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|Content:||50 assays / 100 assays|
|Storage Temperature:|| 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 D-glucose per assay|
|Limit of Detection:||0.18 g/100 g total starch “as is”|
|Total Assay Time:||~ 90 min|
|Application examples:||Cereal flours, food products and other materials.|
|Method recognition:||AACC Method 76-13.01, AOAC Method 996.11, ICC Standard Method No. 168 and RACI Standard Method|
The K-TSTA-50A pack size has been discontinued (read more)
The Total Starch (AA/AMG) Assay Kit is used for the determination of total starch in cereal flours and food products. AOAC Method 996.11, AACC Method 76-13.01.
This kit now contains an improved α-amylase that allows the amylase incubations to be performed at pH 5.0 (as well as pH 7.0).
See our full range of dietary fiber and starch assay kits.
- Very competitive price (cost per test)
- All reagents stable for > 2 years after preparation
- Rapid reaction
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
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
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
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
Collaborative evaluation of a simplified assay for total starch in cereal products (AACC Method 76-13).
McCleary, B. V., Gibson, T. S. & Mugford, D. C. (1997). Cereal Foods World, 42, 476-480.
A procedure for the quantitative analysis of total starch in plant materials has been developed and subjected to a comprehensive interlaboratory study involving 32 laboratories, in accordance with the protocol for collaborative studies recommended by American Association of Cereal Chemists and AOAC International. The method involved treatment of a sample at approximately 95°C with thermostable α-amylase to obtain starch depolymerization and solubilisation. The slurry is then treated with purified amyloglucosidase to give quantitative hydrolysis of the starch fragments to glucose, which is measured with glucose oxidase/peroxidase reagent. Test samples used in the interlaboratory study included modified and native starches, cereal flours and brans, processed cereal products, animal feeds, and plant material. Results were statistically analysed according to AOAC International guidelines (1). The procedure was shown to be highly repeatable (relative standard deviation 2.1-3.9%) and reproducible (relative standard deviation 2.9-5.0%), and on the basis of these results has gained first approval status with AACC (AACC Method 76-13) and approval as AOAC Method 986.11. The method is more robust than a method previously reported (AACC Method 76-12), and 20 samples can be analysed within 2 hr.Hide Abstract
McCleary, B. V., Gibson, T. S., Solah, V. & Mugford, D. C. (1994). Cereal Chemistry, 71(5), 501-505.
The precision of an enzymatic procedure for analysis of total starch in cereal flours and products was determined in a comprehensive inter-laboratory study involving 29 laboratories. Test samples represented a range of sample types, including modified and native starches, cereal flours and brans, processed cereal products, animal feeds, and plant material. Results were statistically analyzed according to AOAC guidelines. The procedure was shown to be highly repeatable (relative standard deviation 1.5-7.3%) and reproducible (relative standard deviation 4.1-11.3%). It is now available, in a slightly modified form, as an assay kit. The assay, therefore, provides a convenient alternative to existing procedures for quantitative measurement of starch in cereal products.Hide Abstract
McCleary, B. V., Solah, V. & Gibson, T. S. (1994). Journal of Cereal Science, 20(1), 51-58.
A rapid and quantitative method has been developed for the determination of total starch in a wide range of materials, including high-amylose maize starches and food materials containing resistant starch. The method allows the analysis of 20 samples in 3 h. A single assay can be performed in 2 h. For a range of samples, the total starch values obtained with this method were significantly higher than those obtained with current standard methods. Two assay formats have been developed. In assay format 1, the sample is incubated solubilised with the chaotropic agent dimethyl sulphoxide (DMSO) to gelatinise the starch, which is then solubilised and partially depolymerised by controlled incubation at ∼ 100°C with a defined level of thermostable alpha-amylase. This allowed near-complete solubilisation of most starches. The remaining starch is then solubilised and the starch fragments are converted to maltose and maltotriose by the combined action of highly purified pullulanase and beta-amylase. After volume adjustment and filtration (if necessary), the maltooligo-saccharides are hydrolysed by high-purity amyloglucosidase to glucose, which is measured with a glucose oxidase/peroxidase reagent. This assay format gave quantitative starch determination in all native starch samples, including high-amylose maize starches. In assay format 2, which is applicable to most starches and cereal flours, the DMSO pre-treatment step is omitted. Samples containing glucose and/or maltosaccharide are pre-washed with aqueous ethanol before analysis.Hide Abstract
Fertilizer Effects on Endosperm Physicochemical Properties and Resistance to Larger Grain Borer, Prostephanus truncatus (Coleoptera: Bostrichidae), in Malawian Local Maize (Zea mays L.) Varieties: Potential for Utilization of Ca and Mg Nutrition.
Nguma, E., Munthali, C., Murayama, D., Onishi, K., Mori, M., Kinoshita, R., Yamashita, S. Kinoshita, M., tani, M., Palta., Palta., J. & Aiuchi, D. (2021). Agronomy, 12(1), 46.
Maize grain hardness influences storage pest resistance, a key characteristic valued by smallholder farmers. The structural changes in the endosperm determine grain hardness and are influenced by agronomic practices. The purpose of this study was to establish whether supply of calcium and magnesium based fertilizers can alter physicochemical properties of local and hybrid maize varieties and reduce the infestation by larger grain borer (Prostephanus truncatus (Coleoptera: Bostrichidae)) during storage. Two local and one hybrid maize varieties commonly grown by smallholder farmers in Malawi were cultivated under three fertilizer treatments (NPK (nitrogen, phosphorous, potassium), NPK plus gypsum, and NPK plus dolomite). After harvest, the grains were classified into flint and dent types, followed by P. truncatus infestation and determination of their physicochemical properties. The addition of gypsum and dolomite fertilizers led to higher levels of amylose, total zein and β-14 zein, traits associated with kernel hardness, compared to the application of NPK fertilizer. Moreover, local maize varieties showed higher resistance to P. truncatus infestation, hardness and biochemical properties associated with hardness (total zein, α-19 and β-14 zein, starch lysophosphatidylcholine, and non-starch free fatty acid) compared to hybrid variety. Our study suggests the potential for utilizing Ca and Mg nutrition in maize to improve kernel hardness, thus adoption of gypsum and dolomite by smallholder farmers may be beneficial against P. truncatus during storage.Hide Abstract
The effect of concentrate feeding strategy and dairy cow genotype on milk production, pasture intake, body condition score and metabolic status under restricted grazing conditions.
Brady, E. L., Kelly, E. T., Lynch, M. B., Fahey, A. G., Pierce, K. M. & Mulligan, F. J. (2022). Livestock Science, 256, 104815.
The objective of this study was to compare the effects of contrasting concentrate feeding strategies and dairy cow genotypes on milk production, pasture intake, energy balance, and metabolic status under restricted grazing conditions. Fifty-eight Holstein Friesian cows were assigned to concentrate feeding strategy and genotype treatments in a 2 ˣ 2 factorial arrangement, in a randomized complete block design. Treatments were balanced for days in milk, parity, previous 305-day milk yield, and body condition score (BCS). The dietary treatments offered over the 11-week experimental period were a low flat rate concentrate allowance of 1.76 kg DM/d typical of a low input system (CON, n = 29) or a “feed to yield” concentrate allowance (FY, n = 29). The FY treatment included feeding a base of 1.76 kg DM plus 0.44 kg DM of concentrates/kg of milk above the base milk yield. All cows were allocated 13 kg DM of grass. The genotype treatments consisted of lower fertility higher milk (LFHM) and higher fertility lower milk (HFLM) cows based on Economic Breeding Index figures. The FY strategy resulted in a higher milk (+ 1.77 kg/d) and a higher fat plus protein yield (+ 0.12 kg/d) and increased BCS (+ 0.12 units) compared to CON. The metabolic status of FY cows differed from CON cows as evidenced by the reduced β-hydroxybutyrate and non-esterified fatty acid concentrations. Genotype did not influence milk output but did affect total dry matter intake (DMI) and BCS. Cows of LFHM tended to have higher yields on the FY resulting in increased milk yield of 11% compared to FY-HFLM cows. Cows of HFLM fed CON had greater fat and protein output of 0.5 kg and 0.5 kg, respectively compared to the CON-LFHM. No differences in feed efficiency was observed between treatments. Despite cows originating from a higher output herd, differences in genotype had a significant effect on the response to the concentrate feeding strategies. These observations are important when identifying suitable genotypes or feeding strategies that most suit grazing systems.Hide Abstract
Sustainable Bioactive Packaging Based on Thermoplastic Starch and Microalgae.
Tedeschi, A. M., Di Caprio, F., Piozzi, A., Pagnanelli, F. & Francolini, I. (2021). International Journal of Molecular Sciences, 23(1), 178.
This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC50 value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging.Hide Abstract
Influence of Age on the Standardized Ileal Amino Acid Digestibility of Corn and Barley in Broilers.
Barua, M., Abdollahi, M. R., Zaefarian, F., Wester, T. J., Girish, C. K., Chrystal, P. V. & Ravindran, V. (2021). Animals, 11(12), 3575.
The aim of this study was to determine the standardized ileal digestibility coefficients (SIDCs) of nitrogen (N) and amino acids (AAs) in corn and barley at six different ages (days 7, 14, 21, 28, 35 and 42) of broilers using the direct method. The apparent AA digestibility coefficients were corrected using age-appropriate basal endogenous AA losses. No age effect (p > 0.05) was noted for the SIDC of N in corn. The average SIDC of indispensable AAs (IAAs) and total AAs (TAAs) was influenced in a quadratic manner (p < 0.05) with the values being higher at day 7 that decreased at day 14, increased and plateaued between days 21 and 35 and dropped again at day 42. The average SIDC of dispensable AAs (DAAs) was influenced linearly (p < 0.05). In barley, the SIDC of N and average IAAs, DAAs and TAAs was affected (quadratic; p < 0.001) by age. The digestibility increased from day 7 to 21 and then plateaued up to day 42. The present findings confirm that the SIDC of AA in corn and barley are influenced by broiler age and that the age effect on AA digestibility may need to be considered for precise feed formulation.Hide Abstract
Metabolic flux analysis of the non-transitory starch tradeoff for lipid production in mature tobacco leaves.
Chu, K. L., Koley, S., Jenkins, L. M., Bailey, S. R., Kambhampati, S., Foley, K., Arp, J. J., Morley, S. A., Czymmek, K. J., Bates, P. D. & Allen, D. K. (2022). Metabolic Engineering, 69, 231-248.
The metabolic plasticity of tobacco leaves has been demonstrated via the generation of transgenic plants that can accumulate over 30% dry weight as triacylglycerols. In investigating the changes in carbon partitioning in these high lipid-producing (HLP) leaves, foliar lipids accumulated stepwise over development. Interestingly, non-transient starch was observed to accumulate with plant age in WT but not HLP leaves, with a drop in foliar starch concurrent with an increase in lipid content. The metabolic carbon tradeoff between starch and lipid was studied using 13CO2-labeling experiments and isotopically nonstationary metabolic flux analysis, not previously applied to the mature leaves of a crop. Fatty acid synthesis was investigated through assessment of acyl-acyl carrier proteins using a recently derived quantification method that was extended to accommodate isotopic labeling. Analysis of labeling patterns and flux modeling indicated the continued production of unlabeled starch, sucrose cycling, and a significant contribution of NADP-malic enzyme to plastidic pyruvate production for the production of lipids in HLP leaves, with the latter verified by enzyme activity assays. The results suggest an inherent capacity for a developmentally regulated carbon sink in tobacco leaves and may in part explain the uniquely successful leaf lipid engineering efforts in this crop.Hide Abstract
Functionality-driven food product formulation–An illustration on selecting sustainable ingredients building viscosity.
Lie-Piang, A., Möller, A. C., Köllmann, N., Garre, A., Boom, R. & van der Padt, A. (2022). Food Research International, 152, 110889.
Currently, food industries typically favour formulation of food products using highly refined techno-functional ingredients of high purity. However, there is a growing interest in less pure techno-functional ingredients with a lower degree of refining as they deliver the same functional properties with reduced environmental impact. We propose that instead of selecting formulations based on purity, they should be selected based on their techno-functional properties. This article illustrates that the shift in perspective may increase the sustainability of food production. The functionality-driven product formulation is explored through a case study in which yellow pea ingredients are selected to increase the viscosity of a salad dressing. The relation between the ingredients (in terms of composition; protein, starch fibre, and a residual fraction) and the final viscosity was quantified and validated using multiple linear regression. The model described the observations well: the final viscosity is mostly dominated by the starch content; protein content has only a marginal impact; and dietary fibre contributes to viscosity with an antagonistic effect with starch. Based on the multiple linear regression model and further formulation optimisation, we identified various combinations of ingredients (with either a high or low degree of refining) that would result in the target final viscosity. An evaluation of the global warming potential of all blends showed that the desired viscosity could be achieved using only isolates, as well as by using only mildly refined fractions. The latter is associated with a global warming potential that is 80% lower than the one based on isolates. This case study demonstrates the proof of concept for this approach, showing it can aid in identifying alternative product formulations with similar techno-functional properties but with a higher sustainability.Hide Abstract
The Physicochemical Properties of Starch Are Affected by Wxlv in Indica Rice.
Feng, L., Lu, C., Yang, Y., Lu, Y., Li, Q., Huang, L., Fan, X., Liu, Q. & Zhang, C. (2021). Foods, 10(12), 3089.
Amylose largely determines rice grain quality profiles. The process of rice amylose biosynthesis is mainly driven by the waxy (Wx) gene, which also affects the diversity of amylose content. The present study assessed the grain quality profiles, starch fine structure, and crystallinity characteristics of the near-isogenic lines Q11(Wxlv), NIL(Wxa), and NIL(Wxb) in the indica rice Q11 background containing different Wx alleles. Q11(Wxlv) rice contained a relatively higher amylose level but very soft gel consistency and low starch viscosity, compared with rice lines carrying Wxa and Wxb. In addition, starch fine structure analysis revealed a remarkable decrease in the relative area ratio of the short amylopectin fraction but an increased amylose fraction in Q11(Wxlv) rice. Chain length distribution analysis showed that Q11(Wxlv) rice contained less amylopectin short chains but more intermediate chains, which decreased the crystallinity and lamellar peak intensity, compared with those of NIL(Wxa) and NIL(Wxb) rice. Additionally, the starches in developing grains showed different accumulation profiles among the three rice lines. Moreover, significant differences in starch gelatinization and retrogradation characteristics were observed between near-isogenic lines, which were caused by variation in starch fine structure. These findings revealed the effects of Wxlv on rice grain quality and the fine structure of starch in indica rice.Hide Abstract
Effect of Heat-Moisture Treatments on Digestibility and Physicochemical Property of Whole Quinoa Flour.
Dong, J., Huang, L., Chen, W., Zhu, Y., Dun, B., & Shen, R. (2021). Foods, 10(12), 3042.
The starch digestion processing of whole grain foods is associated with its health benefits in improving insulin resistance. This study modified the digestibility of whole quinoa flour (WQ) via heat-moisture treatment (HMT), HMT combined with pullulanase (HMT+P), HMT combined with microwave (HMT+M), and HMT combined with citric acids (HMT+A), respectively. Results showed that all the treatments significantly increased (p < 0.05) the total dietary fiber (TDF) content, amylose content, and resistant starch (RS) content, however, significantly decreased (p < 0.05) the amylopectin content and rapidly digestible starch (RDS) content of WQ. HMT+P brought the highest TDF content (15.3%), amylose content (31.24%), and RS content (15.71%), and the lowest amylopecyin content (30.02%) and RDS content (23.65%). HMT+M brought the highest slowly digestible starch (SDS) content (25.09%). The estimated glycemic index (eGI) was respectively reduced from 74.36 to 70.59, 65.87, 69.79, and 69.12 by HMT, HMT+P, HMT+M, and HMT+A. Moreover, a significant and consistent reduction in the heat enthalpy (ΔH) of WQ was observed (p < 0.05), after four treatments. All these effects were caused by changes in the starch structure, as evidenced by the observed conjunction of protein and starch by a confocal laser scanning microscope (CLSM), the decrease in relative crystallinity, and transformation of starch crystal.Hide Abstract
Oat protein concentrates with improved solubility produced by an enzyme-aided ultrafiltration extraction method.
Immonen, M., Myllyviita, J., Sontag-Strohm, T. & Myllärinen, P. (2021). Foods, 10(12), 3050.
The aim of this study was to develop an extraction method to produce highly functional oat protein concentrates. We investigated the possibility of combining enzyme-aided slightly alkaline (pH 8.0) extraction with ultrafiltration and subsequent diafiltration for concentration of the extracted oat proteins. A further aim was to study how the deamidation of oat proteins with protein-glutaminase (PG) improves the solubility of proteins as a function of the following parameters: pH (6.0–9.0), enzyme dosage (4-20 U/g protein), and incubation time (1-4 h) with response surface methodology (RSM). Furthermore, we investigated selected functional properties, such as heat-induced gelation and solubility, of the oat protein concentrates. The chosen parameters for the enzymatic deamidation pre-treatment process by PG were as follows: pH 8.0, dosage 11.0 U/g protein, and an incubation time of 4 h (1 h at native pH and 3 h at pH 8.0). Two oat protein concentrates were produced, non-deamidated and ultrafiltered, and deamidated and ultrafiltered, with protein concentrations of 45.0 and 52.4%, respectively. The solubility of both oat protein concentrates was significantly improved at neutral and slightly alkaline pH compared to the solubility of proteins extracted from the starting material. Additionally, both oat protein concentrates produced equally strong heat-induced gel-like structures at a protein concentration of 10%.Hide Abstract
Genotypic variation in the response of soybean to elevated CO2.
Soares, J. C., Zimmermann, L., Zendonadi dos Santos, N., Muller, O., Pintado, M. & Vasconcelos, M. W. (2021). Plant‐Environment Interactions, 2(6), 263-276.
The impact of elevated CO2 (eCO2) on soybean productivity is essential to the global food supply because it is the world's leading source of vegetable proteins. This study aimed to understand the yield responses and nutritional impact under free-air CO2 enrichment (FACE) conditions of soybean genotypes. Here we report that grain yield increased by 46.9% and no reduction in harvest index was observed among soybean genotypes. Elevated CO2 improved the photosynthetic carbon assimilation rate, leaf area, plant height, and aboveground biomass at vegetative and pod filling stages. Besides the positive effects on yield parameters, eCO2 differentially affected the overall grain quality. The levels of calcium (Ca), phosphorous (P), potassium (K), magnesium (Mg), manganese (Mn), iron (Fe), boron (B), and zinc (Zn) grain minerals decreased by 22.9, 9.0, 4.9, 10.1, 21.3, 28.1, 18.5, and 25.9% under eCO2 conditions, respectively. Soluble sugars and starch increased by 9.1 and 16.0%, respectively, phytic acid accumulation increased by 8.1%, but grain protein content significantly decreased by 5.6% across soybean genotypes. Furthermore, the antioxidant activity decreased by 36.9%, but the total phenolic content was not affected by eCO2 conditions. Genotypes, such as Winsconsin Black, Primorskaja, and L-117, were considered the most responsive to eCO2 in terms of yield enhancement and less affected in the nutritional quality. Our results confirm the existence of genetic variability in soybean responses to eCO2, and differences between genotypes in yield improvement and decreased sensitivity to eCO2 in terms of grain quality loss could be included in future soybean selection to enable adaptation to climate change.Hide Abstract
In vitro gastric digestion and emptying of cooked white and brown rice using a dynamic human stomach system.
Wang, J., Wu, P., Wang, J., Wang, J., Gu, B., Ge, F. & Chen, X. D. (2022). Food Structure, 31, 100245.
In this study, a dynamic in vitro human stomach system was employed to elucidate the influence of structural differences between white and brown rice on gastric emptying and starch digestion. The evolution of gastric digesta particle size distribution, pH, viscosity and starch hydrolysis was investigated during digestion. Due to the protective effect of the outer bran layer against structural breakdown, brown rice showed higher pH buffering capacity, larger digesta particle size and greater rheology, resulting in a delayed gastric emptying and consequently, lower starch hydrolysis in an overall starch digestibility in the stomach than the white rice. The current study has provided quantitative evidence regarding the importance of macrostructure (i.e. the bran layer) in rice gastric digestion that may further impact intestinal absorption. Meanwhile, the particle size was significantly smaller in the digesta emptied out of the stomach in both white and brown rice throughout the digestion compared to that retained in the stomach. This demonstrates an effective size reduction and sieving efficiency exhibited by the in vitro system. It is practically meaningful to use the in vitro system to track the dynamic changes in structural and physicochemical properties of food materials during digestion in the stomach.Hide Abstract
Development of Antioxidant and Nutritious Lentil (Lens culinaris) Flour Using Controlled Optimized Germination as a Bioprocess.
Rico, D., Peñas, E., del Carmen García, M., Rai, D. K., Martínez-Villaluenga, C., Frias, J. & Martín-Diana, A. B. (2021). Foods, 10(12), 2924.
Germination is an efficient and natural strategy that allows the modification of the nutritional value and the nutraceutical properties of seeds, enabling one to tailor the process according to its final use. This study aimed at optimization of germination conditions to produce novel lentil flours with improved nutritional and functional features. Response Surface Methodology (RSM) was applied to model the effect of temperature (15-27°C) and time (1-5 days) on different nutritional and quality parameters of lentil flours including proximate composition, content and profile of fatty acids, content of phytic acid, ascorbic acid and γ-aminobutyric acid (GABA), content and profile of phenolic compounds, antioxidant activity, expected glycemic index (GI) and color during germination. As shown by RSM polynomial models, sprouting promoted the reduction of phytic acid content and enhanced the levels of ascorbic acid, GABA, insoluble phenolic compounds, antioxidant activity and expected GI, and modified the color of the resultant lentil flours. RSM optimization of germination temperature and time using desirability function revealed that the optimal process conditions to maximize the nutritional, bioactive and quality properties of sprouted lentil flours were 21 °C for 3.5 days.Hide Abstract
Qualitative Characterization of Unrefined Durum Wheat Air-Classified Fractions.
Cammerata, A., Laddomada, B., Milano, F., Camerlengo, F., Bonarrigo, M., Masci, S. & Sestili, F. (2021). Foods, 10(11), 2817.
Durum wheat milling is a key process step to improve the quality and safety of final products. The aim of this study was to characterize three bran-enriched milling fractions (i.e., F250, G230 and G250), obtained from three durum wheat grain samples, by using an innovative micronization and air-classification technology. Milling fractions were characterized for main standard quality parameters and for alveographic properties, starch composition and content, phenolic acids, antioxidant activity and ATIs. Results showed that yield recovery, ash content and particle size distributions were influenced either by the operating conditions (230 or 250) or by the grain samples. While total starch content was lower in the micronized sample and air-classified fractions, the P/L ratio increased in air-classified fractions as compared to semolina. Six main individual phenolic acids were identified through HPLC-DAD analysis (i.e., ferulic acid, vanillic acid, p-coumaric acid, sinapic acid, syringic and p-hydroxybenzoic acids). Compared to semolina, higher contents of all individual phenolic components were found in all bran-enriched fractions. The highest rise of TPAs occurred in the F250 fraction, which was maintained in the derived pasta. Moreover, bran-enriched fractions showed significant reductions of ATIs content versus semolina. Overall, our data suggest the potential health benefits of F250, G230 and G250 and support their use to make durum-based foods.Hide Abstract