Rapid Visco Units Research Articles

Physicochemical, Nutritional, and Antioxidant Properties in Seven Sweet Potato Flours.

Sweet potato flour is a key ingredient for the production of new food products worldwide, which imparts desired properties, nutritional value, antioxidants, and natural color to processed foods. However, little information regarding the functional properties of the sweet potato flour is available. In this study, the genetic diversity in the physiochemical, nutritional, and antioxidant properties of wholemeal flour from seven sweet potato varieties was investigated. The total phenolic content (TPC) of the free and bound fractions ranged from 13.85 to 90.74 mg gallic acid equivalent (GAE)/100 g and from 5.07 to 24.29 mg GAE/100 g, respectively. The average protein content of sweet potato was 5.41 g/100 g ranging from 3.40 to 8.60 g/100 g DW. The total amino acid content averaged 45.13 mg/g DW. The average contents of 12 mineral elements were in the order of K > P > Ca > Mg > Mn > Fe > Zn > Cu > Ni > Se > Cr > Cd. K and P contents were the highest among all accessions, which were positively correlated with most of the other minerals. The average starch content of sweet potato was 53.90 g/100 g DW, ranging from 31.68 to 64.90%. The peak viscosity (PV), hot paste viscosity (HPV), and cold paste viscosity (CPV) were in the range of 90.7–318.8 Rapid Visco Unit (RVU), 77.3–208.3 RVU, and 102.6–272.7 RVU, respectively. The hardness values and cohesiveness (Coh) varied among different sweet potatoes, with a range of 8.20–18.48 g and 0.22–0.68, respectively. The gelatinization onset, peak, conclusion temperatures, and enthalpy were in the ranges of 59.39–71.91°C, 70.19–88.40°C, 78.98–95.79°C, 1.85–5.65 J/g, respectively.

Characterization of Striga-Resistant Yellow-Orange Maize Hybrids for Bioactive, Carbohydrate, and Pasting Properties

Understanding the bioactive constituents and physicochemical components in cereals can provide insights into their potential health benefits and food applications. This study evaluated some bioactive constituents, carbohydrate profiles and pasting properties of 16 Striga-resistant hybrids, with yellow-orange kernel color and semi-flint to flint kernel texture, grown in two replications at two field locations in Nigeria. Carotenoids were quantified using HPLC, while other analyses were carried out using standard laboratory methods. The ranges of major carotenoids (μg/g) across the two locations varied from 2.6 to 9.6 for lutein, from 2.1 to 9.7 for zeaxanthin, from 0.8 to 2.9 for β-cryptoxanthin, from 1.4 to 4.1 for β-carotene; with total xanthophylls and provitamin A carotenoids (pVAC) ranging from 5.4 to 17.1 and 1.4 to 4.1 μg/g, respectively. Tannins content ranged from 2.1 to 7.3 mg/g, while phytate ranged from 0.4 to 7.1%. Starch, free sugar, amylose and amylopectin ranged from 40.1 to 88.9%, 1.09 to 6.5%, 15.0 to 34.1%, and 65.9 to 85.0%, respectively. Peak and final viscosities ranged from 57.8 to 114.9 and 120.3 to 261.6 Rapid Visco Units (RVU), respectively. Total xanthophylls, β-carotene, tannins, phytate, sugar, amylose and amylopectin levels, as well as peak and final viscosities, varied significantly (p < 0.05) across the hybrids. Amylose was significantly correlated (p < 0.05) with total xanthophylls, β-carotene, pVAC, phytate and pasting temperature (r = 0.3, 0.3, 0.4, 0.3, 0.3, respectively), but starch significantly correlated with tannins (r = 0.3). Hence, the Striga-resistant yellow-orange maize hybrids have a good combination of bioactive constituents, carbohydrate profile and pasting properties, which are partly influenced by hybrid.

Chemical, Pasting and Sensory Characteristics of Ukpo oka - A Steamed Maize Pudding Formulated From Maize and African Yam Bean Flour

Studies were conducted on the chemical, functional, pasting properties of the flour blends and sensory properties of ukpo oka formulated from of maize- African yam bean flour (AYBF) in order to improve the nutritional content of maize and encourage a wider utilization of the legume AYB. Supplementation of maize and African yam flour was done at 100:0, 50:50, 80:20, 60:40 and 20:80 maize: African yam bean flour, respectively. Proximate composition, functional properties, pasting properties of the flour blends was determined and sensory attributes of the products were also evaluated. The result showed that supplementation of maize with African yam bean flour significantly increased the protein, ash and fiber content of the flour blends with values ranging from 3.91 - 11.08%, 2.90 - 6.60%, 0.67 - 1.82% for protein, ash and fiber contents respectively. The protein, ash and fiber contents increased with addition of African yam bean flour while carbohydrate content of maize- African yam bean blends decreased with increase in the level of African yam bean. The values for functional properties ranged from 0.72 – 0.82g/ml, 99.33 – 323.33%, 9.01 – 19.65%, 690.00 - 978.33%, 0.67 – 1.13%, 0.484 – 1.038% for bulk density, foaming capacity, emulsion capacity, swelling capacity, water absorption capacity and oil absorption capacity respectively. Values for pasting properties of the flour blends expressed in rapid visco unit (RVU) ranges from 129.25 – 209.40, 22.55 – 67.93, 60.21 – 124.62 , 145.25 – 247.67 , 83.37 – 84.56 , 5.47 – 5.97 and 87.19 – 141.35 for peak viscosity, break down viscosity, set back viscosity, final viscosity, pasting temperature, peak time and trough respectively. Set back viscosity and final viscosity increased with increase in the levels of African yam bean while break down viscosity decrease with the increase in the levels of African yam bean. The products were highly rated in all sensory attributes evaluated however aroma decreases with increase in the levels of AYBF. Product made from flour blend 50:50 was the most preferred in terms of general acceptability.

Influence of Acidity in Paste Properties of Modified Corn Starch Through Natural Fermentation

The objective of this research was to carry out the fermentation of corn starch in the same manner as cassava starch fermentation and to study its behavior during the fermentation process, analysing acidity and paste properties. CoS (corn starch) and CaS (cassava starch) were used. The sample was analysed by paste properties and acidity, at time 0, at every 7 days until the end of fermentation and after sun-drying. Regarding viscosity peak, CaS samples showed higher values, in the resistance attribute when comparing CoS and CaS samples those that had the same fermentation time did not present significant difference between them. CoS samples showed no significant difference between break results, but they did differ when compared to CaS samples. Only NCaS (native cassava starch) had greater retrogradation compared to CoS samples. However, the initial samples NCoS (native corn starch) and NCaS did not present differences in final viscosity results. However, they presented the highest values for this parameter with results of 171.50 and 180.50 RVU (Rapid Visco Units), respectively. Correlating results of acidity with paste properties it was observed that with fermentation time and consequent acidity increase, paste properties had important changes, decreasing the values of the measured parameters, only the paste temperature remained constant. It is concluded that the natural fermentation modification of corn starch compared with cassava starch had similarities about acidity. However, for pasting properties were no significant differences and should be better clarified through functional analysis and application product.Keywords: Modified Starch; production; structure; paste properties.

Cooking Characteristics and Antioxidant Activity of Rice-Barley Mix at Different Cooking Method and Mixing Ratio.

This study aimed to compare the phenolic compounds and antioxidant activity of barley at different proportion (0, 5, 10, 15, and 20%), and using different cooking methods. The grains used in this experiment are barley (Hordeum vulgare L. cv. Huinchalssal) and Samkwang rice. The rice-barley mixture was cooked using general and high pressure cooking methods with and without fermented alcohol. The quality characteristics such as water binding capacity, pasting characteristic, water solubility, and swelling power of different proportions of barley were evaluated. The antioxidant characteristics evaluated are total polyphenol, flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azinobis(3-ethylbenothiazoline-6-sulphonic acid) (ABTS) diammonium salt radical scavenging activities. Results showed that peak [195.0~184.0 rapid visco units (RVU)], trough (130.0~116.2 RVU), final (252.0~221.8 RVU), and setback viscosity (57.0~37.5 RVU) decreased correspondingly with the increase in the amount of barley. Water binding capacity (187.31~136.01%) and swelling power (162.37~127.58%) decreased as amounts of barley increases, however the water solubility (5.35~6.89%) increased. Moreover, the total polyphenol and flavonoid, and the DPPH and ABTS radical scavenging activities contents increased as the amounts of barley in the mixture increases. This study generally aims to provide useful information for the manufacturing of processed products.

Flour, dough and bread properties of wheat flour substituted with orange-fleshed sweetpotato flour

ABSTRACTThis study investigated some quality attributes of composite flours, dough and bread from wheat flour substituted with orange-fleshed sweetpotato (OFSP) flour at 0–30% levels. Chemical, functional and pasting properties of flours, rheological properties of dough, as well as chemical composition and physical properties of bread were determined. Protein content of composite flours decreased by 25.51–37.37% at 10–30% OFSP flour substitution. Flour composites were higher in ash (2.12–2.33%), crude fibre (3.28–4.34%), water (1.45–2.08 ml/g) and oil (1.45–1.67 ml/g) absorption capacities. Wheat flour (100%) had maximum peak viscosity of 117.71 Rapid Visco Units (RVU) which decreased by 0.71–30.80% with OFSP flour substitution. Dough from composites had higher hydration (82.15–112.10%) and breakdown torque (0.38–0.42 Nm) but lower stability (1.16–2.38 min), protein weakening (0.06–0.37 Nm), starch gelatinization (0.46–0.81 Nm), stability of hot gel (0.04–0.43 Nm) and starch retrogradation (0.46–0.81 Nm). Bread substituted with OFSP flour had higher total carotenoids (1565.50–5179.27 µg/100 g), weight (193.74–198.50 g) and crumb moisture (27.81–27.91%).

Evaluation of proximate composition and pasting properties of high quality cassava flour (HQCF) from cassava genotypes (Manihot esculenta Crantz) of β-carotene-enriched roots

Cassava farmers are yet to fully exploit its full potential in terms of improvement of livelihood. Forty-five genotypes of cassava genotypes were processed into High Quality Cassava Flour (HQCF). These genotypes were planted in two sets, set 1 comprised 22 clones of β-carotene enriched roots and 3 check clones of white roots and set 2 comprised 18 clones and 2 check clones. The effects of variety on the proximate composition and pasting profile of the flour were investigated. The starch content ranged between 67.1 g/100 g (for 01/1663) and 82.4 g/100 g (for 30572) in set 1 and between 69.6 (01/1560) to 77.8 g/100 g (for Z97/0474) in set 2. Peak viscosity values ranged between 295.6 RVU (rapid visco unit) (30572) and 467.0 RVU (01/1115) across clones in set 1 while for set 2, it ranged from 271.9 RVU (for 01/1404) to 471.3 RVU (for 01/1417). Significant differences (P < 0.05) existed in the proximate composition and pasting properties of the flour from different cassava genotypes investigated. The high peak viscosity exhibited by most genotypes is indicative that the flour may be suitable for products requiring high gel strength and elasticity. The proximate composition compares competitively with values obtainable from conventional clones.

Optimization of the functional characteristics, pasting and rheological properties of pearl millet-based composite flour.

Optimisation of composite flour comprising pearl millet, kidney beans and tigernut with xanthan gum was evaluated for rheological evaluations. The functional properties of the composite flour were optimized using optimal design of response surface methodology. The optimum blends, defined as blends with overall best functional characteristics were run 3 (75.956% pearl millet, 17.692% kidney beans, 6.352% tigernut flours), run 7 (85.000% pearl millet, 10.000% kidney beans, 5.000% tigernut flours) and run 13 (75.000% pearl millet, 20.000% kidney beans, 5.000% tigernut flours). The pasting characteristics and rheological evaluation of the optimized blends were further evaluated in rapid visco units (RVU). Run 7 had the overall best pasting characteristics; peak viscosity (462 RVU), trough (442 RVU), breakdown viscosity (20 RVU), final viscosity (975 RVU), setback (533 RVU), peak time (5.47 min) and pasting temperature (89.60 °C). These values were found to be better than several composite flours consisting mixture of wheat and non-wheat crops. In addition, the rheological characteristics (measured by Mixolab) showed that run 7 is the best in terms of dough stability, swelling, water absorption and shelf stability. Composite flour with 85% pearl millet flour in addition to kidney beans and tigernut flours could therefore serve as a viable alternative to 100% wheat flour in bread production.

Germination of sorghum grain results in significant changes in paste and texture properties.

Germination triggers the protease system of sprouting seeds, leading to the breakdown of proteins into simpler forms that decrease the viscosity of sorghum paste and improve the strength of sorghum gel, allowing the use of germinated sorghum to design new foods that require thickening and gelling.

Argon Plasma Treatment of Tapioca Starch Using a Semi-continuous Downer Reactor

To develop a novel modification process of tapioca starch using low-pressure argon plasma treatment in a large-scale production, a semi-continuous downer reactor was designed to provide a production rate of 0.1–0.5 kg per cycle. Physicochemical and rheological properties of plasma-treated starch were investigated in order to predict the phenomena occurred during the plasma treatment. Native tapioca starch (NTS) was plasma-treated for 1, 3, or 6 cycles, which were referred to as PTS-1, PTS-3, or PTS-6 samples, respectively. Plasma treatment of the NTS resulted in a significant decrease (P < 0.05) in paste clarity and Rapid Visco Analyzer (RVA) breakdown viscosity, and an increase in gel strength of starch. The PTS-1 had the lowest paste clarity of 39.85 %T at 650 nm and breakdown viscosity of 29.71 Rapid Visco Unit (RVU), and the highest gel strength, e.g., G′ = 5.47ω 0.32. With increasing the number of treatment cycles, i.e., the PTS-3 and PTS-6, the paste clarity and breakdown viscosity significantly increased (P < 0.05), while the gel strength decreased. The Fourier transform infrared (FTIR) spectroscopy via relative areas of C–O–C peaks indicated that the PTS-1 had a significant increase (P < 0.05) in the C–O–C cross-linked bonds compared to the NTS, but the effect of depolymerization could further suppress the cross-linking reaction when the number of treatment cycle was increased. Taking an advantage of a very short residence time (less than 0.3 s) in the plasma downer reactor, the semi-continuous process of starch modification could be developed for a commercial production of non-chemically modified starch with a relatively low degree of cross-linking.

Physicochemical and structural characteristics of starches from Chinese hull‐less barley cultivars

SummaryFourteen hull‐less barley cultivars, collected from four major cultivated areas in China, were employed to investigate the structural and physicochemical properties of their starches in this study. Relatively wide variations in physicochemical properties of the starches were observed. Amylose content ranged from 23.1% to 30.0%, swelling power and water solubility index ranged from 12.8 to 19.9 g g−1 and 12.7% to 23.7% respectively. Peak viscosity was from 170 to 346 Rapid Visco Unit (RVU), peak temperature (Tp) of starch gelatinisation was from 55.6 to 61.8 °C and enthalpy of starch retrogradation ranged from 0.3 to 3.1 J g−1. Weight‐based chain‐length proportions of fa, fb1, fb2 and fb3 in amylopectins ranged from 21.65% to 24.95%, 44.48% to 49.44%, 15.56% to 17.19% and 9.83% to 16.66% respectively. Correlation analyses showed that amylose content was inversely related to pasting parameters and enthalpy of gelatinisation. Pasting properties and amylopectin structures were the most important parameters to differentiate starch properties among different hull‐less barley cultivars in this study. This work will be useful for exploring applications of Chinese hull‐less barley starches in food and non‐food industries.

Pasting properties of colored rice starch by ball-mill treatment

Physically modified rice starch by ball-mill is important for making good quality bread, noodles, and several processed foods. The production of rice flour was done by ball-mill in an industrial scale. The effects of ball-mill treatment on the physicochemical properties of rice starch were investigated. The gel pasting properties of Joseongheugchal employed to ball-mill treatment showed that pasting time was 0.44 min shorter than that of the control and it also decreased peak viscosity (PKV), hot peak viscosity (HPV), and cold paste viscosity (CPV). In Hongjinju rice, RVA (rapid visco analyzer) pasting trace was characterized with high peak viscosity (3,448 RVU: rapid visco unit), and cold paste viscosity (2,975 RVU), also with high breakdown viscosity (1,597 RVU). The onset, peak, and conclusion gelatinization temperatures of ball-milled Josengheugchal rice starch were 57.4, 64.2, and 76.5°C, respectively, which were significantly higher than those of the control. The parameters of DSC (Differential scanning calorimetry) of ball-milled Hongjinju rice were 57.9, 65.1, and 77.3°C, respectively. The mean particle size of starch in both Josengheugchal and Hongjinju by ball-milling was decreased. The distribution of mean particle size in ball-milled rice starch was smaller in Josengheugchal than in Hongjinju compared to the native starch. As rice grains were ball-milled, the regions of amorphism were becoming larger and larger at the expense of crystalline regions, and diffraction peak patterns were decreased commonly in two colored rice cultivars. The 13C FT-solid state NMR patterns of starches showed dramatic chemical shifts of the 13C resonances by ball-milled treatment.

Pasting Characteristics, Baking and Sensory Qualities of Cakes from Blends of Cassava and Wheat Flours

Wheat flour was replaced with cassava flour (30 to 100%) to produce cake. Composition and pasting properties of the flours and their composite flour blends were determined. Baking and sensory qualities of the resulting cake samples were evaluated. Protein starch and fiber contents of the cassava and wheat flours were 1.5; 71.50; 1.94% and 10.9; 69.89; 2.81% respectively, which significantly influenced their pasting and baking characteristics and also reflected in their composite blends. Peak, holding, breakdown and final viscosities of the blends ranges from 90.1 to 121.1; 51.6 to 82.7; 38.21 to 42.62; and 93.4 to 125.8 Rapid Visco Unit (RVU) respectively. Specific volume decreased from 1.49 to 1.18 ml/g. Cake of comparable qualities with that obtained from wheat were obtained within 40% substitution level.

Effect of fructooligosaccharides on the physicochemical properties of sour cassava starch and baking quality of gluten-free cheese bread

The present research was undertaken to explore the influence of fructooligosaccharides (FOS) on the functional and thermal properties of sour cassava starch and the quality characteristics of gluten-free (GF) cheese bread. Fructooligosaccharides were used to replace sour cassava starch at substitution level of 9% (SF1), 17% (SF2), and 29% (SF3). The functional and thermal properties of the starch–FOS mixtures were determined by the water absorption index (WAI), water solubility index (WSI), pasting profile analysis, thermal transition temperatures and enthalpy of gelatinization. Moreover, the GF cheese breads with starch–FOS mixtures were analyzed for height, diameter, weight, specific volume and dough moisture content. The sample with the highest FOS content (SF3) presented the lowest WAI (1.44), peak (62.4 rapid visco units (RVU), breakdown (53.4 RVU), final (13.8 RVU), and setback (4.9 RVU) viscosities, dough moisture content (31.7%), and enthalpy of gelatinization (9.5 J/g) and the highest WSI (29.4%) and pasting temperature (69.1°C). The height, diameter and specific volume of GF cheese bread samples made from sour cassava starch were 3.14 cm, 6.35 cm, and 1.49 cm3/g, respectively. The SF1 mixture samples resulted in a 3.01 cm height, 6.34 cm diameter, and 1.55 cm3/g specific volume. According to Brazilian food labeling regulations, the latter product cannot be categorized as “a good source” of fiber because the minimum level of fiber per portion was not reached.eywords: Baking; Fructooligosaccharides; Gluten-free cheese bread; Physicochemical properties; Sour cassava starch

Batter Rheology, Baking, and Sensory Qualities of Cake from Blends of Breadfruit and Wheat Flours

Wheat flour was replaced with breadfruit flour (30 to 100%) to produce cake. The composition and pasting properties of the flours and their composite flour blends were determined. Baking and sensory qualities of the resulting cake samples were evaluated. Protein starch and fiber contents of the breadfruit and wheat flours were 2.6, 61.30, and 7.79% and 10.9, 69.89, and 2.81%, respectively, which significantly influenced their pasting and baking characteristics and also reflected on their composite blends. Peak, holding, breakdown, and final viscosities of the blends ranged from 122.3 to 147, 85.4 to 98.6, 28.74 to 49.18, and 128.6 to 147.4 rapid visco unit, respectively. Specific volume decreased from 1.40 to 1.06 mL/g. Cake with qualities comparable to those produced by conventional methods was obtained within a 30% substitution level.

Exploring the Use of Near Infrared (NIR) Reflectance Spectroscopy to Predict Starch Pasting Properties in Whole Grain Barley

This study aimed to evaluate the ability of using near infrared reflectance (NIR) spectroscopy to predict parameters generated by the rapid visco analyser (RVA) in whole grain barley samples to further study starch pasting characteristics in a breeding program. A total of 130 whole grain barley samples from the University of Adelaide germplasm collection, harvested over three seasons (2009, 2010 and 2011) were analysed using both NIR and RVA instruments and calibrations developed using partial least squares (PLS) regression. The coefficient of determination in cross validation (R2) and the standard error in cross validation (SECV) were 0.88 [SECV = 477.5 (RVU = rapid visco units)] for peak viscosity (PV), 0.82 (SECV = 635.5 RVU) for trough (THR), 0.92 (SECV = 190.4 RVU) for breakdown (BKD), 0.61 (SECV = 151.1 RVU) for setback (SET), 0.84 (SECV = 698.0 RVU) for final viscosity (FV), 0.70 (SECV = 0.54 s) for time to peak (TTP) and 0.36 (SECV = 2.2 min) for pasting temperature (PT). We have demonstrated that NIR spectroscopy shows promise as a rapid, non-destructive method to measure PV in whole grain barley. In this context, NIR spectroscopy has the potential to significantly reduce analytical time and cost for screening novel lines for starch properties for pasting properties.

Physicochemical properties of new starches isolated from Dioscorea opposita Thunb. bulbils

AbstractMorphological, crystal, and physicochemical properties, such as AM content, swelling power, solubility, and pasting properties of starches isolated from three different Shanyaodou (the bulbils of Dioscorea opposita Thunb., named Huaishanyao, Xichangmaoshanyao, and Maoshanyao, respectively) were investigated. The yield of starches was in the range 12.5–20.8% (dry starch/fresh whole bulbils). The AM content of Shanyaodou starches ranged from 33.3 to 36.7%. The shape of the three bulbils starch granules varied from round to oval or elliptic. The mean particle diameter of starch granules varied from 20.17 to 26.34 µm. Shanyaodou starches exhibited a C‐type XRD pattern and the degree of crystallinity was in the range 31.0–34.9%. The pasting peak viscosity, trough viscosity, and final viscosity of Shanyaodou starches ranged from 291.1 to 414.7, 210.8 to 227.0, and 350.0 to 359.2 rapid visco units (RVU), respectively, and the pasting temperature was in the range 83.6–87.3°C. The results showed that some of the Shanyaodou starches could be used in foods production as a thickening agent. The simple method of extraction and the high yield of starch from Shanyaodou might be attractive for production of Shanyaodou starch.

English

The effects of length of fermentation (5, 10, 15, 20 and 25 days) on pasting properties of sour starches produced from six cassava varieties were investigated. There were significant differences (p < 0.05) in pasting properties except pasting temperature and breakdown viscosity, irrespective of the length of fermentation. Peak viscosity ranged from 308.50 to 466.63 rapid visco unit (RVU), trough ranged from 67.25 to 198.75 RVU, break down ranged from 147.71 to 320.25 RVU, final viscosity ranged from 100.29 to 233.00 RVU, set back ranged from 31.59 to 54.58 RVU, peak time ranged from 3.60 to 4.06 min and pasting temperature ranged from 62.85 to 65.45°C. Sour starches made from TMS 30572, TMS 4(2) 1425 and 96/0603 cassava varieties recorded the highest values. Key words: Cassava, fermentation, pasting, starch, varieties.

Physicochemical Properties of Caribbean Sweet Potato (Ipomoea batatas (L) Lam) Starches

The proximate compositions and physicochemical properties of 21 Caribbean sweet potato (Ipomoea batatas (L) Lam) starches were investigated. Proximate composition, amylose, reducing and non-reducing sugars were determined using standard methods. Swelling power and solubility were evaluated and pasting properties of the starches were determined using Rapid Visco Analyzer. Moisture (8.0–12.4%), protein (0.0–0.2%), ash (0.1–0.5%), and reducing (0.3–2.3%) and non-reducing sugar (0.1–0.2%) contents of starches were significantly different (P < 0.05) among the cultivars. Amylose content varied significantly between 12.8–21.3%. Swelling power and solubility ranged between 7.8–31.1% and 1.5–9.6%, respectively. Pasting properties such as peak viscosity measured in Rapid Visco Units (143.2–288.8 RVU), breakdown viscosity (29.4–162.6 RVU), and setback viscosity (15.0–78.8 RVU), pasting temperature (73.5–87.7 °C) and time to pasting temperature (3.6–4.5 min) varied significantly among the cultivars. Breakdown viscosity was poorly correlated with final viscosity attained (r = − 0.0507, P < 0.05); however, pasting temperature was correlated (r = 0.479, P < 0.05) with setback viscosity. The variability observed in the physicochemical properties of the starches was related to specific requirements for use in the production of noodles, pasta, and inclusion in bread and weaning food formulations.

Chemical Structure and Physical Properties of Mung Bean Starches Isolated from 5 Domestic Cultivars

Chemical structure and physical properties of starches isolated from 5 domestic mung bean cultivars (Gyungsun, Geumsung, Sunhwa, Eohul, and Jangan) were examined. The granules were jelly bean like in shape and smooth on surface, and the size was within 10 to 30 microm. Mung bean starches displayed a C(A)-type crystalline structure when judged by the X-ray diffraction patterns. Branch chain-length distribution patterns of amylopectin (AP) revealed that peak chain length of APs was at either DP (degree of polymerization) 12 or DP13. Apparent amylose contents of 5 cultivars by iodine affinity test were 31.7% to 33.8%. Mung bean APs showed a unique molecular size distribution that has not been observed from other plant-derived starches. Two distinct peaks of AP fraction were identified on the size-exclusion chromatogram, and the ratios of these 2 peaks were different depending on the mung bean cultivars. Weight-average chain length (CL(avg)) of APs was in the range of 16.9 (Eohul) and 17.5 (Geumsung). The onset temperature (T(o)) and enthalpy change (DeltaH(gel)) of starch gelatinization were 54.6 to 60.2 degrees C and 11.6 to 13.2 J/g. The DeltaH of the retrograded mung bean starches was 5.5 to 6.6 J/g, which indicated 44.5% to 52.7% of recrystallization. The pasting temperature, peak viscosity, and setback were 66.1 to 69.2 degrees C, 510 to 579 Rapid Visco Unit (RVU), and 66 to 90 RVU, respectively.