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This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was measured by dynamic headspace GC-MS. For each compound the ratio of the flavor release from the beta-glucan solution to the release from aqueous solution, A(rel), was recorded. In general, esters were retained in the beta-glucan matrices in a mass-dependent manner where heavier molecules were retained more. A(rel) for alcohols was found to be significantly larger than for the esters. Whereas A(rel) values for esters were always below unity, this parameter was above unity for alcohols in some preparations of beta-glucan. This implies that relative to esters, alcohols were rejected from some matrices. An increase in the concentration of the beta-glucan products was associated with an increased retention of alcohols and esters. For solutions of oat and barley beta-glucan products at the same concentration, the oat product retained the flavor compounds more strongly. This difference was more pronounced at low concentrations of the beta-glucan products. To investigate the potential of a multivariate approach for the analysis of the flavor release from beta-glucan products, partial least-squares regression was employed on a large selection of calculated molecular descriptors, yielding simple QSPR models capable of explaining the variation in A(rel). The robustness of the QSPR models was verified by cross-validation and permutation tests. The results indicate that the multivariate modeling approach might provide a useful tool for the investigation of flavor release systems similar to those studied here.

Degradation of the potential photosensitizers, riboflavin, chlorophyll, and porphyrin, in Danbo cheese by monochromatic light of wavelength 366, 436, or 546 nm was studied. Three cheeses were investigated, two conventional (16% fat and 25% fat) and one "organic" (25% fat). The effect of illumination was measured by fluorescence spectroscopy and analyzed using multiway and multivariate data analysis. Riboflavin was found to degrade only by 436 nm light, whereas chlorophylls and porphyrins also were influenced by 436 and 546 nm light. The organic cheese had the largest chlorophyll content both before and after similar light exposure, and no change in chlorophyll of this cheese was observed for any of the illumination wavelengths. Upon light exposure of the cheeses, volatile compounds were formed, as analyzed by gas chromatography-mass spectrometry (GC-MS). The relative concentrations of methyl butanoate, 1-pentanol, benzaldehyde, 2-butanone, 2-heptanone, and butyl acetate were found to weakly correlate with the surface fluorescence intensity. 1-Pentanol and the ketones are secondary lipid oxidation products, consistent with a chemical coupling between photosensitizer degradation and formation of volatile lipid oxidation products.

The relations between the sensory quality of 24 different carrot genotypes and content of dry matter, non-volatile and volatile compounds were studied using a multi-block approach called LS-parPLS. The prediction of five sensory attributes; bitterness, sweetness, terpene flavour, green flavour and carrot flavour, gave prediction errors (RMSECV) between 0.98 and 1.36 and correlation coefficients ( r ) between 0.60 and 0.81. The explained Y-variances were between 15.1% and 66.0%. The highest prediction error was observed for the attribute carrot flavour whereas green flavour gave the best prediction. The attributes green flavour, bitterness and terpene flavour showed fairly good predictions ( r /RMSECV/% exp- Y = 0.81/0.98/66.0, 0.79/1.23/62.3 and 0.71/1.04/50.2) whereas sweetness gave an unexpected poor prediction ( r/ RMSECV/% exp- Y = 0.67/1.36/44.6). Non-volatile compounds found to be important predictors were chlorogenic acid (5-CQA), sucrose, 6-methoxymellein (6-MM), falcarindiol (FaDOH), and falcarinol (FaOH). The volatile compounds found to be important predictors are considered as key flavour compounds of raw carrots: terpinolene, β-pinene, sabinene, γ-terpinene, α-pinene, β-bisabolene, caryophyllene and cuparene. In general, the overall results show that the sensory quality variation in the material regarding bitterness, green flavour and terpene flavour are explained by relatively few parameters. Despite that the results revealed some reliable relationships between the sensory attributes, aroma and chemical analysis, a large variance (about 40%) in the sensory block of variables remained unexplained and still needs further investigation for an in-depth understanding of sensory quality. LS-ParPLSc is shown to be feasible for handling several types of data blocks in one regression model.

This study deals with eating quality of pre-peeled potatoes. The effect of raw material quality (cultivar, duration of wound healing and storage) on chemical composition of raw potatoes, and sensory quality and aroma composition of cooked pre-peeled potatoes were determined. Potatoes were knife peeled, vacuum-packed, stored at 4 °C, and evaluated after 6 days of shelf-life. Significant differences in chemical composition, sensory quality and aroma composition were found among the 6 cultivars. Storage (0, 1 1 2 and 6 months) also affected the sensory quality and the aroma composition. For surface hardening an effect of wound healing time (2 or 4 weeks at 14 °C) was observed, since 4 weeks resulted in lower intensity in surface hardening. During long-term storage the intensity in surface hardening decreased. The aroma compounds linalool, methional, nonanal and decanal were correlated to potato flavour and rancidness, whereas off-flavour/off-taste seemed to be correlated to nonvolatile components. Enzymatic browning of potatoes was positively correlated with PPO activity, tyrosin and chlorogenic acid a well as aspartic and glutamic acid, but negatively correlated to caffeic acid. The study showed that the quality of pre-peeled potatoes is very sensitive to raw material quality, and the time of year being processed.

The present paper deals with aroma changes in the production and storage of precooked potatoes, frozen leeks and fruit juices (apple and blackcurrant). In precooked potatoes and frozen leeks development of aliphatic aldehydes results in off-flavours, however, blanching (leeks) and exclusion of oxygen reduce off-flavour formation. In fruit juices high losses of esters and terpenes in the different processing steps are seen and result in juices of poor aroma quality with losses of 80 to 90% of the aroma volatiles. The aroma losses and changes are results of enzyme activity, thermal influence, evaporation and removal by water or waste.

The aim of the present study was to evaluate which purging and cutting method that gives the best relationship between sensory quality and the release of carrot volatiles. Volatile compounds from carrots (cv. Eskimo and cv. Nairobi) were collected from shreds and half-moon cuttings by dynamic headspace sampling using dry (no water added) and wet purging (water added and blended). Headspace samples were analysed by GC-MS. Monoterpenes, sesquiterpenes and irregular terpenes accounted for more than 98% of the total mass of the volatiles. Dry purging had a significant effect on the total volatile mass compared to wet purging, resulting in higher headspace concentrations of major volatile compounds. However, sensory analysis revealed that there were no significant differences between the sensory scores for the used descriptors.

The influence of isolation method on the determination of important aroma compounds in black currant juice was investigated by surface of nasal impact frequency (SNIF) gas chromatography-olfactometry (GC-O). The applied methods were solvent extraction, static headspace, and purge and trap using 15 and 60 min of purge time. By the four methods, a total of 59 odors were observed, and, of these, 44 corresponded to compounds that could be identified. For the headspace methods increasing purge volumes resulted in recoveries of additional, less volatile compounds. The main compound groups recovered by the headspace methods were esters and terpenes, whereas compounds recovered by solvent extraction were not as dominated by fruity odors. For most compounds there was agreement between the size of the SNIF value obtained by GC-O and the amount of the measurable compound found by gas chromatography-mass spectrometry.

Development of potato off-flavor (POF) was examined in precooked vacuum-packed potatoes by GC and sensory analyses. The experiments comprised four varieties grown at two locations. Aroma compounds shown to be potential contributors to POF were determined quantitatively, and their relative importance was interpreted by aroma values based on odor detection threshold values determined in water. There were statistically significant differences in the content of POF compounds between the growing locations and among some of the varieties. The results from the sensory analyses concurred roughly with the GC analyses. (E,E)-2,4-Nonadienal and (E, E)-2,4-decadienal were shown to be the most potent of the POF compounds examined, in addition with hexanal, (E)-2-octenal, and (E)-2-nonenal. Lowering the development of POF in precooked vacuum-packed potatoes should be possible by optimizing the environmental conditions and breeding for suitable varieties.

In this study the effect of sous vide processing, steaming and traditional boiling of broccoli florets on retention of ascorbic acid, vitamin B6 and folacin was investigated. Freshly prepared samples were also sensorily evaluated. In all heat treatments ascorbic acid was found to have the highest retention, and was therefore judged not to be suitable as an indicator for vitamin retention in general. When the three types of heat treatment were compared, boiling showed lowest retention of all the vitamins examined (45–64% in 5 min), whereas sous-vide processing gave the highest retentions (97–100% in 5 min). Retentions during steaming were a little lower (83–100% in 5 min). Sensory evaluation showed that sous-vide cooked and steamed broccoli florets generally had higher acceptability than boiled.

Old Danish apple cultivars might have potential in the production of speciality apple juices with unique flavor qualities. In the present study, aroma analysis was performed on juices from 160 local apple cultivars. Chromatographic data treatment challenges in the analysis of this large number of samples with very different volatile profiles were overcome with PARAFAC2 and PCA. The main compound groups identified were acetate esters, butanoate esters, and alcohols, and there were large differences in the aroma profiles of the juices of the different apple cultivars.