Optimization of Quality Properties of Gluten-Free Bread by a Mixture Design of Xanthan, Guar, and Hydroxypropyl Methyl Cellulose Gums
The objective of this study was to investigate, by means of a D-optimal mixture design, the combined effects of hydroxypropyl methyl cellulose (HPMC), xanthan (XG), and guar (GG) gums on physicochemical, rheological, and textural properties of gluten-free batter and bread. For each of the quality properties measured, a two-factor interaction model was fitted, and the significance of its terms was assessed by analysis of variance. Sticky batters were produced with a combination of high dose of GG (0.60%), high-intermediate dose of HPMC (3.36%), and low dose of XG (0.04%). Combinations of high XG dose (0.60%) and intermediate doses of HPMC (3.08%) and GG (0.32%) rendered GF breads of greater specific volume, while lower bread crust luminosity was obtained with combinations of high GG dose (0.60%), low XG dose (0.04%), and high-intermediate HPMC dose (3.36%). Combinations of high-intermediate HPMC dose (3.36%), high GG dose (0.60%), and low XG dose (0.04%) produced both softer crumbs and bread slices of more open visual texture. By using a desirability function that maximized specific volume while minimizing crust luminosity, crumb hardness, and mean cell density, the optimization of hydrocolloids mixture rendered a value of 0.54, for a combination of 0.24% XG, 0.60% GG, and 3.16% HPMC.
Designing Hydrocolloid-Based Oleogels With High Physical, Chemical, and Structural Stability
Numerous studies conducted have shown a direct relationship between the high consumption of saturated and trans-fats and the risk of suffering from cardiovascular diseases, diabetes, and different cancers. Oleogels, with a suitable lipid profile of mono-, poly-unsaturated fatty acids, and similar functionality to traditional solid fat, can be a healthy alternative in food formulation. The aim of this study is to develop edible oleogels with a healthy and stable lipid profile, using the emulsion-template approach and hydrocolloids as oleogelators. Oleogels were developed from sunflower oil and sunflower oil with a high content of monounsaturated acids, using hydroxypropylmethylcellulose (HPMC) and xanthan gum (XG) as oleogelators. The influence of two drying conditions (60°C for 24 h and 80°C for 10 h 30 min) along with the composition of the oil on the structural, physical, and oxidative stability of oleogels were studied. All oleogels presented a stable network and high physical stability with oil losses <14% after 35 days of storage. Rheological properties showed that oleogels displayed a low frequency dependent and G′ > 105 Pa related to solid gel-like behavior. Oleogels made with sunflower oil rich in monounsaturated fatty acids resulted in higher oxidative stability, with those developed at drying temperatures of 80°C for 10 h 30 min having a greater structural and physical stability.
Testing the Core Empirical Implications of Gottfredson and Hirschi's General Theory of Crime
In A General Theory of Crime, Gottfredson and Hirschi propose that low self-control, in interaction with criminal opportunity, is the major cause of crime. The research reported in this article attempts to test this argument while closely following the nominal definitions presented by Gottfredson and Hirschi. A factor analysis of items designed to measure low self-control is consistent with their contention that the trait is unidimensional. Further, the proposed interaction effect is found for self-reported acts of both fraud and force (their definition of crime). Inconsistent with the theory are (a) the finding that criminal opportunity has a significant main effect, beyond its interaction with low self-control, on self-reported crime and (b) the substantial proportion of variance in crime left unexplained by the theoretical variables. Suggestions are offered for modifying and expanding the theory.