Chapter 1: Introduction
Chapter 2: Theory of the Analytical Procedure
Chapter 3: Kit Content
Chapter 4: Reagent Preparation
Chapter 5: Milling of Samples
Chapter 6: Weighing of Malt Samples & Extraction of Alpha Amylase
Chapter 7: Weighing of Wheat & Barley Flour & Extraction of Alpha Amylase
Chapter 8: Extraction/Dilution of Microbial Enzyme
Chapter 9: Assay Procedure
Chapter 10: Calculations
100 / 200 assays per kit
Prices exclude VAT
Available for shipping
|Content:||100 / 200 assays per kit|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Assay Format:||Spectrophotometer, Auto-analyser|
|Limit of Detection:||0.05 U/mL|
|Reproducibility (%):||~ 3%|
|Total Assay Time:||~ 30 min|
|Application examples:||Cereal flours, fermentation broths and other materials.|
|Method recognition:||AACC Method 22-02.01, AOAC Method 2002.01, ICC Standard No. 303, RACI Standard Method and CCFRA (Flour Testing Working Group Method 0018)|
The Ceralpha Method: α-Amylase test kit is suitable for the specific measurement and analysis of α-amylase in cereal grains and fermentation broths (fungal and bacterial).
Browse the complete list of our enzyme activity assay kits.
- Very cost effective
- All reagents stable for > 2 years after preparation
- Very specific
- Simple format
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- 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 available carbohydrates, digestible, and resistant starch in food ingredients and products.
McCleary, B. V., McLoughlin, C., Charmier, L. M. J. & McGeough, P. (2019). Cereal Chemistry, 97(1), 114-137.
Background and objectives: The importance of selectively measuring available and unavailable carbohydrates in the human diet has been recognized for over 100 years. The levels of available carbohydrates in diets can be directly linked to major diseases of the Western world, namely Type II diabetes and obesity. Methodology for measurement of total carbohydrates by difference was introduced in the 1880s, and this forms the basis of carbohydrate determination in the United States. In the United Kingdom, a method to directly measure available carbohydrates was introduced in the 1920s to assist diabetic patients with food selection. The aim of the current work was to develop simple, specific, and reliable methods for available carbohydrates and digestible starch (and resistant starch). The major component of available carbohydrates in most foods is digestible starch. Findings: Simple methods for the measurement of rapidly digested starch, slowly digested starch, total digestible starch, resistant starch, and available carbohydrates have been developed, and the digestibility of phosphate cross‐linked starch has been studied in detail. The resistant starch procedure developed is an update of current procedures and incorporates incubation conditions with pancreatic α‐amylase (PAA) and amyloglucosidase (AMG) that parallel those used AOAC Method 2017.16 for total dietary fiber. Available carbohydrates are measured as glucose, fructose, and galactose, following complete and selective hydrolysis of digestible starch, maltodextrins, maltose, sucrose, and lactose to glucose, fructose, and galactose. Sucrose is hydrolyzed with a specific sucrase enzyme that has no action on fructo‐oligosaccharides (FOS). Conclusions: The currently described “available carbohydrates” method together with the total dietary fiber method (AOAC Method 2017.16) allows the measurement of all carbohydrates in food products, including digestible starch. Significance and novelty: This paper describes a simple and specific method for measurement of available carbohydrates in cereal, food, and feed products. This is the first method that provides the correct measurement of digestible starch and sucrose in the presence of FOS. Such methodology is essential for accurate labeling of food products, allowing consumers to make informed decisions in food selection.Hide Abstract
Prediction of potential malt extract and beer filterability using conventional and novel malt assays.
Cornaggia, C., Evans, D. E., Draga, A., Mangan, D. & McCleary, B. V. (2019). Journal of Institute of Brewing, 125(3), 294-309.
Colourimetric assays were used to measure the activities of six key hydrolases endogenous to barley: β‐glucanase, xylanase, cellulase, α-amylase, beta‐amylase and limit dextrinase. The analysed barley malt samples were previously characterised by 27 conventional malt quality descriptors. Correlations between enzymatic activities and brewing parameters such as extract yield, fermentability, viscosity and filterability were investigated. A single extraction protocol for all six hydrolases was optimised and used for multi‐enzyme analysis using fully automatable assay formats. A regression analysis between malt parameters was undertaken to produce a relationship matrix linking enzyme activities and conventional malt quality descriptors. This regression analysis was used to inform a multi‐linear regression approach to create predictive models for extract yield, apparent attenuation limit, viscosity and filterability using the Small‐scale Wort rapId Filtration Test (SWIFT) and two different mashing protocols – Congress and a modified infusion mash at 65oC (MIM 65oC). It was observed that malt enzyme activities displayed significant correlations with the analysed brewing parameters. Both starch hydrolases and cell wall hydrolase activities together with modification parameters (i.e. Kolbach index) were found to be highly correlated with extract yield and apparent attenuation limit. Interestingly, it was observed that xylanase activity in malts was an important predictor for wort viscosity and filterability. It is envisaged that the automatable measurement of enzyme activity could find use in plant breeding progeny selection and for routine assessment of the functional brewing performance of malt batches. This analytical approach would also contribute to brewing process consistency, product quality and reduced processing times.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
Measurement of α-Amylase in Cereal, Food and Fermentation Products.
McCleary, B. V. & Sturgeon, R. (2002). Cereal Foods World, 47, 299-310.
In General, the development of methods for measuring α-amylase is pioneered in the clinical chemistry field and then translated to other industries, such as the cereals and fermentation industries. In many instances, this transfer of technology has been difficult or impossible to achieve due to the presence of interfering enzymes or sugars and to differences in the properties of the enzymes being analysed. This article describes many of the commonly used methods for measuring α-amylase in the cereals, food, and fermentation industries and discusses some of the advantages and limitations of each.Hide Abstract
Measurement of α-amylase activity in white wheat flour, milled malt, and microbial enzyme preparations, using the ceralpha assay: Collaborative study.
McCleary, B. V., McNally, M., Monaghan, D. & Mugford, D. C. (2002). Journal of AOAC International, 85(5), 1096-1102.
This study was conducted to evaluate the method performance of a rapid procedure for the measurement of α-amylase activity in flours and microbial enzyme preparations. Samples were milled (if necessary) to pass a 0.5 mm sieve and then extracted with a buffer/salt solution, and the extracts were clarified and diluted. Aliquots of diluted extract (containing α-amylase) were incubated with substrate mixture under defined conditions of pH, temperature, and time. The substrate used was nonreducing end-blocked p-nitrophenyl maltoheptaoside (BPNPG7) in the presence of excess quantities of thermostable α-glucosidase. The blocking group in BPNPG7 prevents hydrolysis of this substrate by exo-acting enzymes such as amyloglucosidase, α-glucosidase, and β-amylase. When the substrate is cleaved by endo-acting α-amylase, the nitrophenyl oligosaccharide is immediately and completely hydrolyzed to p-nitrophenol and free glucose by the excess quantities of α-glucosidase present in the substrate mixture. The reaction is terminated, and the phenolate color developed by the addition of an alkaline solution is measured at 400 nm. Amylase activity is expressed in terms of Ceralpha units; 1 unit is defined as the amount of enzyme required to release 1 µmol p-nitrophenyl (in the presence of excess quantities of α-glucosidase) in 1 min at 40°C. In the present study, 15 laboratories analyzed 16 samples as blind duplicates. The analyzed samples were white wheat flour, white wheat flour to which fungal α-amylase had been added, milled malt, and fungal and bacterial enzyme preparations. Repeatability relative standard deviations ranged from 1.4 to 14.4%, and reproducibility relative standard deviations ranged from 5.0 to 16.7%.Hide Abstract
Analysis of feed enzymes.
McCleary, B. V. (2001). “Enzymes in Farm Animal Nutrition”, (M. Bedford and G. Partridge, Eds.), CAB International, pp. 85-107.
Enzymes are added to animal feed to increase its digestibility, to remove anti-nutritional factors, to improve the availability of components, and for environment reasons (Campbell and Bedford, 1992; Walsh et al., 1993). A wide-variety of carbohydrase, protease, phytase and lipase enzymes find use in animal feeds. In monogastric diets, enzyme activity must be sufficiently high to allow for the relatively short transit time. Also, the enzyme employed must be able to resist unfavourable conditions that may be experienced in feed preparation (e.g. extrusion and pelleting) and that exist in the gastrointestinal tract. Measurement of trace levels of enzymes in animal feed mixtures is difficult. Independent of the enzyme studied, many of the problems experienced are similar; namely, low levels of activity, extraction problems inactivation during feed preparation, non-specific binding to other feed components and inhibition by specific feed-derived inhibitors, e.g. specific xylanase inhibitors in wheat flour (Debyser et al., 1999).Hide Abstract
Sheehan, H. & McCleary, B. V. (1988). Biotechnology Techniques, 2(4), 289-292.
A procedure for the measurement of fungal and bacterial α-amylase in crude culture filtrates and commercial enzyme preparations is described. The procedure employs end-blocked (non-reducing end) p-nitrophenyl maltoheptaoside in the presence of amyloglucosidase and α-glucosidase, and is absolutely specific for α-amylase. The assay procedure is simple, reliable and accurate.Hide Abstract
Measurement of cereal α-Amylase: A new assay procedure.
McCleary, B. V. & Sheehan, H. (1987). Journal of Cereal Science, 6(3), 237-251.
A new procedure for the assay of cereal α-amylase has been developed. The substrate is a defined maltosaccharide with an α-linked nitrophenyl group at the reducing end of the chain, and a chemical blocking group at the non-reducing end. The substrate is completely resistant to attack by β-amylase, glucoamylase and α-glucosidase and thus forms the basis of a highly specific assay for α-amylase. The reaction mixture is composed of the substrate plus excess quantities of α-glucosidase and glucoamylase. Nitrophenyl-maltosaccharides released on action of α-amylase are instantaneously cleaved to glucose plus free p-nitrophenol by the glucoamylase and α-glucosidase, such that the rate of release of p-nitrophenol directly correlates with α-amylase activity. The assay procedure shows an excellent correlation with the Farrand, the Falling Number and the Phadebas α-amylase assay procedures.Hide Abstract
Influence of the addition of different ingredients on the bioaccessibility of glucose released from rice during dynamic in vitro gastrointestinal digestion.
Fernandes, J. M., Madalena, D. A., Vicente, A. A. & Pinheiro, A. C. (2021). International Journal of Food Sciences and Nutrition, 72(1), 45-56.
Rice represents a primary source of carbohydrates in human nutrition. Upon its consumption, the released sugars are mostly absorbed, categorising rice as a high glycemic index food. Addition of ingredients is common practice when cooking rice, which may affect rice digestibility and influence nutrients absorption in the gastrointestinal (GI) tract, enabling a controlled glucose release. In this sense, rice formulations were submitted to a dynamic in vitro GI model, constituted by reactors that simulates peristalsis coupled to filtration membranes, to evaluate carbohydrates hydrolysis and bioaccessibility. Addition of quinoa and wholegrains reduced carbohydrates hydrolysis (i.e. 38.5 ± 5.08% and 57.98 ± 1.91%, respectively) and glucose bioaccessibility (i.e. 25.92 ± 5.70% and 42.56 ± 1.39%, respectively) when compared with brown rice (i.e. 63.86 ± 2.96% hydrolysed and 44.33 ± 1.88% absorbed). Addition of vegetables significantly decreased sample chewiness and resulted in superior hydrolysis (71.75 ± 7.44%) and glucose absorption (51.61 ± 6.25%).Hide Abstract
Whole soybean milk produced by a novel industry-scale micofluidizer system without soaking and filtering.
Li, Y. T., Chen, M. S., Deng, L. Z., Liang, Y. Z., Liu, Y. K., Liu, W., Chen, J. & Liu, C. M. (2021). Journal of Food Engineering, 291, 110228.
Whole soybean milk (WSM) was prepared by an innovatively created industry-scale microfluidizer system (ISMS). Results showed WSM prepared by ISMS (WSMM) at 60, 90 and 120 MPa kept stable spontaneously for 21 days at 4°C, while the one prepared by traditional method (WSMT) stratified on day 14. The aggregation of oil droplets and proteins during storage caused the increase of particle sizes of WSMT, while WSMM showed little change in the form and distribution of oil droplets and proteins, as well as particle sizes. The smaller size, looser microstructure of dietary fiber and higher viscosity of WSMM also contributed to the stability of WSMM. WSMM prepared at 90 and 120 MPa exhibited higher isoflavone contents (0.92 and 1.03 mg/g) than those of WSMT (0.89 mg/g). This research suggested that the ISMS was feasible in producing the WSM with superior stability and nutrition.Hide Abstract
Impact of cultivar and growing conditions on Alpha‐Amylase Properties in Wheat.
Aljabi, H. R. & Pawelzik, E. (2020). Starch‐Stärke, 2000032.
Alpha amylase (α‐amylase) is an endo‐amylolytic enzyme that plays an important role in the starch metabolism in developing wheat grains. However, excessive enzyme activity in post‐harvest wheat grains has adverse effects on grain quality. Therefore, the objective of the study is to determine the influence of cultivars with different growth habits (spring vs winter) and weather conditions on the characterization of native α‐amylase. The results show that winter wheat cultivar (cv.) Cubus show a lower α‐amylase activity than those of spring wheat cv. Amaretto, by escaping the humid weather before harvest. Grains exposed to higher temperatures in Gladebeck have lower enzyme activity in the later stages of ripening than the grains in Torland. On the other hand, wheat α‐amylases from both cultivars have similar properties. They show thermal inactivation at 30°C and acid lability at increasing pH values. The results indicate that a better understanding of the α‐amylase properties could be helpful to develop a suitable management to avoid quality losses in wheat.Hide Abstract
Exploring diverse sorghum (Sorghum bicolor (L.) Moench) accessions for malt amylase activity.
Disharoon, A., Boyles, R., Jordan, K. & Kresovich, S. (2020). Journal of the Institute of Brewing, In Press.
Sorghum is a climate resilient grain cereal crop originating from Africa that has traditionally been used to make a variety of fermented beverages such as pito and baijiu. In Western markets, the use of sorghum to produce beers and beverages has recently risen due to the visibility of a gluten sensitive/intolerant market and a growing interest in unique inputs for beverage production. As such, there is a developing body of research on sorghum as a malted input into beverages. A major limitation to the wider adoption of sorghum as a substrate in mashing is its low activity of amylolytic enzymes, either the result of insufficient activity or inhibition by endogenous compounds. A collection of 42 diverse accessions representing the grain sorghum diversity panel, was evaluated for associations between alpha and beta amylase content, race, origin, and seed colour as well as two classes of amylase inhibitors, phenols and tannins. Among these accessions are several commonly used genetic resources, including reference line BTx623. Notable findings include accessions with high alpha amylase content, sources that may harbour additional high amylase sorghums, associations with grain colour, and populations which may be used to genetically map the trait.Hide Abstract
Effect of hatching time on time to first feed intake, organ development, enzymatic activity and growth in broiler chicks hatched on-farm.
Boyner, M., Ivarsson, E., Franko, M. A., Rezaei, M. & Wall, H. (2020). Animal, 100083.
The conventional commercial hatcheries used today do not allow the newly hatched chicks to consume feed or water. Combined with natural variation in hatching time, this can lead to early hatched chicks being feed-deprived for up to 72 h before being unloaded at the rearing site. This study investigated the effects of hatching time on time to first feed intake and development of organs, digestive enzymes and productivity in terms of growth and feed conversion ratio in chicks hatched on-farm. Chicks were divided into three hatching groups (early, mid-term and late), and assessed over a full production cycle of 34 days. The results revealed that chicks remain inactive for a considerable amount of time before engaging in eating-related activities. Eating activity of 5% (i.e. when 5% of birds in each hatching group were eating or standing close to the feeder) was recorded at an average biological age (BA) of 25.4 h and a proportion of 50% birds with full crop was reached at an average BA of 30.6 h. Considering that the hatching window was 35 h in this study, the average chick probably did not benefit from access to feed and water immediately post-hatch in this case. At hatch, mid-term hatchlings had a heavier small intestine (30.1 g/kg bw) than both early (26.4 g/kg bw) and late (26.0 g/kg bw) hatchlings. Relative length of the small intestine was shorter in late hatchlings (735 cm/kg bw) than in mid-term (849 cm/kg bw) and early (831 cm/kg bw) hatchlings. However, the relative weight of the bursa fabricii was greater in mid-term (1.30 g/kg bw) than in early hatchlings (1.01 g/kg bw). At hatch, late hatchlings were heavier than early and mid-term hatchlings (P < 0.05), but by 3 days of age early hatchlings were heavier than mid-term and late hatchlings (P < 0.01). The only effect persisting throughout the study was a difference in the relative weight of the small intestine, where late hatchlings had heavier intestines than early hatchlings (P < 0.05). Thus, while there were differences between hatching groups, this study showed that the hatchlings seemed capable of compensating for these as they grew.Hide Abstract
A New Approach for Glutinous Rice Breeding through Dull Genes Pyramiding.
Lee, J. Y., Kang, J. W., Jo, S. M., Kwon, Y., Lee, S. M., Shin, D. J., Song, Y-C., Park, D. S., Lee, J-H., Ko,J-M. & Cho, J. H. (2020). Plant Breeding and Biotechnology, 8(4), 405-412.
Glutinous rice is a key grain quality trait occupying an important part during rice processing in most rice growing areas. In this study, a gene pyramiding approach was used to introduce two dull genes, responsible for low amylose content, for glutinous rice breeding using marker assisted selection (MAS). The genotyping results revealed that rice cultivar Milyang319 carries both dull genes on chromosome 6, derived from cv. Milky-queen (Wx-mq) and cv. LGS-soft (du12(t)), respectively. Milyang319 had a significantly low amylose content (9.0%) compared to those observed in donor parents Milky-queen (15.7%) and LGS-soft (14.5%). In addition, the amylogram analysis of Milyang319 showed a similar pattern of glutinous rice. Originally, Milyang319 had a low hardness and more stickiness compared to those recorded in cooked rice of both dull parental lines. Therefore, Milyang319 is proposed as a promising candidate rice cultivar that could be used as a new source of waxy germplasms with same physicochemical features of glutinous rice in further breeding programs.Hide Abstract
Starch hydrolysis during mashing: A study of the activity and thermal inactivation kinetics of barley malt α-amylase and β-amylase.
De Schepper, C. F., Michiels, P., Buvé, C., Van Loey, A. M. & Courtin, C. M. (2020). Carbohydrate Polymers, 117494.
Hydrolysis of starch is key in several industrial processes, including brewing. Here, the activity and inactivation kinetics of amylases throughout barley malt mashing are investigated, as a prerequisite for rational optimisation of this process. Varietal differences were observed in the activity of α- and β-amylases as a function of temperature for six barley and malt varieties. These differences were not reflected in the resulting wort composition after mashing, using three isothermal phases of 30 min at 45°C, 62°C and 72°C with intermediate heating by 1°C/min. Thermal inactivation kinetics parameters determined for α- and β-amylases of an industrially relevant malt variety in a diluted system showed that enzymes were inactivated at lower temperatures than expected. The obtained kinetic parameters could predict α-amylase, but not β-amylase inactivation in real mashing conditions, suggesting that β-amylase stability is enhanced during mashing by components present or formed in the mash.Hide Abstract
Aqueous Two-Phase Systems for Cleanup and Recovery of Enzymes from Plants and Plant-Derived Extracts.
Aguilar, O., Heredia-Olea, E., Perez-Carrillo, E. & Rito-Palomares, M. (2020). "Protein Downstream Processing”, Humana, New York, NY, 65-79.
The increasing interest of the biopharmaceutical industry to exploit plants as a commercially viable production system is demanding the development of new strategies to maximize product recovery. Aqueous two-phase systems (ATPSs) are a primary recovery technique that has shown great potential for the efficient extraction and purification of biological products, from organelles to proteins and low-molecular-weight compounds. The evaluation of different system parameters upon the partitioning behavior can provide the conditions that favor the concentration of contaminants and the desired target protein in opposite phases. The protocols described here provide the basic strategy to explore the use of ATPSs for the isolation and partial purification of native and recombinant proteins from plants and plant-derived extracts.Hide Abstract
High amylose wheat starch structures display unique fermentability characteristics, microbial community shifts and enzyme degradation profiles.
Bui, A., Williams, B., Hoedt, E., Morrison, M., Mikkelsen, D. & Gidley, M. (2020). Food & Function, 6.
A slower rate of starch digestion in the small intestine increases the amount of resistant starch (RS) entering the large intestine, which is associated with health benefits. Although increasing the amylose (AM) content of dietary starch intake is one way to increase RS, the processes involved in gut microbial hydrolysis and fermentation of high AM-RS substrates are poorly understood. In this study, five high AM wheat (HAW) starches ranging from 47% AM to 93% AM and a wild type (37% AM), in both native granular and cooked forms, were subjected to in vitro fermentation with a porcine faecal inoculum. Fermentation kinetics, temporal microbial changes, amylolytic enzyme activities and residual starch were determined. All granular starches showed similar fermentation characteristics, independent of AM level, whereas cooking accelerated fermentation of lower AM but slowed fermentation of high AM starches. HAW starches with a very high AM content (>85%) all had similar fermentation kinetics and short-chain fatty acid end-product profiles. Microbial α-amylase, β-amylase, pullulanase and amyloglucosidase enzymatic activities were all detected and followed fermentation kinetics. HAW starch promoted shifts in the microbial community, with increases of the family Lachnospiraceae and the genus Treponema observed, while the genera Prevotella and Streptococcus were reduced in comparison to 37% AM. Overall, these findings suggest that any HAW starch incorporated into high RS food products would be expected to have beneficial microbiota-mediated effects in terms of fermentation kinetics and end products.Hide Abstract
Effect of Pre-hydrolysis on Simultaneous Saccharification and Fermentation of Native Rye Starch.
Strąk-Graczyk, E. & Balcerek, M. (2020). Food and Bioprocess Technology, 1-14.
The rising population and increasing demand for food place added pressure on the agricultural sector to maintain high process efficiency while implementing environmentally friendly methods. In this study, we investigate the effect of pre-hydrolysis of native rye starch and its influence on the yield of ethanol obtained by simultaneous saccharification and fermentation (SSF) from high gravity rye mashes with 25% and 28% w w-1 dry matter content. Fermentation was carried out in a 3-day system at a temperature of 35 ± 1°C using the dry distillery yeast Ethanol Red (Saccharomyces cerevisiae). The characteristics of the tested raw material and changes in the native rye starch during enzymatic hydrolysis were analyzed using a scanning electron microscope (SEM). The SEM images revealed characteristic changes on the surface of the starch, which was found to have a layered structure, as well as interesting behavior by the yeast during SSF when the glucose concentration in the environment was lowered. Both in the mashes with 25% and 28% w w-1 dry matter, starch pre-hydrolysis did not significantly increase either the initial amounts of sugars available to the yeast or the fermentation efficiency and ethanol yield in comparison to the mashes without this pre-treatment.Hide Abstract
Effect of modified atmosphere packaging of different oxygen levels on cooking qualities and phytochemicals of brown rice during accelerated aging storage at 37°C.
Huang, H., Belwal, T., Li, L., Wang, Y., Aalim, H. & Luo, Z. (2020). Food Packaging and Shelf Life, 25, 100529.
Consumption of brown rice decreased the risk of chronic diseases, which might be due to the presence of phytochemicals. However, the aging process reduced phytochemical contents of brown rice. The present work investigated modified atmosphere packaging (MAP) of different oxygen levels to preserve cooking qualities and phytochemicals of brown rice during aging storage. Compared with other treatments, 90 % N2 + 10 % O2 packaging showed best effect of preserving cooking qualities including texture and microstructure. The oxidation level of brown rice was also the lowest in 90 % N2 + 10 % O2 packaging. After storage, contents of phytosterol (campesterol, stigmasterol, β-sitosterol) and phenolic compounds (gallic acid, p-coumaric acid, ferulic acid, caffeic acid, syringic acid, catechin, quercetin) of brown rice in 90 % N2 + 10 % O2 packaging were significantly higher than those in other packagings. These results indicated that 90 % N2 + 10 % O2 packaging was a suitable MAP method for the retention of acceptable cooking qualities and phytochemical contents of brown rice.Hide Abstract
OsDOG1L-3 regulates seed dormancy through the abscisic acid pathway in rice.
Wang, Q., Lin, Q., Wu, T., Duan, E., Huang, Y., Yang, C., Mou, C., Lan, J., Zhou, C., Xie, K., Liu, X., Zhang, X., Guo, X., Wang, J., Jiang, L. & Wan, J. (2020). Plant Science, 298, 110570.
Seed dormancy is closely related to pre-harvest sprouting resistance. Both plant hormone abscisic acid (ABA) and DELAY OF GERMINATION 1 (DOG1) protein are key regulators of seed dormancy. Their relationship is well reported in Arabidopsis, but little is known in rice. Here, we show that a quantitative trait locus, qSd-1-1 contributes significantly to seed dormancy differences between the strongly dormant indica variety N22 and non-dormant japonica variety Nanjing35. It encodes a DOG1-like protein named OsDOG1L-3 with homology to Arabidopsis DOG1. There were evident promoter and expression differences in OsDOG1L-3 between N22 and Nanjing35, and overexpression or introduction of the N22 OsDOG1L-3 allele in Nanjing35 enhanced its seed dormancy. OsDOG1L-3 expression was positively correlated with seed dormancy and induced by ABA. OsbZIP75 and OsbZIP78 bound directly with the promoter of OsDOG1L-3 to induce its expression. Overexpression of OsbZIP75 increased OsDOG1L-3 protein abundance and promoted seed dormancy. OsDOG1L-3 upregulated expression of ABA-related genes and increased ABA content. We propose that the N22 OsDOG1L-3 allele is a candidate gene for the seed dormancy in QTL qSd-1-1, and that it participates in the ABA pathway to establish seed dormancy in rice.Hide Abstract