (CLDs) of enzymatically debranched duckweed starches were obtained using size-exclusion-chromatography (SEC). The CLDs of both debranched amylose and amylopectin were fitted with models using biologically-meaningful parameters. While there were no significant correlations between amylose content and starch degradation rate, the total amounts of amylose with shorter chain length negatively correlated with undigested starch content, and the amount of amylopectin long chains negatively correlated with the degradation rate coefficient. This provides new knowledge for the utilization of duckweed starches in bioethanol production.
Publisher: Springer Science and Business Media LLC
Date: 17-02-2020
Publisher: Wiley
Date: 07-10-2022
DOI: 10.1111/JTXS.12726
Abstract: The effects of malt protein removal by Neutrase using Canadian and French commercial malts (Malt 1 and Malt 2) on mashing efficiency, and production of violate compounds during fermentation were determined using high performance liquid chromatography (HPLC), headspace‐solid‐phase microextraction coupled with gas chromatography–mass spectrometry analysis (HS‐SMPE‐GC–MS). HPLC results showed that for Malt 1 containing lower free‐ and total‐β‐amylase but higher α‐amylase enzyme activity, Neutrase significantly increased the content of maltose, glucose and maltotriose, whereas for Malt 2, only glucose content increased. For Malt 1, the increased glucose/maltose ratio after Neutrase addition led to higher ethanol concentration than that with no Neutrase (4.06% vs. 2.09%), whereas for Malt 2, no significant differences were observed (2.92% vs. 3.09%). HS‐SPME‐GC–MS showed that for Malt 1 and Malt 2, Neutrase not influenced the violate compounds composition, whereas reduced their contents. This suggests that malt protein removal by Neutras e impairs the production of volatile compounds.
Publisher: Elsevier BV
Date: 03-2022
Publisher: MDPI AG
Date: 11-05-2023
DOI: 10.20944/PREPRINTS202305.0852.V1
Abstract: In current study, the production of microparticles from fifteen commercial sugarcane pulp (SCP) lunch-boxes into different types of food under different conditions was investigated, where we used DI water, 4% HAc, and 95% EtOH to simulate aqueous, acidic, and fatty foods. Results showed that compared with DI water and 95% EtOH, 4% HAc caused the degradation of sugarcane fibers, resulting in the highest number of microparticles released, which was significantly greater than the specified limit value. It was estimated that consumers might intake a total number of 36,400 ~ 231,700 items per meal per lunch-box, of which the proportion of microparticles with particle size between 100 ~ 500 μm was the largest, with a number of 12,376 ~ 130,795 items. Moreover, of all SCP lunch-box except S-11, Al and Fe are the main metals, ranging between 35.16 ~ 1244.04 and 44.71 ~ 398.52 mg/kg, respectively, followed by Pb, Ti, and Sr. Interestingly, unlike other lunch-boxes, the content of Pb in S-11 was the highest, with a number of 136 mg/kg. This study provides important information that the safeness including both the production of microparticles and the metallic elements should be considered for SCP lunch-boxes when in contact with food.
Publisher: The Institute of Brewing & Distilling
Date: 26-12-2018
DOI: 10.1002/JIB.546
No related grants have been discovered for wenwen yu.