José Marcelino Oliveira Cavalheiro

Estudo termogravimétrico e calorimétrico da algaroba

Humidity and ash content of powder and bran of algaroba pods are important quality parameters for biological control during storage. The studies of humidity and ash content were carried out conventional and thermogravimetric methods. Different values were obtained by the various methods. The thermogravimetric method was faster and required less sample for the humidity and ash analyses of the powder and bran of algaroba pods. The differential scanning calorimetry curves of the powder and bran of algaroba pods, dryed at 55 oC, showed two peaks, one corresponding to the gelatinization of starch and the other to the vaporization of water. The samples dryed at 65, 75, 85, 95 and 105 oC showed one peak, corresponding to the vaporization of water.

Dipteryx lacunifera seed oil: characterization and thermal stability

The Dipteryx lacunifera Ducke is an oleaginous legume with high oil and protein content that can be used in human nutrition. The specie is a native of the Piaui and Maranhao state in the north east of Brazil. The measure physico-chemical properties of the oil are specific density, refractive index, acid, peroxide, iodine and saponification values of 0.91, 1.4651, 0.60 (% oleic acid), 2.81, 70.80 and about 179, respectively. Gas chromatographic analysis of the oil showed the presence of 20.6% saturated, 65.1% monounsaturated and 14.3% polyunsaturated fatty acids. The saturated fatty acids C6:0, C8:0, C12:0 and C17:0 were present in trace (<0.01%) amounts while the C16:0, C18:0, C20:0, C22:0 and C24:0 were at concentrations of 10.3, 5.4, 3.4, 0.9 and 0.6% of the total fatty acids. Unsaturated fatty acids C18:1, C18:2, C18:3 and C22:2 contents were 65.1, 14.1, 0.3% and trace (0.01%), respectively. Thermal analysis (TG/DTG) revealed that the thermal decomposition of the oil occurs in two steps corresponding to the unsaturated and saturated fatty acids. The oil, when heated to a temperature of 180o C for 400 min showed smaller loss in mass than commercial soy, sunflower and corn oils. The curve DSC indicated an endothermic event with enthalpy variation (DH) of -56.7 Cal.g-1 in the temperature interval of 340 oC (Ti) the 463o C (Tf), with maximum in 411.1o C (Tm).

Processamento de biscoitos adicionados de óleo de buriti (Mauritia flexuosa L.): uma alternativa para o consumo de alimentos fontes de vitamina A na merenda escolar

OBJETIVO: Este trabalho teve como objetivo desenvolver biscoitos tipo cookie adicionado de oleo de buriti a fim de se analisarem sua aceitacao sensorial e seu valor nutricional, visando a sua utilizacao na merenda escolar, bem como avaliar o consumo de alimentos fontes de vitamina A por escolares. METODOS: Uma formulacao-controle (15% de oleo de soja) e duas formulacoes experimentais (7,5% e 15% de oleo de buriti) foram produzidas e avaliadas quanto a composicao centesimal, conteudo de vitamina A e aceitacao sensorial, testada por 201 escolares. Avaliou-se tambem o consumo de alimentos fontes de vitamina A por esses escolares mediante questionario semiquantitativo contendo 28 alimentos considerados fontes da referida vitamina. RESULTADOS: O biscoito elaborado com 15% de oleo de buriti obteve boa aceitacao, e apresenta maior percentual de proteinas, de minerais e de vitamina A, podendo ser considerado fonte deste ultimo nutriente. Observou-se uma maior frequencia de consumo de alimentos com baixo teor de vitamina A, como tambem uma menor frequencia de consumo dos frutos da regiao Nordeste. CONCLUSAO: Os biscoitos adicionados de oleo de buriti podem ser uma alternativa de inclusao de alimentos fontes de vitamina A na dieta de escolares, no entanto o consumo de frutas e hortalicas fontes dessa vitamina deve ser estimulado, tendo em vista que os escolares consomem pouca variedade de alimentos fontes dessa vitamina, o que aumenta o risco de deficiencia a longo prazo.

Determination of the chemical composition and functional properties of shrimp waste protein concentrate and lyophilized flour

Wastes from the seafood industry can be easily processed into products with new forms of use. The present study was aimed at determining the chemical composition and functional properties of shrimp waste protein concentrate and lyophilized flour. The raw material used in this study consisted of waste (head) of Litopenaeus vannamei. The protein concentrate was obtained by ethanolic extraction, being subsequently submitted to drying in oven at 70° C, while the flour was obtained by lyophilization of shrimp wastes. Moisture, ash, protein and calcium contents showed significant difference between fresh shrimp head waste samples (IN) and protein concentrate and lyophilized flour samples. The protein content for protein concentrate (PC) and lyophilized flour (LF) showed significant increase in relation to protein content in the waste (IN), thus showing that the process for obtaining the protein concentrate was efficient.

Estabilidade térmica das vitaminas A e E em rações e premixes vitamínicos para camarões

The study aimed to evaluate the thermal stability of vitamins A and E on different rations and vitamin premixes used in shrimp farming. Three commercial rations pelleted and disintegrated in two different diameters and two vitamin premixes were used in the experiment. Samples of each ration and premixes were placed in plastic containers and stored under the following conditions: refrigerated environment (6°C±2°C), acclimatized environment (20°C±3°C) and greenhouse environment (40°C±3°C). The levels of vitamins were determined in triplicate in samples at times 0 (control), 5, 10, 15, 20, 25 and 30 days, under the conditions described above. The results were statistically treated by analysis of variance (ANOVA) and the Duncan test was applied at 5% probability. The results showed that the average vitamin A percentage losses in rations were 65%, 60% and 68% for climatized, air-conditioned and greenhouse environments respectively. For the vitamin premix A the percentage of degradation was 78-87% and it was observed higher losses in the climatized and greenhouse environments. With respect to vitamin E, it was observed in the rations lost of 88% to 100% verifying the total losses for the storage in air-conditioned and greenhouse environments. For the vitamin premix E the losses were 71% to 82%. It was concluded that during the storage of feed and premixes vitamins, losses due to thermal degradation showed lack of stability of fat soluble vitamins in the structure of feed and premixes used in feed for shrimp.

Flour production from shrimp by-products and sensory evaluation of flour-based products

The objective of this work was to evaluate the production of flour using by‑products (cephalothorax) obtained from the shrimp (Litopenaeus vannamei) industry, and to perform a sensory analysis of shrimp flour‑based products. Physicochemical and microbiological analyses on fresh cephalothorax and on manufactured flour were performed, as well as the determination of cholesterol content of this flour, and the sensorial evaluation of soup and pastry made with this flour. By the microbiological analyses, no pathogenic microorganism was detected in the samples. Physicochemical analyses of flour showed high levels of protein (50.05%) and minerals (20.97%). Shrimp cephalothorax flour showed high levels of cholesterol. The sensory evaluation indicated a good acceptance of the products, with satisfactory acceptability index (81% for soup, and 83% for pastry), which indicates that shrimp cephalothorax in the form of flour has a potential for developing new products.

Partial evaluation of Dipteryx lacunifera seed kernel as a nutritional food

The Dipteryx lacunifera plant is a native of the states of Piauí and Maranhão in Brazil. The fruit kernel, in spite of having a good potential for food use, is still unexplored. The present work investigates the kernel composition, electrophoretic behavior, amino acids composition, and antinutritional components in defatted kernel flour. The kernel constituted about 6.5% of the fruit. The average weight, length, width, and thickness of the kernel were 1.03 g, and 2.45, 1.44 and 0.58 cm, respectively. The lipid and the protein contents of whole kernel flour were about 41.8 and 13.3 g per 100 g, respectively, while in defatted kernel flour, the protein content was 26.4 g per 100 g on dry weight basis. The polyacrylamide gel in the presence of sodium dodecyl sulfate and 2β-mercapto-ethanol (PAGE-SDS-2βMe) revealed the presence of 12 proteins with molecular weights ranging from 7.8 to 97.3 kDa. The proteins with molecular weights 18.0, 39.6, 57.6, 69.2, and 97.3 kDa were the prominent ones, while those corresponding to 7.8, 12.0, 14.7, 25.3, 31.3, 33.7, and 83.9 kDa were present in small concentrations. Defatted kernel flour did not present trypsin inhibitory and hemagglutinating activity. The tannin content of the flour was 0.63 mg/g. In comparison to FAO reference protein, the defatted flour showed all essential amino acids (except methionine) in good concentrations.

Composição e cinética de degradação do ácido ascórbico em rações para aquicultura

The increasing development of the aquiculture in the last years has stimulated the interest in studying the best form of using the rations, because they increase in up to 60% the total cost of the production. The level of ascorbic acid incorporated in a diet must consider the variation of the raw material, the interactions between nutrients and the losses in the processing, storage, and leaching. The study was conducted to evaluate the thermal stability, photochemistry, and leaching of ascorbic acid on different rations and vitamin premix used in the aquiculture. Samples 1 (pelletized and later disintegrated ration, destined to feeding after-larvae marine shrimps (PL2-PL15) and 5 (vitamin premix) presented the biggest ascorbic acid losses during the thermal degradation, photochemistry, and leaching.

Efeito da embalagem com atmosfera modificada associada ao ácido ascórbico na vida útil de filés de tilápia-do-nilo (Oreochromis niloticus)

This study aimed to evaluate the effect of modified atmosphere packaging associated with ascorbic acid on the shelf life of Nile tilapia fillets, and to determine the most effective treatment for their conservation. To this end, fillets of this species were subjected to four different treatments: T1 (control) aerobically, T2 (1% ascorbic acid + 80% CO2 + 20% O2), T3 (1% ascorbic acid + 100% CO2) and T4 (1% ascorbic acid + vacuum). The samples were subsequently stored at 4 ± 1°C and subjected to microbiological, physical-chemical and sensory evaluations at different intervals. The T3 and T4 treatments were more effective in inhibiting the development of psychrotrophic bacteria and the coliform group of microorganisms with time in the samples analyzed, the presence of Clostridium sulfite reducers not being detected in the fillets of either treatment. However, the results for pH, NTVBs and TBAs showed that treatment T4 stood out as compared to treatment T3, maintaining the freshness features unchanged for a longer time. The results of the sensory analysis showed a reduction in the average scores with time for all the attributes assessed, being significantly affected during the storage period (p<0.05). The sensory evaluation delimited the shelf life of the samples, treatment T4 treatment maintaining better mean scores for a longer period of time of 18 days. Correlating the results of the microbiological, physical-chemical and sensory analyses, it was concluded that treatment T4 (1% ascorbic acid + vacuum) was more effective and therefore the most suitable for the conservation of refrigerated Nile tilapia fillet.

Degradação de α-Tocoferol, retinol e ácido ascórbico durante processamento e armazenamento de rações para camarão

O cultivo de camarao marinho e um setor de grande viabilidade economica, principalmente na regiao Nordeste. Entretanto, a alimentacao dos camaroes e responsavel pelo maior custo no cultivo desses crustaceos, a racao deve ser nutricionalmente eficiente, sendo indispensavel a presenca das vitaminas que sao substâncias fundamentais para o funcionamento do organismo animal, e sua falta resulta frequentemente em crescimento e desenvolvimento deficiente. O retinol, -tocoferol e o acido ascorbico sao vitaminas que atuam em diversos processos metabolicos. Sao indispensaveis em racoes animais porque sao antioxidantes que auxiliam os animais contra o estresse oxidativo. Objetivou-se, neste trabalho, avaliar as perdas das vitaminas durante o processamento das dietas e no periodo de armazenagem. Foram formuladas oito dietas isoproteicas com diferentes niveis de vitamina A, E e C que foram processadas com temperatura de ate 80oC. Apos a fabricacao e depois de 60 dias de armazenagem foram analisadas e quantificadas as vitaminas a fim de descobrir as perdas durante o processamento e apos estocagem. Constatou-se que a vitamina A, que foi adicionada na dieta, foi perdida em ate 99,56%. Ja a vitamina E perdeu no maximo 93,5% e a vitamina C com 70% de perda, durante o processamento. Durante o periodo de armazenagem as perdas foram menores. Pode-se concluir que as vitaminas sao extremamente sensiveis aos fatores que atuam durante a manufatura das dietas, ocasionando perdas consideraveis de vitaminas.