Effects of carbohydrate and noncarbohydrate sweeteners on the orange spirit volatile compounds

Effects of sugar matrices on the release of key aroma compounds in fresh and high hydrostatic pressure processed Tainong mango juices

Sugars are critical components of fruit juice. The binding of sugars and aroma compounds may affect the release of flavor in juices. In this study, the effects of sucrose, glucose, and fructose on the release of active aroma compounds in fresh and high hydrostatic pressure-processed (HPP) Tainong mango juice were evaluated. Using gas chromatography-mass spectrometry/olfactometry and odor activity values, four volatiles were identified as active aroma compounds in fresh and HPP mango juice. Furthermore, Fourier transform infrared spectroscopy and isothermal titration calorimetry illustrated that the sugar-volatile interaction was hydrophobically-driven, with hydrogen bonding to some extent. As the concentrations of sugar were increased in the fresh juice, a significant change in the release of active volatiles occurred, while HPP juice showed stronger retention of the active volatiles. The results suggest that high hydrostatic pressure processing maintained the freshness of mango juice flavor by strengthening aroma retention within the juice matrix.

Study on the release and sensory perception of encapsulated d-limonene flavor in crystal rock candy using the time-intensity analysis and HS-GC/MS spectrometry

This research was conducted to evaluate encapsulated d-limonene perception and release in rock candy. Microcapsules with wall materials of 75/25 of gum Arabic/Maltodextrin by 20% of wall materials) were produced for using in rock candy. To evaluate the flavor release from rock candy by time-intensity method, a model system was developed and time-intensity sensory evaluation was conducted by trained sensory panelists in order to determine the effect of three different matrices (water, water and flavored rock candy, and water with flavored rock candy and citric acid (pH = 3) at three serving temperatures (10, 45, and 75°C) on the perception of d-limonene release. Results showed that release of d-limonene from flavored rock candy with acid citric (pH = 3) at 75°C had the highest perceived sensation whereas the matrix of microcapsule in water at 10°C had the lowest perception. On the other hand, increasing the temperature from 10 to 75°C had significant effects on the release and perception of d-limonene (p < .05). Headspace gas chromatography-mass spectrophotometry confirmed results from time-intensity sensory evaluation, which indicated that the release of d-limonene increased in the presence of sucrose and citric acid (pH = 3).

Gas chromatographic–mass spectrometric fragmentation study of flavonoids as their trimethylsilyl derivatives: Analysis of flavonoids, sugars, carboxylic and amino acids in model systems and in citrus fruits

The fragmentation patterns and quantitation possibilities of three anthocyanidins (pelargonidin, cyanidin, malvidin), one flavonol (quercetin), two flavones (apigenin, luteolin) and two flavanones (naringenin, hesperetin) have been investigated as trimethylsilyl and as trimethylsilyl (oxime) derivatives by gas chromatography-mass spectrometry. Results proved that anthocyanidins and flavanones form trimethylsilyl (oximes), while flavonol and flavones provide simple trimethylsilyl derivatives. In all cases, characteristic fragments of high masses are formed proper for quantitation purposes. Hydrolysis conditions for naringin, hesperidin and rutin have been optimized, resulting in the quantitative release of naringenin, hesperetin and quercetin together with their corresponding saccharides. These basic studies made possible the identification and quantification of the flavonoid, carboxylic-/amino acid and sugar constituents of citrus fruit juices and albedos, without any extraction/enrichment procedure. In total 33 compounds have been determined in hydrolyzed samples, such as 2 flavonoids (naringenin and hesperetin), 6 phenolic acids (trimethoxybenzoic, 4-hydroxybenzoic, vanillic, quinic, chlorogenic and rosmarinic acids), 3 aliphatic carboxylic acids (levulinic, malic, citric acids), phosphoric acid, 4 amino acids (aspartic, glutamic acids, alanine, proline), 9 monosaccharides (xylose, arabinose, rhamnose, fucose, fructose, galactose, glucose, galacturonic acid, sedoheptulose), inositol, sugarphosphate, 5 disaccharides and tocopherol. Measurements were carried out as the trimethylsilyl (oxime) ether/ester derivatives of constituents, in the concentration range of 2 x 10(-3) to 49.9%. Identification level of samples varied between 26.4 and 77.5%, expressed in dry matter content of juices and albedos.