Time filter

Source Type

Microparticles obtained by complex coacervation were crosslinked with glutaraldehyde or with transglutaminase and dried using freeze drying or spray drying. Moist samples presented Encapsulation Efficiency (%EE) higher than 96%. The mean diameters ranged from 43.7 ± 3.4 to 96.4 ± 10.3 μm for moist samples, from 38.1 ± 5.36 to 65.2 ± 16.1 μm for dried samples, and from 62.5 ± 7.5 to 106.9 ± 26.1 μm for rehydrated microparticles. The integrity of the particles without crosslinking was maintained when freeze drying was used. After spray drying, only crosslinked samples were able to maintain the wall integrity. Microparticles had a round shape and in the case of dried samples rugged walls apparently without cracks were observed. Core distribution inside the particles was multinuclear and homogeneous and core release was evaluated using anhydrous ethanol. Moist particles crosslinked with glutaraldehyde at the concentration of 1.0 mM.g-1 protein (ptn), were more efficient with respect to the core retention compared to 0.1 mM.g-1 ptn or those crosslinked with transglutaminase (10 U.g-1 ptn). The drying processes had a strong influence on the core release profile reducing the amount released to all dry samples. Source

Andrade G.C.R.M.,University of Sao Paulo | Freguglia R.M.O.,University of Sao Paulo | Furlani R.P.Z.,Institute Tecnologia Of Alimentos Ital | Torres N.H.,University of Sao Paulo | Tornisielo V.L.,University of Sao Paulo
Journal of the Brazilian Chemical Society | Year: 2011

Tomato crop is frequently damaged by diseases, pests and abiotic stresses, resulting in lower yielding and loss of fruit quality. The intensive use of pesticides in tomatoes without observation of good agriculture practices and regulations has caused great concern with a probable final product contamination. The QuEChERS method of sample preparation was used for the determination of six pesticides (buprofezin, carbofuran, endosulfan-α, endosulfan-β, endosulfan sulfate and monocrotophos) in thirty three tomato samples collected from local market retailers. The method involved extraction with acetonitrile, liquid-liquid partition with addition of MgSO4 and NaCl followed by dispersive solid phase extraction using primary secondary amine sorbent and the analyses were carried out with a gas chromatography/mass spectrometry equipment by ion trap. Recovery studies for different pesticides ranged from 71 to 111% and the relative standard deviation (RSD) was below 15%. No pesticide residue was detected (> LOD) among the thirty three tomato samples analysed. ©2011 Sociedade Brasileira de Química. Source

Sadahira M.S.,Institute Tecnologia Of Alimentos Ital | Lopes F.C.R.,University of Campinas | Rodrigues M.I.,Protimiza Consultoria e treinamento em planejamento de experimentos e otimizacao de processos | Netto F.M.,University of Campinas
Carbohydrate Polymers | Year: 2014

This study aimed at evaluating the effect of three independent variables: biopolymer concentration (egg white proteins and pectin) (2.0-4.0%, w/w); protein:pectin ratio (15:1-55:1); and temperature (70-80 C), at pH 3.0, using a central composite design on the foaming properties (overrun, drainage and bubble growth rate). Foams produced with protein:pectin ratio 15:1 showed the lowest bubble growth rate and the greatest drainage, whereas protein:pectin ratio 55:1 presented the lowest drainage. Complexes obtained with protein:pectin ratio 15:1 were close to electroneutrality and showed larger size (95.91 ± 8.19 μm) than those obtained with protein:pectin ratio 55:1 (45.92 ± 3.47 μm) not electrically neutral. Larger particles seemed to build an interfacial viscoelastic network at the air-water interface with reduced gas permeability, leading to greater stability concerning the disproportionation. Soluble complexes of smaller sizes increased viscosity leading to a low drainage of liquid and inhibiting the bubbles coalescence. © 2013 Elsevier Ltd. Source

The avocado originated in America, and is considered to be one of the most productive plants per unit of cultivated area. Fruits with high lipid levels may be important raw materials for the extraction of oils containing bioactive substances that could reduce the risk of diseases. This work aimed to extract avocado oil using a mechanical process, similar to that employed for olive oil. Water was added to the crushed pulp in a 1:1 ratio and the mixture maintained at 45-50 °C for 40-60 minutes. The oil, water and solids were separated using a three phase centrifuge and the oil filtered. The physicochemical composition of the avocado and of the process byproducts was determined using official AOCS methodology, determining the protein, moisture, ash and oil contents. The fatty acid profile of the avocado oil was determined by gas chromatography, and the saponification and iodine values of the avocado oil calculated based on the fatty acid composition. The oil showed values of between 0.5 and 0.6% free fatty acids; 5.95 to 11.89 meq kg-1 of peroxides; 0.09 to 0.16% moisture; 0.96 to 1.94% of unsaponifiable matter and 74.69 to 88.16 mg kg-1 of chlorophyll. Source

de Moura S.C.S.R.,Institute Tecnologia Of Alimentos Ital | da Tavares P.E.R.,Institute Tecnologia Of Alimentos Ital | Germer S.P.M.,Institute Tecnologia Of Alimentos Ital | Nisida A.L.A.C.,Institute Tecnologia Of Alimentos Ital | Kanaan A.S.,University of Campinas
Food and Bioprocess Technology | Year: 2012

The objective of this study was to monitor the stability of anthocyanin and phenolic compounds contained in two formulations of blackberry jam (traditional and low-sugar) during storage. For that purpose, jams were prepared with varying amounts of hydrocolloids and investigated as to pH, total soluble solids, water activity, total acidity, total anthocyanins and total polyphenols. In order to accompany and assess the levels of phenolic compounds and colour (L*, a* and b*) changes, the samples were stored for 180 days at two different temperatures (10 and 25 °C). The Arrhenius model was used to determine the relationship between the reaction rate (k) at the different storage temperatures, yielding activation energy values of 19 and 12 kcal/mol and Q 10 values of 3. 0 and 2. 0 for traditional and low-sugar jams, respectively. The results show that by the end of the storage time investigated, the anthocyanin compounds had been partially degraded, with the greatest loss being observed in traditional jam stored at 25 °C. Colour stability was also lower in traditional jam as compared to the low-sugar product. © 2011 Springer Science + Business Media, LLC. Source

Discover hidden collaborations