Starch-based noodles: Current technologies,properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.     

A review of microbes and chemical contaminants in dairy products in sub-Saharan Africa

Animal milk types in sub-Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered as potential health hazards. Consumption of contaminated milk products could have serious health implications for consumers. To access the safety of milk products across SSA, studies in the region investigating the occurrences of pathogens as well as chemical compounds such as heat stable toxins and veterinary drug residues in animal milk and its products were reviewed. This is done with a holistic view in light of the emerging exposome paradigm for improving food safety and consumer health in the region. Herein, we showed that several published studies in SSA applied conventional and/or less sensitive methods in detecting microbial species and chemical contaminants. This has serious implications in food safety because the correct identity of a microbial species and accurate screening for chemical contaminants is crucial for predicting the potential human health effects that undermine the benefits from consumption of these foods. Furthermore, we highlighted gaps in determining the extent of viral and parasitic contamination of milk products across SSA as well as investigating multiple classes of chemical contaminants. Consequently, robust studies should be conducted in this regard. Also, efforts such as development cooperation projects should be initiated by all stakeholders including scientists, regulatory agencies, and policy makers to improve the dairy product chain in SSA in view of safeguarding consumer health.     

Lily Starch—An Underutilized and Non-Conventional Source: Properties and Applications

Lily belongs to the genus Lilium of the family Liliaceae. Starch is the main component of lily bulbs which accounts for 53–69% of their dry weight. Lily starch (LS) has B-type X-ray diffraction characterized by a peak at 5.6°, 17°, 22°, and 24°. The swelling and solubility of the LS are significantly higher than rice and corn starches. The gelatinization temperatures of the LS are much lower than maize but higher than wheat and potato starches. The pasting temperature, peak, breakdown, and setback viscosities of lily starches are falling within the range; 66.1–72.7 °C, 1409–3940 cP, 88–1206 cP, and 445–1952 cP, respectively. The range for initial temperature, gelatinization temperature range, and enthalpy for lily starches is also 56.5–64.0 °C, 3.8–10.3 °C, and 3.9–13.9 J g⁻¹, respectively. This review focuses on the recent advances in the understanding of the composition, structure, and properties of lily starches. Furthermore, the limited modification associated with lily starches is also discussed. There is a bold attempt to compare the properties of lily starch with that of the commercial starches of corn and potato.     

Development aid and access to water and sanitation in Sub-Saharan Africa

This paper compares countries’ performance in the water and sanitation sector and analyzes how effectively they used the development aid targeted for this sector. These analyses are validated by presentation of the water and sanitation situation of four case-study countries: Kenya, Madagascar, Burkina Faso and Uganda. The paper also utilizes the innovative Watsan Index of Development Effectiveness, which compares drivers of progress with results achieved and ranks African countries by the level of outcome obtained per unit of available input in the four case-study countries.     

Evaluation of the Mechanical Properties of Reinforcing Steel Bars from Collapsed Building Sites

Mechanical properties of reinforcing steel bars obtained from three different collapsed building sites in Lagos, Nigeria were examined. An optical emission spectrometer was used for chemical composition analysis while the tensile test was carried out using a Universal Testing Machine. The yield strength of the steel bars was found to be higher than BS4449 (GRADE 460B), Nst.65-Mn, and ASTM A706 standards, while their percentage elongations were lower than most of the standards. The steel bars used at the Sango collapse site have higher UTS compared with the standards, while those used at Ilesanmi and Ewuntun collapse sites have UTS values that are in close range with the standards. The reinforcing bar obtained from Ilesanmi collapsed site has higher percentage elongation than ASTM A706 standard but lower than Nst.65-Mn and BS4449 (GRADE 460B) standards. The bars obtained from Sango and Ewuntun collapse sites displayed lower percentage elongation compared with that from Ilesanmi site. All the investigated reinforcing bars possessed reasonably high strength with low ductility. Thus, these bars are susceptible to brittle fracture, which might have contributed to the collapse of the building structures.     

Microstructural Characterization of Thermomechanical and Heat-Affected Zones of an Inertia Friction Welded Astroloy

The behaviour of γ’ phase to thermal and mechanical effects during rapid heating of Astroloy, a powder metallurgy nickel-based superalloy has been investigated. The thermo-mechanical-affected zone (TMAZ) and heat-affected zone (HAZ) microstructures of an inertia friction welded (IFW) Astroloy were simulated using a Gleeble thermo-mechanical simulation system. Detailed microstructural examination of the simulated TMAZ and HAZ and those present in actual IFW specimens showed that γ’ particles persisted during rapid heating up to a temperature where the formation of liquid is thermodynamically favored and subsequently re-solidified eutectically. The result obtained showed that forging during the thermo-mechanical simulation significantly enhanced resistance to weld liquation cracking of the alloy. This is attributable to strain-induced rapid isothermal dissolution of the constitutional liquation products within 150 μm from the center of the forged sample. This was not observed in purely thermally simulated samples. The microstructure within the TMAZ of the as-welded alloy is similar to the microstructure in the forged Gleeble specimens.     

Preparation and characteristics of lactic acid fermented cowpea milk

 Four Lactobacilli were isolated from both commercial cowmilk yoghurt ("Fan" yoghurt) and "wara", a West African soft cheese. They were identified as Lactobacillus acidophilus ("Fan" yoghurt), L. plantarum, L. brevis and unidentified Lactobacillus spp. ("wara"). L. acidophilus and L. plantarum were chosen as starter organisms for the production of a yoghurt-like product from cowpea milk. There was a decrease in the final pH and an increase in the titratable acidity of the cowpea milk samples at the end of the fermentation period. The crude protein, total ash, calcium, potassium and phosphorus values increased in the fermented cowpea milk, while a decrease was obtained for the lipid, moisture and crude fibre contents. A decreasing trend was noted in the phytic acid and trypsin inhibitor of the cowpea flour when processed into milk, followed by a further reduction at the end of fermentation. Consumer acceptability of the cowpea yoghurt varied, with preference being given to the banana and strawberry flavoured samples. Received: 10 June 1996 / Revised version: 17 September 1997     

Ethyl acetate leaf fraction of Cnidoscolus aconitifolius (Mill.) I. M. Johnst: antioxidant potential,inhibitory activities of key enzymes on carbohydrate metabolism,cholinergic, monoaminergic,purinergic, and chemical fingerprinting

In this study, the antioxidant, carbohydrate metabolism, cholinergic, monoaminergic, and purinergic enzyme activities of ethyl acetate leaf fraction of Cnidoscolus aconitifolius were evaluated with the high-performance liquid chromatography (HPLC) analysis. The ethyl acetate fraction of the plant leaf was tested for antioxidant properties, key carbohydrate metabolism, cholinergic, monoaminergic, and purinergic enzyme activities using standard procedures, while the chemical composition of the fraction was evaluated using HPLC. The results revealed that the fraction has higher phenolic compounds than flavonoid and exhibited the ability to scavenge iron chelation and ABTS. The fraction also inhibited the activities of α-amylase and α-glucosidase, acetylcholinesterase, butyrylcholinesterase, monoamine oxidase, tyrosinase, arginase, Ecto-5’-nucleotidase, phosphodieterase-5, angiotensin-I-converting enzyme and encouraged the activity of Na⁺/K⁺-ATPase. The HPLC analysis revealed that the ethyl acetate fraction contained coumaric acid, amentoflavone, hesperidin, protocatechuic acid, kaempferol, dihydromyricetin, quercetin,and rutin. The obtained results in this study suggest that the ethyl acetate fraction obtained from aqueous extracts of Cnidoscolus aconitifolius leaf possessed outstanding antioxidative potentials. Thus, excellent enzyme inhibitory activities probably due to bioactive compounds are also observed in the leaf.     

Isolation,composition, morphological and pasting properties of starches from rice cultivars grown in Nigeria

The isolation, composition, morphology and pasting properties of rice starches from different rice cultivars (N2R, Nerica II rice; IGR, Igbemo rice; ILR, Ilaje rice; and EAR, Efon Alaye rice) were studied. The starches were isolated from their flours by using a modified deproteination method in 0.1% NaOH. The highest starch yield of 65% was obtained from EAR with a residual protein of 0.41% and lowest starch yield of 45.70% from IGR with a residual protein of 0.42%. The AAM concentration of rice starches ranged from 21.88 to 26.04%. The sizes of the starch granules obtained from SEM were between 3 and 8 µm, some of the granules were individual (single) while others were fused (compound granules). The starch granules were small, polygonal and irregular in shape. The pasting parameters were evaluated using rapid visco analyser (RVA). Significant differences were observed in individual pasting parameters such as peak viscosity (PV), breakdown viscosity (BV), final viscosity (FV) and setback viscosity (SV). Cooked ILR starch had the highest PV (279.69 RVU; rapid viscosity units) and BV (52.50 RVU) when compared to the other starches. In contrast, N2R showed the highest FV (329.92 RVU) and SV (102.50 RVU), the latter due to the high concentration of AAM. The results revealed that cultivar has an effect on composition and pasting properties of rice starch.