scholarly journals The Effect of Germinated Sorghum Extract on the Pasting Properties and Swelling Power of Different Annealed Starches

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1602
Author(s):  
Hesham Alqah ◽  
M. S. Alamri ◽  
A. A. Mohamed ◽  
S. Hussain ◽  
A. A. Qasem ◽  
...  

Starches were extracted from chickpea (C.P.), corn (C.S.), Turkish bean (T.B.), sweet potato (S.P.S.), and wheat starches (W.S.). These starches exhibited different amylose contents. The extracted starches were annealed in excess water and in germinated sorghum extract (GSE) (1.0 g starch/9 mL water). The α-amylase concentration in the GSE was 5.0 mg/10 mL. Annealing was done at 40, 50, and 60 °C for 30 or 60 min. The pasting properties of annealed starches were studied using Rapid Visco-Analyzer (RVA), in addition to the swelling power. These starches exhibited diverse pasting properties as evidenced by increased peak viscosity with annealing, where native starches exhibited peak viscosity as: 2828, 2438, 1943, 2250, and 4601 cP for the C.P., C.S., T.B., W.S., and S.P.S., respectively, which increased to 3580, 2482, 2504, 2514, and 4787 cP, respectively. High amylose content did not play a major role on the pasting properties of the tested starches because sweet potato starch (S.P.S.) (22.4% amylose) exhibited the highest viscosity, whereas wheat starch (W.S.) (25% amylose) had the least. Therefore, the dual effects of granule structure and packing density, especially in the amorphous region, are determinant factors of the enzymatic digestion rate and product. Swelling power was found to be a valuable predictive tool of amylose content and pasting characteristics of the tested starches. The studied starches varied in their digestibility and displayed structural differences in the course of α-amylase digestion. Based on these findings, W.S. was designated the most susceptible among the starches and S.P.S. was the least. The most starch gel setback was observed for the legume starches, chickpeas, and Turkish beans (C.P. 2553 cP and T.B. 1172 cP). These results were discussed with regard to the underlying principles of swelling tests and pasting behavior of the tested starches. Therefore, GSE is an effortless economic technique that can be used for starch digestion (modification) at industrial scale.

2017 ◽  
Author(s):  
◽  
Bruce Mawoyo

Amadumbe commonly, known as taro is a traditionally underutilised tuber crop in Southern Africa. Nutritionally, amadumbe corms contain appreciable levels of carbohydrate mainly in the form of starch which is resistant to digestion. It also contains mucilage, a soluble fibre, which is good for the human digestive health. Thus, amadumbe starch and mucilage can be used as functional ingredients in food formulations. The aim of this research was to investigate the effects of genotypes and growth location on the physicochemical properties of amadumbe flour and starch. Eighteen (18) amadumbe genotypes grown in Roodeplaat, Gauteng and Umbumbulu, Kwazulu-Natal, South Africa, were studied. Roodeplaat received a lower annual average rainfall (514 mm) and high environmental temperature (24oC) compared to Umbumbulu (828 mm, 19oC) during the cropping season. Specifically, the influence of growth location and genotypes on the chemical composition (proximate composition and mineral contents) as well as the functional properties of amadumbe flours were investigated. Furthermore, starch was extracted and its physicochemical and functional properties were also studied. The carbohydrate contents (73-81%) of amadumbe flours were substantially high and varied with growth location. Mucilage contents (6-9%) were very low across genotypes in both locations. Water absorption and oil absorption capacities positively correlated to carbohydrates and mucilage in the flour irrespective of growth locations. Swelling power and solubility index was influenced by the amylose content of the flour. Genotype and growth location significantly affected the pasting properties of amadumbe flour. The pasting temperature was very high (approx. 90oC) across genotypes in both locations, while peak viscosity differed significantly (54-242 RVU) for genotypes grown in different environments. The amylose contents (0-14.4%) of amadumbe starches were low and varied significantly with growth location and among genotypes. Three genotypes, G2, G20, and G21 grown in Roodeplaat lacked amylose. Amadumbe starches showed reflective peaks at 2θ=15o and doublet at 17o, 18o and 24o typical of A-type starches. Amadumbe genotypes had small sized (1-5 µm) and polygonal starch granules. Functional properties including water absorption, swelling power, gelatinisation temperature and peak viscosity significantly positively correlated with amylose content. These findings further suggest that water availability could have a major effect on starch synthesis as the two locations received a different amount of rainfall during the growing season. Findings from this study are important for future improvement programmes and selection of appropriate genotypes for industrial production or food application of amadumbe flour and starch.


2021 ◽  
Author(s):  
Ishita Chakraborty ◽  
Indira Govindaraju ◽  
Sintu Rongpipi ◽  
Krishna Kishore Mahato ◽  
Nirmal Mazumder

AbstractStarchy food items such as rice and potato with high carbohydrate content raise blood sugar. Hence, consuming low glycaemic foods is one tool to keep diabetes under control. In this study, potato and brown rice (Njavara rice) starches were subjected to hydrothermal treatments: heat moisture treatment (HMT) and annealing (ANN) to develop starch-based food products fit for consumption by diabetic patients. The effects of hydrothermal treatments on physicochemical properties and in-vitro enzymatic digestion of starch were determined. It was observed that hydrothermal treatments decreased the swelling power (SP)% and increased the water solubility (WS)% of the native starches. Native potato starch (PSN) showed a high SP of 80.33%, while annealed potato starch (PANN) and heat moisture treated potato starch (PHMT) showed SP reduced to 65.33% and 51.66%, respectively. Similarly, the SP % reduced from 64.33% in native brown rice (BRN) to 44.66% in annealed brown rice (BRANN) and 38.33% in heat moisture treated brown rice (BRHMT). WS % increased from 32.86% in PSN to 36.66% in PANN and 40.66% in PHMT. In BRN, the WS % increased from 14.0% to 14.66% in BRANN and 18.33% in BRHMT. Amylose content increased from 13.23% and 14.56% in PSN and BRN to 16.14% in PANN 17.99% in PHMT, 17.33% in BRANN, and 18.98% in BRHMT. The PSN crystallinity index reduced from 33.49 to 30.50% in PANN and 32.60% in PHMT. At 12 h of enzymatic digestion, it was found that the degree of hydrolysis (DoH) of PHMT (31.66%) and PANN (36.82%) reduced when compared to PSN (41.09%). Similarly, BRHMT exhibited the lowest DoH at 12 h compared to BRANN (29.24%) and BRN (35.48%). This study highlights the importance of hydrothermal treatments on starch in developing low glycaemic index commercial starch-based food products.


2011 ◽  
Vol 396-398 ◽  
pp. 1502-1505 ◽  
Author(s):  
Xin Hong Liang ◽  
Gong Ling Zhao ◽  
Zu Feng Guo ◽  
Yu Tang

Abstract. Glucoamylase is an inducible enzyme and generally induced in the presence of starch. Corn starch, wheat starch, sweet potato starch and potato starch were used as the carbon sources to produce the glucoamylase by A. niger FJL0801. The results showed that the maximum glucoamylase activity was 594.511.7 U/mL when 4% sweet potato starch was used as the carbon source, its enzyme activity was increased by 34.9% than potato starch, by 17.2% than wheat starch and by 4.6% than corn starch. In the four media, the adaptive phage of A. niger FJL0801 were all 0-12 h, the logarithmic growth phase all 12-60 h, and the stationary phase all 60-192 h. The maximum biomass of the strain was 1.950.09 μg/mL in the corn starch medium. The glucoamylase activity was inversely proportional to the growth rate of A. niger FJL0801. The final pH value was all within 6.960.057.110.07 in the four midia. There was no significant difference at 0.05 probability level between the pH of the four media at the same fermentation time. The pH change was not the reason for glucoamylase activity by A. niger FJL0801 used different plant starch.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Chinwoo Kwon ◽  
Ha Ram Kim ◽  
Tae Wha Moon ◽  
Seung Hyun Lee ◽  
Chang Joo Lee

This study investigated the structural and physicochemical characteristics of malic acid-treated sweet potato starch. Sweet potato starch mixed with various concentrations of malic acid solution underwent either thermal or nonthermal treatment. Observation of samples under a light microscope ensured the maintenance of granular shape and the Maltese cross. FT-IR spectra displayed a distinct carbonyl peak at 1722 cm−1, and analysis of the degree of substitution (DS) indicated an increase in the extent of ester bonds with increasing concentrations of malic acid. The DS of 2.0M-130 (0.214) was the highest and that of 0.5M-130 was the lowest (0.088) among the reacted starches. In vitro digestion test revealed an increased amount of resistant starch when a high concentration of malic acid was used. In addition, thermally treated samples maintained a higher content of resistant starch (RS) after 30 min of cooking at 100°C. After cooking, 2.0M-130 had an RS fraction of 53.4% which was reduced to 49.9% after cooking, revealing greater heat stability compared with nonthermally treated samples. The structure of malic acid-treated starch was investigated using a differential scanning calorimeter (DSC), an X-ray diffractometer, a rapid visco analyzer (RVA), and analysis of apparent amylose content. The results showed that thermal and malic acid treatment of starch caused not only partial hydrolysis but also rearrangement of the crystalline area and helix structure of starch by esterification. Analysis of malic acid-treated starch, using a rapid visco analyzer showed no pasting properties, due to lack of its swelling caused by the malic acid cross link.


2006 ◽  
Vol 57 (5) ◽  
pp. 531 ◽  
Author(s):  
M. Yamamori ◽  
M. Kato ◽  
M. Yui ◽  
M. Kawasaki

The bread wheat (Triticum aestivum L.) analysed in this study has been produced by genetically eliminating the starch synthase IIa and shows apparent high amylose (HA) in the flour starch. Some starch properties of the HA wheat were analysed. The HA wheat contained 2.8–3.6% resistant starch (RS), much more than the normal (control) wheat, which contained almost no RS. Autoclaving the HA and normal wheat starches increased RS. The former contained 10.5% RS and the latter 5.9 or 6.8% RS. Swelling of the HA wheat starch and its pasting properties using Rapid ViscoAnalyzer (RVA) were investigated. Swelling power (g/g) of the HA wheat in 0.1% AgNO3 and swelling volume (mL/g) in urea solution were significantly less than those of the normal wheat. The RVA profile of the HA wholemeal and starch also differed from the normal. The peak viscosity, minimum viscosity, and final viscosity of HA were low, and breakdown (peak minus minimum viscosity) was very small. These findings show that amount of resistant starch and pasting properties are unique in the HA wheat starch, probably caused by lack of starch synthase IIa.


Author(s):  
Yaoyao Li ◽  
Shaowei Liu ◽  
Xue Liu ◽  
Xiaozhi Tang ◽  
Jian Zhang

Abstract Starch isolated from sweet potato was subjected to different levels of HMT at 15, 20, 25, 30, and 35 %. HMT showed negligible effect on the swelling power of starch. The swelling power was decreased with the increasing of the initial moisture content of the starch. The apparent amylose contents of HMT starches decreased from 24.11 % to 20.56 % with the initial moisture content increasing from 15 % to 35 %. The pasting temperatures enhanced from 73.1 to 81°C (p < 0.05) with the rapidly digestible starch (RDS) contents decreasing from 86.97 to 70.24 % (p < 0.05). Avrami equation analysis showed that HMT reduced the rate of starch retrogradation. The Avrami exponents of native and HMT-35 starches were 0.70 and 0.98 with the recrystallization rates 0.22 and 0.10, respectively. HMT could restrain the starch retrogradation and these results could provide theoretical guidance on sweet potato starch modification.


2020 ◽  
pp. 1-12
Author(s):  
H. D. K. C. Wijesinghe ◽  
K. D. P. P. Gunathilake

Aims: Starch is used in the food industry to impart functional properties and to modify food texture and consistency. In this study starches isolated from six sources using an alkali extraction method were evaluated for physicochemical properties. Study Design: Complete randomized design. Place and Duration of Study: Department of Food Science and Technology, Faculty of Livestock, Fisheries, & Nutrition, Wayamba University of Sri Lanka, Makandura, Gonawila (NWP), Sri Lanka between April 2017 and August 2017. Methodology: Starches were isolated from white rice, foxtail millet, proso millet, cassava, sweet potato and all-purpose wheat flour. Proximate composition, mineral content, physical properties and microscopic characteristics were determined and they were compared. Results: The level of starch extracted was within the range of 27.5-64.1% on a dry basis. Extracted starched contains about 99% carbohydrate in DW and less than 1% non-carbohydrate fraction (protein, fat, fiber and ash and minerals). The amylose content followed the order: proso millet > wheat > foxtail millet > rice > sweet potato > cassava. There was considerable variation in swelling factor, solubility, gelatinization temperature among all starches. Both swelling power and solubility had a positive relationship with temperature and the swelling power (at 90°C) followed the order: corn > cassava > foxtail millet > wheat > proso millet > rice > sweet potato. The gelatinization temperature of starches ranged from 62°C to 76°C. Conclusion: The study would be helpful to better understand the chemical, physical and microscopic characteristics of these starches and the application of novel starches obtain from non-conventional sources which are foxtail millet, proso millet and sweet potato as a thickening agent and a substitute to other common starches in food.


Author(s):  
C. C. Ezegbe ◽  
H. O. Agu ◽  
M. C. Ezeh ◽  
C. S. Anarado ◽  
C. R. Abah ◽  
...  

Custard is a thick, rich, creamy sweet or savory dessert, made mixtures of eggs or egg yolks, milk or cream and commonly consumed in most part of Africa especially Nigeria. This research was carried out to determine the physicochemical properties and sensory characteristics of custard produced from the blends of sweet potato and corn starch enriched with defatted soybean flour. The sweet potato was peeled, washed and diced into small cubes to aid milling while the maize grains were cleaned and soaked in water for 24 hours, and they were separately milled and filtered. The filtrates were allowed to settle for four hours, the starches were obtained and dried at 70°C and 60°C for 8 hours and 5 hours respectively. The soybean was cleaned, soaked, boiled, toasted, dehulled, milled and defatted in petroleum ether. Ten custard samples were then formulated using sweet potato starch, corn starch and defatted soybean flour respectively in the following ratios: 100:0:0; 80:10:10; 70:20:10; 60:30:10; 50:40:10; 40:50:10; 30:60:10; 20:70:10; 10:80:10; 0:100:0. The custard formulations were evaluated for their physicochemical and sensory characteristics, using commercial custard (Checkers custard) as control. The result of the proximate composition showed that moisture, ash, crude fibre, crude protein and carbohydrate content in % ranged from 5.40-18.08, 0.70-3.07, 1.16-6.52, 0.82-5.23, 1.31-9.91 and 68.87-85.25, respectively. The functional properties also showed that least gelation concentration (%), bulk density (g/cm), swelling power and gelatinization temperature (oC) ranged from 4.00-10.00; 0.59-0.83; 6.37-8.02 and 69.2-80.1, respectively. The result showed that the swelling power differed significantly (p<0.05) from each other and some of the samples differed significantly in bulk density, least gelation and gelatinization temperature, respectively. Sensory evaluation carried out on different samples of the custard formulation showed that the control sample (Checkers custard) had the highest score of overall acceptability. The 100% corn starch and 100% sweet potato starch were accepted by the consumers as an alternative to the commercial custard product. The enrichment of custard with soybean contributed to an increase in the nutritional value of the custard.


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