|Content:||100 assays per kit|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Linear Range:||4 to 80 µg of D-glucose per assay|
|Limit of Detection:||1 g/100 g|
|Total Assay Time:||~ 90 min|
|Application examples:||Cereal flours, food products and other materials.|
The Total Starch HK (Hexokinase) Assay Kit for total starch determination in cereal flours and food products.
This assay kit contains an improved α-amylase that allows the amylase incubations to be performed at pH 5.0 (as well as pH 7.0). The method has been further modified by adjusting the D-glucose determination to a hexokinase/glucose-6-phosphate dehydrogenase/NADP+ based format.
See our full range of dietary and starch assay kits.
- Very competitive price (cost per test)
- All reagents stable for > 2 years after preparation
- Simple format
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
McCleary, B. V., Charnock, S. J., Rossiter, P. C., O’Shea, M. F., Power, A. M. & Lloyd, R. M. (2006). Journal of the Science of Food and Agriculture, 86(11), 1648-1661.
Procedures for the measurement of starch, starch damage (gelatinised starch), resistant starch and the amylose/amylopectin content of starch, β-glucan, fructan, glucomannan and galactosyl-sucrose oligosaccharides (raffinose, stachyose and verbascose) in plant material, animal feeds and foods are described. Most of these methods have been successfully subjected to interlaboratory evaluation. All methods are based on the use of enzymes either purified by conventional chromatography or produced using molecular biology techniques. Such methods allow specific, accurate and reliable quantification of a particular component. Problems in calculating the actual weight of galactosyl-sucrose oligosaccharides in test samples are discussed in detail.Hide Abstract
McCleary, B. V., Gibson, T. S. & Mugford, D. C. (1997). Journal of AOAC International, 80, 571-579.
An American Association of Cereal Chemists/AOAC collaborative study was conducted to evaluate the accuracy and reliability of an enzyme assay kit procedure for measurement of total starch in a range of cereal grains and products. The flour sample is incubated at 95 degrees C with thermostable alpha-amylase to catalyze the hydrolysis of starch to maltodextrins, the pH of the slurry is adjusted, and the slurry is treated with a highly purified amyloglucosidase to quantitatively hydrolyze the dextrins to glucose. Glucose is measured with glucose oxidase-peroxidase reagent. Thirty-two collaborators were sent 16 homogeneous test samples as 8 blind duplicates. These samples included chicken feed pellets, white bread, green peas, high-amylose maize starch, white wheat flour, wheat starch, oat bran, and spaghetti. All samples were analyzed by the standard procedure as detailed above; 4 samples (high-amylose maize starch and wheat starch) were also analyzed by a method that requires the samples to be cooked first in dimethyl sulfoxide (DMSO). Relative standard deviations for repeatability (RSD(r)) ranged from 2.1 to 3.9%, and relative standard deviations for reproducibility (RSD(R)) ranged from 2.9 to 5.7%. The RSD(R) value for high amylose maize starch analyzed by the standard (non-DMSO) procedure was 5.7%; the value was reduced to 2.9% when the DMSO procedure was used, and the determined starch values increased from 86.9 to 97.2%.Hide Abstract
Fortified blended foods prepared from fermented milk and cereal: Effect of storage conditions on composition, color, and pasting behavior.
Shevade, A. V., O’Callaghan, Y. C., O’Brien, N. M., O’Connor, T. P. & Guinee, T. P. (2021). Journal of Food Processing and Preservation, 45(5), e15419.
Fortified blended food powders (FBF) were prepared by blending fermented milk with parboiled wheat (FBFw), barley (FBFb), or oats (FBFo), incubating the blend, drying, milling, and fortifying the powder with vitamins, minerals, and refined soya oil. FBFs were stored at 15°C, 30°C, or 37°C for 0-18 months, and evaluated for compositional and functional properties. FBFo had lower contents of lactose and galactose, and higher contents of starch and fat, water-holding capacity (WHC) and pasting viscosity than FBFw or FBFb. Storage time and temperature affected composition (lactose, galactose, and lysine), color, WHC, pasting viscosity, and flow to a degree dependent on cereal type. FBFs stored at 15°C were generally stable over the 18 months, while those stored at 37°C underwent a rapid deterioration in color, WHC, and viscosity after storage times of ≤4 months. Storage of FBF at 15°C is recommended, whereas storage at 37°C should be avoided.Hide Abstract
Mixture design applied for formulation and characterization of vegetal-based fermented products.
Chekdid, A. A., Kahn, C. J., Prévot, E., Ferrières, M., Lemois, B., Choquet, C. & Linder, M. (2021). LWT, 146, 111336.
The present study consists on the characterization of six different flours in order to evaluate their ability to ferment alone and in mixtures. A discrepancy in the composition and physico-chemical characteristics of the flours was recorded. Three of these flours (oats, chickpea and coconut) were selected for the construction of the mixture design, which was used to formulate a base for a fermented vegetable dessert. Oat and chickpea flours have an effect on color accentuation (ΔE = 17.37) as well as on increasing water retention (75.31 g/100 g). During storage, post-acidification of the media to pH 4.42 was recorded, with a water holding capacity ranging from 56.64 to 66.12 g per 100 g, indicating a change in the texture of the mixtures. The fermented plant product showed a high viability of lactic acid bacteria, more than 107 CFU/mL for L. delbrueckii subsp. Bulgaricus and more than 108 CFU/mL for S. thermophiles after 30 days of storage. The use of flours in the formulation of fermented products was demonstrated as an alternative strategy for the development of new vegetable-based desserts.Hide Abstract
Starch and protein recovery from brewer's spent grain using hydrothermal pretreatment and their conversion to edible filamentous fungi-A brewery biorefinery concept.
Parchami, M., Ferreira, J. A. & Taherzadeh, M. J. (2021). Bioresource Technology, 125409.
This study aimed at recovering a highly concentrated starch and protein stream from the brewer’s spent grain (BSG). The effect of pretreatment temperature and retention time on the solubilization of starch and protein; and the generation of fermentation inhibitors were studied. Then, the application of recovered streams for fungal cultivation was evaluated using different edible fungi Aspergillus oryzae, Neurospora intermedia, and Rhizopus delemar. The hydrothermal pretreatment resulted in the highest solubilized starch concentration, 43 g/L, corresponding to 83% solubilization of initial BSG starch content. The highest protein concentration was 27 g/L (48% solubilization of initial BSG protein content). Cultivation with Neurospora intermedia on the recovered streams from the two best pretreatment conditions, 140°C for 4 h and 180°C for 30 min, resulted in pure fungal biomass with the highest protein content 59.62% and 50.42% w/w, respectively. Finally, a brewery biorefinery was proposed for the valorization of BSG.Hide Abstract
Soft Durum Wheat as a Potential Ingredient for Direct Expanded Extruded Products.
Gu, B. J., Kerr, C. J., Morris, C. F. & Ganjyal, G. M. (2021). Journal of Cereal Science, 103184.
Soft durum wheat was extruded to assess the influence of independent parameters (moisture content, screw speed, and barrel temperature each) on system responses (back pressure, torque value, and specific mechanical energy input) and product responses (expansion ratio, unit density, water absorption index (WAI) and water solubility index (WSI)). The lowest barrel temperature (120 °C) and moisture content (16%) with the highest screw speed (250 rpm) resulted in the highest specific mechanical energy input, expansion ratio, and water solubility index in the extrudates. Among the three independent parameters evaluated, moisture content was the most influential factor on the system and product responses. Energy efficiency on solubility (EES) was defined, and the notable impact of moisture content on EES was observed. Extrudates made from soft durum wheat had a reasonable expansion ratio, proving its potential usage in snack and cereal products.Hide Abstract
Solid-state fermentation of stale bread by an edible fungus in a semi-continuous plug-flow bioreactor.
Wang, R., Gmoser, R., Taherzadeh, M. J. & Lennartsson, P. R. (2021). Biochemical Engineering Journal, 169, 107959.
Stale bread, one of the major food wastes, holds great potential to produce new food products by solid-state fermentation using the edible filamentous fungus Neurospora intermedia. Yet, this process is limited to small-scale batch production. In this study, a plug-flow bioreactor was developed and successfully operated semi-continuously without addition of external inoculum. Two critical process parameters namely residence time and inoculum-to-substrate ratio (ISR) were studied in two experimental set-ups, 48 h and ISR 10:65 or 24 h and 20:55. The fermentation performance was assessed by the CO2 evolution rate and starch degradation in the substrate. Both experiments resulted in a relatively stable CO2 evolution rate up to 10 days and the starch content was reduced from 65 % in bread to 40.6 % and 43.2 %, respectively, in the product. Performance of the plug-flow bioreactor was compared to batch fermentation in tray bioreactors using the same ratio of inoculum. No significant differences of the final starch content were observed between the bioreactors, which indicate improved productivity by the semi-continuous process compared to the batch. The fungal biomass yield was calculated to range from 0.12 to 0.5 mol Cbiomass/mole Csubstrate. A material balance of the process revealed that 220 g dry bread and 200 ml water were required to produce 400 g fermented product with a fungal biomass content of 15 % in 24 h.Hide Abstract
Storage of biofortified maize in Purdue Improved Crop Storage (PICS) bags reduces disulfide linkage-driven decrease in porridge viscosity.
Nkhata, S. G., Liceaga, A. M., Rocheford, T., Hamaker, B. R. & Ferruzzi, M. G. (2021). LWT, 136, 110262.
Assessing rheological properties of biofortified maize through post-harvest storage is critical for its successful translation to consumer foods. Changes in flour rheology were assessed following post-harvest storage in Purdue Improved Crop Storage (PICS) of a white and two biofortified orange maize genotypes (OPVI and OPVII). Whole grains were stored in PICS bags with (PICS-oxy) or without (PICS-noxy) oxygen scavenger and compared to storage in traditional polypropylene woven bags. Flour pasting profiles were assessed over 8 months of storage. Initial porridge viscosities from biofortified maize were lower than from white maize. After 8 months, higher viscosities (p < 0.05) were observed in grain stored in PICS relative to woven bags. Sequestration of oxygen had a modest but significant effect (p < 0.05) on peak and final viscosities supporting the notion that oxidative processes mediate these effects. DTT treatment partially restored porridge viscosity suggesting disulfide linkages are involved in rheological changes during storage. Raman spectral analysis suggested storage-induced structural changes to the starch matrix. Overall, storage of biofortified maize in PICS alleviated disulfide linkage-driven decreases in viscosity of cooked porridge. With the potential to improve cooking quality of biofortified maize flours, application of PICS may be useful in translation of these grains to consumers.Hide Abstract
Purification of Sucrose in Sugar Beet Molasses by Utilizing Ceramic Nanofiltration and Ultrafiltration Membranes.
Sjölin, M., Thuvander, J., Wallberg, O. & Lipnizki, F. (2020). Membranes, 10(1), 5.
Molasses is a sugar mill by-product with low value that today is used primarily for animal feed. However, molasses contains large amounts of sucrose which, if purified, could be used for other purposes. In this study, purification by membrane filtration using ceramic tubular ultrafiltration (UF) and nanofiltration (NF) was examined. NF purifies sucrose by removing small compounds, whereas UF removes larger compounds. Based on our results, high filtration fluxes could be obtained, and it was possible to clean the membranes sufficiently from fouling compounds. Sucrose was separated from other compounds, but the separation efficiency was generally higher with diluted molasses compared with concentrated molasses. This could be explained by more severe fouling when filtering dilute molasses or potentially due to aggregate formations in the molasses as our analysis showed. Overall, this study shows the potential of ceramic UF and NF membranes for sucrose purification from molasses.Hide Abstract
Extraction, physicochemical and film properties of polysaccharides from highland barley bran fermented by Aureobasidium Pullulans.
Liu, Q., Liu, P., Zhou, Y., Chang, J., Chen, X., Lyua, Q. & Liu, G. (2020). ES Food & Agroforestry, 1, 85-93.
Plastic packaging films are not recyclable, difficult to degrade and thus threaten the environment and the health of humans and other animals. Therefore, the purpose of the research is to derive edible polysaccharide films from Highland barley bran fermented by Aureobasidium pullulans. Fermentation conditions using UV-mutated A. pullulans were optimized and the rheological, mechanical and barrier properties of edible polysaccharide films were analyzed. The polysaccharides produced by mutagenesis increased by 8.6% after fermentation. The products before and after fermentation contained α- and β-glycosidic bonds, C-O-C, C=O, O-H, and other characteristic peaks of polysaccharides. Post-fermented polysaccharide films (post-FPF) were more moisture resistant than pre-fermented polysaccharide (pre-FPF) and control group (CGPF). Mechanical properties were better for CGPF than post-FPF, but post-FPF had good water solubility. It was feasible to make an edible polysaccharide film with improved water solubility. Post-fermentation polysaccharide films could help to reduce the cost of edible film production and improve the comprehensive utilization of bran.Hide Abstract
Biorefining oat husks into high-quality lignin and enzymatically digestible cellulose with acid-catalyzed ethanol organosolv pretreatment.
Chopda, R., Ferreira, J. A. & Taherzadeh, M. J. (2020). Processes, 8(4), 435.
Oat husks are low-value lignocellulosic residues of oat processing that carry an environmental impact. Their polymers (cellulose, hemicellulose, and lignin) can be converted into a wide variety of value-added products; however, efficient pretreatment methods are needed that allow their fine separation for further tailored valorization. This study pioneered the use of milling-free and low acid-catalyzed ethanol organosolv for the delignification of oat husks, allowing their conversion into three high-quality streams, namely, glucan-rich, lignin-rich, and hemicellulosic compound-rich streams. Temperature, retention time, and solid-to-liquid ratio were found to impact the delignification of oat husks when using a one-factor-at-a-time strategy. The ideal conditions that were found (210°C, 90 min, and solid-to-liquid ratio of 1:2) culminated into glucan and lignin fractions containing 74.5% ± 11.4% glucan and 74.9% ± 7.6% lignin, respectively. These high-purity lignin fractions open the possibility for higher value applications by lignin, potentially impacting the feasibility of second generation biorefineries. The glucan fraction showed 90% digestibility after 48 h of hydrolysis with 10 filter paper units of enzyme cocktail per gram of glucan. Considering the absence of size reduction and high solid loading, together with the quality of the obtained streams, organosolv pretreatment could be a potential strategy for the valorization of oat lignocellulosic residues.Hide Abstract
Profiling of carbohydrates in commercial beers and their influence on beer quality.
Li, M., Du, J. & Zhang, K. (2020). Journal of the Science of Food and Agriculture, 100(7), 3062-3070.
Background: The carbohydrates in beer play an important role as they are essential for fermentation. Any change in their composition may influence the sensory characteristics of the beer and so their determination is of great interest. This study compares the carbohydrates in three types of commercial beer - barley malt beer, wheat beer, and barley malt beer with adjuncts - and examines their influence on beer quality, which is important for selecting raw ingredients and production conditions, and for quality control. Results: Among the oligosaccharides in three types of beer, raffinose was the most, followed by maltotetraose, maltotriose and maltose. Monosaccharides were only present in small amounts. Dextrin, oligosaccharides with 2-6 polymerization degree and non‐starch polysaccharides (NSP) make up 15.90-34.83%, 17.59-38.63%, and 2.33-7.47% of the total carbohydrates in beer, respectively. The dextrin content and NSP content were significantly (P < 0.05) different in wheat beer and barley malt beer, and their content was significantly (P < 0.01) correlated with the content of extracts in beer. Non‐starch polysaccharide, dextrin, trisaccharide, and tetrasaccharide content significantly (P < 0.05) correlated with beer viscosity. These beer samples could be categorized clearly into three groups by principal component analysis. Conclusion: The oligosaccharides in beer reflect yeast utilization, depending on the type of beer. Dextrin, oligosaccharides with 2-4 polymerization, and NSP, were major carbohydrates in beer. Their composition and concentration influenced its characteristics and quality, and played an important role in the discrimination of different beer types.Hide Abstract
High night temperature induced changes in grain starch metabolism alters starch, protein, and lipid accumulation in winter wheat.
Impa, S. M., Vennapusa, A. R., Bheemanahalli, R., Sabela, D., Boyle, D., Walia, H. & Jagadish, S. K. (2020). Plant, Cell & Environment, 43(2), 431-447.
Unlike sporadic daytime heat spikes, a consistent increase in night‐time temperatures can potentially derail the genetic gains being achieved. Ten winter wheat genotypes were exposed to six different night‐time temperatures (15-27°C) during flowering and grain‐filling stages in controlled environment chambers. We identified the night‐time temperature of 23oC as the critical threshold beyond which a consistent decline in yields and quality was observed. Confocal laser scanning micrographs of central endosperm, bran, and germ tissue displayed differential accumulation of protein, lipid, and starch with increasing night‐time temperatures. KS07077M‐1 recorded a decrease in starch and an increase in protein and lipid in central endosperm with increasing night‐time temperatures, whereas the same was significantly lower in the tolerant SY Monument. Expression analysis of genes encoding 21 enzymes (including isoforms) involved in grain–starch metabolism in developing grains revealed a high night‐time temperature (HNT)‐induced reduction in transcript levels of adenosine diphosphate glucose pyrophosphorylase small subunit involved in starch synthesis and a ≥2‐fold increase in starch degrading enzymes isoamylase III, alpha‐, and beta‐amylase. The identified critical threshold, grain compositional changes, and the key enzymes in grain starch metabolism that lead to poor starch accumulation in grains establish the foundational knowledge for enhancing HNT tolerance in wheat.Hide Abstract
Fortified blended food base: effect of co-fermentation time on composition, phytic acid content and reconstitution properties.
Shevade, A. V., O’Callaghan, Y. C., O’Brien, N. M., O’Connor, T. P. & Guinee, T. P. (2019). Foods, 8(9), 388.
Dehydrated blends of dairy-cereal combine the functional and nutritional properties of two major food groups. Fortified blended food base (FBFB) was prepared by blending fermented milk with parboiled wheat, co-fermenting the blend at 35°C, shelf-drying and milling. Increasing co-fermentation time from 0 to 72 h resulted in powder with lower lactose, phytic acid and pH, and higher contents of lactic acid and galactose. Simultaneously, the pasting viscosity of the reconstituted base (16.7%, w/w, total solids) and its yield stress (σ0), consistency index (K) and viscosity on shearing decreased significantly. The changes in some characteristics (pH, phytic acid, η120) were essentially complete after 24 h co-fermentation while others (lactose, galactose and lactic acid, pasting viscosities, flowability) proceeded more gradually over 72 h. The reduction in phytic acid varied from 40 to 58% depending on the pH of the fermented milk prior to blending with the parboiled cereal. The reduction in phytic acid content of milk (fermented milk)-cereal blends with co-fermentation time is nutritionally desirable as it is conducive to an enhanced bioavailability of elements, such as Ca, Mg, Fe and Zn in milk-cereal blends, and is especially important where such blends serve as a base for fortified-blended foods supplied to food-insecure regions.Hide Abstract
Optimization of a simple, accurate and low cost method for starch quantification in green microalgae.
Yong, T. C., Chiu, C. S. & Chen, C. N. N. (2019). Botanical Studies, 60(1), 25.
Background: Lipids 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. Results: A 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. Conclusions: This 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.Hide Abstract
Development of a dehydrated fortified food base from fermented milk and parboiled wheat, and comparison of its composition and reconstitution behavior with those of commercial dried dairy‐cereal blends.
Shevade, A. V., O'Callaghan, Y. C., O'Brien, N. M., O'Connor, T. P. & Guinee, T. P. (2019). Food science & Nutrition, 7(11), 3681-3691.
Dehydrated blends of milk and cereal are reconstituted and consumed as a nutritious soup or porridge in many regions; the composition and reconstitution behavior of the blends are likely to impact on nutritional quality and consumer acceptability of the soup/porridge. Experimental samples of dried fermented milk‐bulgur wheat blend (FMBW) and commercial samples of dried dairy‐cereal blends, namely kishk, tarhana, and super cereal plus corn–soy blend (SCpCSB) were compared for composition, color, water sorption, and reconstitution characteristics. FMBW blends had higher contents of protein, Ca, lactose and lactic acid, lower levels of salt (NaCl) and Fe, and a lighter, more‐yellow color (higher L* and b*‐color co‐ordinates) than tarhana or kishk. Compared with SCpCSB, FMBW had numerically higher levels of protein, lactose, and lactic acid, lower levels of Ca, Fe, Zn, and Mg, and lower pH. Tarhana had highest mean levels of starch, and on reconstitution (133 g/kg) had highest water holding capacity, viscosity during pasting and cooling, yield stress (σ0), consistency coefficient (K), and viscosity on shearing from 20 to 120 s−1 at 60°C. Reconstituted FMBW, kishk, and SCpCSB had similar pasting and flow behavior properties. Overall, the composition (starch, protein, Ca, Mg), pasting and flow behavior characteristics of FMBW were closer to those SCpCSB and kishk than to tarhana. The results suggest that the FMBW powder, on appropriate supplementation with Ca, Fe, Zn and Mg, could be used for the development of customized fortified blended foods for specific groups.Hide Abstract
Manufacturing the ultimate green banana flour: Impact of drying and extrusion on phenolic profile and starch bioaccessibility.
Pico, J., Xu, K., Guo, M., Mohamedshah, Z., Ferruzzi, M. G. & Martinez, M. M. (2019). Food Chemistry, 297, 124990.
Use of banana flours as functional ingredients is growing due to their nutritional benefits derived from phenolics and dietary fiber. However, the effect oven-drying, freeze-drying and extrusion on the phenolic compounds or starch digestibility is not understood. In this work, phenolic acids (gallic acid, caffeic acid), flavan-3-ols (epicatechin, catechin) and flavonols (quercetin-3-O-glucoside and myricetin) were quantified in banana flour processed by different methods. Epicatechin, the most abundant phenolic in all flours (up to 1.93 mg/100 g), was significantly reduced during thermal processing (oven-drying and extrusion). Meanwhile, phenolic acids and flavonols were found to be more thermally stable. Thus, oven-drying and extrusion generally improved the extractability of phenolic acids and flavonols. Freeze-drying resulted in native flours with significantly higher insoluble dietary fiber (up to 43.3%), although the digestible starch fraction was digested more rapidly than the oven-dried counterpart.Hide Abstract
Shevade, A. V., O'Callaghan, Y. C., O'Brien, N. M., O'Connor, T. P. & Guinee, T. P. (2018). Foods, 7(7).
Dairy and cereal are frequently combined to create composite foods with enhanced nutritional benefits. Dehydrated fermented milk-wheat composites (FMWC) were prepared by blending fermented milk (FM) and parboiled wheat (W), incubating at 35°C for 24 h, drying at 46°C for 48 h, and milling to 1 mm. Increasing the weight ratio of FM to W from 1.5 to 4.0 resulted in reductions in total solids (from 96 to 92%) and starch (from 52 to 39%), and increases in protein (15.2-18.9%), fat (3.7-5.9%), lactose (6.4-11.4%), and lactic acid (2.7-4.2%). FMWC need to be reconstituted prior to consumption. The water-holding capacity, pasting viscosity, and setback viscosity of the reconstituted FMWC (16.7% total solids) decreased with the ratio of FM to W. The reconstituted FMWC exhibited pseudoplastic flow behaviour on shearing from 18 to 120 s-1. Increasing the FM:W ratio coincided with a lower yield stress, consistency index, and viscosity at 120 s-1. The results demonstrate the critical impact of the FM:W ratio on the composition, pasting behavior, and consistency of the reconstituted FMWC. The difference in consistency associated with varying the FM:W ratio is likely to impact on satiety and nutrient value of the FMWCs.Hide Abstract
Mariscal‐Moreno, R. M., Cárdenas, F., de Dios, J., Santiago‐Ramos, D., Rayas‐Duarte, P., Veles‐Medina, J. J. & Martínez‐Flores, H. E. (2017). Journal of Food Science, 82(5), 1110-1115.
Tamales were prepared with 3 nixtamalization processes (traditional, ecological, and classic) and evaluated for chemical composition, starch properties, and glycemic index. Resistant starch (RS) in tamales increased 1.6 to 3.7 times compared to raw maize. This increment was due to the starch retrogradation (RS3) and amylose–lipid complexes (RS5) formation. Tamales elaborated with classic and ecological nixtamalization processes exhibited the highest total, soluble and insoluble dietary fiber content, and the highest RS content and lower in vivo glycemic index compared to tamales elaborated with traditional nixtamalization process. Thermal properties of tamales showed 3 endotherms: amylopectin retrogradation (42.7 to 66.6°C), melting of amylose lipid complex type I (78.8 to 105.4), and melting of amylose–lipid complex type II (110.7 to 129.7). Raw maize exhibited X-ray diffraction pattern type A, after nixtamalization and cooking of tamales it changed to V-type polymorph structure, due to amylose–lipid complexes formation. Tamales from ecological nixtamalization processes could represent potential health benefits associated with the reduction on blood glucose response after consumption.Hide Abstract
Ceylan, Y., Kutman, U. B., Mengutay, M. & Cakmak, I. (2016). Plant and Soil, 406(1), 145–156.
Background and Aims: Magnesium (Mg) has diverse functions in plants and plays a critical role in carbohydrate partitioning between source and sink tissues. There is, however, limited information available about the effects of Mg deficiency on grain starch accumulation, yield formation and seed quality in terms of seed germination and seedling establishment in wheat. Methods: In a solution culture experiment, bread wheat (Triticum aestivum) was grown to maturity with low or adequate Mg under greenhouse conditions, and a post-anthesis foliar Mg application was tested on low-Mg plants. The effects of these Mg treatments on i) yield parameters, ii) distribution of starch among sink and source organs, iii) tissue concentrations of Mg and other minerals and iv) seed germination and seedling development were investigated. Results: Low Mg supply did not affect the vegetative biomass production; but substantially reduced the grain yield. Post-anthesis foliar Mg spray significantly minimized yield losses caused by Mg deficiency. Decreases in grain yield by Mg deficiency were due to decreases in individual seed weight rather than seed number per spike. Low Mg depressed the grain and root starch levels, while increasing the leaf starch. Foliar Mg spray largely reversed these effects of Mg deficiency. Seeds obtained from low-Mg plants exhibited severe impairments in germination and seedling establishment. These seed quality traits were also greatly improved by foliar Mg application to maternal plants. Conclusions: Magnesium deficiency reduces grain yield in wheat mainly by limiting the carbohydrate supply to developing seeds and thus by decreasing the seed weight. Since vegetative growth is far less affected than yield formation, Mg deficiency may remain latent until seed-filling. Therefore, foliar Mg application appears to be a promising tool to alleviate Mg deficiency during seed-filling and minimize its impact on yield and seed quality.Hide Abstract