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Food Chemistry: X Dec 2023Currently, the preparation methods and basic physicochemical properties of starch-FA complexes have been widely studied; however, no in-depth research on the regulatory...
Currently, the preparation methods and basic physicochemical properties of starch-FA complexes have been widely studied; however, no in-depth research on the regulatory mechanism of the digestive properties of debranched starch-unsaturated FA complexes has been conducted. Therefore, six fatty acids with different carbon chains and different degrees of unsaturation were complexed with de-branched millet starch in this research, using the microwave method. Microwave millet starch-linoleic acid complex (MPS-LOA) had the highest resistant starch (RS) content, and the structure and physicochemical properties of MPS-LOA were determined using various molecular techniques. The results indicate that MPS-LOA had a resistant starch (RS) content of 40.35% and the most notable fluorescence. The characteristic UV peaks of MPS-LOA were blue-shifted, and new IR peaks appeared. The crystalline structure changed to V-type crystals, the crystallinity increased, and the molecular weight decreased. The enthalpy and coagulability of MPS-LOA increased, and the swelling force decreased. Additionally, MPS-LOA showed enhanced α-glucosidase and α-amylase inhibition, and in-vitro hydrolysis kinetics analysis of MPS-LOA showed a hydrolysis index of 53.8 and an extended glycemic index (eGI)I of 54.6, indicating a low eGI food suitable for consumption by people with type II diabetes. These results provide a theoretical basis for the preparation of amylopectin- and starch-based foods with an anti-enzyme structure and a low glycemic index (GI).
PubMed: 38144796
DOI: 10.1016/j.fochx.2023.100929 -
Food Chemistry: X Dec 2023Nitrogen application delays rice quality deterioration due to changes in its pasting characteristics; however, the underlying mechanisms remain unclear. Using a...
Nitrogen application delays rice quality deterioration due to changes in its pasting characteristics; however, the underlying mechanisms remain unclear. Using a label-free quantitative proteomics approach, we identified differentially expressed proteins (DEPs) during storage in paddy rice treated with different nitrogen levels. On combining the changes in physiological indicators, high-nitrogen treatment was found to downregulate β-1,3-glucanase, reduce the decomposition of cell wall components, downregulate three proteins involved in starch metabolism, decrease the range of the amylose content and increase the range of the amylopectin, upregulate three proteins related to the lysosomal pathway, and enhance glutelin degradation. In addition, it upregulated three proteins related to flavonoid synthesis, which enhanced the stress response ability of rice, thereby contributing to the stability of biological macromolecules. The discovery of these key DEPs provides potential targets for further control over the deterioration of crop seed storage quality.
PubMed: 38144749
DOI: 10.1016/j.fochx.2023.101018 -
Food Chemistry: X Dec 2023Buckwheat is considered as a healthy cereal food, and it is essential to cultivate new buckwheat lines with good starch physicochemical properties for both consumers and...
Buckwheat is considered as a healthy cereal food, and it is essential to cultivate new buckwheat lines with good starch physicochemical properties for both consumers and food producers. Six novel buckwheat (Duoku, Dk) were generated by crossing of Golden buckwheat and Tatary buckwheat, and their kernel appearance properties and starch physicochemical properties were analyzed together with one domestic line (Cimiqiao) and one wild line (Yeku). The results showed that Dk samples had better appearance properties than two control samples. The Dk samples showed lower amylose content, similar amylopectin molecular structure and chain length distributions, and larger starch granules compared with Cimiqiao. The digestion results showed that two Dk samples: Dk6 & Dk9 had high resistant starch content; while the other two Dk samples: Dk37 & Dk38 had a steady glucose releasing rate. The Dk samples also showed high gelatinization temperature, indicating they were good raw materials for producing glass noodle. This study proved that Dk buckwheat had unique starch physicochemical properties, and could be used as new food materials in the future.
PubMed: 38144746
DOI: 10.1016/j.fochx.2023.100949 -
Plants (Basel, Switzerland) Dec 2023To develop optimal management strategies for water and nitrogen fertilizer application in winter wheat cultivation, we conducted a potted experiment to investigate the...
To develop optimal management strategies for water and nitrogen fertilizer application in winter wheat cultivation, we conducted a potted experiment to investigate the effects of different irrigation levels and nitrogen fertilizer treatments on the activity of starch synthesis-related enzymes and the grain quality of winter wheat. The potted experiment consisted of three irrigation levels, with the lower limits set at 50-55% (I), 60-65% (I), and 70-75% (I) of the field capacity. In addition, four levels of nitrogen fertilizer were applied, denoted as N (0 kg N hm), N (120 kg N hm), N (240 kg N hm), and N (300 kg N hm), respectively. The results revealed the significant impacts of irrigation and nitrogen treatments on the activities of key starch-related enzymes, including adenosine diphosphoglucose pyrophosphrylase (ADPG-PPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS), and starch branching enzymes (SBE) in wheat grains. These treatments also influenced the starch content, amylopectin content, and, ultimately, wheat yield. In summary, our findings suggest that maintaining irrigation at a lower limit of 60% to 65% of the field capacity and applying nitrogen fertilizer at a rate of 240 kg hm is beneficial for achieving both high yield and high quality in winter wheat cultivation.
PubMed: 38140412
DOI: 10.3390/plants12244086 -
New Biotechnology Mar 20244-α-glucanotransferases (4αGTs, EC 2.4.1.25) from glycoside hydrolase family 77 (GH77) catalyze chain elongation of starch amylopectin chains and can be utilized to...
4-α-glucanotransferases (4αGTs, EC 2.4.1.25) from glycoside hydrolase family 77 (GH77) catalyze chain elongation of starch amylopectin chains and can be utilized to structurally modify starch to tailor its gelation properties. The potential relationship between the structural design of 4αGTs and functional starch modification is unknown. Here, family GH77 was mined in silico for enzyme candidates based on sub-grouping guided by Conserved Unique Peptide Patterns (CUPP) bioinformatics categorization. From + 12,000 protein sequences a representative set of 27 4αGTs, representing four different domain architectures, different bacterial origins and diverse CUPP groups, was selected for heterologous expression and further study. Most of the enzymes catalyzed starch modification, but their efficacies varied substantially. Five of the 4αGTs were characterized in detail, and their action was compared to that of the industrial benchmark enzyme, Tt4αGT (CUPP 77_1.2), from Thermus thermophilus. Reaction optima of the five 4αGTs ranged from ∼40-60 °C and pH 7.3-9.0. Several were stable for a minimum 4 h at 70 °C. Domain architecture type A proteins, consisting only of a catalytic domain, had high thermal stability and high starch modification ability. All five novel 4αGTs (and Tt4αGT) induced enhanced gelling of potato starch. One, At4αGT from Azospirillum thermophilum (CUPP 77_2.4), displayed distinct starch modifying abilities, whereas T24αGT from Thermus sp. 2.9 (CUPP 77_1.2) modified the starch similarly to Tt4αGT, but slightly more effectively. T24αGT and At4αGT are thus interesting candidates for industrial starch modification. A model is proposed to explain the link between the 4αGT induced molecular modifications and macroscopic starch gelation.
Topics: Solanum tuberosum; Glycoside Hydrolases; Starch; Glycogen Debranching Enzyme System; Peptides
PubMed: 38097138
DOI: 10.1016/j.nbt.2023.12.002 -
Frontiers in Nutrition 2023The health benefits provided by resistant starch have been well documented; however, few studies are available on the resistant starch content of wheat products in...
BACKGROUND/OBJECTIVES
The health benefits provided by resistant starch have been well documented; however, few studies are available on the resistant starch content of wheat products in India. Moreover, few studies have examined the efficacy of resistant starch in wheat products in improving glucose levels. This study was conducted to evaluate the effect of cooking and storage temperature on the formation of resistant starch in Indian wheat products and its effect on blood glucose levels in humans and rats.
METHODS
Wheat products were prepared by common cooking methods including roasting (), boiling (), Shallow frying (), and Deep frying (). They were then stored at different temperatures including freshly prepared within 1 h (T1), stored for 24 h at room temperature (20-22°C) (T2), kept at 4°C for 24 h (T3) and reheated after storing at 4°C for 24 h (T4). The products were then analyzed for proximate composition (moisture, crude protein, crude fat, ash crude fibre, and carbohydrates). The effect of different cooking methods and storage temperatures on Resistant, non-resistant and total starch, total dietary fibre (soluble and insoluble), starch digestion rate (rapidly and slowly digestible starch), amylose and amylopectin content were analysed using standard operating procedures. The effect of products found to have higher resistant starch was studied on the post prandial blood glucose response of 10 healthy individuals using change in by analysing their glycemic index and glycemic load of wheat products. Further, the effect of resistant starch rich on the blood glucose level of rats was also studied. Tukey's test in factorial CRD was used to assess the effect of cooking and temperature on various parameters.
RESULTS
The amount of resistant starch was found to be high in (boiling, 7.74%), followed by (shallow frying, 4.94%), (roasting, 2.77%) and (deep frying 2.47%). Under different storage temperatures, it was found high in products stored at 4°C (T3), followed by products stored at room temperature (T2), reheated products (T4) and lesser in freshly prepared products (T1). The glycemic index and glycemic load were found low in (43, 32.3) and (41.1, 28.6) stored at 4°C (T3) compared to others. The resistant starch content found in stored at T3 was found to be more effective at reducing blood glucose levels in rats from 291.0 mg/100 mL to 225.2 mg/100 mL in 28 days of study compared to freshly prepared (T1) and stored at room temperature (T2).
CONCLUSION
Cooking methods including boiling, roasting and shallow frying increased the amount of resistant starch in foods, but cooking methods such as deep frying decreased the amount of resistant starch in food. Products stored at 4°C and at room temperature for 24 h increased the amount of resistant starch whereas the products that were freshly cooked and reheated decreased the amount of resistant starch in foods. At 4°C the stored products have a high amount of insoluble dietary fibre, slowly digestible starch, high amylose and low glycemic index. They take time to digest, meaning that they slowly increase blood glucose levels. The effect of insoluble dietary fibre and resistant starch in the inhibition of glucose diffusion in the small intestine is suggested to be due to the absorption or inclusion of the smaller sugar molecules. research showed that fibre and resistant starch in the digestive system of rats acts as the main factors in slowing glucose absorption and reducing a rise in blood glucose levels by promoting glycogen synthesis and inhibition of gluconeogenesis.
PubMed: 38089929
DOI: 10.3389/fnut.2023.1284487 -
Scientific Reports Dec 2023Bacterial exopolysaccharides are homopolymeric or heteropolymeric polysaccharides with large molecular weights (10-1000 kDa). Exopolysaccharides' functional uses and...
Bacterial exopolysaccharides are homopolymeric or heteropolymeric polysaccharides with large molecular weights (10-1000 kDa). Exopolysaccharides' functional uses and potential have revolutionized the industrial and medicinal industries. Hence, the aim of the present study was to optimize the production of bacterial exopolysaccharide and apply it as a capping agent for selenium nanoparticles synthesis. Exopolysaccharide (EPS) producing Lactic acid bacteria (LAB) were isolated from dairy products then biochemically characterized and assessed for their potential antimicrobial effect. The most potent EPS producer was identified as Lactiplantibacillus plantarum strain A2 with accession number OP218384 using 16S rRNA sequencing. Overall, FTIR data of the extracted EPS revealed similarity with amylopectin spectrum. H NMR spectrum revealed an α-anomeric configuration of the glycosidic linkage pattern in the polysaccharides while the C NMR spectrum can also be separated into two main portions, the anomeric carbons region (δ 98-102 ppm) and the non-anomeric carbons region (δ 60-81 ppm). Antimicrobial activity of the produced EPS showed maximum activity against Staphylococcus aureus, MRSA, Enterobacter aerogenes, Klebsiella pneumoniae and Candida albicans respectively. The EPS capsule layer surrounding the bacterial cells was detected by TEM study. Optimization of EPS production was evaluated using Taguchi design, trial 23 reported the highest biomass yield and EPS output (6.5 and 27.12 g/L respectively) with 2.4 and 3.3 folds increase (from the basal media) respectively. The optimized exopolysaccharide was used as a capping and stabilizing agent for selenium nanoparticles (EPS-SeNPs) synthesis. Zeta potential, size and PDI of the synthesized nanoparticles were - 19.7 mV, 45-65 nm and 0.446 respectively with strong bactericidal and fungicidal effect against the tested pathogens. Complete microbial growth eradication was recorded after 6, 8 and 10 h against Staphylococcus aureus, Candida albicans and Klebsiella pneumoniae respectively. EPS-SeNPs showed a potent antioxidant effect reached 97.4% and anticancer effect against A549 lung cancer cell line (IC reached 5.324 µg/mL). EPS-SeNPs inhibited cancerous cell growth at S phase. Moreover, molecular studies revealed the anti-apoptotic activity of Bcl2's was inhibited and Bax was activated. The present investigation successfully synthesized selenium nanoparticles through bacterial EPS with significantly high antimicrobial and anticancer activity.
Topics: Humans; Selenium; RNA, Ribosomal, 16S; Polysaccharides, Bacterial; Anti-Infective Agents; Nanoparticles; Lung Neoplasms; Staphylococcus aureus; Candida albicans; Bacteria
PubMed: 38072846
DOI: 10.1038/s41598-023-48921-9 -
Plant Physiology Mar 2024Starch granule morphological homogeneity presents a gap in starch research. Transitory starch granules in wild-type plants are discoid, regardless of species. Notably,...
Starch granule morphological homogeneity presents a gap in starch research. Transitory starch granules in wild-type plants are discoid, regardless of species. Notably, while the shape of starch granules can differ among mutants, it typically remains homogeneous within a genotype. We found an Arabidopsis thaliana mutant, dpe2sex4, lacking both the cytosolic disproportionating enzyme 2 (DPE2) and glucan phosphatase SEX4, showing an unprecedented bimodal starch granule diameter distribution when grown under a light/dark rhythm. dpe2sex4 contained 2 types of starch granules: large granules and small granules. In contrast to the double starch initiation in wheat (Triticum aestivum) endosperm, where A-type granules are initiated first and B-type granules are initiated later, dpe2sex4 small and large granules developed simultaneously in the same chloroplast. Compared with the large granules, the small granules had more branched amylopectin and less surface starch-phosphate, thus having a more compact structure that may hinder starch synthesis. During plant aging, the small granules barely grew. In in vitro experiments, fewer glucosyl residues were incorporated in small granules. Under continuous light, dpe2sex4 starch granules were morphologically homogeneous. Omitting the dark phase after a 2-wk light/dark cycle by moving plants into continuous light also reduced morphological variance between these 2 types of granules. These data shed light on the impact of starch phosphorylation on starch granule morphology homogeneity.
Topics: Arabidopsis; Starch; Arabidopsis Proteins; Phosphorylation; Mutation; Dual-Specificity Phosphatases
PubMed: 38060678
DOI: 10.1093/plphys/kiad656 -
Frontiers in Plant Science 2023The content of resistant starch (RS) was considered positively correlated with the apparent amylose content (AAC). Here, we analyzed two Indica rice mutants, RS111 and...
The content of resistant starch (RS) was considered positively correlated with the apparent amylose content (AAC). Here, we analyzed two Indica rice mutants, RS111 and Zhedagaozhi 1B, similar in high AAC and found that their RS content differed remarkably. RS111 had higher RS3 content but lower RS2 content than Zhedagaozhi 1B; correspondingly, cooked RS111 showed slower digestibility. RS111 had smaller irregular and oval starch granules when compared with Zhedagaozhi 1B and the wild type. Zhedagaozhi 1B showed a B-type starch pattern, different from RS111 and the wild type, which showed A-type starch. Meantime, RS111 had more fa and fb1 but less fb3 than Zhedagaozhi 1B. Both mutants showed decreased viscosity and swelling power when compared with the parents. RS111 had the lowest viscosity, and Zhedagaozhi 1B had the smallest swelling power. The different fine structures of amylopectin between RS111 and Zhedagaozhi 1B led to different starch types, gelatinization properties, paste viscosity, and digestibility. In addition to enhancing amylose content, modifications on amylopectin structure showed great potent in breeding rice with different RS2 and RS3 content, which could meet the increasing needs for various rice germplasms.
PubMed: 38023836
DOI: 10.3389/fpls.2023.1267281 -
Impact of Variation in Amylose Content on Durum Wheat cv. Svevo Technological and Starch Properties.Foods (Basel, Switzerland) Nov 2023Reserve starch, the main component of durum wheat semolina, is constituted of two glucan homopolymers (amylose and amylopectin) that differ in their chemical structure....
Reserve starch, the main component of durum wheat semolina, is constituted of two glucan homopolymers (amylose and amylopectin) that differ in their chemical structure. Amylose is mainly a linear structure formed of α-1,4-linked glucose units, with a lower polymerization degree, whereas amylopectin is a highly branched structure of α-1,4-chains linked by α-1,6-bonds. Variation of the amylose/amylopectin ratio has a profound effect on the starch properties which may impact the wheat technological and nutritional characteristics and their possible use in the food and non-food sector. In this work a set of genotypes, with a range of amylose from 14.9 to 57.8%, derived from the durum wheat cv. Svevo was characterised at biochemical and rheological level and used to produce pasta to better understand the role of amylose content in a common genetic background. A negative correlation was observed between amylose content and semolina swelling power, starch peak viscosity, and pasta stickiness. A worsening of the firmness was observed in the low amylose pasta compared to the control (cv. Svevo), whereas no difference was highlighted in the high amylose samples. The resistant starch was higher in the high amylose (HA) pasta compared to the control and low amylose (LA) pasta. Noteworthy, the extent of starch digestion was reduced in the HA pasta while the LA genotypes offered a higher starch digestion, suggesting other possible applications.
PubMed: 38002170
DOI: 10.3390/foods12224112