0000000000016438
AUTHOR
Barbara Rega
Solid Phase Microextraction (SPME) of Orange Juice Flavor: Odor Representativeness by Direct Gas Chromatography Olfactometry (D-GC-O)
The sensorial quality of solid phase microextraction (SPME) flavor extracts from orange juice was measured by direct gas chromatogrphy-olfactometry (D-GC-O), a novel instrumental tool for evaluating odors from headspace extracts. In general, odor impressions emerging from SPME extracts poorly resembled that of the original orange juice. In an attempt to improve the sensorial quality of extracts, sample equilibration and exposure times were varied on Carboxen/polydimethylsiloxane (CAR/PDMS) and divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) SPME fibers. Best sensorial results were obtained with the DVB/CAR/PDMS fiber exposed for the shortest time; a trained panel of eight assess…
Role of pulp in flavor release and sensory perception in orange juice
This work elucidates the role of suspended solids in sensorial perception and flavor release in orange juice. The coarsest pulp (insoluble particles with a diameter of2 microm) accounted for two major physicochemical effects in orange juice samples: it retained large amounts of aroma compounds, including terpenes and aldehydes, and modified the rheological properties of the juice matrix. These phenomena strongly affected the chemical composition of the vapor phase in the juice samples. On the other hand, orange juice cloud (finest insoluble particles with a diameter of2 microm) also showed a strong retention effect on ethyl butanoate or hexanal, probably due to the occurrence of molecular i…
Sensory evaluation of headspace extracts by direct GC-olfactometry : application to fresh orange juice
National audience
Physical and chemical interactions involved in several flavour compounds/food matrix systems
National audience; Food-matrix components, such as proteins, polysaccharides, and lipids interact with flavour compounds in different ways. Proteins bind flavour compounds mostly by hydrophobic interactions and possible hydrogen bonding, as illustrated by molecular visualisation. Addition of fat induces a great retention of hydrophobic compounds, which depend on the nature of fat, degree of unsaturation, hydrophobic chain length of fatty acids. Addition of hydrocolloids modifies the release of hydrophobic aroma compounds, due to a lower diffusion in the matrix. In jellified systems, gel structure not only affects partition coefficients but also mass transfer coefficients of flavour compound…
Flavour release from pectin gels : effect of texture, molecular interactions and aroma compounds diffusion
Des systemes modeles de confiture a teneurs croissantes en pectine ont ete developpes afin d'observer la liberation d'arome par des matrices gelifiees a tres faible concentration en hydrocolloide. L'addition de pectine modifie la liberation des composes d'arome les plus volatils et hydrophobes. Ce phenomene est strictement lie a la formation d'un reseau gelifie qui, meme a une concentration de 0,1 % en pectine, cause une diminution de la mobilite des composes volatils. Aucune interaction moleculaire specifique n'a ete observee entre composes d'arome et pectine. De plus, il n'y a pas de difference significative entre les coefficients de diffusion des differents composes d'arome, et ce, pour …