Breakdown Viscosity Research Articles

Low-cost nutrient-dense composite flours for children aged 1-5 years developed from locally available foods

Childhood malnutrition persists in low-income countries due to inadequate diet diversity and nutrient density. For seasonal crops, consumers make food substitutions based on price variations which has dietary implications and can cause episodes of nutritional deficiencies. Locally available foodstuffs can be used to formulate low-cost nutritionally adequate food mixtures. Design-Expert® and Nutrisurvey software were used to generate nutrient-dense formulations for the dry season (n=2) and wet season (n=5) from low-cost locally available foods in Eastern Uganda (sweet potatoes, sorghum, soybeans, beans, sesame, groundnuts and maize). Composite flours of the formulations were prepared and cooked following the World Food Program (WFP) recommendations and consumer acceptability determined using a consumer panel (n=43). The most acceptable formulation for the dry season (D2) and the most acceptable formulation for the wet season (R5) were selected for the determination of functional properties (dispersibility, bulk density and water absorption index (WAI) and water solubility index (WSI)), pasting properties (peak viscosity, breakdown viscosity, final viscosity, setback viscosity and peak time), color and nutrient density (energy content, sugars, starch, protein, crude fat, fiber, ash, iron and zinc). D2 contained 25.35g of sorghum, 1.31g of soybeans, 4.34g of beans, 33.11g of sesame and 35.89g of groundnuts per 100g of formulation. R5 contained 4.95g of maize, 20.98g of sorghum, 5.49g of beans, 29.39g of sesame and 39.19g of groundnuts per 100g of formulation. The nutrient densities of D2 and R5 when cooked according to WFP recommendations were also determined. D2 and R5 had high dispersibility (77.2-76.8%), low water absorption index (1.7-2.0g/g) and high water solubility index (0.2-0.3g/g). The pasting properties indicated that the formulations form stable low viscosity pastes that can withstand breakdown during cooking and have high resistance to retrogradation on cooling. Cooked D2 (100g) contained 87.2kcal, 9.5g starch, 2.3g sugars, 5.8g protein, 1.6g fat, 1.7g fiber, 2.3mg iron and 1.6mg zinc. Cooked R5 (100g) had 71.4kcal, 7.1g starch, 2.6g sugars, 4.2g protein, 0.9g fat, 1.0g fiber, 1.9mg iron and 1.4mg zinc. The cooked samples provided more than 50% of the Recommended Nutrient Intake (RNI) for children aged 1-5 years for protein and zinc per serving (200g for children aged 1-3 years and 250g for children aged 4-5 years). Adopting formulations developed in this study can potentially contribute to reducing undernutrition in children aged 1-5 years. Key words: Low-cost nutrient-dense foods, composite flours, infant feeding, pasting properties, malnutrition

Relationships between starch molecular components and eating and cooking qualities of rice using single-segment substitution lines with different Wx loci

Waxy (Wx) gene in rice endosperm synthesizes amylose and amylopectin extra-long chain (ELC). Five rice lines with different Wx locus single-segment substitutions under the same genetic background were investigated for relationships of their starch molecular components and eating and cooking qualities (ECQs) including pasting, thermal, textural and sensory properties. Rice lines with different Wx loci exhibited different ECQs, and their starches had different apparent amylose contents (AACs), true amylose contents (TACs), ELC contents (ELCCs), and amylopectin chain length distributions. The AAC was correlated positively to hardness and cohesiveness of cooked rice, and negatively to adhesiveness and palatability of cooked rice and breakdown viscosity of rice flour. The TAC was correlated positively to gelatinization temperature range and negatively to gelatinization temperature and enthalpy. ELCC showed a positive relationship with pasting peak time of rice flour and chewiness of cooked rice, and could potentially be used as an important reference for rice ECQ evaluation. This study could help the applications of Wx loci in rice quality breeding.

The physicochemical and structural properties and in vitro digestibility of pea starch isolated from flour ground by milling and air classification.

The fine, coarse and parent starches were isolated from pea flour by milling and air-classification. Their structural, thermal, physicochemical properties and in vitro digestibility were investigated. Particle Size Distribution showed the fine starch with the smallest unimodal distribution (18.33 and 19.02μm) displayed higher degree of short-range molecular order and lower number of double helix structure. Scanning Electron Microscopy showed the morphology of the coarse starch granules as uniform in size and lacking protein particles on its smooth surface. Differential Scanning Calorimetry revealed the coarse starch had higher enthalpy changes while Rapid Visco Analysis showed higher peak, trough, and breakdown viscosities for the fine starch. In vitro digestibility featured the fine starch containing lower fast digesting starch contents, but with higher resistant starch content, indicating its resistance to enzymatic hydrolysis. The results could provide theoretical support for application of pea starch in functional foods and the manufacture of emerging starch products.

Shortening growth year improves functional features of kudzu starch by tailoring its multi-scale structure

Kudzu is usually consumed at different growth years, yet the influences of growth years on its multi-scale structures and physicochemical features have not been fully disclosed. In this study, those influences occurred on kudzu starches (KS2, KS10, KS30 and KS50, isolated using precipitation method) were investigated. The granules size, crystallinity, short-range ordered structure, amylose content, intermediate and longer amylose chains reduced but the average thickness of crystalline lamella increased as the rise of growth years. KS2 had lower content of defective crystal structure and higher content of near-perfect crystal structure. Those signified that bulk density of molecules packing into starch substrate was higher for KS2, which was not beneficial for water molecules and enzymes entering into starch granules and thus elevated pasting temperature and reduced digestion rate. Besides, reduced proportions of defective ordered structures and enhanced lipid-amylose complex also reduced digestion rate. Both the peak and breakdown viscosity were in order of KS2 > KS10 > KS30 ≈ KS50. And KS2, KS10, and KS30 exhibited enhanced retrogradation tendency during cooling than KS50 as evidenced by the relative higher setback viscosity. Those results are favor for rational screen and usage of kudzu starch resources with different growth years for food applications.

Physicochemical and sensory attributes of some selected varieties of white yam (<i>Dioscorea rotundata</i>)

The physicochemical and sensory properties of five varieties of Dioscorea rotundata were investigated for their potential end uses. The water absorption capacity, water binding capacity, swelling power, solubility index, pH, and pasting properties of flour processed from the yam tubers were determined. Also, the sensory attributes of pounded yam produced from the tubers were evaluated. In terms of colour, Gbongi had the highest whiteness value (82.27). Lasinrin had the highest moisture content (39.47 %) and swelling capacity (6.11g/g), Efuru had the highest water absorption capacity (132.50%) and pH (6.75). Gbongi had the highest solubility index (13.82%). Awana had the highest peak viscosity (293.70RVU) holding strength viscosity (279.20RVU) and peak time (7.00min). Lasinrin had the highest breakdown viscosity (140.25RVU) setback viscosity (295.00RVU) and pasting temperature (82.55oC) while Efuru had the highest final viscosity (437.83RVU). All the varieties had good ratings for the pounded yam sensory attributes (stretchability, stickiness, mouldability, smoothness, colour, hardness). All the varieties were acceptable regarding the general acceptability of the pounded yam. The qualities of yam cultivars suggested their appropriateness as an alternative for other flour-based pastestypically consumed by Nigerians.

The Effect of Dual-Modification by Heat-Moisture Treatment and Octenylsuccinylation on Physicochemical and Pasting Properties of Arrowroot Starch.

Starch is widely applied in various industrial sectors, including the food industry. Starch is used as a thickener, stabilizer, or emulsifier. However, arrowroot starch generally has weaknesses, such as unstable under heating and acidic conditions, which are generally applied to processing in the food industry. Modifications were applied to improve the characteristics of native arrowroot starch. In this study, arrowroot starch was modified by heat-moisture treatment (HMT), octenylsuccinylation (OSA), and dual modification between OSA and HMT in a different sequence--namely, HMT followed by OSA, and OSA followed by HMT. This study aims to determine the effect of different modification methods on the physicochemical and functional properties of native arrowroot starch. The result shows that both single HMT and dual modification caused damage to native starch granules, such as the formation of cracks and roughness. For single OSA treatment, especially, there is no significant change in granule morphology after modification. All modification treatments did not change the crystalline type of starch but reduced the RC of native starch. Both single HMT and dual modifications (HMT-OSA, OSA-HMT) increased pasting temperature and setback, but, conversely, decreased the peak and the breakdown viscosity of native starch, whereas single OSA had the opposite trend compared with the other modifications. HMT played a greater role in increasing the thermal stability and the retrogradation ability of arrowroot starch. Both single modifications (HMT and OSA) increased the hardness and gumminess of native starch, and the opposite was true for the dual modifications. HMT had a greater effect on color characteristics, where the lightness and whiteness index of native arrowroot starch decreased. Single OSA modification increased swelling volume higher than dual modification. Both single HMT and dual modifications increased water absorption capacity and decreased the oil absorption capacity of native arrowroot starch.

Production and Quality Evaluation of Gluten Free Biscuits from Maize and Soybean Flour Blends

The study evaluated the quality of gluten–free biscuits made from maize and soybean flour blends, and compared them with 100% wheat flour biscuit. Flours were prepared from maize and soybean grains. The soybean flour was used to substitute 5, 10, 15, 20 and 30% of maize flour in order to obtain various flour blends. The chemical composition, functional and pasting properties of the flours and their blends were determined. The flour blends were used to prepare biscuits, which were analyzed for the chemical composition, physical and sensory properties. The results showed that the moisture, protein, fat, fiber, ash, and carbohydrate contents of the flours ranged from 10.58-11.37, 7.30-42.23, 1.82-10.15, 0.34-5.20, 0.85-4.00, 27.84-76.41%, respectively. The phosphorus, iron and magnesium contents varied from 1.24-166.96, 2.31-19.54, 0.01-157.56mg/100g, respectively. The bulk density, foaming capacity, water absorption and oil absorption capacity of the flours and the blends ranged from 0.66-0.68g/cm3, 3.22-29.25%, 85.00-210.00g/g and 80.0-145g/g, respectively. The peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, peak time and pasting temperature decreased with an increase in the level of soybean flour incorporation and ranged from 113.05-127.98, 83.95.97.05, 23.99-41.95, 224.02-409.98, 136.01-325.03, 6.12-7.05, and 55.4-95.0 RVU, respectively. The moisture, protein, fat, fiber, ash, and carbohydrate of the biscuits increased from 4.10-9.19, 34.94-40.38, 27.24-31.39, 6.88-7.93, 0.53-3.79, and 16.99-23.44%, respectively. The phosphorus, iron, and magnesium contents of the biscuits ranged from 47.01-65.91, 3.37-7.08, 0.0018-0.0047mg/100g, respectively. The sensory scores for the biscuit samples decreased with the level of soybean flour. However, the biscuits containing 10% soybean flour was not significantly (p>0.05) different from the 100% wheat flour biscuits in all the sensory attributes evaluated. Therefore, comparable biscuits with 100% wheat biscuit could be produced from the blend of 90 % maize flour and 10% soybean flour.

Exogenous Application of Methyl Jasmonate Promotes Yield and Grain Quality of Rice under Terminal Drought Stress

Exogenous application of methyl jasmonate (MeJA) improves rice drought tolerance, but its effects on rice yield and quality under drought stress during the reproductive phase remain unclear. A pot experiment was conducted to measure rice yield, grain quality, and starch physicochemical properties under three treatments: continuous flooding irrigation throughout the whole growth season (CF), ten days of −40 kPa drought stress at the heading stage (DS), and foliar spraying 100 μmol L−1 MeJA on the first three days of the ten-day −40 kPa heading stage drought stress (DM). An inbred japonica rice variety, Huaidao 5, was the experimental material, and each treatment had 11 replicates for sampling. The results indicated that DS significantly reduced rice yield and quality compared to CF. With increases in superoxide dismutase (+22.2%), peroxidase activities (+10.5%), catalase (+5.0%), and proline content (+5.7%), DM significantly increased 1000-grain weight (+8.6%), filled grain percentage (+3.6%), and yield (+11.1%) compared with DS. Regarding grain quality, DM significantly decreased the chalkiness degree (−12.3%) and protein content (−3.9%) but increased the amylose content (+17.2%) and taste value (+7.3%) relative to DS. In addition, DM improved breakdown viscosity (+17.8%), gelatinization enthalpy (+17.2%), retrogradation enthalpy (+28.0%), 1045/1022 cm−1 ratio (+3.0%), and starch granule morphology compared to DS. In conclusion, exogenous application of 100 μmol L−1 MeJA enhanced the antioxidant capacity of rice leaves, and thus improved starch physicochemical properties to increase grain yield and quality under terminal drought stress.

Avocado seed starch: Effect of the variety on molecular, physicochemical, and digestibility characteristics

Agro-industrial residues can increase environmental pollution owing to poor knowledge of the use of some components, such as dietary fiber, protein, starch, minerals, and bioactive compounds, which can be used in the food industry. This study compared the molecular, physicochemical, and digestibility characteristics of three avocado seed starches (Criolla, Fuerte, and Hass). Starch was extracted through successive washing and sedimentation. The morphology, size distribution, thermal properties, pasting properties, infrared spectra with Fourier transform, size distribution of amylopectin chains, and digestibility of the three avocado seed strains were analyzed. The starch grains were oval and spherical in shape. The average size of Criolla avocado starch (24.55 μm) was the largest, followed by Hass and Fuerte starches (21.37 μm). Higher gelatinization enthalpy (8.55 J/g), gelatinization temperature (75.28 °C), and pasting temperature (75.57 °C) were observed for Fuerte avocado starch, followed by Hass and Criolla starches. Hass avocado starch exhibited higher maximum (836.27 mPa.s), final (1407.37 mPa.s), setback (588.78 mPa.s), and breakdown (17.68 mPa.s) viscosities than Criolla and Fuerte avocado starches. In addition, the probed avocado starches exhibited high content of resistant starch (60.06–68.90%). Therefore, it was demonstrated that differences in the chemical composition and structure of avocado starch can affect the digestibility of native starch.

Effect of Ultrasonic Treatment on Structure and Physicochemical Properties of Pea Starch.

The effects of ultrasonic treatment on the structure and physicochemical properties of pea starch were investigated in this study. The results showed that ultrasonic treatment increased the hydrolysis rate and particle size of pea starch. In the process of treatment, there were some depressions and pores on the surface of pea starch granules. Although the crystallization type of starch was retained, its crystallinity decreased. The pasting temperature of pea starch remained stable after ultrasonic treatment, but its peak viscosity, trough viscosity, cold viscosity, breakdown viscosity and setback viscosity all declined significantly. The transparency of starch paste decreased, but proper ultrasonic treatment could improve the strength of starch gel. The obtained results can provide a reference for the physical modification of pea starch.

Effect of Selected Pre-Treatments on The Functional and Pasting Properties of Pigeon Pea Flour

The effect of three different processing conditions (fermentation, steaming and roasting) on the functional and pasting properties of an under-utilised legume pigeon pea were investigated. This study aimed to optimise these processing conditions for the processing of pigeon peas. Response Surface Methodology (RSM) based on a 3-level full factorial of the Random sample design was selected to optimise the effect of fermentation, steaming and roasting on the quality parameters of pigeon peas. The quality parameters of the pre-treated beans: functional and pasting properties were determined to see the effects of the pre-treatment using standard laboratory procedures. For functional properties, values obtained were: bulk density (0.64 - 0.81)g/ml, water absorption capacity (123.64-174.64)%, oil absorption capacity (78.8-106.13)% , swelling capacity (11.60-27.96)%, foaming capacity 5.57-15.15 and foam stability (0.84 and 6.25)%. Values obtained for pasting properties have their regression coefficient (R2) as peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, peak time and pasting temperature as 0.69, 0.05, 0.51, 0.37, 0.34, 0.07 and 0.54 respectively while the adjusted R2 values for same parameters were 0.39, -0.09, 0.04, -0.25, -0.32, -0.87 and 0.07 respectively. Furthermore, the Coefficient of Variation (CV) derived for peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, peak time and pasting temperature was 8.86, 19.24, 35.03, 4.99, 27.34, 16.57 and 4.29 respectively. The response surface plots depict the effects of steaming temperature and steaming time on the pasting properties of fermented pigeon pea flours. The optimum conditions for the variables investigated with fermented, steamed, and roasted pigeon peas with suitable quality characteristics were fermentation temperature of 270C for 4 days, steaming at 100oC for 20 minutes, and roasting at 1400C for 8 minutes. The pasting properties are also reflective of the functional properties so also the response surface plots. This information will be necessary for the utilisation of pigeon peas with improved physical conditions for exploitation on a large scale.

Effect of varietal differences on chemical and pasting properties of composite wheat-cassava flours produced from low postharvest physiologically deteriorated cassava roots (Manihot esculenta Crantz)

This study investigated the effect of varietal differences on the chemical and pasting properties of composite wheat-cassava flours produced with blend of wheat and high-quality cassava flour from low postharvest physiologically deteriorated (PPD) cassava roots. Wholesome four varieties of yellow-fleshed low PPD cassava roots and one variety of high PPD cassava root were, peeled, washed, grated, pressed, pulverized, flash dried at 120 °C for 8 minutes, milled with cyclone hammer mill fitted with a screen of 250 µm aperture size, cooled and packed into high density polyethylene bag. The high-quality cassava flours (HQCF) were composited with wheat flour and analyzed for chemical and pasting properties. Data obtained were subjected to analysis of variance (ANOVA) using Statistical Package for Social Sciences (SPSS version 25.0) and significant means were separated applying Duncan multiple range test and Pearson’s correlation was also determined. The results depict that moisture, protein, fat, ash, sugar, starch, dry matter and energy value ranged from 12.45 - 13.10 %, 10.30 - 11.65 %, 0.40 - 3.71 %, 0.58 - 0.62 %, 1.75± - 2.08 %, 70.94 - 74.40 %, 86.90 - 87.55 % and 1464.29 - 1531.66 KJ/kg, respectively. Peak, trough, breakdown, final, setback, peak time and pasting temperature ranged from 180.63 - 247.21 RVU, 95.84 - 129.00 RVU, 83.42 - 118.21 RVU, 139.29 - 253.71 RVU, 83.79 - 124.71 RVU, 5.90 - 6.17 min and 69.00 - 73.48 °C, respectively. Considering the relatively high dry matter content, energy value, peak viscosity, low breakdown viscosity and pasting time, flour blends C-C1368-W and C-C0593-W prepared with HQCFs from IITA-TMS-IBA-011368 and IITA-TMS-IBA-070593 cassava varieties could find application in baking and confectionery industry.

Physicochemical characteristics of three potato cultivars grown in different cultivation periods

The composition and properties of potatoes have been comprehensively studied; however, effects of different cultivation periods on these factors remain unclear. Hence, we aim to provide insights for cultivating potatoes with desirable properties by controlling the potato growth time and cultivars. Physico-chemical quality characteristics of three potato cultivars—Chubaek, Superior, and Atlantic—were analysed at different cultivation periods (80, 90, and 100 days). Regardless of cultivation period, total starch and amylose content of the cultivars was as follows: Atlantic > Superior > Chubaek, whereas sucrose and glucose content was in reverse order. The Atlantic cultivar showed the highest dry matter content, whereas Chubaek showed the highest moisture content. In all cultivars, glutamic acid and aspartic acid were the predominant amino acids. Peak viscosity was the highest in Atlantic cultivar and increased as the cultivation period progressed. Final, peak, and breakdown viscosities were positively correlated with starch and amylose content and negatively correlated with glucose, sucrose, and most amino acid content. Hierarchical clustering heatmaps showed that all three cultivars cultivated for 100 days exhibited different patterns from those cultivated for 80 and 90 days. Overall, quality characteristics of the potatoes were more influenced by genetic characteristics than by the cultivation period.

Effect of various pretreatments of potato on the cooking and texture properties of the developed potato-rice noodle.

In order to ascertain optimal potato pretreatment strategy for potato-rice noodle processing, the effect of partial substitution of rice flour with potatoes processed by various pretreatment on rice noodle quality was determined. In this study, raw potato flour (RPF), cooked potato flour (CPF), potato pulp (PP), mashed potato (MP), and rice flour (RF) were prepared. The physicochemical and pasting properties of RF sample, RPF+RF, PP+RF, CPF+RF, and MP+RF blends were investigated relative to their noodle quality. The results indicated that compared to RF, CPF+RF, and MP+RF blends, RPF+RF and PP+RF blends exhibited a lower degree of starch damage, solubility, and breakdown viscosity, as well as higher relative crystallinity, final, and setback viscosity, which are favorable to quality of noodles. Therefore, the noodles made from RPF+RF and PP+RF showed the most desirable cooking quality and texture. In summary, high damaged starch content and excessive amylose content were detrimental to noodle making. Consequently, our research revealed that RPF/pulp (ungelatinized potato materials) blended with rice flour can be employed to produce decent potato-rice noodles. PRACTICAL APPLICATION: Cooked potato flour is main processing method of commercial potato flour and widely used in potato staple food industry. However, the results of our study show that raw potato flour and potato pulp are more suitable for processing of potato-rice noodle than cooked potato flour and mashed potato and can significantly improve the quality of rice noodle. This provides new ideas and insights for the preprocessing of raw potato in the potato staple food industry and the quality improvement of rice noodle. HIGHLIGHTS: The physicochemical properties of potatoes changed with various pretreatments. Excessive amylose content and starch damage were detrimental to noodle making. Partial substitution of rice flour with raw potato flour/pulp improved rice noodle quality. Raw and ungelatinized potato material is preferable for potato-rice noodle making.

Effects of Porphyra haitanensis polysaccharides on gelatinization and gelatinization kinetics of starches with different crystal types

The effects of Porphyra haitanensis polysaccharide (PHP) on the gelatinization and gelatinization kinetics of corn starch (CS), potato starch (PS) and lotus seed starch (LS) were studied. The gelatinization, rheological and thermal enthalpy properties of the samples were measured by a rapid viscosity analyzer (RVA), a rheometer, and a differential scanning calorimeter (DSC), respectively. And the kinetic equations were further established. RVA confirmed that the addition of 0.4 %, 0.8 % and 1.2 % PHP elevated the gelatinization viscosity of CS and LS but decreased that of the PS, and also elevated the thermal balance of CS, PS, and LS, especially PS (The breakdown viscosity was decreased to 363.00 ± 6.08, 370.00 ± 1.15, and 362.00 ± 0.58, respectively). And the rheometer indicated that the addition of 0.4 %, 0.8 % and 1.2 % PHP improved the apparent viscosity of CS, PS and LS, especially PS (The consistency coefficient was increased to 18.26 ± 0.02, 21.71 ± 0.04, and 23.26 ± 0.01, respectively). Eventually, DSC displayed that the addition of 0.4 %, 0.8 % and 1.2 % PHP extended the gelatinization temperature and enthalpy of CS, PS, and LS, especially PS. Among them, the gelatinization temperature (63.40 ± 0.03, 70.26 ± 0.02 and 74.61 ± 0.01, respectively) and the gelatinization enthalpy (1.55 ± 0.01) of PS increased the most with 1.2 % PHP. Moreover, gelatinization kinetics displayed that the addition of 0.4 %, 0.8 % and 1.2 % PHP decreased the rate constants of CS, PS, and LS and accelerated the activation energies of CS (666.37 ± 4.23, 623.89 ± 4.21 and 558.39 ± 2.35, respectively) and PS (752.53 ± 4.13, 699.61 ± 3.78 and 662.15 ± 4.52, respectively) while reducing that of the LS (938.87 ± 3.38, 669.98 ± 4.61 and 491.48 ± 4.29, respectively). Therefore, the addition of PHP at all concentrations inhibited the gelatinization procedure of CS and PS but promoted that of the LS. This study provided a theoretical basis for the creation of new products based on PHP and starch.

Physicochemical properties and molecular structure of starches from different wheat varieties and their influence on Chinese steamed bread.

Starch is one of the key factors for the texture of Chinese steamed bread (CSB). In this study, the molecular structures and physicochemical properties of starches from 11 wheat varieties with amylose content (AC) of 1.75%-28.79% were investigated. Northern style CSB was made using these wheat varieties to explore the structure-property-quality relationship of starches. AC was negatively correlated with the pasting and gelatinization properties. The relative crystallinity (RC) had a negative correlation with AC but a positive correlation with gelatinization. The molecular structure results from the fluorophore-assisted capillary electrophoresis spectrophotometer indicated that the length of short amylopectin chains (βAp,i ) was positively correlated with hot paste and cool paste viscosities. The amount of medium amylopectin chains (hAp,iii ) was positively correlated with peak and breakdown viscosities but negatively correlated with setback viscosity. The hAp,iii had positive correlations with gelatinization temperatures and RC. The amount of long amylopectin chains (hAp,v ) had a positive correlation with peak temperature. For the CSB texture, βAp,i had negative correlations with hardness and chewiness, whereas had a positive correlation with resilience. The hAp,iii was negatively correlated with springiness and resilience. The hAp,v was negatively associated with resilience. PRACTICAL APPLICATION: Starch has a vital role in wheat flour products. Clarifying the structure-property-quality relationship of starches will help illuminate the role of starch molecular structure in CSB production and provide valuable information for the control of CSB quality. It also provides a significant reference for wheat breeding.

Development of Gluten-Free Bread Using Teosinte (Dioon mejiae) Flour in Combination with High-Protein Brown Rice Flour and High-Protein White Rice Flour.

Gluten-free bread is an important product that is under development using different sources, such as rice and starchy plants. Teosinte seeds are utilized by ethnic groups in Honduras to produce gluten-free flour to prepare traditional baked goods and beverages. The quality of gluten-free products could vary depending on flour properties, such as amylose content, particle size, and water absorption capacity. A good strategy for developing baked goods is to mix different cereal grain sources to optimize their physicochemical properties. As a result, the current study aimed to develop bread from novel flours including teosinte (TF), high-protein brown rice (BRF), and high-protein white rice (WRF). Breads were analyzed for hardness, specific volume, and color utilizing a Simplex-Centroid mixture design coupled with the desirability function. Pasting, and rheological characteristics of the flours, were also analyzed. For flour characteristics, TF addition to BRF or WRF decreased the peak, trough, breakdown, setback, and final viscosities, which would result in a more stable bread and decrease the flow index of rice flour dispersions. BRF and WRF had similar pasting properties, except that BRF had a lower breakdown viscosity. For bread characteristics, TF addition to BRF or WRF increased the specific volume and hardness of the bread compared to rice flour alone. L* of the crust and crumb a* values were increased with greater TF in the mixture, whereas TF decreased the crust a*and b* values and crumb L* values when mixed with BRF or WRF compared to rice flours alone. WRF and BRF were similar in crumb color (L* and a*), except that BRF had greater crumb yellowness (b*). Teosinte flour can be used in combination with rice flour to produce bread with good quality.

Some Quality Attributes of Composite Flour and Bread Produced from Wheat and African Walnut

This study explored the potential of African walnut in the formulation of composite flour which can be used for bread production and in various food applications. African walnut flour was produced and used to substitute wheat flour at different levels (5 - 25%) in the production of wheat-African walnut composite flour. Functional and pasting properties of the composite flour were evaluated using standard procedures. Proximate composition, antioxidant activity, some loaf quality attributes and sensory acceptability of bread produced from the composite flour were evaluated using standard procedures. Wheat bread served as control. The composite flour showed varying functional properties which ranged from 2.43 to 3.46 (swelling capacity), 1.15 to 1.85 mL/g (water absorption capacity), 2.15 to 2.75 mL/g (oil absorption capacity), 10.80 to16.60% (foam capacity), 63.0 to 75.0% (dispersibility), 38.92 to 69.92 seconds (wetability), 0.75 to 0.79 g/mL (packed bulk density) and 0.43 to 0.47 g/mL (loose bulk density). Inclusion of African walnut reduced peak viscosity (53.92 – 148.83 RVU), trough viscosity (52.25 – 88.58 RVU), breakdown viscosity (1.67 – 60.25 RVU), final viscosity (74.08 – 191.25 RVU) and setback viscosity (21.83 – 102.67 RVU) of the composite flour. Composite bread had better protein (9.75 – 16.93%), fat (3.42 – 9.94%), ash (1.46 – 2.75%), crude fibre (0.86 – 3.64%) but reduced specific loaf volume (2.36 – 4.18 cm3/g) and loaf height (3.00 – 5.40cm) than the control, and exhibited appreciable antioxidant activity (DPPH: 31.60 – 73.09% and FRAP: 0.51 - 4.25 mg/g). In term of sensory acceptability composite bread samples produced with 5 and 10 % levels of African walnut compared favourably with bread produced from wheat flour. Thus composite flour produced from wheat and African walnut flours showed an array of physicochemical properties which could make it useful in different food applications. Acceptable bread could be produced from wheat flour substituted with African walnut flour at 10% level.

Changes in the structural and physicochemical characterization of pea starch modified by Bacillus-produced α-amylase

In this study, changes in structural and physicochemical properties of pea starch treated with Bacillus-produced α-amylase were determined. The results showed that enzymatically modified pea starch had lower amylose content and granule size but higher branching degree and relative crystallinity. After enzyme hydrolysis, the distribution of A and B1 chains slightly decreased, while the distribution of B2 and B3 chains increased lightly. Enzymatic hydrolysis preferentially occurred in the amorphous region and cannot change the crystalline structure of pea starch. Moreover, pea starch showed lower light transmittance, peak viscosity, breakdown viscosity, pasting temperature, shear viscosity, storage modulus and loss modulus, while the oil adsorption capacity and gelatinization enthalpy significantly increased with increasing α-amylase hydrolysis time. Correlation analysis indicated that α-amylase hydrolysis had different effects on different pea varieties. This research could provide ideas for exploring new applications for enzymatically modified pea starch in food industry. Industrial relevanceThis study found that Bacillus-produced α-amylase significantly changed the amylose content, granule size and viscosity of pea starch, which was helpful to further investigate the modified starch. This technology is expected to widen the applications of pea starch modified by Bacillus-produced α-amylase in food industry, for example as thickener, stabilizer and beverage, to improve the texture, stability and shelf-life of various food products.

Effects of Processing Methods on the Yield, Functional and Pasting Properties of “Garri Analogue” Produced from Different Varieties of Orange Flesh Sweet Potato

Garri is a fermented, dry granular meal produced from cassava roots which is of high carbohydrate content with little of other nutrients. Orange Fleshed Sweet Potato (OFSP) is a root crop with high nutritional properties and so its use for “garri analogue” has been found to be of better nutritional qualities than cassava. However, considerations are yet to be given to the effect of varieties and processing variables of OFSP on the qualities of “garri analogue”. Therefore, this study evaluated the effect of different varieties and processing variables of OFSP on the qualities of “garri analogue”. Three varieties of OFSP (Mother’s Delight, King J and Solo Gold) were procured from local farmers in Osun State. Two different processing parameters: fermentation time (24, 48 and 72h) and particle size (1.4, 1.8 and 2.36mm) were considered. The yield, functional properties (bulk density, water absorption capacity, oil absorption capacity, gelatinization temperature, least gelation concentration and swelling capacity) and pasting properties of the “garri analogue” were evaluated. Data obtained were subjected to Analysis of Variance and means were separated using Duncan Multiple Range Test at 5% level of significance. The yields for the three varieties of OFSP are 0.50, 0.60 and 0.80kg for Mother’s Delight, King J and Solo Gold respectively. Oil absorption capacity (1.40 -3.27 , 1.77 - 2.67 and 1.50 -2.77 g/100g), water absorption capacity (1.70 -4.57 , 2.17 -3.87 and 2.17 -3.87 g/100g), gelling (20.00 – 50.00 , 20.00 – 50.00 and 20.00– 50.00 g/dm3), gelatinization temperature (95.00-100.00, 94.00-100.00 and 94.00-100.00oC), swelling capacity (20.00– 50.00, 20.00– 50.00 and 20.00– 50.00 g/dm3) and bulk density (0.42 -0.53, 0.42 -0.53 and 0.42 -0.53g/ml). Peak viscosity (1.52 x102-4.59 x 102, 3.70 x102 -5.58 x 102 and 2.68 x 102-5.83 x 102 RVU), trough viscosity (1.32-3.22 x 102, 2.65x102 -3.73 x 102 and 1.82. x 102-5.62 x 102 RVU), breakdown viscosity (13.6-1.37 x 102, 1.03 x 102 -93.14 x 102 and 21.64 x 102 -1.14 x 102 RVU), final viscosity (2.09-5.16 x 102, 4.30 x 102 -5.28 x 102 and 2.82 x 102 -6.00 x 102 RVU), setback viscosity (76.72-2.07 x 102, 1.27 x 102 -1.89 x 102 and 1.10 x 102 – 2.36 x 102 RVU), peak time (5.01-6.11, 5.05-5.49 and 5.00-7.00 mins) and pasting temperature (85.13-89.90, 87.58-91.50 and 87.47-92.57oC). The variety that had an effect on the functional and pasting properties of the “garri analogue” was Mother’s Delight, while in term of processing variables on the functional and pasting properties of “garri analogue: from the different varieties are Mother’s Delight and King J. The optimum results in term of the processing variables on the yield, functional and pasting properties from the different varieties are Mother’s Delight and Solo Gold. The optimum results were obtained at 48.00 and 72.00hrs with particle sizes of 1.88 and 2.36mm respectively.