Characterization and utilization of nixtamalised rice flours in the production of cake

In an attempt to provide an alternate rice processing technique and enhance its nutritional quality, Faro 52 (Upland) and Nerica 8 (Lowland) rice grains were subjected to nixtamalisation involving cooking and soaking in a lime solution. The proximate composition, functional properties and pasting characteristics of the nixtamalised and nonnixtamalised rice flours were evaluated. Cakes produced with the rice flours were also subjected to sensory evaluation. Nixtamalisation significantly increased the protein content of upland (NUPRF) and lowland (NLLRF) rice flours by 28.19% and 27.80%, respectively. Nixtamalisation also enhanced the water absorption capacity of the rice flours, while the oil absorption capacity increased significantly. Pasting viscosities of all the nixtamalised flours were lower than their non-nixtamalised samples, while the pasting temperature increased. Nixtamalised rice cakes were not significantly different in colour, texture, flavour and overall acceptability from non-nixtamalised rice cakes. Nixtamalisation may be beneficial in rice processing for enhanced nutritional content and functionality, and the flour may be useful as a thickener and binder in food systems and the production of acceptable cakes.

Application of crude pectolytic enzymes from Saccaharomyces cerevisiae (ATCC 52,712) to starch extraction in Ghana: effects of enzyme technology on pasting characteristics in different cassava varieties

Previous work on enzyme application to starch extraction enhanced yield and starch recovery rates as well as modified some physicochemical properties of starches for potential alternative application to industry. The response of the technology, however, showed some sensitivity to variety. The knowledge gap therefore was to establish whether such physicochemical responses (by the technology) to variety affects the pasting parameters of the starches extracted. The pasting parameters of starches extracted from four different cassava varieties (‘Nkabom’, ‘Afisiafi’, ‘Bankyehemaa’ and ‘Esambankye’), with the aid of crude pectolytic enzymes from the Saccharomyces cerevisiae (ATCC 52,712), were investigated. Although a general response pattern was observed for most of the pasting parameters measured, which includes general enhancements (P < 0.05) in starch gelatinization viscosity, with improvements in gelatinization time and temperature and peak viscosities in most of the varieties, there were significant differences (P < 0.05) in their respective peak time and temperature requirements for the attainment of peak viscosity. Values for the breakdown viscosity were also generally increased (P < 0.05). The technology also increased values for setback viscosity in both the ‘Nkabom’ and ‘Bankyehemaa’ varieties but reduced setback values in the ‘Afisiafi’ and ‘Esambankye’ varieties. As pasting properties are one of the most important characteristics of starch that determine its overall utility, knowledge from this study should inform how adoption of the technology would help diversify the various cassava varieties for appropriate domestic and industrial applications while harnessing its benefits of improved starch yield.

The Influence of the Addition of Nuts on the Thermal and Rheological Properties of Wheat Flour

The aim of the study was to assess the influence of replacing wheat flour with hazelnuts or walnuts, in various amounts, on the thermal and rheological properties of the obtained systems. The research material were systems in which wheat flour was replaced with ground hazelnuts (H) or walnuts (W) in the amount of 5%, 10%, and 15%. The parameters of the thermodynamic gelatinization characteristics were determined by the differential scanning calorimetry method. In addition, the pasting characteristics were determined with the use of a viscosity analyzer and the viscoelastic properties were assessed. Sweep frequency and creep and recovery tests were used to assess the viscoelastic properties of the tested gels. It was found that replacing wheat flour with nuts increased the values of gelatinization temperature, gelatinization, and retrogradation enthalpy, and the degree of retrogradation. The highest viscosity was characteristic of the control sample (2039 mPa·s), and the lowest for the paste with 15% addition of walnuts (1120 mPa·s). Replacing the flour with nuts resulted in a very visible reduction in the viscosity of such systems. In addition, gels based on the systems with the addition of H and W were weak gels (tan δ = G″/G′ > 0.1), and the values of G′ and G″ parameters decreased with the increased share of nuts in the systems. Creep and recovery analysis indicated that the systems in which wheat flour was replaced with hazelnuts were less susceptible to deformation compared to the systems with the addition of W.

A Comparative Study on the Viscoelastic Properties of Wheat, Maize and Cassava Flours as Affected by Some Leguminous Seed Flours

The effects of some leguminous seed flour (LSF) on the viscoelastic properties of wheat, maize and cassava flours were investigated. The aim of the work was to evaluate the effect of the LSF on the pasting characteristics of the flours. There were significant differences in the proximate composition of the flours used in this study. Three LSF namely Brachystegia eurycoma, Detarium microcarpum, and Mucuna sloanei flours were used in this study. The LSF were added differently at 0 and 2% to wheat, maize and cassava flours on dry weight bases, the 0% addition served as the control. The viscoelastic properties were determined using Rapid Visco Analyser (RVA). The results showed that the LSF significantly affected the pasting properties of the wheat, maize and cassava flours. The LSF significantly increased (p>0.05) the breakdown, final, trough and peak viscosities of the wheat and maize flours. However, the LSF significantly (p>0.05) reduced the peak, breakdown and setback viscosities of cassava flour compared to the control.

Physico-Functional and Starch Pasting Properties of Cassava (Manihot Esculenta Cruntz) Flours as Influenced by Processing Technique and Varietal Variations

This study investigated effects of processing technique and varietal variations on the physico-functional, starch pasting and viscoelastic properties of cassava (Manihot Esculenta Crantz) flours using a 3x6 factorial experimental approach. Samples were evaluated for their non-volatile acidity, pH, swelling power, solubility water absorption capacity (27oC and 70oC), colour and starch pasting characteristics of the cassava flours using standard methods. Grating and soaking of the cassava tubers significantly (p<0.05) reduced the pH of all the varieties with concomitant increases in non-volatile acidity. Grating and soaking significantly (p<0.05) reduced the swelling power, solubility and water absorption capacity of the flours. Soaked Chila B flour recorded the highest pasting temperature of 66.9°C whiles soaked Mweulu flour recorded the highest peak viscosity (684 BU), viscosity at 95oC (683 BU) and viscosity at 95oC-hold (359 BU), suggesting that the flours from the different cassava varieties could be targeted for different food and industrial products. Cassava (Manihot esculenta Crantz) is an important root crop in the world and it provides food for about one billion people globally. It contributes significantly to the economy of most tropical countries through processing into various products. Varietal variation in cassava plays a very important role in the production of diversified food products due to its inherent biochemical characteristics such as starch content, sugar content and pasting characteristics. The biochemical composition in the tubers varies according to varieties. Physico-functional and starch pasting properties of cassava are among the most important parameters used to predict the suitability of flours and starches for certain end product uses, and these would aid the selection of appropriate varieties for use in various food and industrial applications.

The Annealing of Acetylated Potato Starch with Various Substitution Degrees

This study aimed to determine the effect of “annealing” acetylated potato starch with a homogenous granule size and various degrees of substitution on the thermal pasting characteristics (DSC), resistance to amylases, rheology of the prepared pastes, swelling power and dynamics of drug release. A fraction of large granules was separated from native starch with the sedimentation method and acetylated with various doses of acetic anhydride (6.5, 13.0 or 26.0 26 cm3/100 g starch). The starch acetates were then annealed at slightly lower temperatures than their pasting temperatures. The annealing process caused an almost twofold increase in the resistance to amylolysis and a threefold increase in the swelling power of the modified starch preparations. The heat of phase transition decreased almost two times and the range of starch pasting temperatures over two times, but the pasting temperature itself increased by ca. 10 °C. The 40 g/100 g addition of the modified starch preparation decreased the rate of drug release from a hydrogel by ca. one-fourth compared to the control sample.

Late-Maturity Alpha-Amylase in Wheat (Triticum aestivum) and Its Impact on Fresh White Sauce Qualities

When wheat experiences a cold-temperature ‘shock’ during the late stage of grain filling, it triggers the abnormal synthesis of late-maturity α-amylase (LMA). This increases the enzyme content in affected grain, which can lead to a drastic reduction in falling number (FN). By commercial standards, a low FN is taken as an indication of inferior quality, deemed unsuitable for end-product usage. Hence, LMA-affected grains are either rejected or downgraded to feed grade at the grain receiving point. However, previous studies have found no substantial correlation between low FN-LMA and bread quality. The present study extends previous investigations to semi-solid food, evaluating the physical quality of fresh white sauce processed from LMA-affected flour. Results show that high-LMA flours had low FNs and exhibited poor pasting characteristics. However, gelation occurred in the presence of other components during fresh white sauce processing. This demonstrates that LMA-affected flours may have new applications in low-viscosity products.

The Improved Chemical, Mechanical, Rheological, and Pasting Characteristics of Protein-Rich Brown Rice by Parboiling Process Integrated with Nitrogen Fertilization

The effects of nitrogen fertilization (NF, 60-100 kg ha-1) and parboiling operation (soaking temperature (SoT, 50-80°C) and steaming time (StT, 10-15 min)) on the protein content (PC), amylose content (AC), gelatinization temperature (GT), hardness value (HV), peak viscosity (PV), trough viscosity (TV), final viscosity (FV), breakdown (BD), setback (SB) point, peak time (PTi), and pasting temperature (PTe) of brown rice were evaluated. Results showed that the GT, HV, FV, and TV were significantly increased by increasing the NF, SoT, and StT levels. An increase in the SoT and StT levels led to a significant reduction in PC, AC, BD, and TV values. The AC (17.13-16.83%) and PV (1605-1588 cP) values were decreased by increasing the NF level, while the PC (8.78-9.46%) and BD (226.9-247.7 cP) values were increased. Rheological parameters of BD (336.4 cP), FV (3608.5 cP), and SB (1843.5 cP) were notably increased using the combined treatment of 100 kg ha-1 NF and of 80°C SoT. The best triple treatments for the improved GT (5.0 °C), HV (19.37 N), as well as FV (3923 cP), and SB (1949 cP) were 60 kg ha-1 NF+80°C SoT+15 min StT, 100 kg ha-1 NF+80°C SoT+15 min StT, and 100 kg ha-1 NF+80°C SoT+10 min StT, respectively.

Effects of the Inclusion of Andrographis paniculata Leaf on the Functional Properties and Pasting Characteristics of Wheat-pearl Millet-Based Flour Blends

This study evaluated flour blends from Wheat, Pearl millet and Andrographis paniculata leaf for functional properties and pasting characteristics profiling. The functional properties such as solubility, gelling capacity, water absorption capacity (WAC), Oil absorption capacity (OAC), Bulk density, foaming capacity and stability and swelling capacity and the pasting characteristics were studied. The inclusion of A. paniculata leaf flour in the blends revealed a significant general increase in water absorption capacity, oil absorption capacity, swelling capacity, and bulk density. However, a general decrease in the foaming capacity, solubility, and least gelation was observed as the inclusion of A. paniculata leaf flour increased. The pasting properties of WPMF (flour blend without the inclusion of A. paniculata leaf flour) exhibited the following values: peak viscosity (658 RVU), breakdown (372 RVU), final viscosity (923 RVU), setback (637 RVU), peak time (5.07 min), and pasting temperature (84.8oC). The inclusion of A. paniculata leaf flour in the blends led to a significant general decrease in all the pasting factors. The inclusion of A. paniculata had a significant effect on the functional and pasting properties of wheat-pearl millet based flour.