Determination of flavor constituents in particular types of flour and derived pasta by heart-cutting multidimensional gas chromatography coupled with mass spectrometry and multiple headspace solid-phase microextraction

Impact of semolina-barley mixture on the volatolomic profile of dough and pasta: characterization by a multivariate chemometric approach

BACKGROUND

Barley flour, known to be rich in various phytochemicals, has been demonstrated to improve the technological and nutritional properties of pasta; however, its volatile profile, on which its aromatic properties depend, also plays an important role in the acceptance of barley-enriched pasta. In the present work, volatile organic compounds (VOCs) of semolina doughs enriched with different percentages of barley and of the related pasta were characterized by solid phase micro-extraction (HS-SPME) coupled to gas-chromatography/mass spectrometry (GC-MS), and evaluated using a multivariate statistical approach, including principal component analysis (PCA), cluster heatmaps, Pearson's and Spearman's correlations, and partial least squares correlation (PLSC).

RESULTS

The effects of single raw materials, and their interactions, were studied to establish their importance in the volatile profile of the samples, and the correlation between the dough VOCs and the processed product VOCs was assessed. The presence of barley flour markedly affected the volatile profile in comparison with the dough obtained with only durum wheat. For alcohols, esters, terpenes, and some aldehydes there was a clear correlation with the percentage of barley. For some of the VOCs, on the other hand, a strong dependence on the ingredients interaction effect due to the mixing stage has been demonstrated.

CONCLUSION

The heatmaps allowed a good graphical visualization of the relationship between molecules and barley percentage, offering the possibility to select the best one according to the desired volatolomic footprint. Pasta with 40% of barley was demonstrated to give pasta with the most complex volatile profile. © 2024 Society of Chemical Industry.

Correlation Analysis between Volatile Compounds and Quality Attributes in Pork Tenderloin in Response to Different Stir-Frying Processes

Volatile compounds and physicochemical properties of meat are significantly changed by cooking processes. This study explored the influence of different stir-frying temperatures and times on the dynamic changes of the physicochemical characteristics and volatiles of pork tenderloin and determined the correlation between them. Results showed that time played more of a role than temperature. At the same temperature, the water content decreased (p < 0.05) and the cooking loss increased (p < 0.05) with stir-frying time extending. The L* value and the b* value showed first an increasing and then decreasing trend (p < 0.05), while the a* value significantly increased (p < 0.05). The higher the cooking temperature of sample, the faster the indexes changed. In stir-fried samples, 50 volatiles were identified. Correlation analysis showed that among the quality attributes, b* value and water content had the strongest impact on volatiles. The water content was negatively correlated with most of the compounds attributed to the desired aroma of stir-fried samples, while the correlation between the b* value and these volatiles was positive. Hence, changes in the types and contents of volatiles in stir-fried pork tenderloin could be predicted by detection of b* value and water content.

Development of an antioxidant formula based on peanut by-products and effects on sensory properties and aroma stability of fortified peanut snacks during storage

BACKGROUND

An antioxidant formula based on peanut skins and hulls was developed and characterized for total and single polyphenols, as well as antioxidant power, considering the contribution provided by each peanut by-product. Subsequently, it was evaluated for its effect on the sensory properties and aroma stability of peanut bars over a 100-day period. To this purpose, snacks fortified, or not, with the natural additive were experimentally produced.

RESULTS

Peanut hulls contributed to a greater extent than skins with respect to boosting the content of bioactives and the antioxidnt activity of the antioxidant formula, which was marked by a phenol content of (approximately 807 mg gallic acid equivalents g^-1 ) and a 2,2-diphenyl-1-picrylhydrazyl activity similar to that of butylated hydroxytoluene (85.96% and 89.30%, respectively). From a sensory perspective, the incorporation of the formulation in snacks caused only a slightly stronger perception of astringent and bitter notes. Pyrazines, phenol, furan and pyrrole derivatives defined the aroma of snacks, being more abundant in fortified than in conventional samples. Such volatiles faded over storage, with different trends in the examined products. For example, the sum of 2,5-dimethylpyrazine, 2-ethylpyrazine and 2,3-dimethylpyrazine was 9.49 and 8.87 ppm at day 15; 5.57 and 7.16 ppm at day 45; and 5.03 and 4.65 ppm at day 100, respectively, in fortified and conventional snacks. Hydroxymethylfurfural decreased constantly over storage in conventional samples and only after day 45 in fortified bars.

CONCLUSION

Overall, the antioxidant formulation did not compromise the sensory desirability of peanut snacks and induced a preservative effect on their aroma, especially during the first 15 days of storage. © 2020 Society of Chemical Industry.

Grape water: reclaim and valorization of a by-product from the industrial cryoconcentration of grape (Vitis vinifera) must

BACKGROUND

The term 'grape (Vitis vinifera) water' refers to a by-product from the cryoconcentration of must that, if not reclaimed, would be considered as wastewater. In this study, the nutraceutical potential of waters reclaimed from the cryoconcentration of Grillo and Moscato musts was evaluated.

RESULTS

Both waters showed physicochemical parameters in agreement with Italian regulation for drinking water, and interesting levels of F^- (3.02-8.02 mg L^-1 ) and SO₄ ^- (52.85-49.34 mg L^-1 ). Inorganic elements, including Mg (5.54-7.78 mg L^-1 ), K (47.12-59.87 mg L^-1 ), Fe (219.09-205.32 μg L^-1 ), and Zn (189.65-127.30 μg L^-1 ), and phenolic contents <35 mg GAE L^-1 contributed to determine moderate antioxidant activities. Considering fatty acid composition, oleic and linoleic acids predominated, being higher in Moscato than Grillo samples (64.42% versus 58.22%, and 5.42% versus 6.07%). Grape waters displayed also rich aroma profiles, including mainly esters, alcohols and terpenoids. The latter components (i.e. linalool and α-terpineol) were more abundant in Moscato than in Grillo (13% versus 8%). Interestingly, some minor volatiles, characterized the vine of provenance (e.g. benzaldehyde and 3-methylbutylacetate in Moscato). All grape waters showed also a considerable fraction of ethyl lactate, six-carbon compounds and acetates, reflecting the proximity of samples to the grapes of origin.

CONCLUSION

In a growing scenario of environmental decay and resource depletion, results from this study support an innovative and profitable waste recycling strategy for the wine industry. © 2020 Society of Chemical Industry.

Highly Informative Fingerprinting of Extra-Virgin Olive Oil Volatiles: The Role of High Concentration-Capacity Sampling in Combination with Comprehensive Two-Dimensional Gas Chromatography

The study explores the complex volatile fraction of extra-virgin olive oil by combining high concentration-capacity headspace approaches with comprehensive two-dimensional gas chromatography, which is coupled with time of flight mass spectrometry. The static headspace techniques in this study are: (a) Solid-phase microextraction, with multi-polymer coating (SPME- Divinylbenzene/Carboxen/Polydimethylsiloxane), which is taken as the reference technique; (b) headspace sorptive extraction (HSSE) with either a single-material coating (polydimethylsiloxane—PDMS) or a dual-phase coating that combines PDMS/Carbopack and PDMS/EG (ethyleneglycol); (c) monolithic material sorptive extraction (MMSE), using octa-decyl silica combined with graphite carbon (ODS/CB); and dynamic headspace (d) with either PDMS foam, operating in partition mode, or Tenax TA™, operating in adsorption mode. The coverage of both targeted and untargeted 2D-peak-region features, which corresponds to detectable analytes, was examined, while concentration factors (CF) for a selection of informative analytes, including key-odorants and off-odors, and homolog-series relative ratios were calculated and the information capacity was discussed. The results highlighted the differences in concentration capacities, which were mainly caused by polymer-accumulation characteristics (sorptive/adsorptive materials) and its amount. The relative concentration capacity for homologues and potent odorants was also discussed, while headspace linearity and the relative distribution of analytes, as a function of different sampling amounts, was examined. This last point is of particular interest in quantitative studies where accurate data is needed to derive consistent conclusions.

The Blossoming of Technology for the Analysis of Complex Aroma Bouquets-A Review on Flavour and Odorant Multidimensional and Comprehensive Gas Chromatography Applications

Multidimensional approaches in gas chromatography have been established as potent tools to (almost) attain fully resolved analyses. Flavours and odours are important application fields for these techniques since they include complex matrices, and are of interest for both scientific study and to consumers. This article is a review of the main research studies in the above theme, discussing the achievements and challenges that demonstrate a maturing of analytical separation technology.

Strategies for Accurate Quantitation of Volatiles from Foods and Plant-Origin Materials: A Challenging Task

The volatile fraction of foods and of plant-origin materials provides functional information on sample-related variables, and gas-phase extractions are ideal approaches for its accurate chemical characterization. However, for gas-phase sampling, the usual procedures adopted to standardize results from solvent extraction methods are not appropriate: headspace (HS) composition depends on the intrinsic physicochemical analyte properties (volatility, polarity, partition coefficient(s)) and matrix effects. Method development, design, and expression of the results are therefore challenging. This review article focuses on volatile vapor-phase quantitation methods (internal standard normalization, standard addition, stable isotope dilution assay, multiple headspace extraction) and their suitability in different applications. Because of the analyte informative role, the different ways of expressing results (normalized chromatographic area, percent normalized chromatographic areas, and absolute concentrations) are discussed and critically evaluated with examples of quality markers in chamomile, process contaminants (furan and 2-methylfuran) in roasted coffee, and key-aroma compounds from high-quality cocoa.