Search results for "Food chemistry"
showing 10 items of 20 documents
Characterisation of the volatile fraction of aromatic caramel using heart-cutting multidimensional gas chromatography
2014
The first aim of our study was to improve characterisation of the volatile fraction of aromatic caramel by applying heart-cutting multidimensional gas chromatography coupled to mass spectrometry and olfactometry (MDGC-MS-O) on targeted odorant fractions. The second aim was to compare the volatile composition of two caramel samples, which differed in terms of their carbohydrate composition and cooking process. MDGC analyses enabled identification of 37 compounds (17 with the addition of pure standard) in the burnt sugar caramel, 20 of which were reported for the first time in caramel. Fifteen compounds were identified as odour-active and described using a range of attributes such as floral, …
Understanding fat, proteins and saliva impact on aroma release from flavoured ice-creams
2017
Publication également référencée sous le numéro WOS:000437803400018; The release profile of fourteen aroma compounds was studied in ice cream samples varying in fat and protein, both in level and type. In vitro aroma release was monitored by solid phase micro-extraction gas chromatography using an innovative saliva reactor, which imitated human chewing under temperature control. The results showed that the effect of the fat type on aroma release was smaller than that of fat level. Ice creams with low fat level released more hydrophobic aroma compounds than ice creams with high fat level. At low fat level more aroma compounds were released from ice creams with lower protein content. At high …
Solutions properties and solute–solvent interactions in ternary sugar–salt–water solutions
2010
International audience; Viscometric constants were used to provide information on solute-solvent interactions in ternary water-sugar-salt solutions. Comparison was made between pure water and aqueous salt solution as solvents affecting the behaviour of small carbohydrates. The determination of intrinsic viscosity was made more accurate by applying triple extrapolation of the three equations (Huggins. Kramer and Meffroy-Biget). Results obtained with this triple extrapolation method were compared to that obtained with the Jones-Dole equation usually used. The B coefficient of the Jones-Dole equation was interpreted in terms of its components (B(size)) and (B(structure)), respectively assigned…
In-pack sonication technique for edible emulsions: Understanding the impact of acacia gum and lecithin emulsifiers and ultrasound homogenization on s…
2018
Abstract The potential of ultrasound as a complementary technique for enhancing the stability of in-packed food emulsions, such as mayonnaise, without changing the conventional packaging material was evaluated. For this purpose, model salad dressing emulsions containing acacia gum and lecithin were stabilized by ultrasound within the package and their physical stability, particle size distribution, color, and consistency were compared to those stabilized by conventional power ultrasound and mechanical homogenization. Although both emulsifiers improved the stability of the emulsions, the stability of lecithin-containing samples was up to 5.4 times higher than the AG-containing counterparts. …
Tomorrow’s Chemistry Today: Concepts in Nanoscience, Organic Materials and Environmental Chemistry
2008
Providing a glimpse into the future, the young scientists contributing here were considered to be the most important for tomorrow's chemistry and materials science. They present the state of the art in their particular fields of research, with topics ranging from new synthetic pathways and nanotechnology to green chemistry. Of major interest to organic chemists, materials scientists and biochemists.
Quality control of fruit juices by using organic acids determined by capillary zone electrophoresis with poly(vinyl alcohol)-coated bubble cell capil…
2015
An enhanced method for the determination of organic acids in several fruit juices by capillary zone electrophoresis (CZE) with direct UV-Vis detection has been developed in this work. First, a study with simulated real juice samples was done to find the best separation conditions. Next, several commercial fruit juices were analyzed, and the organic acid contents were quantified in less than 12 min using a poly(vinyl alcohol)-coated fused-silica 'bubble cell' capillary. The present method is reliable, fast and provides detection limits comprised between 0.1 and 2.5 μg mL(-1). Moreover, different chemometric techniques, based on CZE data, were examined. Linear discriminant analysis allowed th…
The Schroeder paradox or how the state of water affects the moisture transfer through edible films
2012
The objective of this work was to better understand the water permeation through edible films when water is either in its vapour or in its liquid state related to their physico-chemical properties. Film based on iota-carrageenans or sodium alginate, containing or not fat, and encapsulating or not an aroma compound (n-hexanal) have been prepared. Films were conditioned at three different relative humidities, 0%, 43% and 84%. The incorporation of the n-hexanal in both types of biopolymer modifies the mechanical properties of film matrix and has a synergistic effect when associated to fat. Increasing the moisture content induces film plasticization by decreasing the glass transition of the gly…
Matryoshka enzyme encapsulation: Development of zymoactive hydrogel particles with efficient lactose hydrolysis capability.
2019
This report describes an efficient procedure for enzyme encapsulation and its application for the hydrolysis of lactose. The enzymatic material that has been developed consists of hydrogel particles (ca. 3–4 mm of diameter) composed of either alginate or an alginate-agarose combination, in which bacterial cells loaded with a thermostable β-galactosidase are embedded. The cells were rendered fully permeable to the substrate, either chromogenic p-nitrophenyl galactose or lactose, by thermal treatment at 75 °C. Hydrogel particles made of a mixture of alginate and agarose displayed high catalytic activity (i.e. 1 g of beads hydrolyze the lactose equivalent of 100 mL of milk in 15 min) and therm…
Moisture loss, gain and migration in foods and its impact on food quality
2010
Abstract: Moisture loss, gain and transfer, whether originating from exchanges with the atmosphere or with another component of the food, always cause deterioration in the overall quality of the food through softening, toughening, breakdown, and swelling or shrinkage caused by phase transitions or dissolution (Petersen et al., 1999). In most cases, water migrations lead to a deterioration of the overall quality (organoleptic or hygienic) of the food. With a view to better understanding physical deterioration of food and to provide a tool to better control food quality (and give a longer shelf life) this chapter reviews the water relationships in foods with a particular focus on glass-transi…
Food Chemistry: Food quality and new analytical approaches
2016
Peer Reviewed