|Content:||660 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 100 μg of glucose per assay|
|Limit of Detection:||100 mg/L|
|Reaction Time (min):||~ 20 min|
|Application examples:||Wine, beer, fruit juices, soft drinks, milk, jam, dietetic foods, bakery products, candies, fruit and vegetables, tobacco, cosmetics, pharmaceuticals, feed, paper and other materials (e.g. biological cultures, samples, etc.).|
|Method recognition:||Widely used and accepted in clinical chemistry and food analysis|
The D-Glucose test kit contains high purity reagents for the measurement and analysis of D-glucose in cereal extracts and for use in combination with other Megazyme kits.
See more related mono/disaccharide assay kit products.
- All reagents stable for > 12 months after preparation
- Very competitive price (cost per test)
- Simple format
- Standard included
Measurement of available carbohydrates in cereal and cereal products, dairy products, vegetables, fruit and related food products and animal feeds: First Action 2020.07.
McCleary, B. V. & McLoughlin, C. (2021). Journal of AOAC International, qsab019.
Background: The level of available carbohydrates in our diet is directly linked to two major diseases; obesity and Type II diabetes. Despite this, to date there is no method available to allow direct and accurate measurement of available carbohydrates in human and animal foods. Objective: The aim of this research was to develop a method that would allow simple and accurate measurement of available carbohydrates, defined as non-resistant starch, maltodextrins, maltose, isomaltose, sucrose, lactose, glucose, fructose and galactose. Method: Non-resistant (digestible) starch is hydrolysed to glucose and maltose by pancreatic α-amylase and amyloglucosidase at pH 6.0 with shaking or stirring at 37°C for 4 h. Sucrose, lactose, maltose and isomaltose are completely hydrolyzed by specific enzymes to their constituent monosaccharides, which are then measured using pure enzymes in a single reaction cuvette. Results: A method has been developed that allows the accurate measurement of available carbohydrates in all cereal, vegetable, fruit, food, and feed products, including dairy products. Conclusions: A single-laboratory validation was performed on a wide range of food and feed products. The inter-day repeatability (%RSDr) was <3.58% (w/w) across a range of samples containing 44.1 to 88.9% available carbohydrates. The LOD and LOQ obtained were 0.054% (w/w) and 0.179% (w/w), respectively. The method is all inclusive, specific, robust and simple to use. Highlights: A unique method has been developed for the direct measurement of available carbohydrates, entailing separate measurement of glucose, fructose and galactose; information of value in determining the glycemic index of foods.Hide Abstract
Measurement of Starch: Critical evaluation of current methodology.
McCleary, B. V., Charmier, L. M. J. & McKie, V. A. (2018). Starch‐Stärke, 71(1-2), 1800146.
Most commonly used methods for the measurement of starch in food, feeds and ingredients employ the combined action of α‐amylase and amyloglucosidase to hydrolyse the starch to glucose, followed by glucose determination with a glucose oxidase/peroxidase reagent. Recently, a number of questions have been raised concerning possible complications in starch analytical methods. In this paper, each of these concerns, including starch hydrolysis, isomerisation of maltose to maltulose, effective hydrolysis of maltodextrins by amyloglucosidase, enzyme purity and hydrolysis of sucrose and β‐glucans have been studied in detailed. Results obtained for a range of starch containing samples using AOAC Methods 996.11 and 2014 .10 are compared and a new simpler format for starch measurement is introduced. With this method that employs a thermostable α-amylase (as distinct from a heat stable α-amylase) which is both stable and active at 100°C and pH 5.0, 10 samples can be analysed within 2 h, as compared to the 6 h required with AOAC Method 2014.10.Hide Abstract
Megazyme “advanced” wine test kits general characteristics and validation.
Charnock, S. J., McCleary, B. V., Daverede, C. & Gallant, P. (2006). Reveue des Oenologues, 120, 1-5.
Many of the enzymatic test kits are official methods of prestigious organisations such as the Association of Official Analytical Chemicals (AOAC) and the American Association of Cereal Chemists (AACC) in response to the interest from oenologists. Megazyme decided to use its long history of enzymatic bio-analysis to make a significant contribution to the wine industry, by the development of a range of advanced enzymatic test kits. This task has now been successfully completed through the strategic and comprehensive process of identifying limitations of existing enzymatic bio-analysis test kits where they occurred, and then using advanced techniques, such as molecular biology (photo 1), to rapidly overcome them. Novel test kits have also been developed for analytes of emerging interest to the oenologist, such as yeast available nitrogen (YAN; see pages 2-3 of issue 117 article), or where previously enzymes were simply either not available, or were too expensive to employ, such as for D-mannitol analysis.Hide Abstract
Grape and wine analysis: Oenologists to exploit advanced test kits.
Charnock, S. C. & McCleary, B. V. (2005). Revue des Enology, 117, 1-5.
It is without doubt that testing plays a pivotal role throughout the whole of the vinification process. To produce the best possible quality wine and to minimise process problems such as “stuck” fermentation or troublesome infections, it is now recognised that if possible testing should begin prior to harvesting of the grapes and continue through to bottling. Traditional methods of wine analysis are often expensive, time consuming, require either elaborate equipment or specialist expertise and frequently lack accuracy. However, enzymatic bio-analysis enables the accurate measurement of the vast majority of analytes of interest to the wine maker, using just one piece of apparatus, the spectrophotometer (see previous issue No. 116 for a detailed technical review). Grape juice and wine are amenable to enzymatic testing as being liquids they are homogenous, easy to manipulate, and can generally be analysed without any sample preparation.Hide Abstract
Impact of amylose content on the starch branch chain elongation catalyzed by amylosucrase from Neisseria polysaccharea.
Wang, R., Li, Z., Zhang, T., Zhang, H., Zhou, X., Wang, T., Feng, W. & Yu, P. (2021). Food Hydrocolloids, 111, 106395.
In this study, three rice starches with different amylose content were isolated from three rice varieties, followed by chain elongation using amylosucrase from Neisseria polysaccharea (NpAS). Herein, the chain elongation could induce the starch precipitation during the enzymatic reaction. With a higher content of amylose, an earlier precipitation occurred, leading to the decrease of transglycosylation efficiency of the enzyme. Results from X-ray diffraction and thermal property analysis indicated that the crystalline structure of the NpAS-modified starches largely formed at the precipitation point. The elongation at the surface of the starch precipitates, however, would not enable the formation of crystallites. In addition, the amylose might participate in the recrystallization of starch molecules. Digestion kinetics revealed that all of the NpAS-modified starches contained rapidly and slowly digested fractions, the latter of which had a digestion rate being dependent on the structural stability of crystallites (length of double helices). These findings may provide an efficient way to produce chain-elongated starches with desirable functionality and digestibility.Hide Abstract
Causal relations among starch fine molecular structure, lamellar/crystalline structure and in vitro digestion kinetics of native rice starch.
Li, C., Hu, Y., Gu, F. & Gong, B. (2021). Food & Function, In Press.
Native rice starch is a source of slowly digestible starch in e.g. low-moisture baked products, while the molecular and lamellar/crystalline structure giving rise to this low-digestibility property is still largely unknown. In this study, the in vitro digestion kinetics of 11 rice starches with a wide range of amylose content were investigated. Applying the logarithm of slope (LOS) plot to the starch digestograms suggested that only a single first-order kinetics phase existed. More importantly, results for the first time showed that rice starches with shorter amylopectin short chains (DP 10-26) had more perfectly aligned crystalline lamellae and much slower digestion rates than the other starches. Interestingly, no correlations were found between the starch lamellar thicknesses with its digestion rate. It suggests that lamellar perfection plays a dominant role in the determination of native starch digestibility. Furthermore, starches with relatively shorter amylose short and medium chains showed a significantly higher amount of V-type amylose-lipid complex, and smaller maximum digestion extent. These results could help the rice industry develop a new generation of rice products with slower starch digestion rate and more desirable nutritional values.Hide Abstract
Changes in light spectra modify secondary compound concentrations and BVOC emissions of Norway spruce seedlings.
Kivimäenpää, M., Virjamo, V., Ghimire, R. P., Holopainen, J., Julkunen-Tiitto, R., Martz, F., Nissinen, K. & Riikonen, J. (2020). Canadian Journal of Forest Research, (ja).
Our objective was to study how changes in the light spectra affects growth, carbohydrate, chlorophyll, carotenoid, terpene, alkaloid and phenolic concentrations, and BVOC (biogenic volatile organic compound) emissions of Norway spruce (Picea abies) seedlings. This study was conducted during the growth of the third needle generation in plant growth chambers. Two light spectra with the main difference in proportion of blue light (400-500 nm) and equal photon flux densities were provided by LED (light-emitting diode) lamps: 1) control (white light + 12 % blue light) and 2) increased blue light (+B) (white light + 45% blue light). The +B treatment increased needle concentrations of total flavonoids and acetophenones. The major changes in the phenolic profile were an accumulation of astragalin derivatives and the aglycone of picein. +B decreased concentrations of the main alkaloid compound, epidihydropinidine, and it’s precursor, 2-methyl-6-propyl-1,6-piperideine, emission rates of limonene, myrcene and total monoterpenes, and concentrations of a few terpenoid compounds, mainly in stems. Growth, needle carbohydrates and pigments were not affected. The results suggest that supplemental blue light shifts carbon allocation between secondary metabolism routes, from alkaloid and terpenoid synthesis to flavonoid and acetophenone synthesis. The changes may affect herbivory and abiotic stress tolerance of Norway spruce.Hide Abstract
Thermal processing influences the physicochemical properties, in vitro digestibility and prebiotics potential of germinated highland barley.
Huang, L. U., Dong, J. L., Zhang, K. Y., Zhu, Y. Y., Shen, R. L. & Qu, L. B. (2020). LWT, 110814.
This study determined the effects of four thermal processing methods for germinated highland barley (GHB) on its nutritional composition, physicochemical properties, in vitro starch and protein digestibility, and in vitro prebiotic effects. The contents of total dietary fiber (TDF) and total phenols were significantly increased by steaming, microwave, baking and extrusion processing, while the contents of ash, starch and resistant starch were decreased. Except for baking, the other three methods improved the water hydration properties by increasing the water absorption index, water solubility index and swelling power. Thermally processed samples, especially those extruded, exhibited better thermal stability, pasting properties and in vitro protein digestibility, possibly because of the damage to the whole grain powder particles. The thermally processed digesta of GHB promoted the proliferation of Lactobacillus plantarum and L. delbrueckii in a dose-dependent manner, especially for those extruded, followed by those processed by steaming, microwave and baking. A Pearson correlation analysis showed that the prebiotic effect was positively correlated with the content of TDF in the different samples. Overall, thermal processing increased the quality and digestibility of GHB, with extrusion being the most suitable for industrial processing.Hide Abstract
Exploring the potential of microalgae in the recycling of dairy wastes.
Gramegna, G., Scortica, A., Scafati, V., Ferella, F., Gurrieri, L., Giovannoni, M., Bassi, R., Sparla, F., Mattei, B. & Benedetti, M. (2020). Bioresource Technology Reports, 12, 100604.
Culturing microalgae using dairy-wastes offers the opportunity of producing valuable biomass for different industrial applications. The capability of four Chlorella species and a recombinant Chlamydomonas reinhardtii strain to mixotrophically grow in wastewaters from an Italian dairy factory was investigated. A robust algal growth could be efficiently sustained in these wastes, despite the abundance of D-Lactose (~4% w/v), that could not be metabolized by any microalgal species. Non axenic cocultivation of microalgae together with microbial communities from the dairy wastes resulted in a marked decrease of their pollution load, thus reducing the necessity of expensive treatments before their discharge in the municipal sewage system. Microalgae cultivated using dairy-wastes were characterized by a lipid content ranging from 12% to 21% (w/w), with Auxenochlorella protothecoides reaching the highest lipid productivity (~0.16 g/L/d) whereas the transplastomic C. reinhardtii strain expressing a thermostable β-glucosidase reached a recombinant enzyme productivity of 0.18 mg/L/d.Hide Abstract
Improvement of resistant starch content and baking quality of cross-linked soft rice flour.
Lee, C. E., No, J., Lee, K. & Shin, M. (2020). Food Science and Biotechnology, 29(12), 1695-1703.
To increase resistant starch (RS) content of rice flour, soft and normal rice flours were cross-linked with different flour concentrations (40, 50%). RS contents, morphology, and baking qualities of cross-linked Singil rice flour (CSRF) and Hopyeong rice flour (CHRF) were compared. Amylose and protein contents of Singil flour were higher than those of Hopyeong flour. The protein content of CSRF maintained but that of CHRF reduced. Although the RS content increased after cross-linking, the degree of RS was higher 50% flour than 40% flour. The shape of cross-linked rice flour particles changed into starch granules with debris. The overall quality and texture of CSRF40 cupcake showed the highest scores by preference test. These results suggest that CSRF can be used as a high RS rice flour substitute for wheat flour, because soft rice is easy to make flour.Hide Abstract
A mechanistic model to study the effect of the cell wall on starch digestion in intact cotyledon cells.
Rovalino-Córdova, A. M., Montesdeoca, V. A. & Capuano, E. (2020). Carbohydrate Polymers, 253, 117351.
The role of the plant matrix is recognized as the main factor restricting starch digestibility in beans. Several authors have provided insights about the mechanisms behind the reduced starch digestibility in plant matrices. In this study, by means of a mathematical model, we provide a mechanistic explanation of the role played by the cell wall. It was confirmed that starch entrapped within intact cells could only be hydrolysed after α-amylase diffusion through the cell wall. This process is limited by the pores naturally present in the cell wall and the adsorption of α-amylase to the cell wall surface. These factors restrict the concentration of α-amylase available within the cells. The model assumptions are valid under controlled laboratory conditions and were validated with in-vitro digestion data giving very accurate results. The proposed approach provides new information to understand the digestibility of starch, and possibly other macronutrients, in complex food matrices.Hide Abstract
Addition of chickpea markedly increases the indigestible carbohydrate content in semolina pasta as eaten.
Garcia‐Valle, D. E., Bello‐Perez, L. A. & Tovar, J. (2020). Journal of the Science of Food and Agriculture, In Press.
Background: There is a growing interest in increasing dietary fiber (DF) consumption because of the health benefits associated with this nutrient. Pulses are considered a good source of non‐digestible carbohydrates. The aim of this study was to investigate the possibility of substituting semolina with chickpea flour to increase indigestible carbohydrate content without altering the texture of the pasta. Results: Pasta was prepared by extruding semolina–chickpea blends. The protein and DF content in the cooked pasta increased with the chickpea level, with an important contribution of resistant starch (RS) to the DF values. The optimum cooking time decreased as the chickpea content increased, which was related to the degree of starch gelatinization of the raw pasta. The in vitro digestible starch content decreased with the chickpea substitution level, concomitant with the increase in RS content. In general, the texture of the chickpea‐containing pasta was similar to that of semolina pasta. Conclusions: Pending acceptability studies on these pastas may grant their promotion as good fiber sources, probably helpful in the fight against obesity and diet‐related non‐communicable diseases.Hide Abstract
Combination of organic acids and heat-moisture treatment on the normal and waxy corn starch: thermal, structural, pasting properties, and digestibility investigation.
Barretti, B. R. V., Almeida, V. S. D., Ito, V. C., Silva, B. M., Carvalho Filho, M. A. D. S., Sydney, E. B., Memiate, I. M. & Lacerda, L. G. (2020). Food Science and Technology, In Press.
Resistant starch (RS) has gained interesting because of its health benefits as the control of diseases, such as diabetes. Modifications in starches have been applied in order to increase RS content and consequently the range of industrial food applications. The heat-moisture treatment (HMT) combined with the addition of organic acids was the aim of this study, and also to evaluate the in vitro digestibility and other properties of corn starches. In both botanical sources, the RS content increased significantly, for the normal type and the waxy. Among organic acids used, citric, followed by lactic and acetic acid, promoted the most evident alterations and showed promising results in the increasing of RS. The results obtained by this combined method open opportunities for further applications in functional foods as well as starch based encapsulation process.Hide Abstract
In vitro digestion rate of fully gelatinized rice starches is driven by molecular size and amylopectin medium-long chains.
Li, C., Gong, B., Huang, T. & Yu, W. W. (2020). Carbohydrate Polymers, 254, 117275.
In current study, the effects of starch fine molecular structures on its in vitro digestibility at fully gelatinized stage were investigated. The digestion kinetics of 15 fully gelatinized rice starches were obtained and correlated with starch chain-length distributions and molecular size distributions. Both logarithm of slopes and parallel first-order kinetic model were applied to fit the digestion curves to a few kinetics-based parameters. Result showed there were two simultaneous digestion fractions (fast versus slow) for fully gelatinized rice starches. The rate constants of slowly-digestible fraction significantly correlated with starch molecular sizes, especially with that of amylopectin molecules. Hydrodynamically larger amylopectin molecules tend to contain more shorter branches but less long chains. This slows down the starch hydrolysis by α-amylase while the action of AMG is less antagonistically hindered, increasing overall digestion rate. This study provides important information for rice breeders and manufacturers to develop rice products with reduced starch digestibility.Hide Abstract
Nutritional quality and in vitro digestion of immature rice-based processed products.
Miraji, K. F., Linnemann, A. R., Fogliano, V., Laswai, H. S. & Capuano, E. (2020). Food & Function, 11(9), 7611-7625.
Rice is commonly consumed as fully mature grain, but immature rice is considered to have better nutrient and technological properties. This is attributed to changes in content and profile of nutritional and functional compounds during maturation. This study assessed the effect of maturity on nutrient content of rice grains, and in vitro digestibility of starch and protein, for immature rice grains of TXD306 and Lawama varieties. The effect of processing of immature rice into so-called pepeta, traditionally produced from immature rice grains and widely consumed in Tanzania, was studied as well. The results showed reductions in lipid, protein, ash, thiamine, nicotinic acid, nicotinamide, and soluble and insoluble dietary fibre contents during rice grain development. However, no effect of maturity on in vitro starch and protein digestibility was observed. The contents of protein, ash, lipid, nicotinamide, iron, zinc, and total, soluble and insoluble dietary fibre were higher in pepeta from both varieties than in the corresponding rice grains. Protein digestibility of pepeta flour was 58.9% higher than that of cooked rice for variety TXD306, and 73.8% higher for Lawama. Differential scanning calorimetry indicated that starch of processed immature rice was completely gelatinized whereas its susceptibility to digestion in vitro was slightly lower than for cooked rice, possibly due to the higher cellular integrity retained after processing. These results demonstrate that pepeta-type processing improves the nutritional properties of rice and its potential use as a snack or ingredient in cereal-based formulas.Hide Abstract
Glycemic Response and Bioactive Properties of Gluten-Free Bread with Yoghurt or Curd-Cheese Addition.
Graça, C., Mota, J., Lima, A., Boavida Ferreira, R., Raymundo, A. & Sousa, I. (2020). Foods, 9(10), 1410.
The influence of flour replacement by yogurt or curd-cheese additions (from 10% to 20%, w/w) on the glycemic response and bioactivity improvements of gluten-free bread was evaluated. Starch digestibility, measured by an in vitro digestion model, was applied to determine the effect on starch fractions. The bread glycemic index was calculated. Bread antioxidant capacity (2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and ferric-ion-reducing antioxidant power (FRAP) methods) and total phenolic compounds were assessed. Anti-inflammatory properties according to enzymatic matrix metalloproteinase (MMP)-9 inhibitory activity were also studied. Considering the higher level of both dairy products tested (20%, w/w) and comparing with control bread results, a reduction of around 35% in the glycemic response of curd cheese bread was achieved, resulting in intermediate index level (glycemic index (GI) 55-69), with yogurt bread still showing a high glycemic index (GI > 70). In terms of bread bioactivity, curd cheese bread expressed better reducing power effects, whereas yogurt bread showed more effective radical-scavenging capacity. An increase in bread phenolic compounds by yogurt (55.3%) and curd cheese (73.0%) additions (at 20%) were also registered. MMP-9 inhibition activity was higher in the dairy bread than in control bread, suggesting an improvement in terms of anti-inflammatory properties. The supplementation of the gluten-free bread by yogurt or curd cheese was shown to be a promising strategy to reduce the glycemic response and to improve the bioactive properties of the bread, that which can contribute to preventive diets of celiac patients and irritable bowel syndrome individuals.Hide Abstract
Structure and in vitro digestibility on complex of corn starch with soy isoflavone.
Wang, S., Wu, T., Cui, W., Liu, M., Wu, Y., Zhao, C., Zheng, M., Xu, X. & Liu, J. (2020). Food Science & Nutrition, 8(11), 6061-6068.
Rapid starch digestion rate is negative for the normal level of human blood glucose. This study investigated the protective effects of corn starch (CS) complexed with soy isoflavone (SI) on the control of starch digestibility and glycemic index (GI). The structure of the corn starch–soy isoflavone (CS‐SI) complexes was characterized by Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), Thermogravimetric analysis (TGA), and Differential scanning calorimetry (DSC), and the complexes digestibility was evaluated using in vitro digestion model. The results of FT‐IR spectrum showed that, compared with corn starch, new characteristic peaks were not occurred in CS‐SI complexes, and the value of R1047/1022 was decreased, which indicated the short‐range structure of CS‐SI complexes had been reduced. The V‐shaped structure characteristic peaks occurred obviously in CS‐SI complexes detected by XRD patterns, which formed a new crystalline structure. The thermal stability was improved in CS‐SI complexes revealed by TGA and DTG curves that the thermal cracking temperature increased from 315°C to 320°C. The enthalpy (ΔH) of CS‐SI complexes decreased from 2.34 J/g to 1.75 J/g showed by DSC data, which indicated that the ordered structure of starch was destroyed. Furthermore, the content of resistant starch increased from 10.53% to 21.78% and predicted glycemic index (pGI) reduced in CS‐SI complexes. In conclusion, the digestibility and pGI of starch can be improved by complexed with soy isoflavone.Hide Abstract
Kinetic Approach to the Influence of Chia Flour on Glucose Bioaccessibility from Hydrothermally Treated Maize and Quinoa Starch.
Selma-Gracia, R., Haros, C. M. & Laparra, J. M. (2020). Plant Foods for Human Nutrition, 75(4), 592-598.
Starch structure and bioactive ingredients play an implicit role in the control of glucose release at intestinal level reducing the risk of inadequate metabolic response(s). This study performs a comparative kinetic approach to glucose release from hydrothermally treated (HT) maize (MS) and quinoa (QS) starch. Besides, chia flour (CF) (20%, w/w) was added to evaluate its influence of on the apparent diffusion coefficients (Dapp) when subjected to simulated gastrointestinal digestion. Hepatocyte cultures were used to monitor mitochondrial enzymes activity (test MTT) to bioaccessible glucose concentrations. With an increasing temperature, Dapp for both QS and its mixtures with CF were kept unaltered, while those for MS were disrupted progressively affecting glucose bioaccessibility. Principal component analysis revealed differences between maize and quinoa starches, but common features in the corresponding mixtures with CF. Data indicated that quinoa starch helps controlling glucose release and that addition of CF decreased mitochondrial activity in presence of insulin.Hide Abstract
Effect of protein types on structure and digestibility of starch-protein-lipids complexes.
Lin, L., Yang, H., Chi, C. & Ma, X. (2020). LWT, 134, 110175.
Ternary systems of starch, lipids, and protein have been extensively investigated for modulating starch digestibility recently. Nevertheless, how the proteins influenced the formation of starch-protein-lipids complexes was not resolved. This study aimed to investigate the effects of proteins with different isoelectric points (whey protein isolate and A-type gelatin) on structures and digestibility of starch-protein-linoleic acid (LA) complexes. Results showed that proteins and LA significantly increased starch ordered structures and reduced the digestibility. Due to the emulsifiability of proteins, they increased LA solubility in water and thereby promoted the formation of starch-protein-LA complexes. Accordingly, the starch-lipids-protein complexes had more ordered structures and a lower starch digestibility than did the LA- and proteins-complexed starches. Comparing with starch-GE-LA complexes, the starch-WP-LA complexes had more short-range ordered structure, helical structure, and crystals and a lower starch digestibility. The mechanism underlying such an observation should attribute to the differences in intrinsic properties (e.g., isoelectric point) between GE and WP. Proteins (e.g., GE) with an isoelectric point higher than 7.0 may easily compete with starch for LA and retard the formation of starch-protein-lipids complexes comparing with the protein has an isoelectric point lower than 7.0.Hide Abstract
A submerged duckweed mutant with abundant starch accumulation for bioethanol production.
Liu, Y., Xu, H., Wang, Y., Tang, X., He, G., Wang, S., Ma, Y., Kong, Y., Yu, C. & Zhou, G. (2020). GCB Bioenergy, 12(12), 1078-1091.
Duckweed is one kind of promising bioenergy plant with prominent advantages such as fast growth rate and high starch content. However, almost all previous studies focused on the natural duckweed germplasms. In this study, heavy‐ion irradiation was used to establish a mutant library of Lemna aequinoctialis 6002, and one mutant named submarine‐1 (sub‐1) was screened, which could accumulate more starch but with smaller granules. Unexpectedly, under proper external growth conditions such as poor nutritional status and insufficient growth space, sub‐1 mutant would sink underwater due to formation of dense tissue structure and large amount of fine starch particles with the extension of cultivation time. The starch content in the sinking sub‐1 increased to over 45% (dry weight) and was 12% higher than the floating sub‐1, highlighting that submergence can be considered as a spontaneous and efficient indicator for screening of high‐starch duckweed. Additionally, the saccharification efficiency of starch and ethanol yield had increased in sub‐1 mutant compared to the wild type. Based on the unique characteristics of sub‐1 mutant, a cultivation model of submerged duckweed in a simulated aquaculture pond was designed to get more starch‐rich biomass, enabling effective production of renewable bioenergy.Hide Abstract
Status of glycemic index of paddy rice grain (Oryza sativa L.) on infestation by storage pest Sitotroga cerealella.
Kumar, A., Gowda, G. B., Sah, R. P., Sahu, C., Biswal, M., Nayak, S., Kumar, S., Swain, P. & Sharma, S. (2020). Journal of Stored Products Research, 89, 101697.
The harvested paddy rice grains are normally stored by growers under normal conditions. Paddy rice grains are natural food for storage pests like Sitotroga. cerealella, a major insect that appears during paddy storage. The changes in grain composition due to such insect infestation in relation to human health especially the alteration in their Glycemic Index (GI) value have not been studied so far. The present investigation was aimed at studying the effect of S. cerealella infestation on rice grain quality and glycemic index of stored paddy grains. Five diverse rice genotypes with different quality traits were evaluated for grain quality after S. cerealella infestation. The tolerance to insect and variation of grain quality varied with rice genotype significantly. The glycemic index, glycemic load, total carbohydrate, amylose content and resistant starch were affected to a great extent. The consumption of affected grains may create health issue due to imbalance in nutrition and unhygienic condition. Improper storage of paddy after harvesting and processing results in infestation by pests at a large scale. Thus, the grain quality needs to be evaluated to judge the suitability of affected grain for consumption.Hide Abstract