Role Of Starch Research Articles

Mobilization and Role of Starch, Protein, and Fat Reserves during Seed Germination of Six Wild Grassland Species.

Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species (Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica) and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed), but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species.

The Protective Role of Starch on Modulating Toxic Effects of Citrullus Colocynthis on Rat Liver and Intestine

The Protective Role of Starch on Modulating Toxic Effects of Citrullus Colocynthis on Rat Liver and Intestine

Progress in Hydroxyapatite–Starch Based Sustainable Biomaterials for Biomedical Bone Substitution Applications

Hydroxyapatite is a calcium phosphate intensively proposed as a bone substitution material because of its resemblance to the constituents of minerals present in natural bone. Since hydroxyapatite’s properties are mainly adequate for nonload bearing applications, different solutions are being tested for improving these properties and upgrading them near the target values of natural bone. On the other hand, starch (a natural and biodegradable polymer) and its blends with other polymers have been proposed as constituents in hydroxyapatite mixtures due to the adhesive, gelling, and swelling abilities of starch particles, useful in preparing well dispersed suspensions and consolidated ceramic bodies. This article presents the perspectives of incorporating starch and starch blends in hydroxyapatite materials. Based on the role of starch within the materials, the review covers its use as (i) a polymeric matrix in hydroxyapatite composites used as adhesives, bone cements, bone waxes, drug-delivery devices or scaffolds and (ii) a sacrificial binder for fabrication of porous hydroxyapatite scaffolds. The suitability of these materials for bone reconstruction has becomes a reachable aim considering the recent advancements in ceramic fabrication and the current possibilities of controlling the processing parameters.

The roles of starch and lipid in Chlorella sp. during cell recovery from nitrogen starvation

The influence of N-replenishment on cell growth, chlorophyll content, nitrogen uptake, and accumulation of starch and lipid was studied in Chlorella sp. N-starved algal cells were fully recovered within 2days after N-replenishment. Stored starch in N-deficient culture was degraded immediately during recovery process. However, lipid response had a period of delay when suffered from long starvation. During the recovery process, neutral lipid was reduced accompanied by an increase in membrane lipid. It was speculated that starch served as a source of carbon and energy catabolized to support quick recovery of the culture, while lipid preferred to play a structural role that specific fatty acid species were released from storage lipid and as building blocks for quick synthesis of membrane lipid. In light of rapid growth recovery and no net degradation in total fatty acids, a semi-continuous cultivation process might be a potential way to enhance lipid productivity.

The role of starch as transient energy buffer in synchronized microalgal growth in Acutodesmus obliquus

Photosynthetic organisms have evolved to use light efficiently by scheduling their cellular processes, such as growth and cell division, at specific times of the day. During the day, fixed carbon is used for growth and is partially stored as carbohydrates (e.g., starch). It is commonly assumed that this accumulated starch is essential for fuelling up cell division at night. To test this hypothesis, this study investigates growth, cell division and presence of a transitory energy storage (TES) in both the wild-type and starchless mutant strain of Acutodesmus obliquus under light/dark (LD) cycles and nitrogen replete conditions.A. obliquus (formerly known as Scenedesmus obliquus) wild-type utilized light 20% more efficiently under LD regimes compared with continuous light. When exposed to LD regimes, the wild-type scheduled cell division in a 4-hour period starting 2h before ‘sunset’. Starch acted as the major transitory energy storage (TES) compound: it was accumulated during the last part of the light period and was consumed throughout the entire dark period. The slm1 mutant, with a blocked starch synthesis pathway, showed diurnal rhythms in growth and cell division. However, no other carbohydrates nor triacylglycerols took over the role of TES compound in slm1. Therefore, in contrast to what is generally acknowledged, this study shows that neither starch nor any other major alternative TES is required for synchronized growth and cell division in A. obliquus. The starchless mutant did show a reduced growth and cell division rate compared to the wild-type. Starch, thus, plays a major role in efficient harnessing of light energy over LD cycles, likely because the ability to accumulate starch enhances biomass production capacity and accelerates cell division rate in A. obliquus.

Enzyme activities and gene expression of starch metabolism provide insights into grape berry development

Grapes are categorized as a non-climacteric type of fruit which its ripening is not associated to important rises in respiration and ethylene synthesis. The starch metabolism shares a certain role in the carbohydrate metabolic pathways during grape berry development, and is regarded as an important transient pool in the pathway of sugar accumulation. However, the comprehensive role of starch and its contribution to the quality and flavor of grape berry have not been explored thoroughly. In this study, the expression levels of genes enzyme activities and carbohydrate concentrations related to starch metabolism, were analyzed to understand the molecular mechanism of starch accumulation during grape berry development. The results indicated that starch granules in grape berry were located at the chloroplast in the sub-epidermal tissues, acting as the temporary reserves of photosynthetic products to meet the needs for berry development, and relatively high starch contents could be detected at véraison stage. Moreover, both ADP-glucose pyrophosphorylase (EC 2.7.7.27) and sucrose phosphate synthase (EC 2.3.1.14) involved in starch synthesis displayed elevated gene expression and enzymes activities in the sub-epidermal tissue, while α- and β-amylases involved in its degradation were highly transcribed and active in the central flesh, explaining the absence of starch in this last tissue. Change in the gene expression and activities of ADP-glucose pyrophosphorylase, β-amylase and sucrose phosphate synthase revealed that they were regulated by the circadian rhythms in the fruitlets compared with those in the leaves. Both the morphological, enzymological and transcriptional data in this study provide advanced understandings on the function of starch during berry development and ripening that are so important for berry quality. This study will further facilitate our understanding of the sugar metabolism in grape berry as well as in other plant species.

The role of starch and saliva in tribology studies and the sensory perception of protein-added yogurts.

Increasing the protein content of yogurts would be a good strategy for enhancing their satiating ability. However, the addition of protein can affect product palatability, contributing astringency or an inhomogeneous texture. Increasingly, studies mimicking oral tribology and oral lubrication have been attracting interest among food researchers because of their link with oral texture sensations. In the present study, four double-protein stirred yogurts were prepared by adding extra skimmed milk powder (MP) or whey protein concentrate (WPC) and by adding a physically modified starch to each (samples MPS and WPCS, respectively) to increase the consistency of the yogurts. The lubricating properties of the four yogurts were examined by tribological methods with the aim of relating these properties to the sensory perception described by flash profiling. Samples were also analysed after mixing with saliva. The tribology results clearly showed that addition of starch reduced the friction coefficient values regardless of the type of protein. Saliva addition produced a further decrease in the friction coefficient values in all the samples. Consequently, adding saliva is recommended when performing tribology measurements of foods in order to give a more realistic picture. The sensory results confirmed that the addition of starch reduced the astringent sensation, especially in sample WPC, while the MP and MPS samples were creamier and smoother. On the other hand, the astringency of sample WPC was not explained by the tribology results. Since this sample was described as "grainy", "gritty", "rough", "acid" and "sour", further studies are necessary to investigate the role of the number, size, shape and distribution of particles in yogurt samples, their role in astringency perception and their interaction with the perception of the tastes mentioned. Oral tribology has shown itself to be an in vitro technique that may aid a better understanding of the dynamics of in-mouth lubrication and the physical mechanisms underlying texture and mouthfeel perception.

Rethinking Guard Cell Metabolism.

Stomata control gaseous fluxes between the internal leaf air spaces and the external atmosphere and, therefore, play a pivotal role in regulating CO2 uptake for photosynthesis as well as water loss through transpiration. Guard cells, which flank the stomata, undergo adjustments in volume, resulting in changes in pore aperture. Stomatal opening is mediated by the complex regulation of ion transport and solute biosynthesis. Ion transport is exceptionally well understood, whereas our knowledge of guard cell metabolism remains limited, despite several decades of research. In this review, we evaluate the current literature on metabolism in guard cells, particularly the roles of starch, sucrose, and malate. We explore the possible origins of sucrose, including guard cell photosynthesis, and discuss new evidence that points to multiple processes and plasticity in guard cell metabolism that enable these cells to function effectively to maintain optimal stomatal aperture. We also discuss the new tools, techniques, and approaches available for further exploring and potentially manipulating guard cell metabolism to improve plant water use and productivity.

Data on the role of starch and ammonia in green synthesis of silver and iron oxide nanoparticles

Green synthesis of nanoparticles by using starch has recently attracted considerable attention due to their biodegradability, non-toxicity, and cost effectiveness. The data presented in this article are related to the article entitled “Evaluation of antibacterial activity of Ag/Fe3O4 nanocomposites synthesized by using starch” (Ghaseminezhad and Shojaosadati, 2016) [1]. Here, Fe3O4 nanoparticles and silver nanoparticles were synthesized by using starch under alkaline condition. Hydrodynamic diameter of starch and starch coated silver nanoparticles were determined under heat treatment and different pH. This data also display absorbance peak of silver nanoparticles synthesized by starch under different pH conditions (6.5, 8, and 10). Iodometric titration confirmed that both components of starch (amylose and amylopectin) can adsorb on the surface of Fe3O4 nanoparticles.

A review of the recent advances in starch as active and nanocomposite packaging films

Technological advances have led to increased constraints regarding food packaging due to environmental issues, consumer health concerns, and economic restrictions associated therewith. Hence, food scientists and technologists are now more focused on developing biopolymer packages. Starch satisfies all the principle aspects, making it a promising raw material for edible coatings/films. Starch as a package material has grabbed much attention both at academic as well as industrial levels. Besides this, the role of various plasticizers, polys, sugars, and wetting agents are discussed and their importance in packaging industries. Herein, the role of starch as packaging material and nanofillers/composites is discussed in detail. The review summons a comprehensive and current overview of the widely available information and recent advances in starch film packaging.

Structural and functional properties of wheat starch affected by multiple freezing/thawing cycles

The role of starch in frozen dough was investigated by freezing and thawing wheat starch suspension for 3, 7, and 10 cycles. Freezing caused an increasing damaged starch and leaching materials, as well as the morphological changes of the starch granules. After 10 cycles of freezing and thawing, the relative crystallinity and short-range order increased by 4.3% and 0.251, respectively. These changes resulted in a substantial increase in the gelatinization temperatures, melting enthalpy, and pasting viscosities. Freezing/thawing-treated starch (FTS) showed high susceptibility to enzyme hydrolysis while the resistant starch content of 10 FTS decreased by 28%. Compared with the native starch, an apparent decrease was observed in the specific volume of 86% substitution of bread with FTS while the crumb firmness significantly increased (p > 0.05). Our results showed that freezing could significantly alter the structural and functional properties of wheat starch, thus facilitating irreversible structural transformations from dough to bread.

Facile synthesis of silver nanoparticles and their application in dye degradation

Abstract The present article reports a simple, facile and eco-friendly method based on microwave irradiation for the synthesis of silver nanoparticles in aqueous medium using starch as stabilizing agent and a new reducing agent namely hexamine. The silver nanoparticles were characterized by UV–vis, FTIR, XRD and HR-TEM analysis. UV–vis spectroscopic studies provided sufficient evidences for the formation of nanoparticles. The role of starch in the synthesis and stabilization of the nanoparticles was obtained from FTIR studies. The XRD and HR-TEM investigations clearly demonstrated the crystalline nature of the nanoparticles. From the TEM images, the silver nanoparticles were found to be spherical and of nearly uniform size with an average diameter of 18.2 ± 0.97 nm. The nanoparticles showed excellent catalytic activity in the degradation of methyl orange and rhodamine B by NaBH4.

Role of Starch in Biaxial Extensional Viscosity of Flour Dough

Biaxial extensional viscosity of the doughs prepared from gluten and wheat starch at six ratios and from gluten and starch of different sources at a fixed ratio was determined in this work. The doughs containing more starch have lower viscosity. Increasing starch from 60% to 80% gives a marked increase in viscosity. The viscosity of the doughs containing foxtail millet starch and potato starch is much higher than that of the doughs containing corn and wheat starches. Both amount and type of starch are important for the biaxial extensional viscosity of dough, while the size of starch is not a vital factor.

Reduction of Nitrate in Agricultural Soils by Bio-electrokinetics

High nitrate concentration in surface soils is a serious concern for the agricultural industry throughout the world. Nitrate reduction can be achieved by chemical or biological processes; however, these processes are difficult to achieve in-situ because of the low permeability of clays. This study evaluates bio-electrokinetic processes for nitrate treatment in low-permeability soils. The concept is based on using iron electrodes to generate an electric field and a reducing environment in the soil to facilitate nitrate reduction by existing bacteria. Experiments were conducted using starch as an additive for microbial activity in the anolyte. Three sets of experiments were conducted under 0.5, 1.0, and 2.0 V cm−1 voltage gradient, and using starch as an anolyte for enhancing existing microbial activity in the soil. Initial nitrate concentration in the soil (agricultural soil collected from Jinju, Korea) was between 782 and 800 mg kg−1. Removal of 100% nitrate was achieved in the soil under 0.5 and 1.0 V cm−1 due to the combined effect of biological and iron reduction. A control experiment with iron electrodes, but without starch, was not as effective. Ammonium was also effectively removed by the combined action of starch and iron under 0.5 and 1.0 V cm−1. The role of starch with iron on the nitrate and ammonium removal process is evaluated along with the role of transport by electro-osmosis and electro-migration. The bacterial action on denitrification and nitrification is assessed and the relationship between pH and the efficiency of nitrate reduction in the bio-EK systems is evaluated.

Thermoplastic starches: Properties, challenges, and prospects

AbstractThermoplastic starch (TPS) polymers were reviewed in this article. This review was categorized into the following studies: the role of starch as a thermoplastic polymer, transformation and melting mechanisms, plasticization and plasticizers, reactive extrusion (REX) and modifications, retrogradation, biodegradability, filler and blenders, and nano‐particle incorporation in thermoplastic starch. This categorization allows us to understand the developments in this field in recent years and shows that the major challenges in the future are reducing sensitivity to moisture and retarding retrogradation of the thermoplastic matrix. Moreover, nano‐particles such as clay can be used in TPS matrices to overcome these disadvantages.

Beyond Opioid Patient-Controlled Analgesia

Postoperative pain control in patients undergoing spine surgery remains a challenge for the anesthesiologist. In addition to incisional pain, these patients experience pain arising from deeper tissues such as bones, ligaments, muscles, intervertebral disks, facet joints, and damaged nerve roots. The pain from these structures may be more severe and can lead to neural sensitization and release of mediators both peripherally and centrally. The problem is compounded by the fact that many of these patients are either opioid dependent or opioid tolerant, making them less responsive to the most commonly used therapy for postoperative pain (opioid-based intermittent or patient-controlled analgesia). The purpose of this review was to compare all published treatment options available that go beyond intravenous opiates and attempt to find the best possible treatment modality.

To dose or not to dose: that is the (starch) question ...

The present study describes the impact on renal function of a modern starch used for resuscitation in the intensive care unit. The role of starch in renal dysfunction, the importance of the definition of acute kidney injury and acute renal failure, and hyperoncoticity are reviewed.

Variation in carbon content and size in developing fruit of Actinidia deliciosa genotypes

This study identifies the developmental processes contributing to variation in green-fleshed kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson var. deliciosa) fruit dry matter content (DM) and fresh weight (FW) by comparing genotypes with either high or low final DM. Results are compared with the model for fruit development, the tomato (Solanum lycopersicum L.). Differences in final composition were attributable to a higher rate of starch accumulation from 70 days after anthesis in high DM genotypes, with no other consistent differences in accumulation of soluble sugars or organic acids. High DM genotypes had 70% higher starch content and differed from low DM genotypes in the allocation of carbon between storage and other components. DM was negatively correlated with final fruit FW only in high DM genotypes, whereas starch was a constant proportion of dry weight (DW), suggesting a dilution effect rather than an interaction between fruit size and carbohydrate metabolism. Compared with tomato, the organic acids, particularly quinic acid, contributed more to estimated osmotic pressure during growth in FW than the soluble sugars, regardless of final composition or size. Seed mass per unit FW was highest in high DM genotypes, suggesting a previously unrecognised role for kiwifruit seeds in accumulation of carbohydrate by the pericarp. Anatomical comparisons also identified a role for differences in the packing of the two principal cell types, with an increased frequency of the larger cell type correlated with reduced DM. These genotypes demonstrate that kiwifruit differs from tomato in the role of starch as the principal stored carbohydrate, the reduced importance of dilution by growth in FW and the more minor role of the sugars compared with the organic acids during fruit development.

Roles of Starch in Surimi Seafood: A Review

Surimi seafood is a cooked gel product that utilizes fish protein from surimi to produce seafood analog products. Starch is the second most important ingredient used in the manufacture of surimi seafood due to its water holding ability and capacity to partially replace fish proteins while maintaining desired gel characteristics at a reduced cost. Typically, starch is added to surimi seafood formulations at 4–12%. Functional properties of surimi seafood to control wetness, stickiness, and/or thermal stability upon different storage and serving temperatures have been extensively studied using modified starches. There is a great need to review the role of starches in various applications of surimi seafood.

The Role of Wheat Flour Constituents, Sugar, and Fat in Low Moisture Cereal Based Products: A Review on Sugar-Snap Cookies

Much research has been done to understand the contribution of different flour constituents to the cookie quality. Most authors agree on the role of starch in cookies, which, although it is the main flour constituent, has a relatively small influence on cookie quality. Flour proteins, which are quantitatively less important than starch, seem to have a more pronounced role in cookie baking. However, in literature, there is no consensus about their role and influence on the product quality. As for starch, there is much more agreement about the role of non-starch polysaccharides and flour lipids. Not only flour, but also other ingredients of the cookie (dough) formula, such as shortening (fat), sugar, and water are important for the quality of the end product. We here provide the different points of view in this area and speculate on the functionality and quality determining properties of flour constituents, sugar, fat, and water and their role and influence during the different stages of cookie baking and on the end quality of sugar-snap cookies.