01:16 Theory of the Analytical Procedure
02:33 Kit Content & Reagent Preparation
06:15 Weighing of Samples
06:44 A. Starch Pretreatment
12:04 B. Precipitation of Amylopectin with Con A & the Determination of Amylose
16:11 C. Determination of Total Starch
18:35 Determination of D-Glucose in Amylose & Total Starch Fractions
20:37 Calculation of Amylose Content
100 assays per kit
Prices exclude VAT
Available for shipping
|Content:||100 assays per kit|
|Storage Temperature:|| Short term stability: 2-8oC, |
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Limit of Detection:||Amylose 5-95% of total starch content|
|Total Assay Time:||~ 120 min|
|Application examples:||Cereal starches, flours, pure starches and foods.|
|Method recognition:||Novel method|
The Amylose/Amylopectin test kit is suitable for the measurement and analysis of amylose/amylopectin ratio and content in cereal starches and flours. Based on a Con A precipitation procedure.
See our full list of polysaccharide test kits.
- Very cost effective (cost per test)
- All reagents stable for > 12 months after preparation
- Only enzymatic kit available
- Accurate and reliable amylose / amylopectin ratio determination
- Simple format
- Standard included
McCleary, B. V., Charnock, S. J., Rossiter, P. C., O’Shea, M. F., Power, A. M. & Lloyd, R. M. (2006). Journal of the Science of Food and Agriculture, 86(11), 1648-1661.
Procedures for the measurement of starch, starch damage (gelatinised starch), resistant starch and the amylose/amylopectin content of starch, β-glucan, fructan, glucomannan and galactosyl-sucrose oligosaccharides (raffinose, stachyose and verbascose) in plant material, animal feeds and foods are described. Most of these methods have been successfully subjected to interlaboratory evaluation. All methods are based on the use of enzymes either purified by conventional chromatography or produced using molecular biology techniques. Such methods allow specific, accurate and reliable quantification of a particular component. Problems in calculating the actual weight of galactosyl-sucrose oligosaccharides in test samples are discussed in detail.Hide Abstract
McCleary, B. V., Gibson, T. S. & Mugford, D. C. (1997). Journal of AOAC International, 80, 571-579.
An American Association of Cereal Chemists/AOAC collaborative study was conducted to evaluate the accuracy and reliability of an enzyme assay kit procedure for measurement of total starch in a range of cereal grains and products. The flour sample is incubated at 95 degrees C with thermostable alpha-amylase to catalyze the hydrolysis of starch to maltodextrins, the pH of the slurry is adjusted, and the slurry is treated with a highly purified amyloglucosidase to quantitatively hydrolyze the dextrins to glucose. Glucose is measured with glucose oxidase-peroxidase reagent. Thirty-two collaborators were sent 16 homogeneous test samples as 8 blind duplicates. These samples included chicken feed pellets, white bread, green peas, high-amylose maize starch, white wheat flour, wheat starch, oat bran, and spaghetti. All samples were analyzed by the standard procedure as detailed above; 4 samples (high-amylose maize starch and wheat starch) were also analyzed by a method that requires the samples to be cooked first in dimethyl sulfoxide (DMSO). Relative standard deviations for repeatability (RSD(r)) ranged from 2.1 to 3.9%, and relative standard deviations for reproducibility (RSD(R)) ranged from 2.9 to 5.7%. The RSD(R) value for high amylose maize starch analyzed by the standard (non-DMSO) procedure was 5.7%; the value was reduced to 2.9% when the DMSO procedure was used, and the determined starch values increased from 86.9 to 97.2%.Hide Abstract
Gibson, T. S., Solah, V. A. & McCleary, B. V. (1997). Journal of Cereal Science, 25(2), 111-119.
A modified procedure for the determination of amylose in cereal starches and flours based on complex formation between the lectin concanavalin A (Con A) and amylopectin has been developed and characterised. The assay format is suitable for multi-sample analysis, allowing the analysis of up to 20 samples per day. In the procedure, the amylopectin in a solubilised, lipid-free starch sample is precipitated by reaction with Con A and removed by centrifugation. The amylose remaining in the supernatant is then determined after amylolytic hydrolysis to glucose and expressed as a proportion (%) of the glucose derived from amylolytic hydrolysis of the total starch in a separate aliquot of the solubilised sample (i.e. prior to Con A treatment). The Con A procedure correlates well (r>0•993) with existing Con A-based and iodine-based procedures and yields a linear standard curve for starch samples containing from ∼0 to ∼100% amylose. Advantages of this modified Con A procedure for amylose determination include its applicability to flour samples without the need for prior starch purification; it allows the simultaneous estimation of total starch and does not require a calibration curve. Repeated analyses of a set of samples yielded repeatability (within laboratory) relative standard deviations of <5% for pure starches and ∼10% for flours. A commercially available assay kit has been developed to facilitate the use of the Con A procedure in routine amylose determinations.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 high-amylose resistant starch on the glycogen structure of diabetic mice.
Wang, Z., Hu, Z., Deng, B., Gilbert, R. G. & Sullivan, M. A. (2022). International Journal of Biological Macromolecules, 200, 124-131.
Glycogen is a complex branched glucose polymer found in many tissues and acts as a blood-glucose buffer. In the liver, smaller β glycogen particles can bind into larger composite α particles. In mouse models of diabetes, these liver glycogen particles are molecularly fragile, breaking up into smaller particles in the presence of solvents such as dimethyl sulfoxide (DMSO). If this occurs in vivo, such a rapid enzymatic degradation of these smaller particles into glucose could exacerbate the poor blood-glucose control that is characteristic of the disease. High-amylose resistant starch (RS) can escape digestion in the small intestine and ferment in the large intestine, which elicits positive effects on glycemic response and type 2 diabetes. Here we postulate that RS would help attenuate diabetes-related liver glycogen fragility. Normal maize starch and two types of high-amylose starch were fed to diabetic and non-diabetic mice. Molecular size distributions and chain-length distributions of liver glycogen from both groups were characterized to test glycogen fragility before and after DMSO treatment. Consistent with the hypothesis that high blood glucose is associated with glycogen fragility, a high-amylose RS diet prevented the fragility of liver-glycogen α particles. The diets had no significant effect on the glycogen chain-length distributions.Hide Abstract
Physicochemical and nutritional properties of starches from nine Canadian‐grown peas compared with six commercial starches.
Lu, Z. H., Lu, Y., Donner, E., Liu, Q. & Bing, D. (2021). Legume Science, 1-4.
The physicochemical properties and nutritional fractions of the starches isolated from nine Canadian-grown peas, including marrowfat, green, and yellow pea types, were studied and compared with six commercial starches, to explore the unique properties of these pea starches. These nine pea starches were found to have high apparent amylose content (marrowfat peas, 51.3%–51.6%; yellow peas, 50.6%-53.8%; and green peas, 49.9%-54.2%) and a higher tendency than most commercial starches to retrograde. Although their physicochemical properties were not drastically different, a green pea variety, Limerick, stood out for its significantly high apparent amylose content (54.2%) and also the highest resistant starch (RS) content after cooking (29.5%), the latter even comparable with a commercial high amylose corn starch (29.8%). Principal component analysis indicated that amylose content, amylose leaching, and Rapid Visco Analyzer (RVA) parameters at the cooling stage are significantly positively correlated to the starch nutritional fractions of cooked samples. Cluster analysis showed a clear pattern that the RS content in cooked starches increased with the increasing amylose content in these starch samples. In general, these pea starches were rich in slowly digestible starch and high in RS after cooking (>16%). This study highlighted the unique properties of these pea starches, including their high amylose content, and ease of gelatinization yet strong tendency toward retrogradation, which resulted in superior final pasting viscosity and high RS content; thus, these pea starches could be the best alternative to commercial high amylose starches, to address the latter's deficiencies in pasting properties when applying in gel-based low glycemic index (GI) foods.Hide Abstract
Drying processes of OSA-modified plantain starch trigger changes in its functional properties and digestibility.
Chávez-Salazar, A., Álvarez-Barreto, C. I., Hoyos-Leyva, J. D., Bello-Pérez, L. A. & Castellanos-Galeano, F. J. (2022). LWT, 154, 112846.
In the production of starch, the drying process is a unit operation that can affect its functional properties; however, there is scarce information about the effect of dying process on modified starches such as OSA (2-octenyl-succinic anhydride) plantain starch. The modified starch was dried by convection (50°C) and spray drying (Ti = 150°C). The physicochemical, morphological, functional and digestibility characteristics of the samples were assessed. The gelatinized samples showed an increase in the SDS fraction related to starch modification, and the convection-dried sample showed an increase in the RS fraction. The drying process that presented a high nutraceutical starch fraction (SDS plus RS) was convection drying (58%). The drying process affects the functional properties of OSA-modified plantain starch due to a partial loss of organization within the granular structure of the modified starch, which is reflected in the spray-dried sample as high WAI (2.46 ± 0.04 g.100 g-1), SP (2.48 ± 0.1 g.100 g-1), low WSI (2.07 ± 0.1 g.100 g-1), high pasting peak viscosity (0.39 Pas-1) and low onset gelatinization temperature (66.0 ± 0.1°C) and gelatinization enthalpy (6.3 ± 0.1 J g−1). The differences in the functional properties can be relevant to different industrial-technological applications.Hide Abstract
Physicochemical characteristics, microstructure and health promoting properties of green banana flour.
Khoza, M., Kayitesi, E. & Dlamini, B. C. (2021). Foods, 10(12), 2894.
This study aimed to investigate the proximate composition, mineral content, functional properties, molecular structure, in vitro starch digestibility, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (DPPH, FRAP) of green banana flour (GBF) cultivars grown in South Africa. With proximate composition, Finger Rose and Pisang Awak had the highest protein (4.33 g/100 g) and fat (0.85 g/100 g) content, respectively. The highest ash content (3.50 g/100 g) occurred with both Grand Naine and FHIA-01 cultivars. Potassium and copper were the most abundant and least minerals, respectively. Pisang Awak cultivar had the highest water absorption capacity (67.11%), while Du Roi had the highest swelling power (0.83 g/g) at 90 °C. Scanning electron microscopy (SEM) images revealed that starch granules from all GBF cultivars were irregular in shape and they had dense surfaces with debris. All the GBF cultivars had similar diffraction patterns with prominent peaks from 15°-24° diffraction angles. The resistant starch (RS) and amylose content of the FHIA-01 cultivar indicates that the GBF has the potential to lower risks of type 2 diabetes and obesity. The highest TPC, TFC and antioxidant activity occurred with the Grande Naine cultivar. Based on their functional characteristics, the Grand Naine and FHIA-01 GBF cultivars could potentially be used as raw materials for bakery products as well as for the fortification of snacks.Hide Abstract
Nutritional composition and physicochemical properties of oat flour sieving fractions with different particle size.
Gu, Y., Qian, X., Sun, B., Ma, S., Tian, X. & Wang, X. (2021). LWT, 145, 112757.
Nutritional constituents, hydration, pasting, and thermal properties of oat flour sieve fractions (74–180 μm) and the relationship between composition and characteristics were studied. Starch constituents, protein components (except for albumins), and saturated fatty acids (SFA) were mostly distributed in small particle fractions, while total protein, albumin, dietary fiber (DF), lipids, and unsaturated fatty acids (UFA) were abundant in large particle fractions. Amino acids (except for Tyr and Gly) of group I, II, and III were significantly lacking in S2 (150-180 μm), and Cys decreased from 2.51% to 1.50% with the decrease in sieving particle sizes. The largest particles showed the highest water solubility index (WSI, 9.90%), the medium particles (100-132 μm) exhibited the highest pasting viscosities (final viscosity of 4148 cP), and the smallest particles had the maximum gelatinization enthalpy (ΔH, 3.2 J/g). Correlation analysis demonstrated that except for the basic components, Glu, Cys, Iso, Phe, C16:0, C18:0, and C18:2n6c also significantly affected the WSI and pasting properties of oat flour, while amylose, Gly, Ala, Val, Met, and C20:1 were highly correlated with thermal properties. The results are useful for oat processing and the development of oat-based products with specific particle size range to achieve desirable characteristics.Hide Abstract
Yield, grain quality and starch physicochemical properties of 2 elite Thai Rice cultivars grown under varying production systems and soil characteristics.
Sangwongchai, W., Tananuwong, K., Krusong, K., & Thitisaksakul, M. (2021). Foods, 10(11), 2601.
Rice production systems and soil characteristics play a crucial role in determining its yield and grain quality. Two elite Thai rice cultivars, namely, KDML105 and RD6, were cultivated in two production systems with distinct soil characteristics, including net-house pot production and open-field production. Under open-field system, KDML105 and RD6 had greater panicle number, total grain weight, 100-grain weight, grain size, and dimension than those grown in the net-house. The amounts of reducing sugar and long amylopectin branch chains (DP 25–36) of the RD6 grains along with the amounts of long branch chains (DP 25–36 and DP ≥ 37), A-type starch granules, and average chain length of the KDML105 were substantially enhanced by the open-field cultivation. Contrastingly, the relative crystallinity of RD6 starch and the amounts of short branch chains (DP 6–12 and DP 13–24), B- and C-type granules, and median granule size of KDML105 starch were significantly suppressed. Consequently, the open-field-grown RD6 starch displayed significant changes in its gelatinization and retrogradation properties, whereas, certain retrogradation parameters and peak viscosity (PV) of KDML105 starches were differentially affected by the distinct cultivating conditions. This study demonstrated the influences of production systems and soil characteristics on the physicochemical properties of rice starches.Hide Abstract
Effects of dietary amylose to amylopectin ratio on growth performance, carcass quality characteristics and meat fatty acids in Chinese Qinchuan cattle.
Piao, M. Y., Hu, F. M., Kong, F. L., Liu, Y. L., Wang, S., Cui, K., Diao, Q. & Yan, T. U. (2021). Journal of Integrative Agriculture, 20(12), 3256-3269.
This study evaluated the effects of the dietary starch amylose/amylopectin ratio on growth performance, rumen fermentation and blood parameters, carcass characteristics and marbling score, and meat fatty acid profiles and transcriptional changes in the genes involved in the gluconeogenesis pathway in Chinese Qinchuan cattle. Forty-five cattle were randomly divided into three groups. The bulls were fed a control diet (middle amylose/amylopectin ratio=0.47) or diets with either waxy corn starch (WS) inclusion (low amylose/amylopectin ratio=0.23) or pea starch (PS) inclusion (high amylose/amylopectin ratio=0.60) for 90 days. The bulls were individually allowed to receive the diets at the daily amount of at least 2.1% of their individual BW twice daily. The bulls were weighed at 45-day intervals, and blood and rumen fluid samples were also collected at 45-day intervals. The bulls were slaughtered and longissimus thoracis (LT) samples were collected for meat quality measurements. Compared with PS, the average daily gain (ADG) and feed efficiency in control and WS were increased (P<0.05) during d 0 to 45. However, the feed efficiency in PS was increased (P<0.05) compared with the control and WS during d 46 to 90. During the whole feeding trial, the ADG in control and WS showed trends that were higher (0.05<P<0.1) than that of PS, while other growth performance measures and feed intake did not differ (P>0.05) among the three groups. Compared with PS, the serum insulin concentration in WS was increased (P<0.05) at d 45, but not at d 90. Compared with control and WS, the serum SOD and T-AOC concentrations in PS were increased (P<0.05) at d 45, but not at d 90. Compared with control, the rumen microbial crude protein contents in WS and PS were increased (P<0.05) at d 0, while those of control and WS were higher (P<0.05) than that of PS at d 45, but not at d 90. Compared with PS, the backfat thickness in control and WS were increased (P<0.05), however, the marbling score and expression of genes related to the gluconeogenesis pathway in liver of the three groups did not differ (P>0.05). Chemical and physio-chemical compositions of LT did not differ (P>0.05) among the three groups. In conclusion, diets with low or middle amylose/amylopectin ratios increased the backfat thickness, and tended to improve ADG, but had no effect on other carcass characteristics, fat content in the LT, or the expression of hepatic genes related to the gluconeogenesis pathway in Chinese Qinchuan cattle.Hide Abstract
Effect of wheat bran dietary fiber on structural properties of wheat starch after synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae.
Wang, Z., Yan, J., Ma, S., Tian, X., Sun, B., Huang, J., Xiaoxi, W. & Bao, Q. (2021). International Journal of Biological Macromolecules, 190, 86-92.
This study investigated the changes in the structure of wheat starch after synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae at different wheat bran dietary fiber (WBDF) levels. The results showed that WBDF was slightly resistant to the decrease in acidity within the fermentation system. The amylose content decreased from 32.12% to 19.92% (P < 0.05), amylose/amylopectin ratio decreased from 0.47 to 0.25 (P < 0.05), and relative crystallinity decreased from 12.17% to 9.40% (P < 0.05) in the samples containing WBDF compared with the control. Scanning electron microscopy showed more eroded starch as the WBDF level increased. Fourier-transform infrared spectroscopy revealed a decrease in the starch-hydrogen binding absorbance in the 3600-3000 cm-1 wavemumber; and the 1047/1022 and 995/1022 cm-1 data indicated an increase in the degree of order and degree of double helix of the samples containing WBDF. The results of the study might help understand the interaction between dietary fibers and starch during fermentation and guide the production of fermented high-fiber flour products.Hide Abstract
Effects of fermentation on the structure and physical properties of glutinous proso millet starch.
Bian, X., Chen, J. R., Yang, Y., Yu, D. H., Ma, Z. Q., Ren, L. K., Wu, N., Chen, F., Liu, X., Wang, B. & Zhang, N. (2022). Food Hydrocolloids, 123, 107144.
This study investigated the effects of spontaneous and Lactobacillus plantarum (LP) fermentation on structure glutinous proso millet starch (GPM) and physical properties. In order to explore starch changes by fermentation for quality regulation of fermented food glutinous proso millet and improve properties of modified GPM starch products. The molecular weight, amylopectin chain length distribution, morphological properties, short-range ordered structure, and crystal structure of GPM starch were analyzed. Results showed that compared with the non-fermented GPM starch, amylose content of spontaneous and LP-fermented GPM starch increased then decreased, with the latter decreasing faster. There were no changes in the Type A structures of spontaneous fermented, LP-fermented, and non-fermented GPM starch. After 24 h of LP fermentation, higher water swelling power, and lower GPM starch solubility were obtained compared to non-fermentation and spontaneous fermentation. The decrease in pasting properties and thermal properties while increasing GPM starch properties was shown after fermentation compared to non-fermentation experiments. Besides, LP fermentation showed faster changes of these properties than spontaneous fermentation. In conclusion, our findings showed that fermentation could improve GPM starch properties, benefiting fermented GPM products and as a modification method for GPM starch. Especially, LP fermentation was more effective than spontaneous fermentation.Hide Abstract
Dry-heat processing at different conditions impact the nutritional composition and in vitro starch and protein digestibility of immature rice-based products.
Miraji, K. F., Linnemann, A. R., Fogliano, V., Laswai, H. S. & Capuano, E. (2021). Food & Function, 12(16), 7527-7545.
Immature grain represents a precious nutritional source in many rural Africa areas. To optimize processing of immature rice into pepeta (a traditional rice-flakes produced from immature rice grains), immature rice (TXD306 variety) harvested at 18 and 26 days after 50% heading were processed in the laboratory under different soaking (0 and 12 h) and roasting temperature (80, 100 and 120°C) regimes. Riboflavin, nicotinic acid, nicotinamide and iron concentration increased with severity of roasting temperature, while thiamine has an opposite trend. Heating promoted the transformation of insoluble into soluble dietary fiber, increased lipid digestibility decreasing protein one, which showed the highest value when rice was roasted at 100°C. Soaking before roasting significantly increased moisture and iron content while slightly increased riboflavin, nicotinic acid and nicotinamide when compared to unsoaked products. Among roasted products, starch digestibility increased with roasting temperature. Microstructure analysis indicated a complete loss of cell wall integrity in cooked rice, determining a complete starch and protein digestion while this is delayed in raw rice and roasted products. We concluded that roasting at 100°C is the optimum temperature to produce pepeta of the highest protein digestibility and low starch digestibility. Soaking before roasting at 120°C is best when retaining micronutrients is considered.Hide Abstract
In vitro faecal fermentation outcomes and microbiota shifts of resistant starch spherulites.
Liu, J., Liu, F., Arıoğlu‐Tuncil, S., Xie, Z., Fu, X., Huang, Q. & Zhang, B. (2021). International Journal of Food Science & Technology, In Press.
In the present study, we prepared A- and B-type polymorph-resistant starch spherulites (RSSs) with a wide range of crystallinity, and elucidated the relation between crystalline structure and faecal microbial fermentation outcomes. A- and B-type polymorphic RSSs displayed similar fermentation rate throughout entire process with final gas production of 11.8–13.2 mL, suggesting that the crystalline pattern and crystallinity cannot effectively control the fermentation rate of starches. The acetate and butyrate concentration of A-type RSS decreased with the increase of crystallinity respectively, and highly crystalline B-type RSS reduced the production of acetate (8.4 mM) and propionate (2.1 mM). RSSs with different crystalline types showed similar microbial community structure but distinct key bacteria species. A-type RSSs greatly promoted the abundance of butyrogenic bacteria (i.e., Roseburia faecis and Lachnospiraceae), whereas B-type RSSs tended to proliferate Prevotella copri associated with propionate production. Our findings shed new light on design and manufacture of starch-based functional ingredients with enhanced gut health.Hide Abstract
Effects of different amylose contents of foxtail millet flour varieties on textural properties of Chinese steamed bread.
Li, S., Zhao, W., Min, G., Li, P., Zhang, A., Zhang, J., wang, Y., Liu, Y. & Liu, J. (2021). Processes, 9(7), 1131.
In order to improve the nutritional value and quality of steamed bread, and promote the industrial development of the whole-grain food industry, a texture analyzer was used to study the effects of cultivars of whole foxtail millet flour (WFMF) on the texture of Chinese steamed bread (CSB). Orthogonal partial least squares discriminant analysis (OPLS-DA) was also conducted. The addition of different cultivars of WFMF significantly altered the height-diameter ratio, specific volume, hardness, cohesiveness, gumminess, and chewiness of CSB (p < 0.05). Large amounts of foxtail millet flour significantly increased the hardness, gumminess and chewiness of the bread (p < 0.05), and the bread height-diameter ratio, specific volume, cohesiveness and springiness significantly decreased (p < 0.05). We screened sensory evaluation, chewiness, specific volume, and hardness as the signature differences in the quality components according to the variable influence on the projection (VIP) values. OPLS-DA could distinguish the addition levels of different samples.Hide Abstract
Variability in waxy (Wx) allele, in-vitro starch digestibility, glycemic response and textural behaviour of popular Northern Himalayan rice varieties.
Naseer, B., Naik, H. R., Hussain, S. Z., Shikari, A. B. & Noor, N. (2021). Scientific reports, 11(1), 1-10.
Eight commonly cultivated and consumed rice varieties of Northern Himalayan regions and a popular high amylose rice variety were characterized at Wx locus and evaluated for resistant starch (RS), in-vitro starch digestibility, predicted glycemic index (pGI), glycemic load (GL) and textural parameters. Cytosine and thymine repeats (CT)n at waxy locus (Wx) showed high association with apparent amylose content (AAC). Both pGI and GL varied substantially within the selected varieties. The pGI was relatively lower in high and intermediate amylose Indica varieties compared to low amylose Japonica ones. However, Koshikari despite being a low amylose variety showed relatively lower pGI and GL, due to its higher RS, dietary fiber, protein and fat content. It was thus presumed that in addition to AAC, RS and other grain components also affect the glycemic response. Inherent resistance to enzymatic hydrolysis was also found to be higher in firm textured and less sticky rice varieties. The genotypes-Lalat, Basmati-1509 and Koshikari, in view of their low to moderate pGI and relatively higher RS content, can be explored in future breeding programmes to develop rice varieties whose consumption will help to prevent hyper/hypo glycemic responses in Northern Himalayan regions, where daily staple diet is rice.Hide Abstract
Composition of Different Carbohydrate Fractions in Potatoes: Effect of Cooking and Cooling.
Raigond, P., Parmar, V., Thakur, A., Lal, M. K., Changan, S. S., Kumar, D., Dutt, S. & Singh, B. (2021). Starch‐Stärke, 2100015.
Effect of cooking methods (boiling, microwaving, pressure cooking) and storage conditions (-20, 4, 12°C) on resistant starch (RS), amylose, and sugars in the Indian cultivars, viz., Kufri Pukhraj and Kufri Chipsona-1 is investigated. Starch decreased significantly in Kufri Pukhraj and non-significantly in Kufri Chipsona 1 with a concomitant significant increase in reducing sugars and sucrose in cooked potatoes. Storage of microwaved tubers at 4°C for 48 h results in 4-6% reduction in starch content with 66-109% and 16-18% increase in reducing sugars and sucrose, respectively. Increase in RS content at -20, 4 and 12°C after 48 h is 14%, 21%, and 27% after microwaving, 12%, 25%, and 23% after boiling, and 13%, 15%, and 20%, respectively, after pressure cooking. Amylose showed high positive correlation with RS at 4°C (R = 0.756) and 12 h storage (R = 0.924). The study reveals that storage of microwaved potatoes at 12°C for 48 h increases the RS to a higher extent, therefore, these cooking and storage conditions may be used by potato consumers. Due to inverse relation of RS and amylose with glycemic index they can be used for indirect estimation of glycemic index.Hide Abstract
Effects of ultrasound-assisted enzymolysis on the physicochemical properties and structure of arrowhead-derived resistant starch.
Liang, Q., Chen, X., Ren, X., Yang, X., Raza, H. & Ma, H. (2021). LWT, 147, 111616.
The effects of ultrasound-assisted enzymolysis on the physicochemical properties and structure of arrowhead-derived type 3 resistant starch (RS3) were investigated. Compared with the traditional enzymolysis, ultrasonic treatment significantly (p < 0.05) increased the resistant starch yield by 34.46%. Enzymolysis reaction kinetics revealed that ultrasound-assisted enzymolysis remarkably increased the enzymolysis rate and amylose content. After ultrasound treatment, RS3 displayed higher solubility, swelling power, transparency, and water absorption capacity. The results of particle-size distribution, differential scanning calorimetry, X-ray diffraction, Fourier transform-infrared spectroscopy, and scanning electron microscopy analyses demonstrated that RS3 prepared by ultrasound-assisted enzymolysis exhibited a larger granule size, higher crystallinity, a more ordered and stable double helix structure with increased surface roughness compared to those of RS3 prepared by traditional enzymolysis. These findings provide a theoretical background for the preparation of RS3 using an ultrasound-assisted enzymatic method and will promote the development of ultrasound chemistry in starch science and technology.Hide Abstract
Tracking physical breakdown of rice-and wheat-based foods with varying structures during gastric digestion and its influence on gastric emptying in a growing pig model.
Nadia, J., Olenskyj, A. G., Stroebinger, N., Hodgkinson, S. M., Estevez, T. G., Subramanian, P., Singh, H., Singh, R. P. & Bornhorst, G. M. (2021). Food & function, 12(10), 4349-4372.
There is currently a limited understanding of the effect of food structure on physical breakdown and gastric emptying of solid starch-based foods during gastric digestion. Moisture uptake, pH, particle size, rheological, and textural properties of six solid starch-based diets from different sources (Durum wheat and high amylose white rice) and of different macrostructures (porridge, native grain, agglomerate/couscous, and noodle) were monitored during 240 min of gastric digestion in a growing pig model. Changes in the physical properties of the gastric digesta were attributed to the influence of gastric secretions and gastric emptying, which were both dependent on the buffering capacity and initial macrostructure of the diets. Differences between the proximal and distal stomach regions were found in the intragastric pH and texture of the gastric digesta. For example, rice couscous, which had the smallest particle size and highest buffering capacity among the rice-based diets, had the shortest gastric emptying half-time and no significant differences between proximal and distal stomach digesta physical properties. Additionally, a relationship between gastric breakdown rate, expressed as gastric softening half-time from texture analysis, and gastric emptying half-time of dry matter was also observed. These findings provide new insights into the breakdown processes of starch-based solid foods in the stomach, which can be beneficial for the development of food structures with controlled rates of breakdown and gastric emptying during digestion.Hide Abstract