ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of glass transition on rates nonenzymic browning in food systemsRaivo. Karmas, M. Pilar Buera, and Marcus. KarelCite this: J. Agric. Food Chem. 1992, 40, 5, 873–879Publication Date (Print):May 1, 1992Publication History Published online1 May 2002Published inissue 1 1992https://pubs.acs.org/doi/10.1021/jf00017a035https://doi.org/10.1021/jf00017a035research-articleACS PublicationsRequest reuse permissionsArticle...

ABSTRACT Sugar‐ (fructose, xylose, glucose, lactose, maltose, sucrose) glycine solutions of water activity adjusted to 0.90 (by adding NaCI) were heated at 45–65°C. The behavior fructose‐glycine was well described by a zero‐order reaction model, but for the other sugars fractional‐order (∼ 0.5) kinetic model necessary. Activation energies fructose and sucrose systems 25.7, 29.3 36.6 kcah/mole, respectively. At pH 6 descending order color development xylose > glucose lactose maltose...

Abstract Amorphous poly(vinylpyrrolidone) (PVP) varying in molecular weight (MW) (10 000, 24 and 40 000) was used to study the effect of on glass transition temperature ( T g ). measured by differential scanning calorimetry (DSC). Blends with several diluents (water, butylamine, glycine, hexanal, xylose, glucose, lysine) were also analyzed blend composition evaluated. The average blends PVP‐plasticizer well described previously reported relationships developed for synthetic polymers....

Abstract The objective of the present work was to study effect bread storage temperature on starch retrogradation, using water activity measurement and X‐ray diffractometry technique analyse changes produced in crumb firmness such as recrystallization. When storing with crust, crust tends trap moisture from crumb, resulting a dehydration faster staling. For temperatures 25 4°C, decreases function time whereas at −18°C it is maintained an almost constant level for 23 days. During storage,...

ABSTRACT This review examines recent published suggestions that “water dynamics” may be applied instead of water activity (a w ) determination to predict microbial stability concentrated and intermediate moisture food systems. Factors such as the relative effectiveness additives for antimicrobial stabilization through a ‐lowering (i.e. glucose vs fructose, glycerol propylene glycol) importance glass transition temperature an indicator were examined, based on available experimental data....

The objective of the present work was to analyze molecular and supramolecular changes bread starch relate firmness increase during storage with recrystallization water hydration levels migration in gluten-free bread. At studied conditions supercooled region state diagram, at a temperature between Tg (glass transition temperature) Tm (melting temperature), feasible crystallize. crystalline degree followed by intensity X-ray diffraction peaks. During storage, occurred from crumb towards crust....

ABSTRACT The thermal stability of enzyme invertase in reduced‐moisture model systems maltodextrin (MD), polyvynilpyrrolidone (PVP; MW 40,000) and trehalose heated at 90°C was studied. Significant inactivation observed glassy PVP MD kept well below their glass transition temperature (T g ), but the fairly stable rubbery systems. However, moisture contents which allowed crystallization rapid observed. Invertase PVP, could not be predicted on basis this particularly true for trehalose....

ABSTRACT The kinetics of color changes due to caramelization various single sugar solutions (fructose, xylose, glucose, maltose, lactose, and sucrose) water activity adjusted 0.90 (by adding NaCl) heated at temperatures (45–65°C) was studied. A zero‐order a “mixed”‐order kinetic model were satisfactorily used describe the rate formation. Fructose xylose browned much more rapidly than those lactose or sucrose. Activation energies for development fructose in range 25–30 kcal/mole, while...

Abstract BACKGROUND: Cyclodextrins (CDs) are able to enhance the solubility, stability and bioavailability of several bioactive hydrophobic compounds by complex formation. They can also be used for removal undesired components (such as cholesterol, off‐flavors or bitter components) present in foods. Although many patents account use cyclodextrins cholesterol from dairy foods, there is no available information on effect water encapsulation efficiency sterols CDs. The aim this work was study...

Abstract BACKGROUND The antioxidant capacity of anthocyanins (AC) rapidly degrades during storage, highlighting the need for their stabilization. conformational properties and high proline content sodium caseinate (NaCAS), combined with formation NaCAS microgels in presence tara gum (TG) acid gelation, suggest its potential as an effective stabilizing or encapsulating agent AC. RESULTS Spectrofluorimetric results a complex between Fourier transform infrared spectroscopy demonstrated that TG...