Abstract The objective was to develop and characterize biodegradable films with antimicrobial and antioxidant action, using poly(butylene adipate-co-terephthalate) (PBAT) incorporated with OEO - essential oil (Origanum vulgare). The degradation temperature of the OEO increased after incorporation into the PBAT matrix, however, the degradation of the matrix did not undergo considerable changes. The films showed increase in elongation and modulus of elasticity with presence of OEO, however, it reduced the maximum tension. The permeability of the films was reduced with OEO presence. The spectra (FTIR) showed the presence of the functional groups attributed to the bioactive compounds (Carvacrol) of OEO. The films presented high antioxidant activity and effective antimicrobial action, reducing Staphylococcus aureus in 53 days and psychrotrophic microorganisms in up to 28 days of storage. The films showed to be efficient with antioxidant activity and antimicrobial action with indication to be used as packaging of sliced mozzarella cheese.

ABSTRACT Polyhydroxyalkanoates (PHA) are biocompatible and biodegradable polyesters produced by prokaryotic microbes for energy storage and carbon reserve. These polymers are an option to diminish the massive impact caused by inadequate disposal of synthetic plastics. In this study, evaluation and characterization of PHA produced by Cupriavidus necator (IPT 026 and IPT 027) and Burkholderia cepacia (IPT 119 and IPT 400), using soybean as substrate, were carried out (soybean 15 g L-1, pH 7.0, 150 rpm, 72 hours). The highest polymer production was achieved using IPT 027 (0.84 ± 0.07 g L-1). All PHA produced showed the characteristic bands of polyester functional groups in the FTIR spectra. Polymers synthesized by Cupriavidus necator exhibited initial temperatures of degradation superior to 300oC and higher molecular weights than the ones produced by Burkholderia cepacia, which in turn, exhibited lower crystallinity (inferior to 30%), revealing high influence of the microorganism strain on PHA properties and production.

Composites strengthened with nanocellulose have been developed with the aim of improving mechanical, barrier, and thermal properties of materials. This improvement is primarily due to the nanometric size and the high crystallinity of the incorporated cellulose. Cassava starch films plasticized with glycerol and incorporated with nanocellulose from coconut fibers were developed in this study. The effect of this incorporation was studied with respect to the water activity, solubility, mechanical properties, thermal analysis, and biodegradability. The study demonstrated that the film properties can be significantly altered through the incorporation of small concentrations of nanocellulose.

The aim of this study was to evaluate the production of polyhydroxyalkanoates (PHAs) by fermentation of Crude Glycerin, a byproduct of the biodiesel industry, by Cupriavidus necator IPT 026, 027 and 028. The influence of fermentation time and temperature in shake flasks were evaluated. The highest PHA production (2.82 g L-1) occurred at 35 ºC for 72 h of fermentation. The melting and initial thermal degradation temperatures of this PHA were 177.9 ºC and 306.33 ºC, respectively, with 55% crystallinity. FTIR spectrum was similar to those reported in literature. The polymer obtained presented three different methyl esters of hydroxyalkanoates in its composition, with molecular weight of 630 kDa. Bacteria can use Crude Glycerin as an inexpensive substrate to produce value-added biodegradable products, such as PHA.

Foi estudada a otimização do processo de produção de goma xantana a partir de casca de cacau ou soro de leite como fonte de carbono, e determinou-se o rendimento da goma obtida pela bioconversão de casca de cacau e soro de leite com a Xanthomonas campestris 1182. A goma foi produzida em meios com potássio e nitrogênio a 25 °C, 250 rpm por 120 horas. Os rendimentos foram: 2,335 g.L-1 para a sacarose; 4,995 g.L-1 para a casca de cacau seca e 12,01 g.L-1 utilizando soro de leite. Portanto, é viável a produção de goma xantana utilizando fontes de carbono como a casca de cacau e o soro de leite.

The optimization of the production process of xanthan gum from cocoa husks or milk whey as carbon source was studied, and the production rate of gum obtained by the bioconversion of cocoa pods and whey was determined, using Xanthomonas campestris 1182. The gum was produced in a medium with potassium and nitrogen at 25 °C, 250 rpm for 120 hours. The results were: 2.335 g.L-1 for sucrose; 4.995 g.L-1 for cocoa dry pods and 12.01 g.L-1 using whey. Therefore, the production of xanthan gum is feasible upon using carbon sources such as cocoa hulls and whey.

Goma xantana é um biopolímero comercial produzido por fermentação de glicose e Xanthomonas com larga aplicação industrial. O objetivo deste trabalho foi estudar a síntese e a viscosidade da goma obtida por cepas nativas de Xanthomonas campestris utilizando soro de mandioca como substrato fermentativo alternativo. Três tipos de Xanthomonas foram utilizados. A maior produção foi de 13,83 g.L-1 obtida do meio fermentativo com X. campestris mangiferaeindicae a 25 ºC, 250 rpm por 120 horas apresentando uma viscosidade aparente de 96,14 cP na concentração de 2,0% de solução de xantana a 25 s-1, 25 ºC. O uso do resíduo industrial de soro de mandioca para biossíntese da xantana é uma alternativa de baixo custo para o processo fermentativo e um destino para esse soro.

Xanthan gum is a commercial biopolymer produced by fermentation of glucose and Xanthomonas with many industrial applications. The objective of this work was to study the synthesis and the viscosity of xanthan obtained from native strains of Xanthomonas campestris using cassava as an alternative fermentative substrate. Three kinds of Xanthomonas were used. The highest production was 13.83 g.L-1 obtained with X. campestris mangiferaeindicae fermented at 25 ºC, 250 rpm during 120 hours and presenting apparent viscosity 96.14 cP in the concentration of 2.0% of xanthan solution at 25 s-1, 25 ºC. The use of the industrial residue of cassava serum for biosynthesis of xanthan is a low cost alternative for the fermentation process and a noble use for this waste.

The presence of chloramphenicol residues in goat milk can cause toxic effects in the population. The present work consists of the optimization and validation of analytical methodology for determination of chloramphenicol residues in goat milk by GC/ECD. The extraction was made with ethyl acetate and the clean-up with SPE-C18. The identification was made by comparison of retention time and GC/MS, and the quantification by external standard. The method was selective, linearity (0.998), precise (5.8-13.4%), exact (69.87-73.71%) and robust. The LOD and LOQ of method were 0.030 and 0.10 μg/kg, respectively. The method was efficiently for analysis of chloramphenicol in goat milk.

Um método simples e rápido para a preparação da amostra e quantificação simultânea de açúcares e polióis em sorvetes "diet"/"light" por CLAE-IR foi investigado. Os açúcares frutose, glicose, lactose, maltose, sacarose, juntamente com glicerol e sorbitol foram separados. Diferentes variáveis foram testadas na preparação da amostra e nas condições cromatográficas para a separação dos componentes. A melhor condição para a separação dos analitos da matriz foi obtida através de duas extrações consecutivas com água : etanol (1:8 v/v, seguida de 1:4 v/v). Para a separação cromatográfica em uma coluna CLC-NH2 , a fase móvel foi composta de acetonitrila: água (77,5:22,5 v/v) na vazão de 1mL/min, a 30 ºC. O tempo de corrida foi menor do que 20 min. Amostras de sorvetes "diet"/"light" de 3 diferentes marcas, com sabores de morango, chocolate, flocos e baunilha, recolhidas em Campinas-SP, apresentaram valores de açúcares totais entre 9-15%. Somente os sorvetes com sabor morango apresentaram frutose (0,1-0,5%), e somente aqueles sorvetes com sabor de flocos mostraram a presença de sacarose em maiores quantidades. Os maiores valores de açúcares foram encontrados para lactose, independente da marca ou sabor testados (3,5-10%). As quantidades de sorbitol variaram de 3-4%. A mesma análise foi realizada com sorvete normal (controle) que apresentou valor de açúcares totais de aproximadamente 29%, sendo que destes 16,8%, foi sacarose. Não foram detectados polióis. Na amostra de sorvete controle foi realizado teste de recuperação de sorbitol (99,3%). Os valores encontrados foram comparados com os valores permitidos pela legislação.

A simple fast method for sample preparation and the simultaneous quantification of sugars and polyols in diet/light ice creams, using HPLC-RI, was investigated. The sugars fructose, glucose, lactose, maltose and sucrose, together with glycerol and sorbitol, were separated. Different variables were tested both for sample preparation and for the chromatographic conditions used to separate the components. The best conditions to separate these components from the matrix were by way of two extractions with water:ethanol (1:8 v/v followed by 1:4 v/v). The chromatographic separation using an CLC-NH2 column with a mobile phase consisting of acetonitrile:water (77.5:22.5 v/v) with flow rate of 1mL/min, at 30ºC. The run time was less than 20 min. Samples of three different brands of strawberry, chocolate, chocolate chip and vanilla ice cream, all collected in Campinas-S.P., presented values for total sugars between 9 and 15%. Only the strawberry flavored ice creams showed the presence of fructose (0.1-0.5%) and only the chocolate chip ice creams showed the presence of sucrose in higher quantities. The sugar found in greatest amounts was lactose (3.5-10%), whatever the brand or flavor. Sorbitol was present in amounts of 3-4%. The same analyses was applied to non-light ice cream, which presented value for total sugars of approximately 29%, of which 16.8% was sucrose, polyols not being detected. Sorbitol recovery was tested in one of these samples(99.3%). The values encountered were compared with the values legally permitted.

Do extrato aquoso, congelado e liofilizado dos frutos do açaizeiro, foram extraídas as antocianinas e após purificação e separação das duas principais frações as mesmas foram identificadas usando métodos químicos, espectroscópicos e CLAE. As antocianinas foram identificadas como cianidina-3- arabinosídeo e cianidina-3-arabinosil-arabinosídeo. O teor de antocianinas totais no caso do fruto do açaizeiro foi determinado e o valor encontrado foi de 263mg/100g casca.

From the liophylized commercialy frozen extract of the fruit of Euterpes oleracea (açaí) two anthocyanins were isolated and identified as cianidin-3-arabinoside and cyanidin-3-arabinosylarabinoside. The percentage of total anthocyanins in the peels of the fruits was 263 mg/100g peel.