Setback Viscosity Research Articles

Characterization of ulvan polysaccharide extracted from Ulva pertusa and its effect on thermal, rheological, and gelling properties of rice flour

Three ulvan fractions (UPs 1–3) were extracted from Ulva pertusa via hot-water extraction. UP1 exhibited a molecular weight of 729,151 Da, while UPs 2 and 3 ranged from 19,952 to 750,384 Da. These fractions differed in monosaccharide, uronic acid, and sulfate levels. Zeta potentials for polysaccharide solutions (0.2–0.6 % w/v) ranged from −34.4 to −25.1, all demonstrating shear-thinning behavior. Incorporating UPs 1–3 solutions (0.2–0.6 % w/v) with rice flour increased gelatinization temperatures and modified pasting properties, increasing peak time, peak viscosity, and trough viscosity while reducing breakdown, final, and setback viscosities. Ulvan polysaccharide improved the viscous behavior of rice flour paste, indicated by increased loss modulus and tan δ (p > 0.05). Furthermore, ulvan polysaccharide improved the microstructure and texture of rice flour gel, with UP1 (0.6 % w/v) forming denser matrices and better texture. Molecular docking analysis suggested that hydrogen bonding is the primary interaction between rice glutelin and ulvan components.

Jicama (Pachyrhizus spp.), a nonconventional starch: Effects of citric acid and heat−moisture treatment on properties of starch and its application in film

AbstractBackground and ObjectivesThis study investigated the effects of citric acid (CA) and heat–moisture treatment (HMT) on the properties of jicama starch (JS). Furthermore, it explores the potential of modified jicama starch for film preparation.FindingsThe amylose content of the JS increases after HMT and decreases for CA‐modified starch. CA and HMT modification lowered the swelling power, solubility, peak viscosity, breakdown viscosity, final viscosity, setback viscosity, and crystallinity percentage compared to the native JS. After modification, there was an increase in the transition and pasting temperature of JS. The strong peak for the control and treated JS was observed at around 1008 cm−1 wavenumber in the Fourier transform infrared spectroscopy. SEM showed the overlapping and clusters of the granules in all the modified JS. Modified JS‐based film significantly affects the water solubility, barrier, and mechanical properties of film. The film's SEM showed that the CA‐ and HMT‐modified films had more homogeneous surfaces than the native JS film.ConclusionsHMT and CA modification significantly impacted JS properties and improved the film properties for further application.Significance and NoveltyThis study's findings will facilitate selecting an appropriate treatment to enhance the properties of JS for applications in food formulation and sustainable packaging.

Structure and physicochemical properties of starches from six accessions of the genus Pueraria in China

Kudzu (Pueraria lobata) root contains abundant starch, but the physicochemical properties of kudzu starch are not well understood. In this study, we compared the compositions and physicochemical properties of starches isolated from six Pueraria accessions in China. Caige starch exhibited the highest purity (96.99 %) and amylose content (24.76 %), while Yege starch contained higher levels of puerarin (493.37 μg/g) and daidzein (38.68 μg/g). All kudzu starches were rich in resistant starch, with RS2 content ranging from 38.61 % to 46.22 % and RS3 content from 3.59 % to 6.04 %. The granules of kudzu starches varied in morphology, with Yege starch featuring larger polygonal granules. The kudzu starches presented either A-type or A-type-like C-type diffraction patterns. Caige starch had a higher IR2 value (1.28), higher gelatinization temperatures, wider temperature ranges, and greater enthalpy changes. Yege (JX) starch exhibited the highest peak viscosity but the lowest setback viscosity and pasting temperature. Fenge starch showed the highest final viscosity, with Fenge (ZJ) starch demonstrating the highest crystallinity (25.7 %) and IR1 value (0.80). These results indicated that kudzu starches derived from various Pueraria species possess unique structural and physicochemical properties, which provide significant potential for applications in food and other industrial fields.

Application of Silica Nanoparticles Improved the Growth, Yield, and Grain Quality of Two Salt-Tolerant Rice Varieties under Saline Irrigation.

Salt stress significantly reduces rice yield and quality and is a global challenge, especially in arid and semi-arid regions with limited freshwater resources. The present study was therefore conducted to examine the potential of silica nanoparticles (SiO2 NPs) in mitigating the adverse effects of saline irrigation water in salt-tolerant rice. Two salt-tolerant rice varieties, i.e., Y liangyou 957 (YLY957) and Jingliangyou 534 (JLY534), were irrigated with 0.6% salt solution to simulate high-salt stress and two SiO2 NPs were applied, i.e., control (CK) and SiO2 NPs (15 kg hm-2). The results demonstrated that the application of SiO2 NPs increased, by 33.3% and 23.3%, the yield of YLY957 and JLY534, respectively, compared with CK, which was primarily attributed to an increase in the number of grains per panicle and the grain-filling rate. Furthermore, the application of SiO2 NPs resulted in a notable enhancement in the chlorophyll content, leaf area index, and dry matter accumulation, accompanied by a pronounced stimulation of root system growth and development. Additionally, the SiO2 NPs also improved the antioxidant enzyme activities, i.e., superoxide dismutase, peroxidase, and catalase activity and reduced the malondialdehyde content. The SiO2 NPs treatment effectively improved the processing quality, appearance quality, and taste quality of the rice. Furthermore, the SiO2 NPs resulted in improvements to the rapid viscosity analyzer (RVA) pasting profile, including an increase in peak viscosity and breakdown values and a reduction in setback viscosity. The application of SiO2 NPs also resulted in a reduction in crystallinity and pasting temperature owing to a reduction in the proportion of B2 + B3 amylopectin chains. Overall, the application of silica nanoparticles improved the quality of rice yield under high-salt stress.

Pasting, rheology, structural properties and in vitro digestibility of potato starch complexes co-gelatinized with squash polysaccharides

The effects of extraction of squash polysaccharide from water (WESP) and subcritical water (SWESP) on gelatinization, rheology, thermodynamic, micro-structure, freeze-thaw stability and digestibility of potato starch (PS) were studied. The WESP and SWESP decreased peak viscosity, trough viscosity, breakdown viscosity, final viscosity, storage modulus and loss modulus of PS. Conversely, the setback viscosity, pasting temperature and peak time increased. All gel samples belonged to the weak gel system. The thermodynamic and fourier spectroscopic results demonstrated a significant retardation of PS retrogradation in the presence of WESP and SWESP. It was consistent with the microstructure characterization detected by scanning electron microscopy that both WESP and SWESP had a significant inhibitory effect on the formation of the PS gel structure. Moreover, the existence of WESP and SWESP compromised the freeze-thaw stability of PS gel. Meanwhile, WESP and SWESP also affected the digestibility of PS and reduced the eGI value of PS, which was conducive to stabilizing blood sugar fluctuations. This study helped to better understand the interaction of PS with WESP/SWESP in the gel system, and supplied a way to improve the quality of PS-related products. In addition, it also contributed to the industrial production and application of WESP and SWESP.

Structural characterization and physicochemical properties of grain amaranth starch

With potato starch (PS) and corn starch (CS) as the controls, the structure and physicochemical properties of grain amaranth starch (GAS) and its binding with dihydromyricetin were investigated in this study. The results indicated that GAS granules were small in size (3.21 ± 0.13 μm) and had a low amylose content (11.57 ± 0.91%). GAS exhibited low paste clarity, solubility, and swelling power, but demonstrated good freeze-thaw stability and resistance to retrogradation. Although the pasting temperature of GAS was high (75.88 ± 0.03 °C), its peak viscosity, breakdown viscosity, and setback viscosity were significantly lower than those of PS and CS. GAS was classified as A-type starch, with a high molecular weight and broad distribution (Mw, 3.96 × 107 g/mol; PDI, 2.67). For its chain length distribution, chain B1 had the highest proportion (50.09%), while chain B3 had the lowest proportion (13.50%). The complexation of GAS with dihydromyricetin effectively enhanced its ABTS and DPPH free radical scavenging capacities.

Optimisation of dry heat treatment conditions for modification of faba bean (Vicia faba L.) starch

Faba bean is a protein-rich starchy grain that is underutilised in the UK. The starch of faba bean can be modified using environmentally friendly methods like dry heat treatment (DHT) to enhance functional and its physicochemical properties. This study investigated the impact of dry heat temperature and time on the structure, functional and physicochemical properties of faba bean starch (FBS) using a two-factor central composite rotatable design. Factors (DHT temperature:100–150 °C and DHT time:0.5–5 h) with their respective α mid-point values led to 13 experimental runs. Selected pasting and functional properties were measured as response variables. Corn starch was included as a reference and compared with the FBS modified using the optimized conditions. DHT increased peak (approx. 2205–2267 cP), final (approx. 3525–3642 cP) and setback (approx. 1887–1993 cP) viscosities but decreased the amylose content of FBS. Colour, as measured by lightness value, morphology and crystalline type were not altered but the starches showed a loss of order and an increase in crystallinity after DHT. FBS appeared resilient to DHT but showed higher swelling power and pasting properties compared to the corn starch control. The optimum DHT conditions to produce starch with desirable properties are a temperature of 100 °C for 0.1716 h, with a desirability factor of 66 %.

Nutrient Composition, Physical Characteristics and Sensory Quality of Spinach-Enriched Wheat Bread.

Food innovation that utilises agricultural waste while enhancing nutritional value is important for waste valorisation and consumer health. This study investigated incorporating spinach (Spinacia oleracea), as a model leafy agricultural waste, into wheat bread. We analysed the nutrient content, colour, texture, sensory attributes and purchase/consume intention ratings. Adding 10-40% spinach (w/w) yielded loaves with similar heights but significantly different colour and texture (p < 0.05) from white bread. Increasing spinach decreased total carbohydrates (including starch) while significantly increasing other nutrients (protein, fibre, iron, magnesium, potassium, zinc, calcium, vitamins A, C, E, folate, niacin, pyridoxine, nitrate/nitrite and polyphenols) (p < 0.05). Spinach addition increased bread porosity, linked to higher pasting parameters (peak, trough, breakdown, final and setback viscosity) with reduced pasting time and temperature. Texture analysis resulted in decreased hardness, chewiness, gumminess and firmness while increasing cohesiveness, with maximum resilience at 20% spinach enrichment. Sensory analysis with 21 untrained panellists revealed decreased visual appeal, less preferred taste, odour and overall liking (p < 0.05) with increasing spinach, with no significant difference in texture acceptance, but the 20% enrichment had comparable acceptance to white bread. Enriching staple foods like bread with leafy vegetable waste offers a promising approach for increasing daily vegetable intake.

Comparisons of Appearance and Eating Quality Traits Between Early and Late Maturing Soft Rice

Soft Japonica rice is popular in Yangtze River Delta of China in recent years because of its high eating quality. In this study, high eating quality soft Japonica rice with early and late maturity was used to analyze their eating quality traits. The appearance, texture, and physicochemical characteristics, gelatinization and pasting properties, and fine structures between early and late maturing soft rice were compared. Early maturing soft rice had higher whiteness, chalkiness, gelatinization temperature, peak viscosity, breakdown viscosity, long branch-chain amylopectin, amylopectin chains (DP &amp;gt; 25), and molecular weight than late maturing soft rice. The higher gelatinization and pasting properties in early maturing soft rice probably be attributed to its higher amount of long branch-chain amylopectin, proportions of amylopectin chains (DP &amp;gt; 25) and molecular weight, compared with late maturing soft rice. Late maturing soft rice had higher amylose content, gel consistency, short branch-chain amylopectin, amylopectin short chains (DP 6&amp;ndash;12), setback viscosity, and consistence viscosity than early maturing soft rice. The appearance and eating quality of late maturing soft rice were significantly higher than those of early maturing soft rice.

Effect of Different Fertilizer Types on Quality of Foxtail Millet under Low Nitrogen Conditions.

In order to clarify the effect of different fertilizers on foxtail millet quality under low nitrogen conditions, we used JGNo.21 and LZGNo.2 as experimental materials and set up five treatments, including non-fertilization, nitrogen, phosphorus, compound, and organic fertilizers, to study the regulation of different fertilizer types on agronomic traits, nutrient fractions, and pasting characteristics of foxtail millet under low nitrogen conditions. Compared with the control, all of the fertilizers improved the agronomic traits of JGNo.21 to a certain extent. Nitrogen and compound fertilizer treatments reduced the starch content of JGNo.21; the starch content was reduced by 0.55% and 0.07% under nitrogen and compound fertilizers treatments. Phosphorus and organic fertilizers increased starch content, and starch content increased by 0.50% and 0.56% under phosphorus and organic fertilizer treatments. The effect of each fertilizer treatment on protein content was completely opposite to that of starch; different fertilizer treatments reduced the fat content of JGNo.21 and increased the fiber content. Among them, nitrogen and phosphorus fertilizers increased the yellow pigment content; the yellow pigment content increased by 1.21% and 2.64% under nitrogen and phosphorus fertilizer treatments. Organic and compound fertilizers reduced the content of yellow pigment; the yellow pigment content was reduced by 3.36% and 2.79% under organic and compound fertilizer treatments. Nitrogen and organic fertilizers increased the fat content of LZGNo.2; the fat content increased by 2.62% and 1.98% under nitrogen, organic fertilizer treatment. Compound and phosphorus fertilizer decreased the fat content; the fat content decreased by 2.16% and 2.90% under compound and phosphorus fertilizer treatment. Different fertilizer treatments reduced the cellulose and yellow pigment content of LZGNo.2. The content of essential, non-essential, and total amino acids of JGNo.21 was increased under compound and nitrogen fertilizer treatments and decreased under organic and phosphorus fertilizer treatments. The content of essential, non-essential, and total amino acids of LZGNo.2 was significantly higher under compound, nitrogen, and organic fertilizer treatments compared with control and significantly decreased under phosphorus fertilizer treatments. Nitrogen and compound fertilizer treatments significantly reduced the values of peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, and pasting time of each index of JGNo.21; phosphorus and organic fertilizer treatments improved the values of each index. In contrast, the pasting viscosity of LZGNo.2 increased under phosphorus fertilizer treatment and decreased under nitrogen fertilizer treatment. Reasonable fertilization can improve the quality of foxtail millet, which provides a scientific theoretical basis for improving the quality of foxtail millet.

Responses of rice qualities to temperature and light in three different ecological environments in karst regions

Rice cultivation in Karst regions shows significant variations in both yield and quality due to temperature and light. Herein, 241 varieties including 198 indica rice and 43 japonica rice were planted in three ecological regions to investigate responses of rice qualities to meteorological factors. Results showed that in regions with higher average temperature (25.43 °C) and less daily sunshine hour (2.53 h/day), the appearance qualities (chalkiness degree, chalkiness rate and size) and processing qualities (brown rice percentage, head rice and milled rice percentages) were significantly reduced (p < 0.05). A total of 723 samples in three ecological environments were grouped into 4 clusters, arranged in descending order of cluster scores. In high-scoring cluster, the processing quality, appearance quality, protein content, hot paste viscosity, consistence viscosity, and setback viscosity were negatively correlated with temperatures (average temperature, temperature difference, effective accumulated temperature, maximum and minimum temperatures) from heading to mature stages, but positively correlated with sunshine hours. Apparent amylose contents were negatively correlated with temperatures but not significantly correlated with sunshine hours. In low-scoring cluster, only the processing quality had significant correlations with meteorological factors. These findings revealed the interaction between temperature and light for the formation of rice quality.

Effects of Huangjing polysaccharides on the properties of sweet potato starch

Huangjing polysaccharides (HJP) have been shown to have many functions, however little was known about HJP on starch properties. This study investigated the effects of HJP from raw Huangjing (RHJP), high pressure steamed Huangjing (HPSHJP) and nine steamed and nine solarized Huangjing (NNHJP) on the properties of sweet potato starch (SPS). Results showed that HJP reduced setback viscosity (SB) of SPS. HJP decreased hardness, cohesiveness and chewiness, but increased the springiness of SPS gels. RHJP decreased tan δ of the starch gel but HPSHJP and NNHJP were less effective at higher frequencies. HJP increased the solubility but decreased the swelling power of SPS. Starch gel with HJPs showed a denser structure as observed by scanning electron microscopy. HJP decreased the relative crystallinity (RC) of the starch gel where HPSHJP was more effective than RHJP and NNHJP. HJP increased the degree of order (DO) while decreased the degree of double helix (DD) of SPS gels where RHJP was more effective than HPSHJP. Furthermore, HJP decreased the gelatinization enthalpy (ΔH) values of SPS with HPSHJP and NNHJP more effective. In conclusion, HJP could potentially improve the properties of SPS based foods but the changes of HJP after food processing require further investigation.

Effect of nitrogen fertilizer on the quality traits of Indica rice with different amylose contents.

Nitrogen is a key factor affecting the quality of rice. Studying the impact of nitrogen fertilizer on the taste, physicochemical properties, and starch structure of Indica rice with different amylose contents is of great significance for scientifically fertilizing and cultivating high-quality rice varieties for consumption. The results indicate that increasing nitrogen fertilizer application reduces the amylose content and increases the protein content, resulting in a decrease in taste quality. Simultaneously, it reduces the intergranular porosity of starch particles, improving the appearance and milling quality of rice. Compared to the N1 treatment (nitrogen fertilizer application rate of 90 kg ha-1), the taste of low-amylose rice (Yixiangyou 2115) and high-amylose rice (Byou 268) decreased by 14.24% and 19.79%, respectively, under N4 treatment (nitrogen fertilizer application rate of 270 kg ha-1). The effect of nitrogen fertilizer on low-amylose rice is mainly reflected in increased rice hardness, enthalpy value, and setback viscosity, resulting in a decline in taste. The effect of nitrogen fertilizer on high-amylose rice is mainly reflected in a decrease in peak viscosity, an increase in gelatinization temperature, and crystallinity under high nitrogen levels. Increasing nitrogen fertilizer application can improve the appearance and milling quality of rice, but it also leads to an increase in protein content, hardness, gelatinization enthalpy, decrease in breakdown value, and a decline in palatability. In practical production, different production measures should be taken according to different production goals. © 2024 Society of Chemical Industry.

Comparative Analysis of Maize Physico-Chemical Parameters and Mycotoxin Levels in Dual Environments.

Maize (Zea mays L.) stands as a vital staple food globally, holding significant nutritional and economic value. However, its susceptibility to mycotoxin contamination under stressful environmental conditions poses a considerable concern. This study aimed to assess the quality and pasting characteristics of maize varieties across two distinct regions and examine the occurrence of mycotoxins influenced by climatic factors. Five maize varieties were cultivated in triplicate in the Golegã and Coruche regions. The nutritional composition (protein, fat, fiber, ash, starch, and lutein), pasting properties, and mycotoxin levels were evaluated. A statistical analysis revealed notable differences in the nutritional profiles of the maize varieties between the two regions, particularly in the protein and lutein content. The peak viscosity ranged from 6430 to 8599 cP and from 4548 to 8178 cP in the maize varieties from the Coruche and Golegã regions, respectively. Additionally, a significant correlation was observed between the climatic conditions and the grain nutritional quality components (p < 0.05). The M variety showed the highest ash content, protein content, final viscosity, and setback viscosity and the lowest peak viscosity. The Y variety revealed the lowest fat, fiber, and lutein content and the maximum peak viscosity. The incidence of mycotoxins was notably higher in the varieties from Coruche, which was potentially attributable to higher temperatures and lower precipitation levels leading to more frequent drought conditions. Fumonisin B1 was detected in 58% of the varieties from Coruche and 33% of the samples from Golegã, while deoxynivalenol was found in 87% and 80% of the varieties from Coruche and Golegã, respectively. The H variety, which was harvested in Coruche, exhibited the highest number of fumonisins and higher amounts of protein, lutein, and fat, while fumonisins were not detected in the Golegã region, which was potentially influenced by the precipitation levels. The K variety revealed higher protein and lutein contents, a lower amount of fat, excellent pasting properties (a higher peak viscosity and holding strength and a lower peak time), and no fumonisins B1 or B2. This variety may be considered well adapted to higher temperatures and drier conditions, as verified in the Coruche region. In conclusion, our study underscored the profound impact of environmental factors on the quality and occurrence of mycotoxins in maize varieties.

Interaction of anthocyanins, soluble dietary fiber and waxy rice starch: Their effect on freeze-thaw stability, water migration, and pasting, rheological and microstructural properties of starch gels

This study aimed to investigate the effect of the interaction of black rice anthocyanins (BRA), soluble dietary fiber from extruded rice bran (ES) and waxy rice starch (WRS) on the physicochemical properties of starch gels, including gelatinization properties, rheological properties, freeze-thaw stability, water migration, molecular structure and gel microstructure. The results showed that the pasting temperature (PT) of the mixtures was increased, and the peak viscosity (PV), trough viscosity (TV), final viscosity (FV) and setback viscosity (SV) were significantly reduced when ES and BRA were added to WRS in different proportions (ES:BRA, 4:0, 4:0.4, 4:1, 4:2, 8:0, 8:0.8, 8:2, 8:4). Both ES and BRA could enhance the viscosity of WRS gels, and ES exhibited strong ability on improving the strength of gels. The presence of ES and BRA improved the water retaining capacity of WRS gels, but weakened the freeze-thaw stability. ES, BRA and WRS formed non-covalent bonds (hydrogen bonds) through hydrophilic groups during gelatinization, which improved the gel properties. In addition, the steric hindrance formed by ES and BRA inhibited starch retrogradation. These results might contribute to the development of starch-based food formulations with good quality.

Evaluación de las propiedades proximales, estructurales, morfológicas fisicoquímicas y de digestibilidad in vitro en mezclas de harinas de ñame y batata

Yam (Dioscorea spp.) and sweet potato (Ipomeas batata) flours must be treated through modification processes because they have limitations in their physicochemical and structural properties for use in agri-food matrices. This study aimed to evaluate the effect of different proportions of flours on the proximate, structural, morphological, physicochemical, pasting, and in vitro digestibility properties of yam and sweet potato flour blends. Flours were obtained by drying the tubers with hot air at 55 °C, and mixtures were prepared at 25:75, 50:50, and 75:25 w/w sweet potato and yam flour proportions, respectively. The yam starch granules were spherical, oval, irregular, and larger than those of sweet potatoes, which are ovoid and flared. Furthermore, yam and sweet potato granules presented with type-B and type-A diffraction patterns, respectively, which, together with the starch content, amylose, non-starch components, and their molecular interactions, influenced the decrease in the molecular order and degree of crystallinity of the flour blends, without altering the morphological characteristics of the simple flours. Additive and non-additive effects were observed on flour blends’ swelling power and water absorption capacity. Likewise, breakdown and setback viscosity increased, which decreased thermal stability, increased the tendency to retrogradation, and elevated the fractions of rapidly digestible starch and resistant starch. These results suggest the high potential of flour blends in preparing baked products from the Caribbean Region, such as white bread, cookies, and cakes.

Techno-functional and nutritional variations of Cardaba banana flour as influenced by different modification techniques

The majority of gluten-free flours have significant techno-functional shortcomings as well as occasionally poor nutritional quality, all of which necessitate modifications. Thus, the objective of this study was to determine how different modification techniques such as fermentation, pre-gelatinization, acetylation, oxidation, and acid-thinning influence the nutritional, functional, pasting, and thermal properties of Cardaba banana flour – a gluten free flour. Oxidized flour exhibited improved setback viscosity and trough, in addition to protein and crude fibre. The technological parameters and general nutritional profiles of the flour were not considerably improved by acid-thinning and acetylation modifications. However, the most significant and crucial nutritional, functional, pasting and thermal properties of the flour experienced a substantial improvement during pre-gelatinization and fermentation treatments. Total phenol contents and antioxidants, dietary fibre, resistant, slowly digestible and rapidly digestible starches, essential mineral elements such as Na, K, P and nutritional important mineral ratios, Na/K, and Ca/P, as well as functional, pasting, and thermal stability indices, were improved during fermentation and pre-gelatinization, thus indicating the potential of these methods to minimize the inherent drawbacks of the native flour. Pre-gelatinization and fermentation technologies could considerably improve the technological, functional and nutritional characteristics of Cardaba banana and improve its food and industrial applications.

Modified Arrowroot Starch: Impact of Multiple Acetylation on Physical, Chemical, and Physicochemical Characteristics

Abstract Modifying single-acetylated starch in arrowroot starch has improved starch quality, especially in paste clarity properties. It was conducted to determine the effect of the double acetylation modification method on the physical, chemical, and physicochemical characteristics of modified arrowroot starch. It used a completely randomized design with variations in the concentration of acid acetate and the immersion time of single acetylation modification. The best single Acetylated Starch is the treatment of variations in adding 2% acetic acid concentration for 60 minutes soaking time, which then proceeds with double acetylation modification. Double acetylation has a paste clarity level of 25.02%, moisture content of 13.33%, Amylose Content of 30.62%, Water Absorption of 3.77 g/g, Swelling power of 9.30 g/g, and Solubility of 5.19%. The pasting properties have a Peak Viscosity of 5716 cP, Through Viscosity of 2336 cP, Breakdown Viscosity of 3380 cP, Final Viscosity of 2750 cP, Setback Viscosity of 414 cP, Peak Time of 5 minutes, and Pasting Temperature 70.90°C. The dual acetylation improves the solubility and swelling power compared with single acetylation and unmodified starch.

Characteristics of sorghum flour modified with physical and enzymatic treatments

This study evaluated the physicochemical and thermal properties of modified sorghum flour. The modified sorghum flour was obtained through extrusion -enzymatic treatment using thermostable-&amp;alpha; amylase at various feed moisture levels. The results showed that unmodified sorghum flour had the average chemical composition of sample being 87.06% carbohydrate, 9.8% protein, 0.32% fat and 0.64% ash. The unmodified and modified sorghum flour differed in their properties. The swelling power and solubility changed from 16.21 (g/g) to 4.64(g/g) &amp;ndash; 28.20 (g/g) and from 4.68% to 4.25%&amp;ndash;83.81% respectively. A wide range of pasting properties were noticed, such as peak viscosity (54 cP-3028 cP), breakdown viscosity (59 cP-1029 cP), setback viscosity (-106.50&amp;ndash;2351 cP). Peak viscosity was not detected when the modification was performed at high feed moisture (FM 35%) treatment combined with the addition of thermostable-&amp;alpha;amylase. Additionally, the onset, peak, and conclusion temperatures of gelatinization, and the enthalpies of modified flours were lower than those of unmodified ones. Morphological changes in the surface of starch granules were noticed as shown by pore formation through SEM observation. This study provided insights into the future direction of extrusion combined with enzymatic treatment for the selective modification of sorghum flour functional properties.

Effect of Bambara Groundnut Flour (Vigna subterranea) Inclusion on the Functional, Pasting, Physical and Proximate Properties of Composite Cassava-bambara Flour

This study evaluated the effect of Bambara groundnut flour inclusion on the functional, pasting, physical properties and proximate compositions of composite flour (CF) from cassava and Bambara groundnut. Cassava variety (IITA-TMS-IBA011368) and Bambara groundnut were processed into flour and blended together based on D-Optimal mixture design with an outcome of eight experimental samples using Design Expert Software (Version 12.0). The flour blends were analyzed for functional, pasting, physical properties (color), baking strength and proximate composition. Data obtained were analyzed using analysis of variance and means were separated using Ducan’s Multiple Range Test. Range of results for bulk density, water absorption capacity, swelling index, solubility index and oil absorption capacity of the composite flour are 0.64-0.80g/mL, 0.38-1.37%, 0.77-0.91%, 6.00-8.65, 1.58-2.97, respectively. The peak viscosity, trough, breakdown viscosity, final viscosity, setback viscosity, peak time and pasting temperature ranged from 162.84±2.09 to 426.50±1.83 RVU, 77.96±2.71 to 195.59±8.91 RVU, 84.88±0.63 to 234.75±5.58 RVU, 158.92±4.34 to 293.17±1.34 RVU, 76.88±18.04 to 101.42±5.08 RVU, 4.10±0.03 to 5.93±0.00 min and 75.05±0.05 to 94.78±0.38 oC, respectively. The baking strength characteristics of the flour blends such as moisture, ash, color, wet gluten, zenleny dry protein and wet protein ranged from 11.55 to 12.55%, 0.50 to 1.25%, 88.65 to 90.55, 8.35 to 13.80, -2.35 to 41.25, 4.92 to 13.85% and 4.53 to 11.99 %, respectively. Moisture, ash, fibre, fat, protein and carbohydrate of the composite flour ranged from 7.57 to 11.87%, 0.42 to 2.40 %, 1.78 to 3.00%, 2.81 to 5.62%, 8.42 to 12.68% and 67.61 to75.99%, respectively. Flour lightness, redness and yellowness ranged from 33.22 to 54.10, -2.89 to-1.14, 5.94 to 9.35, respectively. The inclusion of Bambara groundnut flour had a significant effect on the functional (swelling index, water and oil absorption capacity), pasting (peak, trough and final viscosity) and proximate (ash, fat and carbohydrate) properties of the flour blends.