Metabolic parameters and risk factors associated with abdominal obesity among female adolescents in public schools in the Distrito Federal (Brazil)

This study aimed to estimate the prevalence of abdominal obesity and investigate their association with parameters markers of metabolic syndrome (MS) and its risk factors in female adolescents. It is a cross-sectional study with 150 adolescents from 10 public schools in the Federal District, Brazil. The presence of abdominal obesity was considered by measuring waist circumference above the 80th percentile, according to Taylor et al. (2000). The associated factors included sociodemographic characteristics, health status of adolescents and their parents, physical activity, eating habits, blood pressure and biochemical profile. The abdominal obesity prevalence ratio (PR) was estimated by Poisson regression model, with 95% CI. Among the adolescents studied (age= 15.6 +/- 0.8 years; BMI = 21.0 +/- 3.0 kg/m2), prevalence of abdominal obesity was 20%, and this condition was not associated with sociodemographic variables, physical activity and diet. However, abdominal obesity was significantly associated with intake of less than 4 meals a day (PR = 2.27; IC95% 1.27-4.10), previous obesity (PR = 2.36; IC95% 1.31-4.01), history of parental chronic disease (PR = 3.55; IC 95% 1.63-7.75), fasting insulin = 15 uUi/mL (PR = 3.05; IC 95% 1.36-6.82) e HDL-c > 40 mg/dL (PR = 0.39; IC95% 0.23-0.67). In this population, modifiable factors, family history and determinants of MS, such as insulin and HDL-c were associated with abdominal obesity, which points to the need for effective health promotion among adolescents.     

Factors associated with adiposity in normal weight female adolescents with adequate and high percent body fat: elaborating a risk model

Factors associated with adiposity in normal weight female adolescents with adequate and high percent body fat: elaborating a risk model. This study was carried out to evaluate the factors associated with adiposity in normal weight adolescents presenting appropriate or high percent body fat, who attended the public schools in Vi?osa county-Minas Gerais/Brazil. A total of 118 female adolescents at age range from 14 to 19 years and have already presented the menarche were evaluated. The adolescents were divided into 2 groups: G1 with high percent body fat and G2 with appropriate percent body fat. The following variables were evaluated: anthropometric, body composition, lifestyle and the family history of non-communicable chronic diseases. In subsample, the basal energy consumption was determined by indirect calorimetry. The G1-grouped adolescents showed higher values for most anthropometric and body composition variables (p < 0.001). No differences were observed (p > 0.05) for basal metabolism and metabolism of lean body mass, smoking habit, total energy consumption and protein and lipid as well between groups. When comparing the physical activity level, the G1 adolescents spent more time with 1-level sedentary activities whereas the G2 ones showed higher total caloric consumption with daily activities (p < 0.001). According to risk factors under analysis, the variables related to lifestyle, as distinguishing the use of sweeteners (OR = 13.47), provided higher contribution to excessive adiposity in the normal weight adolescents. The detailed analysis of the body composition as well as the risk factors associated with excessive body fat makes possible the early diagnosis and the development of more appropriate intervention means.     

Development and optimization of cultured goat cream butter

A central composite design 2²+star based on response surface methodology was used for development and optimization of a cultured goat cream butter formulation (cultured). The goat milk cream was inoculated with freeze-dried mesophilic aromatic lactic cultures and showed an increase in acidity and a aromatic lactic cultures and showed an increase in acidity and a decrease in lactose content when the concentration of lactic cultures was increased. An optimized temperature of 28°C was chosen for fast acid production in the goat milk cream. The lactic culture concentration significantly affected flavor, sensory texture, and overall quality, but the fermentation process were an inoculum dosage of 8.8 U/100 L and a fermentation time of 7 h at 28°C. This cultured formulation achieved optimal sensory quality in the attributes appearance, flavor, texture, and overall quality. At refrigerator temperature (4°C) the cultured formulation behaved as a solid and lacked spreadability, whereas it had ideal spreadability at 15°C when the solid fat content (SFC) was around 18.0%. At room temperature (18–25°C) the SFC was between 11 and 8%, respectively.     

Statistical Copolymers of l,l-lactide and ε-caprolactone

Summary Copolymers of l,l-lactide with -caprolactone have been investigated in order to develop valuable biodegradable materials for medical applications. The syntheses of homopolymers and copolymers of l,l-lactide and -caprolactone by ring-opening bulk polymerization were performed using stannous octoate as initiator at 120 °C. The compositions of the copolymers were systematically varied by polymerization of monomer mixtures containing from 10 to 90 95 of -caprolactone, at 10% step of variation. High polymerization conversions were observed for homopolymers and copolymers syntheses. Synthesized products were characterized by gel permeation chromatography (GPC) and nuclear magnetic resonance spectrometry (NMR). The analyses of the segment lengths by ¹³C-NMR spectroscopy indicated the predominance of random copolymers formation and the transesterification reaction was not detected.     

MgAlLi Mixed Oxides Derived from Hydrotalcite for Catalytic Transesterification

Abstract  

MgAl hydrotalcite was synthesized and used as support for Li impregnation. MgAlLi oxides were obtained from heat treatment of the Li/MgAl hydrotalcite. These materials were characterized and evaluated as catalysts for model transesterification reactions. MgAl showed negligible activity under mild reaction conditions (50 °C and 0.5 h) whereas Li incorporation greatly increased the activity. The activities were correlated to their basicity determined by TPD of CO₂. Reuse tests showed catalyst deactivation after the third cycle, probably due to lithium leaching. However, the contribution to a homogeneous reaction has been dismissed. MgAlLi revealed to be a promising catalysts for transesterification reaction and thus for biodiesel production.     

Influence of the acid–basic character of oxide surfaces in dispersants effectiveness

Physical–chemical surface character has been described as a determinant factor in adsorbing polyelectrolytes onto oxide surfaces. Since basically composed by hydroxyl groups, the acidity or basicity induced by the bulk lattice in such groups seems to be of great relevance in the adsorption process. The influence of such properties in the adsorption of polyacrylic acid derivated polymers onto SnO₂ and Al₂O₃ surfaces is, therefore, studied in this paper. Polyacrylate acid molecules are observed to hardly adsorb onto the SnO₂ surface but strongly adsorb, as reported previously, onto the alumina surface. This behavior is explained based on the pronounced difference in relation to the acidity of both surfaces and, in this sphere of thought, a basic polymer (Chitosan; CS) is discussed as a functional dispersant for powders with acid surface character, such as SnO₂. Zeta potential measurements showed that this polymer raises the SnO₂ potential to +30 mV without pH variations.     

Interesterification of tallow and sunflower oil

The objective of this study was to manufacture a shortening using chemical interesterification (IT) of tallow-sunflower oil blends to replace fish oil in the present formulation, which is now in short supply in Chile. The significant variables of the IT process were obtained by 2⁴⁻¹ fractional factorial design. The proportion of tallow (T) in the blend, catalyst concentration, and reaction temperature had a significant effect on the melting point (mp) (P≤0.05). IT of tallow and sunflower oil blends (90∶10 and 70∶30) diminished the mp, dropping point, and refractive index compared to tallow. However, a noninteresterified 90∶10 blend mp was not significantly different from tallow. IT produced a solid fat content (SFC) profile of IT90∶10 blend that was appropriate for use in shortenings for the baking industry. Blending and IT of the 90∶10 blend increased the melting profile of the tallow and the melting range from −40 to 60°C while the endotherms of the middle-melting triacylglycerols (TAG) decreased. The IT90∶10 blend hardnesswas 70% lower than tallow hardness, and the crystal network was composed of large spherulites in a network. IT resulted in an appropriate method to improve physical properties of tallow, whereas blending did not significantly modify it. The interesterification changed the SFC profile of IT90∶10, giving a more appropriate shortening for use in the baking industry.     

Calcium/chitosan spheres as catalyst for biodiesel production

Chitosan, an abundant biopolymer extracted from crustacean shells, can be used as a structuring agent by the insertion of calcium oxide and used as a catalyst in transesterification reactions. These calcium‐incorporated chitosan spheres were calcined in order to obtain a porous calcium catalyst without organic material. The materials were characterized using X‐ray diffraction, thermogravimetric analysis, Fourier transform infrared and X‐ray photoelectron spectroscopies, temperature‐programmed desorption of CO₂, scanning electron microscopy and specific surface area analysis. Afterwards the calcined calcium/chitosan spheres were used in the transesterification reaction of sunflower oil with methanol. The conversion of sunflower oil to methyl esters (Y_FAME), under optimized reaction conditions, which were determined by factorial experimental design (X_MR, 1:9; X_CAT, 3 wt%; time, 4 h; temperature, 60 °C; magnetic stirring, 1000 rpm), was 56.12 ± 0.32 wt%. These results show that chitosan can be used as a precursor for the formation of calcium/chitosan spheres, yielding a porous calcium oxide (with higher surface area) that can be used as an alkaline catalyst for biodiesel production. © 2014 Society of Chemical Industry