Quantification Of Starch Research Articles

Analysis of metabolic compounds and antitumorigenic effects of Albizia niopoides and Senegalia polyphylla leaves

The objective of this study was to quantify metabolic compounds in leaves of A. niopoides and S. polyphylla and to evaluate the antitumor potential of extracts from both species in cervical tumour cells. The physiological analyses performed were quantification of starch, sucrose, phenolic compounds and proteins. An aqueous extract was prepared and added to the SiHa cell line at concentrations of 10, 100 and 1000 μg/mL at 4h, 24h, 48h and 72h. Cell morphology, proliferation and viability were analysed. The species showed a large amount of starch and phenolic compounds. Treatment with the extract of both species caused morphological changes in SiHa cells and exhibited antiproliferative effects at a concentration of 1000 µg/ml. In cell viability test, only A. niopoides showed a significant reduction. The study presented the effects of the species against a cervical cancer cell line, where A. niopoides has already shown to be a promising plant drug.

Characterization of temperate and tropical popcorn populations and GWAS for zeins and starch contents

AbstractBecause measuring expansion volume (EV) is simple and inexpensive, popcorn breeders have developed high‐quality single crosses ignoring the contents of zeins, starch, lipids, and cellular wall components in selection. However, some methods of quantification of these quality‐related traits can be applied to popcorn breeding, increasing the selection efficacy for quality. The objectives of this study were to assess methods of zeins and starch quantification that can be used in popcorn breeding, characterize a temperate and a tropical populations for zeins and starch contents and identify candidate genes for these quality‐related traits. We genotyped and phenotyped 286 plants. For quantification of total zeins and zein subunits we choose the ‘lab‐on‐a‐chip’ microfluidic electrophoresis. For quantification of starch and amylose/amylopectin, we choose the Megazyme's Amylose/Amylopectin kit assay. The temperate population has superior EV (36.0%), a higher level of the 19 kDa zein subunit (32.0%), lower levels of the 21, 22 and 27 kDa subunits (−1543.0%, −40.0% and −47.0%, respectively) and no statistical difference for the 10 kDa zein content, relative to the tropical population. Although there are statistical differences between the two populations regarding starch, amylose, and amylose/amylopectin ratio, the differences are not significant (−2.0% to 8.0%). Thirteen candidate genes were identified for the 19 and 22 kDa zeins, two for amylose and one for starch, with emphasis on the genes coding for the 19 and 22 kDa alpha‐zeins, located on chromosome 4. The evaluated quantification methods can be used in popcorn breeding but for a limited number of samples, mainly because costs.

Chemical and Sensory Properties of Waffles Supplemented with Almond Skins.

Almonds are one of the most produced nuts worldwide and numerous studies have shown that they have nutritional and medicinal characteristics, which gives them the possibility of being applied in various products. However, several by-products are generated during their production, which have characteristics of interest but remain underutilised, namely, the almond skins. This work aimed to study samples of waffles supplemented with almond skins. The waffles were evaluated for their total polyphenol content, antioxidant capacity, total flavonoids, ortho-diphenols, soluble sugars, starch, texture, and colour. They were also sensorially evaluated using a panel of tasters specialised in this type of evaluation and a quantitative descriptive analysis test (QDA) sensory test. The results showed that the waffles with the highest levels of phenolic compounds as well as the highest antioxidant activity (by the ABTS, DPPH, and FRAP methods) were the waffles supplemented with 10% almond skin. The total phenol contents obtained for the prepared extracts varied between 0.127 mg GAE/g and 0.415 mg GAE/g, the flavonoid contents ranged from 0.067 mg CAE/g to 0.339 mg CAE/g and the ortho-diphenol contents varied between 0.163 mg ACE /g and 0.303 mg ACE/g. Regarding the quantification of soluble sugars, the values were presented in percentage of fresh weight, and ranged from 30.148 to 38.054%; regarding the quantification of starch, the percentages varied from 14.488 to 21.982%. Sensorially, we verified that the samples were statistically different in terms of the descriptors "colour", "roasted aroma", and "dissolubility", with a higher score in these descriptors for the waffles with 10% of almond skin. This process of obtaining waffles, which can be industrialised, is interesting from both a nutritional point of view and for the possibility of creating new, differentiated, and innovative products.

Confocal Raman microspectroscopy combined with spectral screening algorithms for quantitative analysis of starch in rice

Starch is one of the main components of rice. The feasibility of confocal Raman microspectroscopy (CRM) combined with spectral screening algorithms for quantitative detection of starch in rice was investigated in this paper. Firstly, the Raman spectra of the samples were processed by pre-processing and spectral screening algorithm of the data. Secondly, the quantitative starch detection models were respectively established by correction set by partial least squares regression, particle swarm optimization-support vector regression, gray wolf optimizer-support vector regression (GWO-SVR) as well as back propagation neural network. After that, the quantitative starch detection models were validated using the prediction set. Eventually, the related coefficient of the prediction set, root mean square error of the prediction set, and mean relative error of GWO-SVR starch quantification detection model combined with normalization and IPLS screening were respectively 0.8915, 1.03%, and 1.08%. The experimental results manifested that the swift and precise detection of starch content in rice by CRM was workable after proper pre-processing and spectral screening algorithm.

Label-free live microalgal starch screening via Raman flow cytometry

Microalgal carbon fixation attracts much attention as an environmentally friendly source of biomaterials. In this context, microalgal starch plays an important role because it can be converted to bioethanol and bioplastics. However, optimizing culturing conditions and generating strains with higher starch productivity is still a challenge primarily due to the lack of methods for screening starch content at a single-cell level; established starch quantification methods are time-consuming, reagent-consuming, and destructive. Here we report a high-throughput, starch-screening method based on Raman flow cytometry by measuring molecular vibrations that can be used in suspended cells in their growth medium. Our method obtains the full fingerprint spectrum of starch, providing increased specificity when compared to narrow-band Raman spectroscopy methods. Specifically, we demonstrated label-free, single-cell-resolved screening of intracellular starch in cells of microalgal species Chromochloris zofingiensis that overcame the above problems and achieved >30–100 times higher event rate than previous methods, which enabled the acquisition of >20 times more cells in a fraction of the time. We screened the single-cell starch contents of about 28,000 C. zofingiensis cells cultured under 14 different conditions (~2000 cells per condition) to adjust culture conditions for starch accumulation. Comparing the data against Lugol staining and bulk-sample enzymatic starch quantification showed the potential of Raman flow cytometry for mean starch quantification. Raman flow cytometry showed higher sensitivity than Lugol staining and linear dependence with the mean per-cell starch ratio obtained from enzymatic starch quantification. Raman flow cytometry enables single-cell label-free metabolite quantification and paves the way to accurate, cost-effective optimization of culturing conditions, with future applications in the screening of starch hyper-producing microalgae following mutagenesis or from environmental samples.

The corewood of 25-year-old Hevea brasiliensis from two rubber plantations has high starch content

In Brazil after 25 to 30 years of rubber production, when yield starts to drop, rubber trees are felled and destined for firewood and charcoal, despite the good mechanical properties and workability of the wood, and relatively low production costs. Wood with low starch content could be destined for the production of higher added-value products with potential to spare deforestation of many native forest species, but in rubberwood, starch increases palatability by wood borers and accelerates fungal degradation, thus compromising wood durability and the quality of timber. The aim of this study is to determine whether removal of the outer part of wood or varying the season of logging would result in wood with lower starch content. We measured the content of starch using enzymatic hydrolysis, the radial distribution of starch grains by light microscopy, and the corresponding seasonal variation of starch in 25-year-old felled trees. Rubberwood had large amount of starch in its entire trunk, increasing from the inner to the outer region, before decreasing in the outermost sapwood. Starch content was lower in summer, although higher than in other timber species. After relating the data to a comprehensive bibliographic survey of starch quantification in rubberwood, it was concluded that there are no technological arguments to destine the inner part of rubber tree trunks to the production of higher value products.

Optimized Spectrophotometry Method for Starch Quantification

Starch is a polysaccharide that is abundantly found in nature and is generally used as an energy source and energy storage in many biological and environmental processes. Naturally, starch tends to be in miniscule amounts, creating a necessity for quantitative analysis of starch in low-concentration samples. Existing studies that are based on the spectrophotometric detection of starch using the colorful amylose–iodine complex lack a detailed description of the analytical procedure and important parameters. In the present study, this spectrophotometry method was optimized, tested, and applied to studying starch content of atmospheric bioaerosols such as pollen, fungi, bacteria, and algae, whose chemical composition is not well known. Different experimental parameters, including pH, iodine solution concentrations, and starch solution stability, were tested, and method detection limit (MDL) and limit of quantification (LOQ) were determined at 590 nm. It was found that the highest spectrophotometry signal for the same starch concentration occurs at pH 6.0, with an iodine reagent concentration of 0.2%. The MDL was determined to be 0.22 μg/mL, with an LOQ of 0.79 μg/mL. This optimized method was successfully tested on bioaerosols and can be used to determine starch content in low-concentration samples. Starch content in bioaerosols ranged from 0.45 ± 0.05 (in bacteria) to 4.3 ± 0.06 μg/mg (in fungi).

Selective detection of starch in banana fruit with Raman spectroscopy

To develop an analytical method for rapid quantification of starch in agricultural produce, we measured the Raman spectra of ripening banana fruit and compared the obtained data to those of standard starch, sugar, and fiber chemical samples. Standard starches exhibited distinctive Raman bands, which were similar to the spectral features in green banana before ripening. Moreover, these banana-derived Raman bands gradually weakened during 10 d of storage. Standard sugars (glucose, sucrose, and fructose) exhibited Raman bands in both solid and liquid states, whereas standard fibers exhibited broad spectra and no such bands. Although the sugar content increased, no sugar bands were observed in the banana fruit even after ripening. A correlation was found between the Raman bands and starch content obtained by chemical analysis. These results demonstrate that Raman spectroscopy can selectively provide information regarding starch in banana fruit and be applied as an analytical method for rapid starch quantification.

Sessile drop evaporation approach to detect starch adulteration in milk

Milk adulteration is a major challenge faced by the dairy sector. Starch is a common milk adulterant with negative impact on consumer health. The major shortfalls in the present methods for detection and quantification of starch in milk are the higher limit of detection (LOD) and the need for additional chemical reagents. Hence, developing a chemical-free method with lower LOD for starch in milk is urgently required, especially in low- and middle-income countries. We propose a sessile drop evaporation-based approach to detect starch adulteration in milk. The influence of starch adulteration on the evaporative deposition patterns is studied using light microscopy as a function of dilution level (10–50%, v/v), starch type (potato and tapioca starches) and starch concentration (0.005–0.2%, w/v). The dried deposit patterns formed after drying drops of pristine and adulterated milk at 60 °C are dictated by the competing effects of outward capillary flow and inward Marangoni flows. Confocal Raman spectroscopy indicated the presence of fatty acids and other lipophilic constituents at the center, a combination of proteins and lipophilic constituents at the edge, and starch in regions close to the coffee stain, i.e., at the edge of the dried deposits. Higher level of water addition and lower level of starch adulteration resulted in the formation of coffee ring deposits with larger width. Surface profilometry indicated a decrease in the height of coffee-ring with increase in the concentration of both water and starch. The width and maximum height of edge deposits thus measured are proposed as the parameters to quantify starch concentration in milk. The proposed approach is effective in detecting starch concentration as low as 0.005% (w/v), as well as identifying the starch type, thereby facilitating facile, rapid, chemical-free, and in situ detection of starch adulteration in milk.

The transcriptome landscapes of citrus leaf in different developmental stages.

The temporal expression profiles of citrus leaves explain the sink-source transition of immature leaves to mature leaves and provide knowledge regarding the differential responses of mature and immature leaves to biotic stress such as citrus canker and Asian citrus psyllid (Diaphorina citri). Citrus is an important fruit crop worldwide. Different developmental stages of citrus leaves are associated with distinct features, such as differences in susceptibilities to pathogens and insects, as well as photosynthetic capacity. Here, we investigated the mechanisms underlying these distinctions by comparing the gene expression profiles of mature and immature citrus leaves. Immature (stages V3 and V4), transition (stage V5), and mature (stage V6) Citrus sinensis leaves were chosen for RNA-seq analyses. Carbohydrate biosynthesis, photosynthesis, starch biosynthesis, and disaccharide metabolic processes were enriched among the upregulated differentially expressed genes (DEGs) in the V5 and V6 stages compared with that in the V3 and V4 stages. Glucose level was found to be higher in V5 and V6 than in V3 and V4. Among the four stages, the largest number of DEGs between contiguous stages were identified between V5 and V4, consistent with a change from sink to source, as well as with the sucrose and starch quantification data. The differential expression profiles related to cell wall synthesis, secondary metabolites such as flavonoids and terpenoids, amino acid biosynthesis, and immunity between immature and mature leaves may contribute to their different responses to Asian citrus psyllid infestation. The expression data suggested that both the constitutive and induced gene expression of immunity-related genes plays important roles in the greater resistance of mature leaves against Xanthomonas citri compared with immature leaves. The gene expression profiles in the different stages can help identify stage-specific promoters for the manipulation of the expression of citrus traits according to the stage. The temporal expression profiles explain the sink-source transition of immature leaves to mature leaves and provide knowledge regarding the differential responses to biotic stress.

Optimization of a simple, accurate and low cost method for starch quantification in green microalgae

BackgroundLipids and starch are important feedstocks for bioenergy production. Genetic studies on the biosyntheses of lipids and starch in green microalgae have drawn significant attention recently. In these studies, quantifications of lipids and starch are required to clarify the causal effects. While lipids are assayed with similar procedures worldwide, starch in green microalgae has been measured using various methods with deficiencies in accuracy or high cost.ResultsA simple, accurate and low cost procedure for routine quantification of starch in green microalgae was developed. This procedure consists of quick-freezing of the cells, solvent extraction of the pigments, 134 °C autoclaving and glucoamylase double digestions of starch, followed by a glucose assay using the dinitrosalicylic acid reagent. This procedure was optimized to quantify starch in small volumes of green microalgal culture. The accuracy of starch quantification using this procedure was 102.3 ± 2.5% (mean ± SD, n = 6), as indicated by using cornstarch as internal controls. The working protocol is available at http://dx.doi.org/10.17504/protocols.io.2mhgc36.ConclusionsThis quantification approach overcomes the current problems in the starch quantification of green microalgae such as inaccuracy and high cost. This approach would provide an opportunity to compare the effects of genetic, physiological or cultivation manipulations on the productivity of starch in green microalgae elucidated in different labs, which is essential in the enhancement of lipid productivity studies in microalgae.

Young seedlings adapt to stress by retaining starch and retarding growth through ABA-Dependent and -independent pathways in Arabidopsis

The metabolism of starch, the major resource of carbohydrates and an essential determinant of plant fitness in plants, often exhibits plasticity in response to challenging environmental conditions. Previous study of leaf starch turnover under abiotic stresses documented conflicting patterns. To understand this discrepancy and examine the process in more detail, we grew Arabidopsis seedlings under a series of typical stress conditions, observed and quantified leaf starch content at different time. By electron microscope, iodine staining and starch quantification, we confirm that short-term (<8 h) stress treatments, such as osmotic stress, high salinity, caused rapid starch decrease during the night while long-term (>56 h) stresses increased starch content significantly. Exogenous abscisic acid (ABA) induced similar effects to the abiotic stresses. Comparison of the starch content in wild type (WT) and the ABA receptor quadruple mutant pyr1;pyl1;pyl2;pyl4 suggests that the stress-induced starch turnover change is also mediated by ABA-independent pathways. In addition, more energy supply caused severer growth defect under stress conditions. And the transcription levels of both starch biosynthesis enzymes (APL1 and APL3) and starch degradation enzymes (SEX1, SEX4, BAM1 and BAM3) exhibited differential increase under long-term stresses. Taken together, our data strongly suggest that young seedlings adapt to stress by retaining starch and retarding growth through both ABA-dependent and -independent pathways.

Quantification of starch content in germinating mung bean seedlings by terahertz spectroscopy

To investigate the potential of terahertz spectroscopy to monitor and quantify starch in plants, terahertz spectra (3.0–13.5 THz) of mung bean plants 1–7 days after germination were examined and compared to those of starch and its constituent saccharides (standard reagents). Day 1 seedlings showed similar spectral features with standard starch, and absorption peaks gradually disappeared in the subsequent 6 day growth period. To interpret this result and identify useful peaks for starch quantification, standard starch and day 1 seedlings were hydrolyzed by α-amylase in vitro. Since both standard starch and seedlings showed that absorption peak at 9.0 THz disappeared after amylase hydrolysis, this peak is sensitive to changes in starch. Additionally, intensity of this peak was correlated with starch content as quantified by chemical analysis (r = 0.98). Our results indicate terahertz spectra of seedlings can provide an identifiable peak that is attributed to starch and not affected by the constituent saccharides.

Productivity of Rhizomes and Starch Quantification in Cultures of Different Vegetative Propagules of Arrowroot

Arrowroot rhizomes are rich in carbohydrate and are commonly grown by family farmers who have an important source of income in this activity and play a prominent role in the conservation of the species. There are few studies on the phytotechnical aspects of culture. The objective of this work was to evaluate the productive capacity of the &amp;lsquo;common&amp;rsquo; arrowroot using different sizes and forms of propagation, aiming at the production of rhizomes and arrowroot starch, in different agricultural crops. The experimental design was the randomized block in a 4 &amp;times; 2 factorial scheme, with 6 replicates. Four types of rhizome propagation (rhizomes-seeds of small size with a weight of 20 to 30 g; rhizomes-seeds of average weight between 30.01 to 45 g; rhizomes-seeds of large size weighing between 45.01 a 60 g, and seedlings produced in tissue culture), in two agricultural years (2015/2016 and 2016/2017). The variables total production, number of rhizomes, extraction yield and total starch production were evaluated. The type of propagule used interfered in the yield of rhizomes (9.85 to 34.75 t ha-1) and in the production of arrowroot starch (1.76 to 7.68 t ha-1). The vegetative propagation with pieces of rhizomes-seeds between 20 and 60 g was more viable than the micropropagation technique. Although the soil and climate conditions showed differences between the agricultural crops studied, they did not significantly influence the yield of rhizomes and arrowroot starch, by the type of propagule used.

Combining Histochemical Staining and Image Analysis to Quantify Starch in the Ovary Primordia of Sweet Cherry during Winter Dormancy.

Changes in starch in small structures are associated with key events during several plant developmental processes, including the reproductive phase from pollination to fertilization and the onset of fruiting. However, variations in starch during flower differentiation are not completely known, mainly due to the difficulty of quantifying the starch content in the particularly small structures of the flower primordia. Here, we describe a method for the quantification of starch in the ovary primordia of sweet cherry (Prunus avium L.) by using an image analysis system attached to the microscope, which allows relating the changes in starch content with the different phases of dormancy from autumn to spring. For this purpose, the dormancy status of flower buds is determined by evaluating the bud growth of shoots transferred to controlled conditions at different moments in winter time. For the quantification of starch in the ovary primordia, flower buds are sequentially collected, fixed, embedded in paraffin wax, sectioned, and stained with I2Kl (potassium iodide-iodine). Preparations are observed under the microscope and analyzed by an image analyzer that clearly distinguishes starch from the background. Starch content values are obtained by measuring the optical density of the image that corresponds to the stained starch, considering the sum of the optical density of each pixel as an estimation of the starch content of the frame studied.

A suitable enzymatic method for starch quantification in different organic matrices

Starch can represent 70–80% of the cereals grains (on a dry matter basis) used for livestock feeding. Several methods have been developed to estimate the feed starch contents of energy feed sources. However, the efficiency of these methods to evaluate the starch content in other feed sources, as well as other types of samples used to evaluate starch availability in the gastrointestinal tract, such as digesta and faeces, remains unclear. Furthermore, most of the currently used starch analysis methods have not been effectively evaluated, being only applied to samples of sporadic experiments, without a wide-ranging validation of the procedures and results. Here, we propose a modification of a method for analysing the starch content in different organic matrices normally evaluated in ruminant nutrition studies. The evaluated organic matrices were: soybean meal, soybean hull, Tifton 85 Bermuda grass hay, abomasal digesta, and faeces.•The modified method is more feasible than the original procedures.•The modified method estimates the starch contents in different organic matrices with accuracy and precision.

Anther and pollen development in sweet cherry (Prunus avium L.) in relation to winter dormancy.

Anther and pollen development is a highly conserved process in angiosperms, but while pollen formation in annual plants occurs in a few days, in temperate woody perennials, it requires several months. How anther and pollen development is framed in terms of seasonality plays a clear part in reproductive success. In this study, seasonal anther and pollen development is characterized in two sweet cherry cultivars over 2years, paying special attention to the period of dormancy and unveiling the role of starch in this process. We evaluated starch content from the autumn until bud burst with the help of an image analysis system fitted to a light microscope. Microscope observations allowed the temporal relationship of pollen development to the phenological stages of flower and bud development to be determined. In both cultivars and years, anther and pollen development followed the same pattern. Development was halted by dormancy, when the anthers showed no morphological changes until several weeks after chilling fulfillment, until the milder temperatures reactivated development. After dormancy, starch was accumulated in the connective tissue until tracheary element differentiation. Quantification of starch in the connective tissue of anthers revealed its importance in supporting pollen meiosis and subsequent anther growth.

Evaluation of the Starch Quantification Methods of Musa paradisiaca, Manihot esculenta, and Dioscorea trífida Using Factorial Experiments.

Background Starch and its products are used in a variety of ways for both the food and nonfood industries. A factorial experiment is carried out with two factors to explain the behavior of the percentage of starch, where the factors correspond to the extraction method and to the raw material. Method Three methods were used in triplicate: the first followed the official technique of the Association of Official Analytical Chemists (AOAC), to perform acid hydrolysis and quantification of starch by Titulation; the second method involved the colorful reaction with iodine using the UV equipment to measure the absorbance and calculate the percentage of starch; as a third method the FTIR was used, through which the concentration of the starch was calculated by the area under the curve obtained from the spectrum. Results there is an effect of both the method and the raw material on the percentage of starch, while there was no effect of the interaction; the Tukey test indicates that the highest average percentage of extraction occurs with the extraction method by Titulation and with the starch of Manihot esculenta. Conclusion It is used as raw material. The method of quantification of starch by UV-VIS spectroscopy was the best for the study samples because it presented less deviation in relation to the FTIR and Titulation methods.

Fast measurement of starch content in cold-treated seedlings by infrared spectra

ABSTRACTDespite the importance of starch for tree growth, methodological challenges in starch analysis slow down the research on its ecological importance. In this study, a rapid monitoring method was developed for measuring starch content in Pinus taeda L. seedlings after cold treatments. A linear mixed-effects model was used to analyze the effects of cold treatments, seedling tissue types and their interaction on starch content. Mid-infrared (MIR) and near-infrared (NIR) spectra were surveyed, and the results were analyzed using partial least squares regression to determine the starch content. The determination coefficient for calibration and residual predictive deviation were compared between MIR and NIR models to assess the variability of the established models. The results showed that the effects of cold treatments, seedling tissue types and their interaction on starch content were significant. Compared to MIR spectra, NIR spectra is more suitable to estimate starch content in the seedlings. Using NIR spectra, roots provided the most accurate estimates of starch content. The presented guidelines regarding data accuracy as a function of MIR/NIR spectra of samples represent an important methodological reference for starch quantification, which will improve the understanding of the fundamental role of starch in seedlings against environmental forces.

Quantification of Starch in Guard Cells of Arabidopsis thaliana.

In this protocol, we describe how to quantify starch in guard cells of Arabidopsis thaliana using the fluorophore propidium iodide and confocal laser scanning microscopy. This simple method enables monitoring, with unprecedented resolution, the dynamics of starch in guard cells.