This study investigated the influence of stepwise blanching over the kinetics of osmotic dehydration process and over the physical characteristics of pumpkin (Cucurbita moschata). The 23 factorial design and response surface methodology was used to optimize the blanching process. The independent variables for blanching were temperature, blanching time and holding time. These independent variables showed different effects on the two studied answers: texture and color. The kinetics of osmotic dehydration were investigated using 50% and 65% sucrose solutions, using samples previously blanched by both stepwise and conventional means. The diffusivity values for the water and sucrose were similar for the two components, showing greater gains of solute than loss of water in many samples. Blanching affected the color of the pumpkin, whereas osmotic dehydration did not change it significantly. The impregnation process maintained or even increased the tissue firmness when compared to the blanched samples. 相似文献
The crude extract containing inulinase from Rhodotorula mucilaginosa was obtained by submerged fermentation. Inulinase was immobilized on chicken eggshell by physical adsorption and covalent crosslinking, using glutaraldehyde as a crosslinking reagent, and Celite by adsorption. Fructooligosaccharides production was performed using immobilized inulinase (5%, w/v) and inulin substrate solution under experimental conditions evaluated through Doehlert experimental design. The production of inulinase was optimized for concentrations of D-glucose and yeast extract at 12.5 and 0.5 g/L, respectively, resulting in an optimal activity of 0.62 U. The optimal pH and temperature for enzyme activity were 8.0 and 75 °C, respectively, leading to an optimal activity of 3.54 U. The highest immobilization efficiency (46.27%) was obtained upon immobilization on Celite. Immobilization by adsorption to eggshell allowed for specific activity of 4.15 U/g, and adsorption to Celite resulted in specific activity of 3.70 U/g. The highest titer in fructooligosaccharides was obtained with an initial inulin concentration of 250 g/L (25%, w/v), and a reaction time of 16 h. Hence, immobilized inulinase proved to be a promising catalyst for fructooligosaccharides production since the formulation is performed through a simple, low-cost, and large-scale applicable methodology.
A rural producer who wishes to market organic products must obtain the Brazilian Organic Conformity Assessment System seal and consider a series of criteria for certification. The objective of this article is to identify which criteria should take priority and which organic conformity assessment mechanism (certification by Audit or by the Participatory Guarantee System—SPG) is the most appropriate option for a rural producer who wishes to obtain the seal of organic certification. After a bibliometric analysis, the researchers used the Analytic Hierarchy Process multicriteria method. A sensitivity analysis was also carried out to investigate variations in the priorities of the criteria and certification alternatives. The results indicated the following order of priority of the criteria: cost, market access, and producer availability. SPG was the most relevant assessment mechanism. 相似文献
Fatty acid composition of common carp (Cyprinus carpio), Nile tilapia (Oreochromis niloticus) and tambacu, a hybrid of tambaqui (Colossoma macropomum) and pacu (Piaractus mesopotamicus), was evaluated by gas chromatography. Raw, roasted and steamed fishes with and without skin were analyzed fresh and after 15, 30 and 45 storage days at −20 °C. Total lipid content was 9.3 g/100 g in carp, 0.79 g/100 g in tilapia and 1.3 g/100 g in tambacu with skin, with reductions of about 63%, 39% and 71% in the fishes without skin, respectively. The carp showed a high content of monounsaturated fatty acids (about 50%). In tilapia, palmitic and oleic acids were present in larger proportion, 26.55% and 23.86%, respectively. In tambacu, the fatty acid profile was 37% saturated, 34% monounsaturated and 21% polyunsaturated. Fatty acid composition did not present wide variations due to storage time and preparation, indicating that the storage and cooking methods used did not interfere in fatty acid composition. 相似文献
In Brazil, there are numerous blackberry cultivars under cultivation, however, only a few cultivars, such as the Guarani, are displayed/used for processing. In this context the aim of this work was to study the effects of different Brazilian blackberry cultivars (Guarani, Brazos, Comanche, Tupy, Cherokee, Caingangue, and Choctaw) on the physicochemical characteristics, texture profiles and the consumer acceptance of the resulting jelly to identify the potential use of these cultivars in the jelly industry. It is feasible to produce blackberry jellies with the Tupy, Comanche, Brazos, Guarani, and Choctaw cultivars because these jellies demonstrated good acceptability combined with good productivity. Consumers were shown to have a preference for a less adhesive, more acidic jelly. This study provides a useful insight about the Brazilian blackberry cultivar potential in jelly processing. 相似文献