Soluble Amylose Content Research Articles

Characterization of the Starch Extracted from an Ancestral Andean Meal: Chuño

AbstractThe ancestral method of preparing chuño (freeze‐dried potato) involves three steps: freezing, soaking, and drying. The objective of this study is to identify the changes in microstructure, in physicochemical properties, and rheology of gels and suspensions of Andean potato starches caused by the procedure used to obtain chuño. A laboratory simulation of the procedure is performed using the potato variety “Rosadita” (Solanum tuberosum ssp. Andigenum). From the tests carried out on the starches extracted from the chuño obtained in the field and in the laboratory, differences phosphate content and gelatinization temperature are found. Marked differences are observed with respect to the control starch in the soluble amylose content, RVA profiles, textural attributes, and dynamic and viscous rheological properties. The chuño starches present greater resistance to granular breakdown. These observations suggest a different hydration, swelling, and gelation mechanism for the Rosadita and chuño starch samples compared to conventional potato starch and at the same time a modification due to the effect of freezing, which is more noticeable in the chuño obtained at −5 °C.

Effect of surfactant and fat on chapati making quality and control of its staling

Chapati is an unleavened flat baked product and it is prepared using whole wheat flour. One of the problems with chapatis is that they stale rapidly during storage and therefore, they have to be consumed immediately after their preparation. With changing socio-economic conditions and lifestyles, there is an increasing demand for ready to eat chapatis. In the present study, to control staling, chapatis were prepared using whole wheat flours of four different varieties by incorporating additives such as surfactant and fat. The chapatis stored at room temperature for 24 h, 48 h, 72 h and 96 h were evaluated for their quality parameters such as moisture content, chemical properties, sensory attributes, microstructure and amylograph characteristics. The moisture, soluble starch and soluble amylose contents in control chapatis decreased steadily with storage time and at the end of 96 h, the decrease in moisture, soluble starch and soluble amylose contents in chapatis prepared from different varieties were 3–8%, 80–82% and 78–85%, respectively. However, these changes were found to be at a very lesser rate in chapatis prepared from doughs treated with glycerol monostearate (GMS) and fat compared to that of control. Decrease in amylograph paste viscosity was more in control chapatis during storage compared to that of treated chapatis. Scanning electron microscopic studies of chapatis stored up to 96 h revealed that starch granules were uniform in both GMS and fat treated chapatis, when compared to control chapatis. Sensory studies showed that overall quality scores for chapatis prepared from GMS and fat treated doughs did not show any significant differences on storage. Thus, the results suggested that incorporation of surfactant and fat in dough not only improved the overall quality attributes of chapatis but also controlled their staling, during their storage.

Influence of parboiling of red paddy varieties by simple hot soaking on physical, nutrient, phytochemical, antioxidant properties of their dehusked rice and their mineral, starch, and antioxidant's bioaccessibility studies.

The objective of this study was to know about the effect of simple parboiling on physical properties, proximate composition, phenolic compounds, and antioxidant activity. These were studied in raw and parboiled paddy varieties as well as bioaccessibility of specific nutrients (minerals, starch, and antioxidants). The pigmented rice paddy varieties such as Jyothi, Meter & Athikaraya were parboiled by hot soaking treatment after soaking for 2, 2½, and 3hr. Athikaraya rice showed high protein, low ash in raw and parboiled than other varieties. Amylose equivalents of all three varieties exhibited in the range of 24%-27% (d.b). Whereas, the soluble amylose content showed 12.7, 8.7, and 7.7% (d.b) in Athikaraya, Meter and Jyothi rice varieties, respectively. Jyothi rice showed less cooking time and more cooking volume. Athikaraya showed high phenolic content and antioxidant properties compared to other two varieties. The dialysability of minerals, starch, and antioxidants were increased due to simple hot soaking parboiling. PRACTICAL APPLICATIONS: The present study has the significance in assessing the variation among different pigmented rice varieties after parboiling by simple hot soaking with various soaking periods. The industrial advantage of this method is, there is no usage of boiler for cooking the paddy by steam, which was economically better. The information gained by this study might be beneficial for consumers and suppliers regarding the quality of the selected pigmented rice varieties with respect to nutrient composition, antioxidant activities, and bioaccessibility of minerals, starch, and antioxidants. Ultimately, the present study can lead to better appreciation of pigmented rice and assist food processors in selecting rice variety with unique characteristics for specialty food preparations.

Effect of blanching and drying temperatures on starch-related physicochemical properties, bioactive components and antioxidant activities of yam flours

The effects of blanching (in boiling water for 1min) and different hot air drying temperatures (40 °C, 60 °C and 80 °C) on the polyphenol oxidase (PPO), peroxidase (POD) and antioxidant activities, main bioactive components, as well as the starch-related physicochemical properties of yam flours were studied. The results of PPO and POD activities, and total flavone and total soluble polyphenol contents showed that blanching was effective to inhibiting enzymatic browning of yams, and the substrate of enzymatic browning reaction may be mainly flavonoid ingredients. The sample of H-40 had higher allantoin and total soluble polyphenol content, stronger DPPH scavenging activity and reducing power. From the results of scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR), the blanching yams was found contain partly gelatinized starch granules, and had lower crystallinity. The H-40 and H-80 samples had higher RS contents and lower GI values. Furthermore, the protein and soluble amylose contents, solubility and swelling power at 90 °C of the blanching yams were lower than those of the yams without blanching. We can effectively apply these flours in various products based on their characteristics.

Effect of grain moisture content during milling on pasting profile and functional properties of amaranth fractions.

Evaluation of functional properties of milled fractions of grain amaranth may be useful to decide the end uses of the grain. Hence, pasting profiles of amaranth fractions obtained by milling the grains at different moisture contents were studied in relation with their starch profile and also with their swelling power and solubility indices. It was observed that, for flour fraction, the viscosity parameters were lowest at 14-16% moisture content. Swelling power and solubility indices of the samples varied as a function of grain moisture content. The middling fraction also showed similar pasting pattern with the variation of grain moisture content. The seed coat fractions showed higher gelatinization temperature compared to that of fine flour and middling fractions. However, starch content of the fine seed coat fraction was comparable with that of the flour and middling fractions. The coarse seed coat fraction showed lower viscosity parameters than the other samples. Viscosity parameters correlated well among themselves while, they did not show significant correlation with the starch content. However, the viscosity parameters showed negative correlation with the soluble amylose content. The study revealed that, the fractions obtained by milling the grains at different moisture content show differential pasting profiles and functional properties.

Control of chapati staling upon treatment of dough with amylases and xylanase

Chapati doughs were treated with amylases and xylanase, and were evaluated for various quality parameters such as texture, microstructure, amylograph characteristics, sensory properties, soluble starch and soluble amylose contents. On storage for 96 h, decrease in moisture content, increase in shear force, decrease in paste viscosity, decrease in soluble starch and soluble amylose contents were observed in control chapatis. However, upon treatment with enzymes, there were marginal changes in the above parameters. Microstructure studies indicated uniformity in starch granules in enzyme treated chapatis, while absence of uniformity in starch granules was observed in control chapatis. Overall quality scores for chapatis prepared from enzyme treated dough did not change significantly on storage, unlike control chapatis. Among the treatments, bacterial α-amylase and its combination with xylanase performed well. Thus, studies indicated that incorporation of these enzymes in dough retard staling of chapatis by bringing about the changes in the starch and rheological properties of chapatis.

Effect of the Addition of Stearic Acid on Starch Properties

The effect of the addition of stearic acid on properties of wheat, mung bean and potato starches were studied. Soluble amylose content in three kinds of starches was significantly reduced. Both λmax values and the 630/520 nm ratio were decreased. Stearic acid added starches showed a significantly higher pasting temperature, breakdown and setback compared to the native starches as measured by RVA. Texture properties analysis showed that hardness of wheat and mung bean starches significantly decreased, while that of potato starch significantly increased after the addition of stearic acid. Diffraction peaks of wheat, mung bean and potato starches appeared at 22° which indicated that complex formation by X-ray diffraction

Effect of popping on sorghum starch digestibility and predicted glycemic index

Effect of popping on carbohydrate, protein, phytic acid and minerals of three varieties (pop sorghum, maldandi and red sorghum) of sorghum were studied. Significant changes (p ≤ 0.05) in the starch degradability including total and soluble amylose content, and resistant starch occurred due to popping; in-vitro protein digestibility along with the content of albumin proteins increased. Starch characteristics had substantial differences among these three varieties which are based on the nature of endosperm and amylose content. Phytic acid content had a reduction of 20%-25% after popping. Glycemic index (GI) determined from kinetic study of enzymatic hydrolysis of sorghum starch was between 85 and 92; the rate constant for hydrolysis for these three varieties were in the range of 0.025 and 0.029min(-1). Popping helped to control phytic acid content in sorghum and enhanced protein as well as starch digestibility.

Influence of amylases and xylanase on chemical, sensory, amylograph properties and microstructure of chapati

Effect of enzymes on the quality of chapati – the flat unleavened bread made from different wheat varieties was studied. Doughs treated with fungal α-amylase, bacterial α-amylase, xylanase and combination of bacterial α-amylase and xylanase were examined for chapati making quality. The shear force of chapatis treated with bacterial α-amylase, xylanase, fungal α-amylase and combination of bacterial α-amylase and xylanase were in the range of 2.5–2.8 N, 2.3–2.5 N, 3.5–3.7 N and 2.2–2.5 N, respectively, and they were found to be lower and significantly different than that of their corresponding controls (4.7–6.5 N). Soluble starch and soluble amylose content of the chapatis prepared from dough treated with amylases were significantly different than that of control. Chapatis prepared from dough treated with bacterial α-amylase had shown higher amount of soluble amylose (around 0.5 g/100 g) compared to other treatments (0.2–0.25 g/100 g). In chapatis prepared from dough treated with bacterial α-amylase, and combination of bacterial α-amylase and xylanase, the amylograph paste viscosities were 38–66 BU, and were very much lower and significantly different from that of control (232–390 BU) may be due to the residual enzyme activities. The microstructures of chapatis prepared from dough treated with enzymes were uniform with distorted starch granules surrounded with protein matrix, while in control, the starch granules were spherical with protein matrix overlapping on one another to form aggregation. Chapatis prepared from dough treated with enzymes had softer texture, better pliability and higher overall quality scores compared to control.

Effects of Heat Shock Treatment on Rice Quality during Storage (Part 1): — Changes in Starch Components and Fat Acidity —

Harvested rice (cv. Koshihikari) was microwave-radiated up to 60, 70 and 80°C and kept heat-treated for 0, 1 and 3 min, dried and then stored at 40°C for 6 months. A pronounced change in chemical properties of control rice during storage was observed such as increase in fat acidity, soluble sugars, total amylose and insoluble amylose content, while a decrease was founded in total starch content, and soluble amylose content. The above changes also occurred in heat shock treated rice, but with certain extent of delay. The heat shock treatment (HST) delayed the increasing rate of fat acidity. The HSTs at 60 and 70°C were effective in keeping the values of total amylose and insoluble amylose content low. The results showed that HST would benefit rice quality maintenance during storage.

Influence of Lipids Isolated from Soybean Seed on Different Properties of Cassava Starch

AbstractThe effect of lipids isolated from soybean seeds on the properties of cassava starch was investigated. Both polar and non‐polar lipid fractions were complexed with starch and the physicochemical and rheological properties were examined. The FTIR spectra of the complexed starches showed all the absorption bands characteristic of native starch with an extra minor peak at 2355 cm‐1.The complexes prepared using the polar lipid fraction in diethyl ether as solvent exhibited a swelling volume of 32.5 mL/g compared to 36.9 mL/g for petroleum ether as solvent. A similar effect was observed with the non‐polar fraction. The apparent amylose content of the complexes was found to be lowered as a result of complexation. Total and soluble amylose contents and water‐binding capacity of the complexes were higher while their enzyme digestibility was noticeably lowered. The peak viscosity of the complexes was suppressed as a result of complexation. The polar layer exhibited a greater influence on the viscometric properties of the complexes with a higher breakdown ratio and hence higher stability. When compared to native starch, the percentage light transmittance of the complexes was noticeably reduced. The results indicate a considerable influence of the isolated lipid fractions on starch properties which can be useful in food and industrial applications.

Effect of Sodium Dodecyl Sulphate on the Physicochemical, Thermal and Pasting Properties of Cassava Starch

AbstractThe effect of different concentrations of sodium dodecyl sulphate (SDS) on cassava starch properties after complexation and in situ addition were studied. The swelling volume of the starch‐SDS complexes increased to a maximum of 100 mL/g with increase in concentration of SDS (even at 0.004 mol SDS) with a corresponding decrease in solubility. During in situ addition also, a similar but gradual behaviour was observed for swelling volume and solubility. The apparent and total amylose contents showed an irregular trend. The soluble amylose content decreased with increase in concentration of SDS. In vitro enzyme digestibility of starch‐SDS complexes was significantly lowered compared to that of native starch. The water‐binding capacity showed an initial decrease followed by a significant increase at higher concentrations of SDS. DSC studies showed that in addition to the gelatinisation endotherm, a peak corresponding to the melting of the starch‐SDS complex was obtained in the case of in situ addition of the surfactant. The peak viscosity of starch during in situ addition of SDS exhibited a rapid increase except at the highest concentration. The peak viscosity of starch‐SDS complexes underwent an initial reduction followed by a gradual increase at higher concentrations. The breakdown, setback and pasting temperature were also affected.

Effect of amylose on starch pastes viscoelasticity and cooked grains stickiness in rice from seven argentine genotypes

Abstract The content of soluble amylose (SAM) in starches from seven novel argentine genotypes was measured. Viscolelastic properties ( G max ′ , G′, G′, tg θ y η∗) in systems with different starch concentrations (5%, 10%, 15% and 20% w/w) were evaluated by dynamic rheometry. Elasticity dependence upon concentration followed the power law and increased with amylose content. The SAM content explained the differences in elasticity between genotypes of similar total amylose (TAM) content. It was found that a minimum TAM and SAM should be required in order to reduce stickiness in cooked grains.

Determination of the amylose–amylopectin ratio of starches by iodine-affinity capillary electrophoresis

This paper describes the application of capillary electrophoresis to separate and quantify the main polysaccharide components, amylose and amylopectin, present in starch samples. The separation is based on the well-known affinity of these compounds to iodine. The starch components could be effectively separated in less than 7 min using an uncoated fused-silica ‘bubble cell’ capillary. The proposed method has been applied for the quantitative determination of the soluble amylose content and the ratio amylose–amylopectin in commercial starches. It is shown that the present method is reliable, gives detection limits in the order of 0.1 mg mL−1, is faster than other methodologies reported in the literature, and can be easily applied to the analysis of different starches. In spite of differences in solubility of amylopectin from different sources, a reasonable estimate of the amylose–amylopectin ratio could be made. Additionally, it was shown that the resulting profiles obtained after hydrolysis with isoamylase and α-amylase can provide information on the structure of the starches studied.

Determination of the amylose–amylopectin ratio of starches by iodine-affinity capillary electrophoresis

This paper describes the application of capillary electrophoresis to separate and quantify the main polysaccharide components, amylose and amylopectin, present in starch samples. The separation is based on the well-known affinity of these compounds to iodine. The starch components could be effectively separated in less than 7 min using an uncoated fused-silica ‘bubble cell’ capillary. The proposed method has been applied for the quantitative determination of the soluble amylose content and the ratio amylose–amylopectin in commercial starches. It is shown that the present method is reliable, gives detection limits in the order of 0.1 mg mL −1, is faster than other methodologies reported in the literature, and can be easily applied to the analysis of different starches. In spite of differences in solubility of amylopectin from different sources, a reasonable estimate of the amylose–amylopectin ratio could be made. Additionally, it was shown that the resulting profiles obtained after hydrolysis with isoamylase and α-amylase can provide information on the structure of the starches studied.

Effect of steam pressure treatment on the physicochemical properties of Dioscorea starches.

Dioscorea alata and Dioscorea rotundata starches were subjected to steam pressure treatments (0.35, 0.7, and 1.05 kg cm(-)(2)) for different periods. The total amylose content in the treated starches was not significantly affected, but the soluble amylose content decreased 3-5-fold. Reducing values and lambda(max) of the iodine complexes were unaffected. Viscosity of the starch paste was reduced by the treatments, and at higher pressures and longer time of treatments, the peak viscosity values were reduced to very low values. Pasting temperatures were enhanced considerably. Swelling volumes underwent reduction, but no change in solubility occurred. Clarity and paste stability were markedly lowered. The results suggest that starch granules are compressed by the steam pressure treatment, leading to vast changes in physicochemical properties.

Effect of Pretreatment of Fresh Amorphophallus paeoniifolius on Physicochemical Properties of Starch

Fresh roots of Amorphophallus paeoniifolius were separately pretreated with sodium hexametaphosphate (SHMP), potassium metabisulphite (KMS), sodium chloride (NaCl), and ammonium hydroxide (NH4OH) within a range of 1–5% (w/v) concentration and glyceryl monostearate (GMS) at 0.025–0.125% concentration. The quality of starch extracted from pretreated roots was compared with that obtained from fresh roots by direct aqueous extraction. The starch samples prepared from chemically pretreated roots showed characteristic changes in properties of water soluble amylose content, swelling and solubility and α-amylase susceptibility. X-ray diffraction of starch samples from chemically pretreated roots although resembled that of control, there was noticeable shift with respect to their ‘d’ spacing and Io/Imax values.

Quality changes in market cassava chips infested by insects

The biochemical changes occurring in dried cassava chips collected from various marketing centres in Kerala (India) due to insect infestation were studied. Araecerus fasciculatus (Degeer) was the most important pest of plain sun-dried cassava chips and Sitophilus oryzae (L.) and Rhyzopertha dominica (F.) were the important pests of parboiled chips. There was substantial reduction in starch and sugar content in fully infested plain dried chips as compared to the uninfested chips (83.5-77.9% for starch and 6.95-1.53% for sugar). Reduction in starch was more pronounced in fully infested parboiled chips (78-57%) while sugar increased nearly three fold (6.0–15.7%). Total and soluble amylose contents and reducing values were not significantly affected in plain dried chips due to infestation. Viscosity underwent only slight reduction in plain dried chips while in parboiled chips, the reduction was noticeable even at a partially infested stage. Although there was reduction in starch content due to insect infestation, starch quality did not change much in plain dried chips, indicating the possibility of using such infested chips in animal feed formulations and in the manufacture of commodity chemicals.

Content of starch and sugars and in vitro digestion of starch by alpha-amylase in five minor millets.

Five varieties of minor millets were studied for their amylose, soluble amylose, amylopectin, soluble amylopectin, reducing sugar, total sugar and starch contents. Pure starch was isolated from each variety and the enzymic degradation of starch by porcine pancreatic alpha-amylase were examined with and without gelatinisation. Gelatinised sample of Echinochloa frumentacea (var. K2) showed minimal hydrolysis and gelatinised sample of Panicum miliaceum (var. CO3) showed maximum hydrolysis of starch by porcine pancreatic alpha-amylase. Gelatinised starch was highly susceptible to enzymic digestion when compared to ungelatinised starch. The extent of starch degradation varied from 71 to 85 percent in gelatinised samples and starch degradation in ungelatinised sample varied from 10 to 18 percent.

Functional properties of the starchy flour extracted from cassava on fermentation with a mixed culture inoculum

AbstractThe functional properties of the starchy flour extracted from six varieties of cassava subjected to fermentation by a mixed culture inoculum comprised of lactobacilli, streptococci, corynebacteria and yeast cells are examined. Apparent reduction in total and soluble amylose contents is observed. Differential scanning calorimetry of the samples indicated that the enthalpy of gelatinisation was reduced, while the gelatinisation temperature was enhanced. A marked reduction in Brabender viscosity values of starch from fermented tuber was observed, but the X‐ray diffraction pattern was unaffected. All these changes were attributed to the presence of fibrous material and consequent reduction of starch in unit volume rather than any change in the starch granule structure.