Total Starch HK Assay Kit

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.

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%.

Brewers spent grain (BSG), the main solid byproduct of brewing, is annually generated by ca 37 million tons worldwide, which due to limited application, mostly ends up in landfills. This study aims to separate BSG’s fractions (lignin, cellulose, and hemicellulose) by ethanol organosolv pretreatment. Lignin-rich fractions were recovered using a two-step separation technique. The effects of temperature, retention time, and ethanol concentration on the quantity and quality of fractions were studied. The temperature considerably impacted the quality and quantity of obtained fractions, while other parameter effects greatly depended on the temperature. Substantial hemicellulose removal (90 %) along with lignin removal (56 %) and recovery (57 %) were obtained at 180°C. The highest lignin purity (95 %) was obtained at the pretreatment conditions of 180°C, 120 min, and 50 % ethanol concentration. This work provides an alternative route for BSG utilization, mitigating its environmental impact while enhancing the economy of a brewery.

Grape phylloxera (Daktulosphaira vitifoliae) can infest both roots and leaves of Vitis species. In commercial vineyards planted with Vitis vinifera scions grafted on rootstocks, grape phylloxera infestation is generally limited to root feeding. Vineyards are, however, increasingly subjected to vineyard-wide foliar infestations that last throughout the growing season. While some vineyards are affected by the infestation pressure of external leaf-feeding populations, other annually affected V. vinifera vineyards do not have these in their vicinity. Much is known about the damage potential of grape phylloxera root feeding; however, data on how phylloxera leaf infestation affects V. vinifera grapevines in commercial vineyards are lacking. This study, therefore, aimed to assess whether grapevine growth and yield are affected due to leaf infestation as it occurred in three commercial vineyards in the study area. Treatments were based on phylloxera leaf infestation and additional defoliation. Single-leaf carbon acquisition was measured with gas exchange analyses on healthy and galled leaves. Pruning weight and internode length were measured to assess the effect of leaf infestation and the effect of plant growth and vigour on leaf gall outbreaks. Yield quantity and quality were measured, and grapes were vinified for sensory analyses. Furthermore, using enzymatic analyses, non-structural carbohydrates were analysed in perennial wood. A significant decrease in sugar content in grapes (10 %) and starch reserves in perennial wood (11 %) was found in the most heavily infested vineyard. Grape must of infested plants in another vineyard furthermore showed a significantly higher level of titratable acid (7.5 %). Significant infestation effects seen in one vineyard were not significant in the other two vineyards. No significant differences were seen for carbon acquisition, harvest quantity, wine sensory analysis, pruning weight or internode length. The overall effect of phylloxera leaf infestation in the studied vineyards was, therefore, marginal. Grapevine vigour did not differ between infested vines, insecticide-sprayed vines, and vines on which no leaf infestation outbreaks took place. By analysing phylloxera leaf infestation under field conditions, these preliminary results form a basis for future long-term field studies about phylloxera leaf feeding on Vitis vinifera within the context of other biotic and abiotic plant stresses.

Maitake (Grifola frondosa) is a medicinal mushroom known for its peculiar biological activities due to the presence of functional components, including dietary fibers and glucans, that can improve human health through the modulation of the gut microbiota. In this paper, a Maitake ethanol/water extract was prepared and characterized through enzymatic and chemical assays. The prebiotic potential of the extract was evaluated by the growth of some probiotic strains and of a selected probiotic consortium. The results revealed the prebiotic properties due to the stimulation of the growth of the probiotic strains, also in consortium, leading to the production of SCFAs, including lactic, succinic, and valeric acid analyzed via GC-MSD. Then, their beneficials effect were employed in evaluating the vitality of three different healthy and tumoral colorectal cell lines (CCD841, CACO-2, and HT-29) and the viability rescue after co-exposure to different stressor agents and the probiotic consortium secondary metabolites. These metabolites exerted positive effects on colorectal cell lines, in particular in protection from reactive oxygen species.

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.

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.

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.

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.

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 C_biomass/mole C_substrate. 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.

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.

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.

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.

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.

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 23^oC 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.

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.

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.

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.

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.