Key fuel characteristics and techno-economic aspects of torrefied rubberwood biomass pellets produced by incorporating various cassava-based binders at varied doses.

Improving energy content and hydrophobic nature of woody biomass can be pursued through torrefaction. This gives torrefied biomass with a low bulk density, potentially increasing storage and transport costs. To overcome this issue, densifying the torrefied biomass is necessary. However, poor binding of particles makes densification challenging without using a binder. Therefore, the aim of this study was to investigate the physicochemical characteristics and techno-economic aspects of torrefied rubberwood biomass (TRWB) when pelletized using various cassava-based binders at different blending ratios. The selected binders included cassava starch (CS), cassava pulp (CP), and cassava chip (CC). Each binder at 5%, 10%, or 15% (wt.) was mixed with TRWB and water before pelletizing using a flat die machine. The results revealed that pelletizing TRWB with different cassava-based binders at various blending ratios influenced the physicochemical characteristics of the TRWB pellets, particularly dimensions, bulk density, fuel and atomic ratios, and energy content. The TRWB pellets demonstrated energy densities in the range of 7.95-11.39 GJ/m3, and their mechanical durability and fine content fell within acceptable ranges. The TRWB pellets maintained their shape during 120 min of water soaking, with water absorption levels varying by binder dose. The pelletizing ability, material, and energy costs of TRWB pellets depend on binder type and dose. CP can be applied as a binder for pelletizing torrefied rubberwood biomass. However, the mechanical durability of the product needs to be above the user requirement or standard.

Effect of the seed coating with biomass of Dunaliella salina on early plant growth and in the secondary metabolites content of Coriandrum sativum.

The environmental and health risks associated with the application of synthetic chemical inputs in agriculture increased the demand for technologies that allow higher performance and quality of vegetable crops by implementing synergistic materials with the principles of sustainability. In this work, the seed coating with the biomass of Dunaliella salina incorporated in a bioplastic film of Manihot esculenta (cassava) was evaluated as an initial growth and secondary compounds stimulator of Coriandrum sativum (coriander) plants. The obtained results demonstrated that the coating stimulated an increase in the germination percentage (28.75%) and also in concentration of bioactive compounds, such as the six-fold increment of caffeic acid (13.33 mg 100 g-1). The carbohydrates, lipids, and proteins present in the microalgae biomass seem to be responsible for these increments once they are known for providing energy to the seedling development and coordinating the secondary metabolites synthesis. As conclusion, we consider the coating with biomass of D. salina an alternative for crop improvement that contributes to the development of sustainable agricultural practices.

Effects of vacuum packaging storage of minimally processed cassava roots at various temperatures on microflora, tissue structure, starch extraction by wet milling and granule quality.

BACKGROUND: Vacuum package storage is commonly applied to reduce postharvest deterioration in minimally processed cassava roots. However, the influence of vacuum packaging conditions on root end-use quality is poorly understood. Hence, the effects of vacuum packaged storage at ambient, refrigerated and freezing temperatures on microflora, cassava tissue structure and starch extraction by wet milling were studied. RESULTS: Vacuum packaged storage temperature strongly affected cassava root quality. Minimal adverse effects were obtained with frozen storage. With refrigerated storage, there was negligible microbial growth but some disruption of the parenchyma cell wall structure suggestive of chilling injury. With ambient temperature storage, there was considerable Lactobacilli dominated fermentation. This caused substantial cell degradation, probably due to the production of extracellular cellulolytic and other cell wall degrading enzymes. A benefit of this cell wall breakdown was that it substantially improved starch extraction with wet milling from the stored cassava pieces; by 18% with pieces that had been ambient vacuum packaged and wet milled using a 2000 µm opening screen. However, ambient temperature storage resulted in some starch granule pitting due to the action of extracellular amylases from the fermenting microorganisms. CONCLUSION: The best vacuum packaging storage conditions for minimally processed cassava depends on application and cost. For short-term storage, refrigeration would be best for vegetable-type products. For several months storage, freezing is best. For wet milling applications, this could be combined with subsequent short-term ambient temperature storage as it improves starch extraction efficiency and could reduce distribution energy costs. © 2021 Society of Chemical Industry.

Dietary exposure and risk assessment of cyanide via cassava consumption in Chinese population.

The intake of cassava would probably induce adverse health effects since there are toxic cyanide in cassava. However, the risk assessment of cassava consumption has not been reported in China. Therefore, this paper aimed to evaluate the dietary risks of cassava cyanide and proposed a maximum residue limit (MRL) for cyanogenic glycosides (CNGs) in cassava. The retention rate of CNGs and CN- were 61% and 11% after boiling, respectively. The acute dietary exposure of CN- and CNGs were 0.6-fold and 1.7-fold of acute risk reference dose, respectively. There was no chronic health risk across all populations concerning cassava consumption. The MRL of CNGs was proposed as 200 mg/kg in cassava. Risk assessment of cyanide for foods rich in CNGs was suggested to be based on CNGs quantification rather than that of CN-.

Biodegradable films based on commercial κ-carrageenan and cassava starch to achieve low production costs.

Biodegradable films have been a great alternative compared to non-renewable sources because of their cytocompatibility, biodegradability, and antimicrobial features. These properties may raise the foodstuff shelf life, reducing costs and economic losses. Indeed, biodegradable films can also reduce the environmental pollution promoted by non-biodegradable conventional packs. For the first time, biodegradable films were produced by casting commercials kappa-carrageenan (κ-car) and cassava starch at different κ-carrageenan/cassava starch weight ratios. Physical, thermal, and mechanical properties were evaluated. Apparent opacity and color analyses suggest that the films present high transparency. The sample 0κ-c supported a film with high water solubility (39.22%) and a low swelling degree (391.6%). The lowest water vapor permeability (WVP) was observed for 50κ-c (3.01×10-8g (Pams)-1). The oil permeability varied from 0.0033 to 0.0043mmm2 d-1. The 100κ-c and 75κ-c films (with high κ-carrageenan contents) had higher stiffness (19.23 and 25.88MPa, respectively) than the 25κ-c and 0κ-c films with elongation at break (ε) of 21.60 and 67.65%, respectively. The thermal stability increased as the starch concentration raised in the blend. We produced low-cost biodegradable films from commercial polysaccharides. These films can be used as food packs.

Plant tissue analysis as a tool for predicting fertiliser needs for low cyanogenic glucoside levels in cassava roots: An assessment of its possible use.

The use of plant tissue analysis as a tool for attaining low cyanogenic glucoside levels in cassava roots, has hardly been investigated. Just as the quality of crops is improved through the use of plant tissue analysis, the same can probably be done to consistently attain the lowest possible cyanogenic glucoside levels in cassava roots. High levels of cyanogenic glucosides in consumed fresh cassava roots or in their products have the potential of causing cyanide intoxication, hence the need to lower them. An experiment was thus conducted to assess the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production in cassava roots. Total hydrogen cyanide (HCN) levels in cassava roots were used to assess cyanogenic glucoside production. Using NPK fertiliser application to induce changes in plant nutritional status, the main objective of the study was investigated using the following sub-objectives; (1) to determine the effects of increased NPK fertiliser application on cassava root HCN levels; (2) and to show the occurrence of relationships between changes in nutrient levels in plant 'indicator tissue' and HCN levels in cassava roots. The study was a field experiment laid out as a split-plot in a randomized complete block design with three replicates. It was repeated in two consecutive years, with soil nutrient deficiencies only being corrected in the second year. The varieties Salanga, Kalinda, Supa and Kiroba were used in the experiment, while the NPK fertiliser treatments included; a control with no fertiliser applied; a moderate NPK treatment (50 kg N + 10 kg P + 50 kg K /ha); and a high NPK treatment (100 kg N + 25 kg P + 100 kg K /ha). A potassium only treatment (50 kg K/ha) was also included, but mainly for comparison. The root HCN levels of Salanga, Kalinda and Kiroba were significantly influenced by NPK fertiliser application in at least one of the two field experiments, while those of Supa remained uninfluenced. Changes in plant nutritional status in response to fertiliser application were thus shown to influence cyanogenic glucoside production. The results of the multiple linear regression analysis for the first field experiment, generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by decreasing concentrations of nitrogen, potassium and magnesium in plants, or by improving plant calcium concentrations along with NPK fertiliser application. However, in the second field experiment (with corrected soil nutrient deficiencies) the regression analysis generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by improving either one or a combination of the nutrients phosphorous, zinc and potassium in plants along with NPK fertiliser application. Although the results obtained in the two experiments had been contradicting due to slight differences in how they were conducted, the study had nonetheless demonstrated the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production; confirming the possible use of plant tissue analysis in predicting fertiliser needs for the consistent attainment of low cyanogenic glucosides in cassava roots.

Highly water resistant cassava starch/poly(vinyl alcohol) films.

Biodegradable films were prepared based on cassava starch (CS) and poly(vinyl alcohol) (PVA). To increase its tensile strength and flexibility, CS (20-60 wt%) was blended with PVA at various weight ratios (80-40 wt%). Triethylamine (TEA) was added as a homogeneous catalyst to increase intermolecular interaction and induce miscibility between CS and PVA. The crystallinity and hydrophobicity of blend films containing 20 wt% CS were promoted by the elimination of residual acetate groups in PVA. The number of hydrogen bonds in these blend films increased, which led to stronger interaction and more compact molecular packing between CS and PVA chains. The poor water resistance that limits the shelf-life and applications of CS blends was improved. The addition of TEA to blend films containing 20 wt% CS increased water resistance by 80% and tensile strength by as much as 440%. The development of greater structural integrity yielded ecologically sustainable, low-cost, biodegradable films with excellent physical and mechanical properties.

Potential Human Health Risk Assessment of Heavy Metals via Consumption of Root Tubers from Ogoniland, Rivers State, Nigeria.

This study was designed to investigate the concentration of heavy metals and their associated human health risk via consumption of root tubers cultivated in three major communities in Ogoniland, Rivers State, Nigeria. The concentration of heavy metals, especially, Cr and Pb in soil, indicates a moderate contamination (˃ 1.00 mg/kg) level. The concentrations of heavy metals in the root tubers Manihot esculenta, Colocasia esculenta, and Dioscorea alata harvested from Choba, Kpean, and Bodo City ranged from 0.20 ± 0.01-0.84 ± 0.04, 0.01 ± 0.001-0.09 ± 0.02, 0.01 ± 0.002-0.63 ± 0.04, 2.11 ± 0.03-11.8 ± 2.12, and 6.30 ± 1.18-118.6 ± 0.19 mg/kg for Cr, Pb, Ni, Mn, and Fe respectively, while Cd had the same value of 0.01 ± 0.001 mg/kg in the three samples across the three sites. The bio-accumulation factor (BAF) for Cd was ˃ 1. The estimated daily intake were below the FAO/WHO permissible limit, while the target hazard quotient (THQ) has a trend of Mn> Fe> Pb> Cd> Ni> Cr, and were ˂ 1 for all the sampling areas. The HI values for M. esculenta for children in Choba, Kpean, and Bodo City were ˃ 1, indicating that children among the local populace were susceptible to heavy metals health risks. The carcinogenic risk (CR) value of Cr indicates that there was appreciable lifetime cancer risk for Cr as the CR value in all the sampling sites were ˃ 10-4. Furthermore, CR values of Ni and Cd were also within the predicted lifetime risks of carcinogens. Heavy metal contamination of root tubers cultivated in Ogoniland may posed a great health risk to local populace especially for children via consumption of root tubers.

The industrial applications of cassava: current status, opportunities and prospects.

Cassava (Manihot esculenta Crantz) is a drought-tolerant, staple food crop that is grown in tropical and subtropical areas. As an important raw material, cassava is a valuable food source in developing countries and is also extensively employed for producing starch, bioethanol and other bio-based products (e.g. feed, medicine, cosmetics and biopolymers). These cassava-based industries also generate large quantities of wastes/residues rich in organic matter and suspended solids, providing great potential for conversion into value-added products through biorefinery. However, the community of cassava researchers is relatively small and there is very limited information on cassava. Therefore this review summarizes current knowledge on the system biology, economic value, nutritional quality and industrial applications of cassava and its wastes in an attempt to accelerate understanding of the basic biology of cassava. The review also discusses future perspectives with respect to integrating and utilizing cassava information resources for increasing the economic and environmental sustainability of cassava industries. © 2017 Society of Chemical Industry.

A single-step method for RNA isolation from tropical crops in the field.

The RNAzol RT reagent was used to provide pure RNA from human cells. We develop a protocol using RNAzol RT reagent to extract pure RNA from plants tissues and demonstrate that this RNA extraction method works not only at room temperature but also at elevated temperatures and provides the simplest and most effective single-step method to extract pure and undegraded RNA directly from tropical plants in the field. RNA extraction directly in a complex field environment opens up the way for studying gene-environment interactions at transcriptome level to decipher the complex regulatory network involved in multiple-stress responses.

In vitro assessment of the genotoxic and cytotoxic effects of boiled juice (tucupi) from Manihot esculenta Crantz roots.

The population of Pará (a state in Brazil) has a very characteristic food culture, as a majority of the carbohydrates consumed are obtained from cassava (Manihot esculenta Crantz) derivatives. Tucupi is the boiled juice of cassava roots that plays a major role in the culinary footprint of Pará. Before boiling, this juice is known as manipueira and contains linamarin, a toxic glycoside that can decompose to hydrogen cyanide. In this study, the cytotoxic and genotoxic effects of tucupi on cultured human lymphocytes were assessed using the comet assay and detection of apoptosis and necrosis by differential fluorescent staining with acridine orange-ethidium bromide. Tucupi concentrations (v/v) were determined using the methylthiazole tetrazolium biochemical test. Concentrations of tucupi that presented no genotoxic effects (2, 4, 8, and 16%) were used in our experiments. The results showed that under our study conditions, tucupi exerted no genotoxic effects; however, cytotoxic effects were observed with cell death mainly induced by necrosis. These effects may be related to the presence of hydrogen cyanide in the juice.

Modified Dietary Fiber from Cassava Pulp and Assessment of Mercury Bioaccessibility and Intestinal Uptake Using an In Vitro Digestion/Caco-2 Model System.

The ability of modified dietary fiber (MDF) generated from cassava pulp to modulate the bioaccessibility and intestinal absorption of heavy metals may be helpful to mitigate health risk associated with select foods including select fish high in methyl mercury. Using a coupled in vitro digestion/Caco-2 human intestinal cell model, the reduction of fish mercury bioaccessibility and intestinal uptake by MDF was investiaged. MDF was prepared from cassava pulp, a byproduct of tapioca production. The highest yield (79.68%) of MDF was obtained by enzymatic digestion with 0.1% α-amylase (w/v), 0.1% amyloglucosidase (v/v) and 1% neutrase (v/v). MDF and fish tissue were subjected to in vitro digestion and results suggest that MDF may reduce mercury bioaccessibility from fish to 34% to 85% compared to control in a dose-dependent manner. Additionally, accumulation of mercury from digesta containing fish and MDF was only modestly impacted by the presence of MDF. In conclusion, MDF prepared from cassava pulp may be useful as an ingredient to reduce mercury bioavailability from food such as fish specifically by inhibiting mercury transfer to the bioaccessibile fraction during digestion.

Production of raw starch-degrading enzyme by Aspergillus sp. and its use in conversion of inedible wild cassava flour to bioethanol.

The major bottlenecks in achieving competitive bioethanol fuel are the high cost of feedstock, energy and enzymes employed in pretreatment prior to fermentation. Lignocellulosic biomass has been proposed as an alternative feedstock, but because of its complexity, economic viability is yet to be realized. Therefore, research around non-conventional feedstocks and deployment of bioconversion approaches that downsize the cost of energy and enzymes is justified. In this study, a non-conventional feedstock, inedible wild cassava was used for bioethanol production. Bioconversion of raw starch from the wild cassava to bioethanol at low temperature was investigated using both a co-culture of Aspergillus sp. and Saccharomyces cerevisiae, and a monoculture of the later with enzyme preparation from the former. A newly isolated strain of Aspergillus sp. MZA-3 produced raw starch-degrading enzyme which displayed highest activity of 3.3 U/mL towards raw starch from wild cassava at 50°C, pH 5.5. A co-culture of MZA-3 and S. cerevisiae; and a monoculture of S. cerevisiae and MZA-3 enzyme (both supplemented with glucoamylase) resulted into bioethanol yield (percentage of the theoretical yield) of 91 and 95 at efficiency (percentage) of 84 and 96, respectively. Direct bioconversion of raw starch to bioethanol was achieved at 30°C through the co-culture approach. This could be attractive since it may significantly downsize energy expenses.

Establishment and assessment of an integrated citric acid-methane production process.

To solve the problem of extraction wastewater in citric acid industrial production, an improved integrated citric acid-methane production process was established in this study. Extraction wastewater was treated by anaerobic digestion and then the anaerobic digestion effluent (ADE) was stripped by air to remove ammonia. Followed by solid-liquid separation to remove metal ion precipitation, the supernatant was recycled for the next batch of citric acid fermentation, thus eliminating wastewater discharge and reducing water consumption. 130U/g glucoamylase was added to medium after inoculation and the recycling process performed for 10 batches. Fermentation time decreased by 20% in recycling and the average citric acid production (2nd-10th) was 145.9±3.4g/L, only 2.5% lower than that with tap water (149.6g/L). The average methane production was 292.3±25.1mL/g CODremoved and stable in operation. Excessive Na(+) concentration in ADE was confirmed to be the major challenge for the proposed process.

Corrin-based chemosensors for the ASSURED detection of endogenous cyanide.

Cassava (Manihot esculenta Crantz) is a staple food for more than 500 million people, especially in Africa and South America. However, its consumption bears risks as it contains cyanogenic glycosides that convert enzymatically to toxic cyanide during cell damage. To avoid serious health problems by unintentional cyanide intake, this dangerous product of decomposition must be removed before consumption. For monitoring such food processing procedures and for controlling the quality and safety of cassava products on the market, a convenient and reliable analytical method for routine applications without laboratory equipment is required. This Perspective summarizes the authors' work on corrin-based chemosensors for the ('naked-eye') detection of endogenous cyanide in cassava samples. Considering selectivity, sensitivity, handling and speed of detection, these systems are superior to currently applied methods. Based on these properties, the development of a test kit for application by rural farmers in remote locations is proposed.

Are biofortified staple food crops improving vitamin A and iron status in women and children? New evidence from efficacy trials.

Biofortification is the breeding of crops to increase their nutritional value, including increased contents of micronutrients or their precursors. Biofortification aims to increase nutrient levels in crops during plant growth rather than during processing of the crops into foods. Emerging research from 8 human trials conducted in the past decade with staple food crops that have been biofortified by traditional plant breeding methods were presented in this symposium. Specifically, data from 6 efficacy and 2 effectiveness trials were discussed to assess the effects of regular consumption of these enhanced staple crops on improving population vitamin A and iron status and reducing the burden of micronutrient deficiencies in targeted populations living in South Asia, Sub-Saharan Africa, and Latin America. Biofortified food crops appear to have a positive impact on nutritional and functional health outcomes, as the results from the trials suggest. Additional implementation research will be needed to ensure maximization of the beneficial impact of this intervention and a smooth scaling up to make biofortification a sustainable intervention in public health. The challenge for the global health community remains how to take this efficacious intervention and implement at large scale in the real world.

Utilization of by-products derived from bioethanol production process for cost-effective production of lactic acid.

The by-products of bioethanol production such as thin stillage (TS) and condensed distillers solubles (CDS) were used as a potential nitrogen source for economical production of lactic acid. The effect of those by-products and their concentrations on lactic acid fermentation were investigated using Lactobacillus paracasei CHB2121. Approximately, 6.7 g/L of yeast extract at a carbon source to nitrogen source ratio of 15 was required to produce 90 g/L of lactic acid in the medium containing 100 g/L of glucose. Batch fermentation of TS medium resulted in 90 g/L of lactic acid after 48 h, and the medium containing 10 % CDS resulted in 95 g/L of lactic acid after 44 h. Therefore, TS and CDS could be considered as potential alternative fermentation medium for the economical production of lactic acid. Furthermore, lactic acid fermentation was performed using only cassava and CDS for commercial production of lactic acid. The volumetric productivity of lactic acid [2.94 g/(L·h)] was 37 % higher than the productivity obtained from the medium with glucose and CDS.

Economic and environmental assessment of syrup production. Colombian case.

This work presents a techno-economic and environmental assessment of the glucose syrups production from sugarcane bagasse, plantain husk, cassava husk, mango peel, rice husk and corncobs. According to the economic analysis, the corncob had both, the lowest production cost (2.48USD/kg syrup) and the highest yield (0.61kgofsugars/kg of wet agroindustrial waste) due to its high content in cellulose and hemicellulose. This analysis also revealed that a heat integration strategy is necessary since the utilities consumption represent an important factor in the production cost. According to the results, the pretreatment section requires more energy in the syrup production in comparison with the requirements of other sections such as production and sugar concentration. The environmental assessment revealed that the solid wastes such as furfural and hydroxymethylfurfural affected the environmental development of the process for all the agroindustrial wastes, being the rice husk the residue with the lowest environmental impact.

Cost analysis of cassava cellulose utilization scenarios for ethanol production on flowsheet simulation platform.

Cassava cellulose accounts for one quarter of cassava residues and its utilization is important for improving the efficiency and profit in commercial scale cassava ethanol industry. In this study, three scenarios of cassava cellulose utilization for ethanol production were experimentally tested under same conditions and equipment. Based on the experimental results, a rigorous flowsheet simulation model was established on Aspen plus platform and the cost of cellulase enzyme and steam energy in the three cases was calculated. The results show that the simultaneous co-saccharification of cassava starch/cellulose and ethanol fermentation process (Co-SSF) provided a cost effective option of cassava cellulose utilization for ethanol production, while the utilization of cassava cellulose from cassava ethanol fermentation residues was not economically sound. Comparing to the current fuel ethanol selling price, the Co-SSF process may provide an important choice for enhancing cassava ethanol production efficiency and profit in commercial scale.