Secagem do resíduo de acerola (Malphigia emarginata D.C.): estudo do processo e avaliação do impacto sobre o produto final

Brazil, one of the largest agricultural producers in the world, has managed in recent years to significantly improve its production. However, in response to this advance in the agro-industrial sector, the generation of agro-industrial residues has also increased. New technological alternatives have to be implemented in order to bring economic and rational use of this material and drying is one of the possible choices. Considering the great importance that bioactive compounds present for food science and technology, this research aims to evaluate the air-drying process of acerola residue in a tray convective drier under controlled temperature (60, 70 e 80ºC), air velocity (4.0, 5.0 e 6.0 m/s) and material width (0.5, 0.62 e 0.75 cm) by applying an experimental planning 23 + 3. Based on that, the impact on physical-chemical characteristics, color, bioactive compounds concentration and antioxidant activity of dried acerola waste was evaluated, having the in natura and freeze dried waste as control groups. Dried acerola residue presented natural pigments, mainly carotenoids (143.68 - 68.29 mg/g) and anthocyanins (290.92 - 90.11 mg/100 g), which explain the red and yellow instrumental color parameters observed. The acerola residue powder is also rich in phenolic compounds (3261.11 -2692.60 mgGAEeq/100g), proanthocyanidins (61.33-58.46 eq/100g), ascorbic acid (389.44 739.29 mg/100 g) and DPPH antioxidant activity (20.91 24.72 μg Trolox eq/g). Results show decreased concentration of phenolic compounds, anthocyanins, carotenoids, proanthocyanidins and ascorbic acid caused by the air-drying process. However, even after the observed drying losses, the acerola residue powder can be considered a high value food ingredient, considering the high bioactive compounds concentration found in the final product, as well as the colorimetric characterization and microbiological stability of the dried powder

Produção de enzimas por fungos em fermentação semi-sólida utilizando bagaço de coco e pedúnculo de caju como substratos

The production of enzymes by microorganisms using organic residues is important and it can be associated with several applications such as food and chemical industries and so on. The objective of this work is the production of CMCase, Xylanase, Avicelase and FPase enzymes by solid state fermentation (SSF) using as substrates: bagasse of coconut and dried cashew stem. The microorganisms employed are Penicillium chrysogenum and an isolated fungus from the coconut bark (Aspergillus fumigatus). Through the factorial design methodology and response surface analysis it was possible to study the influence of the humidity and pH. For Penicillium chrysogenum and the isolated fungus, the coconut bagasse was used as culture medium. In another fermentation, it was used the mixture of coconut bagasse and cashew stem. Fermentations were conducted using only the coconut bagasse as substrate in cultures with Penicillium chrysogenum fungus and the isolated one. A mixture with 50% of coconut and 50% of cashew stem was employed only for Penicillium chrysogenum fungus, the cultivation conditions were: 120 hours at 30 °C in BOD, changing humidity and pH values. In order to check the influence of the variables: humidity and pH, a 2 2 factorial experimental design was developed, and then two factors with two levels for each factor and three repetitions at the central point. The levels of the independent variables used in ascending order (-1, 0, +1), to humidity, 66%, 70.5% and 75% and pH 3, 5 and 7, respectively. The software STATISTICA TM (version 7.0, StatSoft, Inc.) was used to calculate the main effects of the variables and their interactions. The response surface methodology was used to optimize the conditions of the SSF. A chemical and a physic-chemical characterization of the coconut bagasse have determined the composition of cellulose (%) = 39.09; Hemicellulose (%) = 23.80, Total Lignin (%) = 36.22 and Pectin (%) = 1.64. To the characterization of cashew stem, the values were cellulose (g) = 15.91 Hemicellulose (%) = 16.77, Total Lignin (%) = 30.04 and Pectin (%) = 15.24. The results indicate the potential of the materials as substrate for semisolid fermentation enzyme production. The two microorganisms used are presented as good producers of cellulases. The results showed the potential of the fungus in the production of CMCase enzyme, with a maximum of 0.282 UI/mL and the Avicelase enzyme the maximum value ranged from 0.018 to 0.020 UI/ mL, using only coconut bagasse as substrate. The Penicillium chrysogenum fungus has showed the best results for CMCase = 0.294 UI/mL, FPase = 0.058 UI/mL, Avicelase = 0.010 UI/mL and Xylanase = 0.644 UI/ mL enzyme, using coconut bagasse and cashew stem as substrates. The Penicllium chrysogenum fungus showed enzymatic activities using only the coconut as substrate for CMCase = 0.233 UI/mL, FPase = 0.031 to 0.032 UI/ mL, Avicelase = 0.018 to 0.020 UI/mL and Xylanase = 0.735 UI/ mL. Thus, it can be concluded that the used organisms and substrates have offered potential for enzyme production processes in a semi-solid cultivation

O Gênero requerimento na perspectiva sociorretórica: análise da produção de graduandos no ambiente acadêmico-administrativo da UFRN

In administrative settings of public institutions, many activities are conducted through writing practices. Concerning this, writing is always connected to an activity we intend to perform. Among those practices, the genre request consists of an instrument through which the requirer addresses to an institution in order to request something under the support of legislation. Considering our work experience in a public institution of higher education, we elected - as object of our research - the genre request produced by undergraduates within the administrative domain of the Federal University of Rio Grande do Norte (UFRN) due to its importance in this context. For this, the theoretical framework adopted refers to the socio-rethorical conception of genre studies, which understands the genre as forms as rhetorically typified action (MILLER, 2009a; SWALES, 1990; BAZERMAN, 2009). Regarding methodology, it is a research associated to a qualitative approach (BODGAN; BIKLEN, 1994; CHIZZOTTI, 2010) whose discussion inserts into the field of Applied Linguistics. The data were generated from samples of requests and their users replies in questionnaires, interviews and verbal protocols of writing. The data analysis is based on the ethnographic methods of genre analysis postulated by Devitt, Reiff and Bawarshi (apud JOHNS et al., 2006). These analyses indicated that the requests are not always fully accomplished due to a lack of comprehension about the genre and its rhetorical situation on the part of the producers. It must probably happen - among other reasons - because these students may not have understood that several factors, such as: context, audience and purpose, affect the text production. We believe that one possibility to make the practice of this genre more efficient is to develop a more simple and practical way of elaborating requests, taking the needs imposed by the rhetorical situation as a basis

Coerção e ruptura estilísticas na poesia potiguar: a construção do ethos inventivo do poeta Jorge Fernandes

Within the poetic scenario of Rio Grande do Norte the publication of Livro de Poemas de Jorge Fernandes, in 2007, marks, in the imagery of the Potiguar community of poetry readers, producers and critics, the beginning of the social circulation of an inventive ethos associated with the poet Jorge Fernandes de Oliveira (1887-1953). Regarding the event mentioned earlier as a point of reference, this research investigates the construction of such ethos based on the counterpoint between the poet s individual stylistic choices and the stylistic options that prevailed in the lyric production of the Twenties in the 20th Century. The corpus comprises poetic texts (by the poet under discussion and by other poets who were, then, regarded as icons of the poetry of Rio Grande do Norte) and texts representative of local literary criticism (produced both during the Twenties and in other decades of the last century). Support to this analysis is grounded in Mikhail Bakhtin s theory of the utterance (mainly regarding style) and in Dominique Maingueneau s theory of the utterance (mainly regarding ethos). During the course of this investigation, the research has outlined an inventory of the prevailing individual stylistic choices of Jorge Fernandes de Oliveira and the reasons why such choices point out towards the inventive ethos associated with the poet.

Bairro Planalto, Natal-RN: agentes, usos e conflitos

This research has the goal to analyze the urban setting of the Planalto neighborhood, in Natal /RN, seeking to unravel the processes, agents and contradictions associated with the production of the space. The choice of neighborhood is justified by the observation that changes in its urban setting have been growing in speedy way. We highlight the performance of the housing market, in partnership with the state, and the construction of condominiums and buildings closed by the housing program Minha Casa, Minha Vida. This has favored the reproduction of a new " urban reality in the neighborhood, setting an urban standard that differs from the original morphology, seen as peripheral within the urban dynamics of the city. The research is a qualitative study, through documents, interviews with stakeholders, and photographic documentation. In this perspective , we seek to understand the current phase (2000s) the production of space in the neighborhood process through the development of the housing market , as an extension of the urban development in central zone of Natal/RN, analyzing the performance of agents and their producers the "new " uses redefining the "old ". Thus, it can be seen that there is in the neighborhood, urban reality in a pluralistic constitution, from the existence of different social classes inhabiting the same space. On this way, the city is produced from the appropriation of space by different social classes, although due to the economic condition of each of them

Fractais e percolação na recuperação de Petróleo

The complex behavior of a wide variety of phenomena that are of interest to physicists, chemists, and engineers has been quantitatively characterized by using the ideas of fractal and multifractal distributions, which correspond in a unique way to the geometrical shape and dynamical properties of the systems under study. In this thesis we present the Space of Fractals and the methods of Hausdorff-Besicovitch, box-counting and Scaling to calculate the fractal dimension of a set. In this Thesis we investigate also percolation phenomena in multifractal objects that are built in a simple way. The central object of our analysis is a multifractal object that we call Qmf . In these objects the multifractality comes directly from the geometric tiling. We identify some differences between percolation in the proposed multifractals and in a regular lattice. There are basically two sources of these differences. The first is related to the coordination number, c, which changes along the multifractal. The second comes from the way the weight of each cell in the multifractal affects the percolation cluster. We use many samples of finite size lattices and draw the histogram of percolating lattices against site occupation probability p. Depending on a parameter, ρ, characterizing the multifractal and the lattice size, L, the histogram can have two peaks. We observe that the probability of occupation at the percolation threshold, pc, for the multifractal is lower than that for the square lattice. We compute the fractal dimension of the percolating cluster and the critical exponent β. Despite the topological differences, we find that the percolation in a multifractal support is in the same universality class as standard percolation. The area and the number of neighbors of the blocks of Qmf show a non-trivial behavior. A general view of the object Qmf shows an anisotropy. The value of pc is a function of ρ which is related to its anisotropy. We investigate the relation between pc and the average number of neighbors of the blocks as well as the anisotropy of Qmf. In this Thesis we study likewise the distribution of shortest paths in percolation systems at the percolation threshold in two dimensions (2D). We study paths from one given point to multiple other points. In oil recovery terminology, the given single point can be mapped to an injection well (injector) and the multiple other points to production wells (producers). In the previously standard case of one injection well and one production well separated by Euclidean distance r, the distribution of shortest paths l, P(l|r), shows a power-law behavior with exponent gl = 2.14 in 2D. Here we analyze the situation of one injector and an array A of producers. Symmetric arrays of producers lead to one peak in the distribution P(l|A), the probability that the shortest path between the injector and any of the producers is l, while the asymmetric configurations lead to several peaks in the distribution. We analyze configurations in which the injector is outside and inside the set of producers. The peak in P(l|A) for the symmetric arrays decays faster than for the standard case. For very long paths all the studied arrays exhibit a power-law behavior with exponent g ∼= gl.

Mundo de medo: inquisição e cristãos-novos nos espaços coloniais capitanias de Pernambuco, Itamaracá e Paraíba (1593-1595)

Founded in 1536, the Court of the Holy Office of the Portuguese Inquisition was established as an ecclesiastical institution, but at the same time subordinate to the real powers. Among the main victims of persecution effected by the Holy Office, were the New Christians - Jews forcibly converted in 1497 or their descendants - that due to their socio-religious were repeatedly accused of heresy. This paper conducted a survey that sought to understand the historical performance of the Inquisition in Brazil in the sixteenth century on the New Christians, especially those accused of secretly retaining the religious customs of the Mosaic law, given the investigative and punitive procedures employed by the Inquisition as part of a set of actions that produce social insecurities and producers / broadcasters of fear in the populations under scrutiny. In this sense, the approach was based on the analysis of documents produced on the first visit of inspection performed in Brazil inquisitorial sixteenth century, concerning the captaincy of Pernambuco and Paraiba Itamaracá (1593-1595), not excluding, however, the sources of the first stage of visitation that occurred between 1591-1593 in the province of Bahia de Todos os Santos, even though its use is ancillary and punctual. The objective of this research was to understand the consequences of inquisitorial procedures generated on the imaginary, and the Inquisition, using the expressions and signs of fears relating to individuals contained in the New Christian complaints to the Holy Office as documentary evidence of the fear caused by the Holy Tribunal. The adoption of specific behaviors by the New Christians in the home - these spaces are appropriate and adapted to the detriment of the religious practices of Judaism features - characterizes the spatial perspective of the study, thus indicating a further objective of the study: to understand how the New Christians experienced domestic spaces in a historical context marked by behavioral surveillance generally considered morally condemned and suspected of heresy. The research was conducted to analyze the complaints and quantitative survey of some indices of documentation for the understanding of overall charges and how individuals New Christians were concerned with the domestic space, using them to maintain criptojudaica religiosity, transformed places housing often esnogas, makeshift synagogue for meetings and celebrations of Judaizing New Christians. The formulations of Michel de Certeau on appropriations and meanings of space - presented by the author in the metaphor of "practice areas" - were integrated into the workforce in order to understand the ways in which the New Christians appropriated the colonial houses, designed these spaces a very specific language in the Crypto, in which women are prominent figures. The works of Jean Delumeau and Bartholomé Benassar integrate the discussion of the Inquisition and the sensibilities of fear in the work performed. The analysis allowed the documentation to understand the meaning and the extent related to the general fear that the Inquisition represented. Some complaints are indicative of fears that can be perceived implicitly based on behaviors and attitudes adopted by the New Christians, others, however, are direct expressions of fear caused by allusion or initiative of the actions of the Inquisition in colonial Brazil in the sixteenth century

Levantamento exploratório da composição e frações proteicas do leite bovino em propriedades leiteras

The direct relationship with the processing, industrial yield and price of milk, the importance of the centesimal composition of milk and their protein fractions has increased for both the dairy industry and for the producers, so it is important to identify the possible causes on variation of these components. The aim of this study was to evaluate the effect of the seasons, order of calving and lactation phase on milk composition and protein fractions in dairy farms in the Agreste and Leste meso-regions, of Rio Grande do Norte State (RN). Milk samples were taken in seven milk farms directly from the bulk tanks except for one farm where samples were taken from higher milking cows producers and heifers. The experiment was done in seven properties with milk samples taken directly from the bulk tanks and in one property were collected from higher production cows and heifers. Composition analyses were carried out for both experiments and sensorial trial was performed for the second experiment only. The data results were submitted to analysis of variance (ANOVA) and Tukey test performed for 5% significance level. In the first experiment was observed response of the seasons, dry and rainy season; while in the second, the effect of the order of calving and lactation phase had influence on milk composition and protein fractions. There was significant response (p < 0.05) for season effects but due to farms. The rainy season had higher averages in the protein, lactose, total solids and nonfat dry extract. Multiparous cows had higher CCS, NUL and PCAS milk contents; while, first calving heifers showed higher average for the sensory attribute, color of milk. The final third of lactation was responsible for the elevation of the levels of almost all milk components and their protein fractions

Caracterização da caprinocultura nas microrregiões da chapada do Apodi e de Angicos do Estado do Rio Grande do Norte

The objectives of this study were to characterize the goat production systems and to identify the factors limiting the production chain and develop solutions to improve the goat industry in the Rio Grande do Norte State, Brazil. One hundred and sixty two questionnaires were applied to goat farmers looking for productive, economic and social information about the utilized systems in the micro regions of Chapada do Apodi and Angicos. The majority producers interviewed were male, aging from 31 to 50 years old, attended elementary school, associated to farm organizations and living with his family on farm. Their main concerns are feeding the heard and animal theft. Their average farmlands areas range from 11 to 50 hectares. Goat meat is the main production in Chapada do Apodi whereas milk is produced by farmers in Angicos micro region. The majority of goat production works with an extensive system, with low technological inputs. It was detected that the meat and milk production as the marketing of goat products is not well conducted. Other point to be improved is to increase the meat and dairy goat products to be available for consumers. Goat systems for meat and milk production has great to potential for this micro regions, although public policies for an organized supply chain is needed

Infância na publicidade: um estudo sobre o trabalho de crianças na publicidade na cidade de Natal-RN

In Brazilian scene the child labor is a serious and relevant theme regarding issues that involve infancy, arousing the interest and concerning of public and private institutions, and organized civil society. Thus, the child labor is forbidden by the law, considered that the child worker have a distinguished life experience, especially because it is demanded them the early mature of some skill, generating implications on their physical, emotional, cognitive, social and psychological development. Observing those issues, we proposed think the child labor, over and above those considered the worst forms of one and more found in literature, what lead us to think the child labor in the advertising. In that way, this research aimed to investigate the insertion and development conditions of children who work in advertisements, and the possible effects on their lives in the face of that insertion. Participated of this study: three advertising agencies, six video producers companies, one child model s agent and five children with their respective families. Those children were four boys and two girls, with ages between seven and eleven years old, which one that have accomplished four or more advertisements, in Natal city, Rio Grande do Norte. Based on social-historical perspective, we used the semi-structured interview as methodological instrument, which underlays the comprehension of the data obtained in field research processes. This study revealed that when children are inserted in the advertising activities they are submitted to irregular and adverse work situations, what occurs in others productive activities mentioned in the literature. The data still exposed that the family is the main responsible to the children insertion in the advertisement work; moreover, there is an ambiguousness of wishes in relation of that activity. On the other hand, we realized that the legal content concerning to the child labor forbidding, carries contradictory aspects in face of the ECA s 149 article, that one, under some conditions, allows that a child take part in the activities of advertising context. This highlights the necessity of a rigorous evaluation of the children insertion in the advertising, in order to ensure the whole children and adolescents protection. This study put in evidence the complexity that involves the child labor in this context, mainly, due to the exposition and manipulation of the childish image on the media. Besides, we understand that the discussion on this subject should be stimulated and, therefore, enlarged this on over and above those considered the worst forms of child labor

O Serviço Residencial Terapêutico: cartografias de um híbrido no contexto da desinstitucionalização em saúde mental

This thesis seeks to uphold the idea that the therapeutic residential service, as hybrid device and recent process of deinstitutionalization in mental health, works as a problem producer while it also indicates challenges and potentialities in this process, the attention on mental health and on its own care production. To that end, we work with the prospect map with which we approach reality as the subjectivities production field which transformations and intensities are the major thought propellants. From this perspective, it was possible to produce three "purpose maps" from meetings with actors and groups involved with the TRS and the theoretical study carried out. On the first map we mapped the conditions of possibility of this device and its design in the midst of the process of institutionalization and health policies. We indicate on it the TRS configuration as a hybrid and we hassled its proposition as a means of "social rehabilitation" that can work as a social homogeneity mechanism. On a second map, we cartographied mental captures through images and ways historically built from madness presented in the biopolitical contemporary game and we indicated that the resistance to such catches should be built on a politic daily basis as important vectors of the institutionalization process in mental health. Finally, on a third map we mapped the carefulness produced in the TRS, by analyzing the transition psychiatric hospital - TRS and the caregivers´ team work. On this mapping, the care, for the weakness in the coresponsibility field, is reveled crossed by mental, disciplinary and normality elements, but it is also built in resistance born from links in the intersubjective field of the caring work. We conclude, then, that the TRS power and the deinstitutionalization process itself were in building and strengthening affective labor micro political networks of life and liberty producers

Avaliação termoanalítica da eficiência de antioxidantes na estabilidade oxidativa do biodiesel de mamona

The biodiesel is defined as the mono-alkyl ester derived from long-chain fatty acids, from renewable sources such as vegetable oils or animal fat, whose use is associated with the replacement of fossil fuels in diesel engine cycle. The biodiesel is susceptible to oxidation when exposed to air and this process of oxidation affects the quality of fuel, mainly due to long periods of storage. Because of this, the oxidation stability has been the focus of numerous researches since it directly affects the producers, distributors and users of fuel. One of the possibilities to increase the resistance of biodiesel is the autoxidation treatment with inhibitors of oxidation. The antioxidants can be used as potential inhibitors of the effects of oxidation on the kinematic viscosity and the index of acidity of biodiesel, thereby increasing oxidative stability. This work aims to examine the efficiency of antioxidants, α-tocopherol and butylated hydroxy-toluene (BHT), added the biodiesel content of remembrance through Pressurized-Differential Scanning Calorimetry (P-DSC), Thermogravimetry (TG) and Petrology. The results showed that the use of antioxidant BHT, at the concentration of 2000ppm, increased resistance to oxidation of the biodiesel and oxidative induction time (OIT), which is a better result as antioxidant than the α-tocopherol. With the thermogravimetric analysis, it was observed that the biodiesel presented an initial decomposition temperature of lower tendency than that of oil, demonstrating to be more volatile, bearing great similarity to the diesel and being characterized as an alternative fuel. The rheological analysis indicated that each sample of biodiesel behaved as a Newtonian fluid

Estudo da água produzida em diferentes zonas de produção de petróleo, utilizando a hidroquímica e a análise estatística de parâmetros químicos

Over exploitation of oil deposits on land onshore or offshore, there is simultaneous generation of waste water, known as produced water, which represents the largest waste stream in the production of crude oil. The relationship between the chemical composition of oil and water production and the conditions in which this process occurs or is favored are still poorly studied. The area chosen for the study has an important oil reserve and an important aquifer saturated with freshwater meteoric. The aim of this work is to study some chemical parameters in water produced for each reservoir zone of production in mature oil fields of Açu Formation, using the hydrochemical and statistical analysis to serve as a reference and be used as tools against the indicator ranges water producers in oil producing wells. Samples were collected from different wells in 6 different areas of production and were measured 50 parameters, which can be classified into three groups: anions, cations and physicochemical properties (considering only the parameters that generated values above detection limits in all samples). Through the characterization hydrochemistry observed an area of water and chlorinated sodium, chlorinated calcium or magnesium (mixed) in well water in different areas of Açu, by applying a statistical treatment, we obtained a discriminant function that distinguishes chemically production areas. Thus, it was possible to calculate the rate of correct classification of the function was 76.3%. To validate this model the accuracy rate was 86%

Caracterização de resíduo sólido formado em biodiesel de sebo bovino

Biodiesel production has increased over the last decade because of the benefits associated with this fuel, including renewability, domestic feedstock, lower toxicity, and biodegradability. From 2008, the use of beef tallow as a feedstock for biodiesel production in Brazil has increased in significance, representing the second largest source of biodiesel, after soybeans. However, the performance of biodiesel in cold weather conditions is worse than diesel because of deposition of insoluble at low temperatures, accelerating the plugging of fuel filters and injectors of the vehicle engine. Studies have been conducted on beef tallow biodiesel, mostly related to the properties of thermal and oxidative stability. However, few studies have described the nature of the precipitate formed and its influence on product quality. Research suggests that the cause of deposition is related to the nature of saturated esters and monoacylglycerols as inducing agents. This study monitored the levels of mono-, diand triacylglycerols, the oxidation stability and the cold filter plugging point (CFPP) in beef tallow biodiesel samples from two commercial producers in Brazil for a period of twelve months. Filtered precipitates were analyzed by comparative techniques of GCFID, HPLC-UV/VIS, HPLC-MS-IT-TOF and TG to verify the nature, using monopalmitin and monostearin as reference standards. The formation of precipitate reduced the levels of monoacylglycerols in the beef tallow biodiesel. GC-FID and LCMS- IT-TOF results confirmed the nature of the deposit as saturated monoacylglycerols, predominantly monostearin and monopalmitin as the second major component. Moreover the TG analysis of the residue indicated similar thermal decomposition of the reference standards. The precipitate did not affect the oxidation stability of beef tallow biodiesel and the CFPP characteristic of blends up B60. However, the presence of iron reduced significantly the oxidation stability of biodiesel

Caracterização de resíduo sólido formado em biodiesel de sebo bovino

Biodiesel production has increased over the last decade because of the benefits associated with this fuel, including renewability, domestic feedstock, lower toxicity, and biodegradability. From 2008, the use of beef tallow as a feedstock for biodiesel production in Brazil has increased in significance, representing the second largest source of biodiesel, after soybeans. However, the performance of biodiesel in cold weather conditions is worse than diesel because of deposition of insoluble at low temperatures, accelerating the plugging of fuel filters and injectors of the vehicle engine. Studies have been conducted on beef tallow biodiesel, mostly related to the properties of thermal and oxidative stability. However, few studies have described the nature of the precipitate formed and its influence on product quality. Research suggests that the cause of deposition is related to the nature of saturated esters and monoacylglycerols as inducing agents. This study monitored the levels of mono-, diand triacylglycerols, the oxidation stability and the cold filter plugging point (CFPP) in beef tallow biodiesel samples from two commercial producers in Brazil for a period of twelve months. Filtered precipitates were analyzed by comparative techniques of GCFID, HPLC-UV/VIS, HPLC-MS-IT-TOF and TG to verify the nature, using monopalmitin and monostearin as reference standards. The formation of precipitate reduced the levels of monoacylglycerols in the beef tallow biodiesel. GC-FID and LCMS- IT-TOF results confirmed the nature of the deposit as saturated monoacylglycerols, predominantly monostearin and monopalmitin as the second major component. Moreover the TG analysis of the residue indicated similar thermal decomposition of the reference standards. The precipitate did not affect the oxidation stability of beef tallow biodiesel and the CFPP characteristic of blends up B60. However, the presence of iron reduced significantly the oxidation stability of biodiesel