Cassava Residue Research Articles

Agro-Waste, a Solution for Rural Electrification? Assessing Biomethane Potential of Agro-Waste in Inhambane Province, Southern Mozambique

In this study, we investigated the biomethane potential of cassava peels from the four most common varieties of cassava grown in Inhambane Province in Mozambique, Chinhembue, Cussi, Cizangara and Nhassumbi. Agro-wastes from coconut wood and jambolan wood processing were also analyzed to give a complete analysis of the most significant sources of agro-waste in the province. The macromolecular composition (carbohydrates, lipids and proteins) was determined and used to calculate the theoretical maximum biochemical methane potential (BMP). The results show that cassava fiber and cassava peel, which are considered to be waste, are viable resources for biomethane production. Further, the results show that cassava fiber and cassava peel have a higher biomethane potential compared with sawdust, and are therefore more suitable for biomethane production. A study to investigate the effect of toxic cyanogenic glycosides and lignin on cassava peels, using pre-treatment techniques to enhance biogas yield, should be carried out. An estimate of how much electricity can be generated based on the availability of agro-waste (cassava residues) and the amount of biomethane produced in our laboratory experiment was carried out. The amount of electricity that can be produced is enough to provide a valuable contribution to the production process in small and medium sized enterprises (SMEs) and in the cassava industry, or some other use in the rural setting.

How are the properties of biocomposite foams influenced by the substitution of cassava starch for its residual sources?

Two residues from the cassava processing industry, cassava inner bark and gelatinized starch, were applied as substitutes for native cassava starch in the development of foams using a thermocompression process (180 °C, 6 min, 7 MPa). The starchy pastes were also submitted to a pre-gelatinization step in a water bath (80 °C, 2 min) to evaluate the effect of this step on the properties of the foams. The thickness measurements seemed to be more influenced by the starch amount in the formulations, while the bulk density and the water absorption capacity (WAC) were more influenced by the starch source and its chemical composition. In general, the pre-gelatinization seemed to have affected more directly the properties of the biocomposites fabricated solely with cassava starch. Moreover, these pre-gelatinized biocomposites presented greater mechanical resistance and higher elongation values. Biocomposites with the incorporation of cassava inner bark presented lower WAC (84% after 90 min), demonstrating their high potential for application as a quick-use packaging for low-moisture foods. These results showed that the non-necessity of the pre-gelatinization step could lead to an increase in biocomposites’ fabrication speed due to the elimination of the water bath heating stage, minimizing production costs. Besides that, it is important to highlight the cost reduction related to the use of cassava residues instead of native cassava starch.

COMPARATIVE STUDY USING RAW AND TREATED CASSAVA AND LEMON RESIDUES IN THE REMOVAL OF NICKEL (II)

Increasing pollution of water bodies by heavy metals from different anthropogenic activities, mainly of industrial nature, generates a high level of danger due to accumulation. Within a given time, heavy metals reach high concentrations in living organisms, especially those around sites of discharge. The objective of this research was to evaluate the adsorption capacity of dried lemon (Citrus limon) and cassava (Manihot esculenta Crantz) peels, raw or treated with citric acid, to remove Ni (II) in synthetic aqueous solution with 100 mg L-1 of metal. To assess adaptation and characterize these bio-adsorbents, biomasses were washed with distilled water. They were dried at 90 °C for 24 h and then ground in a mill. The modification of the cassava and lemon peels was carried out with 0.6 M citric acid; followed by adsorption and kinetic tests that were carried out in a discontinuous system. The biomaterials were characterized by chemical, elemental and Fourier transform infrared spectroscopy (FTIR) analysis. We found that both biomasses are composed mostly of carbon and cellulose. The FTIR showed the presence of carboxyl, amino, carbonyl and hydroxyl functional groups, which intervene in the adsorption process. Lemon and cassava peels showed 95.8% adsorption capacity of Ni (II) ions, and 75.69% removal of the contaminants. The best adsorbent particle sizes were 0.5 mm for lemon, and 1 mm for cassava peel, the two biomasses at pH 6. The best fit of the experimental data was Freundlich’s model and the pseudo-second-order model best described adsorption kinetics in the Ni (II) removal process. Treatment of the biomasses with citric acid did not render a significant improvement in metal removal. The best conditions for an efficient adsorption process were achieved using a specific particle size for lemon, 0.5 mm, and 1 mm for cassava residues.

The effect of crystallization time on structure, microstructure, and catalytic activity of zeolite-A synthesized from rice husk silica and food-grade aluminum foil

This study was conducted to evaluate the effect of crystallization time on the structure, microstructure, and catalytic activity of zeolite-A synthesized from rice husk silica and food-grade aluminium foil. Three samples were prepared with fixed crystallization temperature of 100 °C and crystallization times of 48, 72, and 96 h, followed by calcination at 550 °C for 6 h. The samples were characterized using XRD and SEM then used in pyrolysis of mixed solid cassava residue and palm oil. The bio-crude oil (BCO) produced was analyzed using the GC-MS technique. For comparison, a commercial zeolite-A was also characterized and used as the catalyst. Characterization using XRD revealed that zeolite-A has formed at a 48 h crystallization period, with sodalite as a minor component, and crystallization time of 72 h resulted in optimum growth of the zeolite-A. The results of SEM indicated the presence of cubic crystal, most evidently in the sample synthesized with crystallization time of 72 h. This particular sample is the most comparable to a commercial zeolite-A. Pyrolysis experiments produced BCO with hydrocarbons as the main components, with relative percentages of biogasoline fraction (C6–C12) in the range of 71.88–91.47% in the samples produced using synthesized zeolite and 97.52% using commercial zeolite.

Feeding Value Assessment of Substituting Cassava (Manihot esculenta) Residue for Concentrate of Dairy Cows Using an In Vitro Gas Test.

Simple SummaryCassava (Manihot esculenta) residue is a by-product of cassava processing. Although it contains residual nutrients, it is highly perishable. Decayed cassava residue pollutes the environment and leads to major losses in feed. If cassava residue could be utilized as a dairy cow feedstuff, these problems could be solved. Our study showed that cassava residue is a good alternative to concentrate in the feed of Holstein cows. Furthermore, our data demonstrate the efficacy of the application of cassava residue as a feed for dairy cows and could help solve the shortage of feed resources in China.The feeding value of replacing concentrate with cassava (Manihot esculenta) residue in the feed of Holstein cows was confirmed using an in vitro gas test. The treatments consisted of 0% (control, CON), 5%, 10%, 15%, 20%, 25%, and 30% inclusion of cassava residue in fermentation culture medium composed of buffer solution (50 mL) and filtrated rumen fluid (25 mL). The parameters analyzed included the kinetics of gas production and fermentation indexes. Forty-eight hours later, there were no significant differences on in vitro dry matter disappearance (IVDMD), pH, and microbial crude protein (MCP) content among treatments (p > 0.05). However, the “cumulative gas production at 48 h” (GP48), the “asymptotic gas production” (A), and the “maximum gas production rate” (RmaxG) all increased linearly or quadratically (p < 0.01). The GP48 was significantly higher in the 25% treatment compared to the other treatments, except for the 30% (p < 0.01). The A was significantly larger in the 25% treatment compared to the other treatments, except for the 20% and 30% (p < 0.01). The RmaxG was distinctly larger in the 25% treatment compared to other treatments (p < 0.01); moreover, the “time at which RmaxG is reached” (TRmaxG) and the “time at which the maximum rate of substrate degradation is reached” (TRmaxS) were significantly higher in the 25% treatment than the CON, 20%, and 30% treatments (p < 0.01). Additionally, the content of ammonia-N (NH3-N) in all treatments showed linearly and quadratically decreases (p < 0.01), whereas total volatile fatty acid (VFA), iso-butyrate, butyrate, and iso-valerate contents changed quadratically (p = 0.02, p = 0.05, p = 0.01, and p = 0.02, respectively); all of these values peaked in the 25% treatment. In summary, the 25% treatment was associated with more in vitro gas and VFA production, indicating that this cassava residue inclusion level may be used to replace concentrate in the feed of Holstein cows. However, these results need to be verified in vivo.

Biodigestão anaeróbia da manipueira gerada na casa de farinha no município de Branquinha/AL, Brasil

RESUMO: A manipueira é um dos resíduos gerados no processamento da mandioca (Manihot esculenta Crantz) durante a produção de farinha, sendo esse subproduto potencialmente tóxico devido à presença de ácido cianídrico (HCN). Para reduzir esse composto químico, levando em conta os riscos do descarte irregular no solo e curso d’água, a manipueira pode ser tratada a partir da fermentação ou digestão anaeróbia por um determinado período. O objetivo do trabalho foi avaliar o biodigestor de sistema descontínuo (batelada) como possível alternativa de reaproveitamento deste resíduo líquido, além de analisar a possibilidade de produzir biogás para contribuir com o desenvolvimento sustentável dos pequenos produtores do Assentamento Eldorado dos Carajás, Branquinha, AL. Foram realizadas coletas e análises com intuito de averiguar o comportamento da manipueira quando sujeita ao processo anaeróbio, considerando as variáveis temperatura e pH (acidez e alcalinidade) antes e após o confinamento do material residual no biodigestor. O modelo tipo batelada apresentou resultados satisfatórios quanto ao desempenho e viabilidade econômica, pois todos os materiais utilizados são de custo mínimo e de fácil manuseio. É necessário o aprimoramento de fontes alternativas para destinar e tratar os resíduos gerados nas casas de farinha do estado de Alagoas.&#x0D; PALAVRAS-CHAVE: Resíduo líquido da mandioca, Fermentação, Fontes alternativas.

Availability of cassava residues and by-products for goat production in cassava based farming system

A study was carried out to investigate into the availability of cassava residues and by products and the utilization of the residues for goat production in Odeda local government area of Ogun state. Data was collected through a structured questionnaire coupled with occasional farm visits and personal interviews, from the farmers involved in the production of goats and cassava. Results showed that cassava is a major crop in the area and the cultivation of different cassava varieties is common. Cassava leaves, peels and sieviate were the common residues and by-products available and most farmers used these residues to feed their goats. The response of goats to cassava residues based diets was investigated using sixteen (16) West African dwarf goats, aged 4 to 6 months with average body weight of 6.5kg in a completely randomized design. The four treatments used namely (diets A to D) contained varying levels of cassava leaves, peels and sieviate and were repli performance increased (P &lt; 0.05) with increasing level of cassava leaves in the diets. Weight gain of goats ranged from 30.02 to 37.85g/day across the dietary treatments. In conclusion, cassava residues are readily available in the study area and the response of goats fed diet C consisting 50% cassava leaves, 30% cassava peels and 20% cassava sieviate produced the best performance in terms of feed intake, digestibility and weight gain. This can therefore be recommended as best combination strategy in making use of cassava residues in goat feeding in Nigeria. &#x0D;

Effects of pressure densification on strength and properties of cassava waste briquettes

Cassava waste has the potential to be used as an energy source. The aim of this study was to analyze the effects of pressure densification on the properties of cassava residue briquettes, especially on the strength of the briquettes. It was used three compaction pressures: 102, 153, and 204 MP A and three pressing hold times: without holding pressure time, 60s, and 120 s, to produce briquettes without heating and verify their formation concerning the compaction. The proximate analysis provided 72.50% to volatile, 13.10% to Fixed carbon, and 14.45% to ash; the higher heating value (HHV) was 17.12 MJ/kg. The cassava rhizome waste (bulk density) showed an energy density of 2.04 GJ/m3. With densification, it obtained an energy density of 15.7 GJ/m3, representing an increase of up to 7.7 times. We obtained higher durability (94,1%) for time pressing of 120s and pressure of 204 MP A. The briquette volumetric stabilization occurred 24 h after production, and we observed that the briquettes produced with a higher compaction pressure showed greater density and resistance. Cassava rhizome biomass showed good energy properties. The densification process can be an alternative to solving transportation, handling, and cassava rhizome residues.

Thermal behaviors and kinetics for fast pyrolysis of chemical pretreated waste cassava residues

Abstract In the present study, thermal decomposition behaviors and kinetics for fast pyrolysis of acid/alkali pretreated waste cassava residues were investigated. The results demonstrated that chemical pretreatments apparently loosened the compact structure of cassava residue and benefited to the sufficient contact with acid/alkali sites. Acid/alkali pretreatments enriched the product varieties and had remarkable influence on the adjustment of product formation. Particularly, the pyrolysis behavior obviously shifted to low-temperature zones for pretreated samples. Low heating rate significantly promoted the formation of anhydrosugars with 27% levoglucosan produced, while elevating heating rate contributed to furfural production. Some oxygenated-chemicals, such as acetic acid, hydroxyacetone and 4-hydroxydihydrofuran-2(3H)-one, were apparently formed in the presence of alkali metal. Noticeably, the generation of most gaseous products was restrained for those acid-impregnated cassava residues. Moreover, kinetic study suggested that the apparent activation energy for waste cassava residue pyrolysis was significantly lowered, further verifying the positive role of chemical pretreatments.

Determinação dos valores energéticos e da composição química do resíduo seco de fecularia para frangos de corte

O objetivo do trabalho foi determinar os valores energéticos e a composição química do resíduo seco de fecularia (RSF) para frangos de corte. Os tratamentos foram distribuídos em um delineamento experimental inteiramente casualizado, em um esquema fatorial 2x5, constituídos de dois sexos e cinco níveis de inclusão do RSF (0; 10; 20; 30 e 40%), totalizando dez tratamentos e quatro repetições, com quatro aves por unidade experimental. O período experimental teve duração de dez dias, sendo cinco dias de adaptação e cinco de coleta de excretas. As amostras de excretas, rações e RSF foram secas em estufas de circulação forçada de ar a 55ºC. A composição bromatológica para o RSF foi de 89,86% de MS, 0,98% de PB, 3519 kcal kg-1 de EB, 0,19% de EE, 27% de FDN, 19,5% de FDA, 0,33% de cálcio, 0,43% de fósforo, 0,46% de potássio, 0,12% de magnésio, na matéria natural. Os valores médios de energia metabolizável aparente (EMA), EMA corrigida pelo balanço de nitrogênio (EMAn), coeficiente da EMA (CMA) e coeficiente da EMAn (CMAn) do RSF, na matéria natural, foram de 1598 kcal kg-1, 1605 kcal kg-1, 45,42% e 45,61%, respectivamente. De acordo com as equações o valor de EMAn encontrado pode variar de 1789 kcal kg-1 a 1808 kcal kg-1.

Carcass characteristics and meat quality of slow-growing broilers fed diets containing dry residue of cassava, with or without the addition of carbohydrases.

This study evaluated the carcass and portion yield and meat quality of slow-growing broilers fed diets with increasing levels of dry residue of cassava (DRC), with or without the addition of carbohydrases. A total of 1100 Label Rouge male broilers were distributed in a completely randomized 2 × 5 factorial design (with or without the addition of carbohydrases and five levels of DRC [0, 2.5, 5.0, 7.5, and 10.0%]), with five replicates and 22 birds per experimental unit. No interaction (P > 0.05) was observed between enzyme addition and DRC levels for the carcass yield, portion yield (back, legs, wings, breast), or abdominal fat variables. There was an interaction (P < 0.05) between the addition of enzyme and DRC on breast pH15min post-mortem and the a* intensity of the breast in a colorimetry test. There was a quadratic effect on b* intensity independent of adding enzymes, with the lowest intensity predicted at 8.89% DRC. Regarding feet color, increasing DRC supplementation (independent of enzyme supplementation) led to an increase and decrease in L* and b* intensity, respectively (P < 0.05). Moreover, there was a quadratic effect on a* intensity, with a lower level of intensity predicted at 6.93% DRC (P < 0.05), regardless of the inclusion of enzymes. The inclusion of up to 10% dry residue of cassava in slow-growing broiler diets does not affect carcass and portion yield or the qualitative characteristics of the meat but does reduce the color of the breast meat and feet.

Effect of Cassava Residue Substituting for Crushed Maize on In Vitro Ruminal Fermentation Characteristics of Dairy Cows at Mid-Lactation.

Simple SummaryCassava processing and utilization generates many byproducts, such as cassava residue. On one hand, this residue still contains many nutrients like starch, fiber and minerals. On the other hand, it pollutes the environment if not be utilized properly. Lactating dairy cows need to control the body weight for smooth calving, but too much high energy feed material like maize can influence their lipid metabolism. Cassava residue may be a good option for them since it can be used not only as roughage, but also can provide energy for dairy cows. Therefore, this study was conducted to investigate the effect replacing high energy feedstuff crushed maize with cassava residue on in vitro fermentation characteristics of dairy cows in mid-lactation. This may help provide further in vivo tests with data support, which finally, could alleviate feed shortages, reduce environmental pollution and improve economic benefits of dairy farming.This study was conducted to investigate the effect of using cassava residue to replace crushed maize on in vitro fermentation characteristics of dairy cows at mid-lactation and provide guidance for its utilization. The study included seven treatments with four replicates, which used 0% (control, CON), 5%, 10%, 15%, 20%, 25% and 30% cassava residue to replace crushed maize (air-dried matter basis), respectively. A China-patented automated trace gas recording system was used to perform in vitro gas tests; rumen fluids were collected from three dairy cows at mid-lactation. In vitro dry matter digestibility (IVDMD), gas production (GP), pH, ammonia–N (NH3-N) and microbial protein (MCP) content were analyzed after in vitro incubating for 3, 6, 12, 24 and 48 h, respectively; volatile fatty acid (VFA) content was analyzed after in vitro culturing for 48 h. The results showed that with the increase of substitution ratio of cassava residue, the asymptotic gas production (A) increased quadratically (p < 0.05), cumulative gas production at 48 h (GP48) and the maximum rate of substrate digestion (RmaxS) increased linearly and quadratically (p < 0.05), the time at which the maximum gas production rate is reached (TRmaxG) increases linearly (p < 0.05). In addition, asymptotic gas production in 30% was significantly higher than the other treatments (p < 0.05), RmaxS in 25% and 30% were significantly higher than CON, 5% and 10% (p < 0.05). In addition, with the increase of substitution ratio of cassava residue, when in vitro cultured for 6 h and 12 h, NH3–N content decreased linearly and quadratically (p < 0.05). NH3–N content in 30% was significantly lower than the other treatments except 20% and 25% (p < 0.05) after cultivating for 6 h. Moreover, the content of iso-butyrate, iso-valerate, valerate and total VFA (tVFA) decreased linearly and quadratically (p < 0.05), acetate decreased quadratically (p < 0.05) with the increase of substitution ratio of cassava residue. In conclusion, when the cassava residue substitution ratio for crushed maize was 25% or less, there were no negative effects on in vitro ruminal fermentation characteristics of dairy cows at mid-lactation.

Changes in biochemical composition of cassava and beet residues during solid state bioprocess with Pleurotus ostreatus

The development of the Pleurotus ostreatus in cassava ( Manihot esculenta ) and beet ( Beta vulgaris ) residues via solid state bioprocess (SSB) was evaluated in terms of variation of proximate composition, phenolic compounds, minerals, in vitro digestibility, fungal growth and lipase activity. The substrates were cultured at 30 °C for 35 days and sampled every 5 days. The amount of protein, and fibers of cassava residues, increased by 125.7%, and 253.2%, respectively. The beet residue showed a protein increment of 57.6%, and fibers of 232.7%. In beet residues, the lipid increase was of 261.7% while that for cassava residues was of 136.2%. The cassava residue showed a reduction in phenolic compounds from 18.07 mg of acid galic equivalent (AGE)/g to 4.17 mg AGE/g and beet from 30.96 mg to 3.50 mg. In vitro digestibility increased by 5.24% in cassava residues and 29.38% in beet residues. P. ostreatus reached 8.63 CFU/g (15 days) in cassava residue and 6.08 CFU/g (25 days) in beet residue. Maximum lipase activity was 0.71 U/g (35 days) in beet residues and 0.46 U/g (20 days) in cassava residues. Both beet and cassava residues presented nutritional enrichment (carbohydrate reduction and increase of other compounds) and increased in vitro digestibility with P. ostreatus via SSB. This application presents great biotechnological potentiality, e.g. the utilization as a low-cost nutrient source for animal feed.

Effect of replacing conventional feeds with tropical agricultural by‐products on the growth performance, nutrient digestibility and ruminal microbiota of water buffaloes

This study investigated the effect of replacing corn grain, soybean meal and wheat bran with tropical agricultural by-products, such as palm kernel cake (PKC), cassava residue and dried distiller's grain with solubles (DDGS), on the dry matter intake (DMI), growth performance, apparent nutrient digestibility, ruminal short-chain fatty acids (SCFA) and ruminal microbial communities of water buffaloes. Thirty healthy 15-month-old crossbred water buffaloes with a similar initial body weight of 353.1±23.7kg were randomly allocated into three dietary experimental groups, and they were fed with same forage but three different concentrates for 50days fattening. The dietary treatments were as following: typical concentrate (TC, 65% corn+15% wheat bran+15% soybean meal), partial replacement concentrate Ⅰ (PRC I, 50% corn+22.5% corn gluten+22.5% PKC) and partial replacement concentrate Ⅱ (PRC II, 50% corn+22.5% cassava residue+22.5% DDGS). The results showed that the average daily gain of the PRC II group was the highest, and the DMI, acid detergent fibre digestibility and neutral detergent fibre digestibility value of the three groups were different and in the following order: PRC II group>TC group>PRC I group. The crude protein digestibility of PRC II was higher than that of the TC and PRC I groups (p<.05). The ruminal concentrations of total SCFA, acetate, propionate and butyrate of TC group were higher than the other two groups (p<.05). The PRC I group had the highest Bacteroidetes-to-Firmicutes ratio (B/F) and relative abundance of the genus Prevotella, while the PRC II group had the lowest B/F and relative abundance of Prevotella. In conclusion, using PKC and corn gluten to completely replace common feed ingredients in the buffalo concentrate ration decreased, while using cassava residue and DDGS increased animal growth performance, mainly due to the different combination influenced nutrient digestibility and ruminal microbial community composition was shifted.

Preparation and Properties of Cassava Residue Cellulose Nanofibril/Cassava Starch Composite Films.

Because of its non-toxic, pollution-free, and low-cost advantages, environmentally-friendly packaging is receiving widespread attention. However, using simple technology to prepare environmentally-friendly packaging with excellent comprehensive performance is a difficult problem faced by the world. This paper reports a very simple and environmentally-friendly method. The hydroxyl groups of cellulose nanofibrils (CNFs) were modified by introducing malic acid and the silane coupling agent KH-550, and the modified CNF were added to cassava starch as a reinforcing agent to prepare film with excellent mechanical, hydrophobic, and barrier properties. In addition, due to the addition of malic acid and a silane coupling agent, the dispersibility and thermal stability of the modified CNFs became significantly better. By adjusting the order of adding the modifiers, the hydrophobicity of the CNFs and thermal stability were increased by 53.5% and 36.9% ± 2.7%, respectively. At the same time, the addition of modified CNFs increased the tensile strength, hydrophobicity, and water vapor transmission coefficient of the starch-based composite films by 1034%, 129.4%, and 35.95%, respectively. This material can be widely used in the packaging of food, cosmetics, pharmaceuticals, and medical consumables.

Ruminal fermentation kinetics of by-products using the semi-automatic technique of in-vitro gas production

ABSTRACT The objective of this study was to develop a specific equation for the conversion of pressure values (psi) to volume (ml) for the Laboratory of Bromatology of the Federal University of Western Pará. To this end, the ruminal fermentation kinetics of regional feedstuffs were evaluated using the semi-automatic technique of in-vitro gas production. To set up the targeted equation, samples of ground corn, soybean meal, rice bran, Mombasa grass, cupuassu pie, cassava residues, and banana leaves were incubated and the pressure and volumes of the gases produced during the fermentation process were measured at predetermined times and related. These data on the volume of produced gases were used to determine, by applying the bi-compartmental logistic model, the ruminal fermentation kinetics parameters. The equation found for the laboratory was V = 0.3757P2 + 1.5972P + 0.2189. Ground corn and cassava residue showed a higher degradation rate of non-fibrous carbohydrates (0.120 and 0.163 %/h respectively) and higher final gas volume (228.91 and 273.17 ml/g of DM, respectively). As for the degradation rate of fibrous carbohydrates, ground corn (0.023 %/h), rice bran (0.023 %/h), and cassava residue (0.021 %/h) presented the highest degradation rate. Thus, a specific equation to be used at the Laboratory of Bromatology of the Federal University of Western Pará was identified, according to the method applied and the altitude of the premises. Ruminal fermentation kinetics of cassava residue and rice bran showed the same parameters as corn, which may suggest the possibility of replacing corn in the diet of ruminant animals.

Bromatological quality of silage from cassava residues: fractionation of proteins and carbohydrates

ABSTRACT The objective of this study was to evaluate the quality of silage in the upper third of cassava levels of inclusion of cassava peel, 0, 100, 200, 300, 400 g/kg out based on natural matter (NM) with 60 days of storage on fermentative profile, aerobic stability, chemical composition and protein and carbohydrate fractionation. The material was ensiled in 15 experimental silos, the experimental design adopted was completely randomised, with five treatments and three repetitions. The inclusion of cassava peel in silage from the aerial part of the cassava promoted an increasing linear effect for dry matter content. The contents of crude protein, neutral detergent fibre and acid detergent fibre decreased linearly (P &lt; 0.05) with the inclusion of cassava peel in the silage. The inclusion of the bark promoted an increase in carbohydrate levels. Protein and carbohydrate fractions were influenced by the addition of cassava peel, decreasing the unavailable and/or indigestible fraction (Fraction C) of proteins and carbohydrates. The inclusion of cassava peel up to the level of 400 g/kg NM in silage from the aerial part of the cassava improves the fermentation process, aerobic stability and the chemical composition of the silage, and reduces the indigestible fractions of carbohydrates and proteins.

Energetic Values and Inclusion Levels of the Dry Residue of Cassava in Broiler Diet

ABSTRACT The objective of this study was to evaluate the energetic values of dry residue of cassava (DRC) and the effects of its inclusion in broiler diets on performance, intestinal morphometry, protein and fat deposition rate, and carcass and cut yields. In experiment I, two metabolism trials were carried out from 11-21 and from 31-41 days of age. The birds were distributed in a completely randomized design and DRC was included at levels of 10, 20, 30 and 40% in the basal diet. In experiment II, 980 male chicks were distributed in a completely randomized design with seven treatments (0; 2; 4; 6; 8; 10; 12% DRC) and seven replicates. DRC levels did not influence (p>0.05) the energetic values. From days 1-7, weight gain (WG) had a linear adjustment, and the inclusion of up to 6% of DRC from d 1-7, and the feed conversion ratio (FCR) had a tendency (p=0.060) with quadratic effect (p=0.001), and the worst FCR was observed with the inclusion of 5.81% of DRC. From d 1-21 of age, the WG decreased linearly, with the increasing of DRC while the FCR increased linearly. Breast yield decreased linearly with increasing levels of DRC inclusion. The addition of the residue reduced the protein deposition rate (PDR) and did not alter the (fat deposition rate) FDR. The metabolizable energy of DRC was 1534 kcal kg-1 (11-21 d), 1746 kcal kg-1 (d 31-42) and can be included up to 6% until d 42 in the broiler`s diet without harming the performance.

The Effect of Crystallization Time on Structure, Microstructure, and Catalytic Activity of Zeolite-A Synthesized from Rice Husk Silica and Food Grade Aluminum Foil

This study was conducted to evaluate the effect of crystallization time on structure, microstructure, and catalytic activity of zeolite-A synthesized from rice husk silica (RHS) and food grade aluminium foil. There samples were prepared with fixed crystallization temperature of 100 oC and crystallization time of 48, 72, and 96 hours, followed by calcination at 550 oC for 6 hours, and then characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). For catalytic activity assessment, the zeolites were used in pyrolysis of mixed solid cassava residue (SCR) and palm oil, and biocrude oil (BCO) produced was analysed using GC-MS technique. Characterization using XRD technique revealed that zeolite-A has been produced at 48-hour crystallization period, with sodalite as minor component, and crystallization time of 72 hours was found to result in optimum growth of zeolite-A. Formation of zeolite-A structure is supported by the results of SEM, which clearly indicated the presence of cubic crystal. The three zeolites were found to produce BCO with hydrocarbon as the main component, with practically pure hydrocarbon was obtained using zeolite with crystallization time of 72 h as catalyst.

Amylase from Bacillus sp. Produced by Solid State Fermentation Using Cassava Bagasse as Starch Source.

Abstract Amylases are enzymes involved in starch hydrolysis, generating the most diverse products, such as maltose, glucose and dextrins. This work aimed the study of the production of amylolytic enzymes via solid-state fermentation (SSF) using “crueira”, an essentially starchy cassava residue, as substrate-support and Bacillus sp. as microorganism. For the implementation of the experimental part, a Central Composite Design (CCD) with three variables (initial moisture, pH and temperature) was made. Each test was examined at 24, 48 and 72 hours by the method of starch dextrinizing activity. The optimum production conditions were 60% initial moisture, pH 6 and 37 °C. The maximum yield was 437.76 U/g in 72 hours of fermentation. The optimum temperature of enzyme performance was 65 °C. The pH optimum range was 4 to 6. The Co2 +, Ca2 + and K+ ions positively influenced the activity of enzymes and the Fe2+ ion had no effect on enzymatic activity. On the other hand, the ions Hg2+, Zn2+, Cu2+, Mn2+ and Mg2+ adversely influenced enzymatic activity. Therefore, producing amylases from Bacillus sp. and using crueira as a substrate is possible.