The Potential of Plum Seed Residue: Unraveling the Effect of Processing on Phytochemical Composition and Bioactive Properties.

Bioactive compounds extracted from plum seeds were identified and quantified, aiming to establish how the brandy manufacturing process affects the properties and possible cascade valorization of seed residues. Extraction with n-hexane using Soxhlet has provided oils rich in unsaturated fatty acids (92.24-92.51%), mainly oleic acid (72-75.56%), which is characterized by its heart-healthy properties. The fat extracts also contain tocopherols with antioxidant and anti-inflammatory properties. All the ethanol-water extracts of the defatted seeds contain neochlorogenic acid (90-368 µg·g-1), chlorogenic acid (36.1-117 µg·g-1), and protocatechuate (31.8-100 µg·g-1) that have an impact on bioactive properties such as antimicrobial and antioxidant. Anti-amyloidogenic activity (25 mg·mL-1) was observed in the after both fermentation and distillation extract, which may be related to high levels of caffeic acid (64 ± 10 µg·g-1). The principal component analysis showed that all plum seed oils could have potential applications in the food industry as edible oils or in the cosmetic industry as an active ingredient in anti-aging and anti-stain cosmetics, among others. Furthermore, defatted seeds, after both fermentation and distillation, showed the greatest applicability in the food and nutraceutical industry as a food supplement or as an additive in the design of active packaging.

Removal of biogenic amines from wines by chemisorption on functionalized silica and effects on other wine components.

The effectiveness of several functionalized silica materials (cation-exchange materials) for the removal of biogenic amines from wines, and the effects on other wine components and organoleptic characteristics were evaluated. Results have shown that mesoporous silica material bi-functionalized with phosphonic and sulfonic acids allowed the removal of histamine, putrescine, cadaverine, spermine and spermidine from wines, although the dose must be adapted for each wine according to the removal requirements and wine characteristics. A plus of the adsorbent developed is that it can be recovered and re-used for at least 3 treatments. Immediately following the treatments, a decrease in the levels of linear ethyl esters (ethyl hexanoate, ethyl octanoate and ethyl decanoate) was observed, although these levels were re-equilibrated after several days reducing this undesired side effect. A slight, but perceptible, effect on wine color was observed, probably due to the slight decrease in the pH of the wine produced by the treatments. On the basis of the sensory analysis that focused only on the aroma of the wines, the proposed technique would be more adequate for wines aged in barrels than for young wines.

Formation of patulin-glutathione conjugates induced by pulsed light: A tentative strategy for patulin degradation in apple juices.

Patulin is a toxic mycotoxin usually associated with apple products. Due to its unhealthy effects for humans, its content is regulated by the food safety authorities. The removal or degradation of this mycotoxin in contaminated apple juices has been studied with different approaches with uneven effectiveness. However, a strategy based on the chemical reaction between patulin and glutathione (GSH), in order to generate the conjugates that are formed during cell detoxification process, is an innovative approach yet to be evaluated. In this work, the formation of patulin-GSH conjugates activated by the application of pulsed light treatments and catalyzed by Fe2+ ions was evaluated. The study of patulin degradation and effect of the GSH/Fe2+ molar ratio showed that a molar ratio of 5 allows an adequate catalytic effect of the metal ions. In addition, mono-substituted patulin-glutathione adducts were identified as the main type of generated conjugates.

Removal of biogenic amines from hydroalcoholic solutions by functionalized silica.

The structure and the cation-exchange functional groups of hybrid silica materials were evaluated for the effective detoxification of hydroalcoholic solutions containing eight toxic biogenic amines (BA) usually found in fermented beverages. Results show the effectiveness of the removal is related to the number of amino functions in the extracted molecule, retention by the solid being more effective in the case of multiple amino groups, since retention is stabilized through interaction with the material surface at several points. BA with one amino function (isoamylamine, tyramine, ß-phenylethylamine), in general, showed a weak retention by the solids. For BA with more than two amine groups (spermine, spermidine), the removal rate was close to 100% for all studied materials. For histamine, cadaverine and putrescine, the removal percentages were higher with a lamellar structured sulfonic acid functionalized material and with bifunctional materials (SBA-15 type and macroporous) containing sulfonic/phosphonic acid groups obtained by co-condensation sol-gel route.

Aroma profile design of wine spirits: Multi-objective optimization using response surface methodology.

Developing new distillation strategies can help the spirits industry to improve quality, safety and process efficiency. Batch stills equipped with a packed column and an internal partial condenser are an innovative experimental system, allowing a fast and flexible management of the rectification. In this study, the impact of four factors (heart-cut volume, head-cut volume, pH and cooling flow rate of the internal partial condenser during the head-cut fraction) on 18 major volatile compounds of Muscat spirits was optimized using response surface methodology and desirability function approaches. Results have shown that high rectification at the beginning of the heart-cut enhances the overall positive aroma compounds of the product, reducing off-flavor compounds. In contrast, optimum levels of heart-cut volume, head-cut volume and pH factors varied depending on the process goal. Finally, three optimal operational conditions (head off-flavors reduction, flowery terpenic enhancement and fruity ester enhancement) were evaluated by chemical and sensory analysis.

Floral aroma improvement of Muscat spirits by packed column distillation with variable internal reflux.

The organoleptic quality of wine distillates depends on raw materials and the distillation process. Previous work has shown that rectification columns in batch distillation with fixed reflux rate are useful to obtain distillates or distillate fractions with enhanced organoleptic characteristics. This study explores variable reflux rate operating strategies to increase the levels of terpenic compounds in specific distillate fractions to emphasize its floral aroma. Based on chemical and sensory analyses, two distillate heart sub-fractions obtained with the best operating strategy found, were compared with a distillate obtained in a traditional alembic. Results have shown that a drastic reduction of the reflux rate at an early stage of the heart cut produced a distillate heart sub-fraction with a higher concentration of terpenic compounds and lower levels of negative aroma compounds. Therefore, this sub-fraction presented a much more noticeable floral aroma than the distillate obtained with a traditional alembic.

Characterization of the Aroma-Active, Phenolic, and Lipid Profiles of the Pistachio (Pistacia vera L.) Nut as Affected by the Single and Double Roasting Process.

The pistachio (Pistacia vera L.) nut is one of the most widely consumed edible nuts in the world. However, it is the roasting process that makes the pistachio commercially viable and valuable as it serves as the key step to improving the nut's hallmark sensory characteristics including flavor, color, and texture. Consequently, the present study explores the effects of the single-roasting and double-roasting process on the pistachio's chemical composition, specifically aroma-active compounds, polyphenols, and lipids. Results showed the total polyphenol content of increased with the roasting treatment; however, not all phenolic compounds demonstrated this behavior. With regard to the aroma and aroma-active compounds, the results indicated that roasting process results in the development of characteristics and pleasant aroma of pistachio samples due to the Maillard reaction. With regard to lipids, the pistachio roasting treatment reduced the concentration of CN38 diacylglycerides while increasing the amount of elaidic acid.

Impact of bentonite additions during vinification on protein stability and volatile compounds of Albariño wines.

Today, bentonite continues to be one of the most used products to remove proteins in white wines in order to avoid their precipitation in bottles. However, excessive use of bentonite has negative effects on the aroma of final wine, so the optimization of the dose and the time of its application are important for winemakers. This paper analyzes how applying an equal dose of bentonite at different stages (must clarification; beginning, middle, and end of fermentation) affects the macromolecular profile, protein stability, physical-chemical characteristics and aromatic profile of the wine obtained. The results showed the addition during fermentation (especially in the middle and at the end) reduced the total dose required for protein stabilization of Albariño wines and maintained the sensory characteristics of this variety.

Feasibility and application of a retronasal aroma-trapping device to study in vivo aroma release during the consumption of model wine-derived beverages.

New types of wine-derived beverages are now in the market. However, little is known about the impact of ingredient formulation on aroma release during consumption, which is directly linked to consumer preferences and liking. In this study, the optimization and validation of a retronasal aroma-trapping device (RATD) for the in vivo monitoring of aroma release was carried out. This device was applied to assess the impact of two main ingredients (sugar and ethanol) in these types of beverages on in vivo aroma release. Two aroma-trapping materials (Lichrolut and Tenax) were firstly assayed. Tenax provided higher recovery and lower intra- and inter-trap variability. In in vivo conditions, RATD provided an adequate linear range (R (2) > 0.91) between 0 and 50 mg L(-1) of aroma compounds. Differences in the total aroma release were observed in equally trained panelists. It was proven that the addition of sugar (up to 150 mg kg(-1)) did not have effect on aroma release, while ethanol (up to 40 mg L(-1)) enhanced the aroma release during drinking. The RATD is a useful tool to collect real in vivo data to extract reliable conclusions about the effect of beverage components on aroma release during consumption. The concentration of ethanol should be taken into consideration for the formulation of wine-derived beverages.

Impact of glutathione-enriched inactive dry yeast preparations on the stability of terpenes during model wine aging.

The impact of the addition of glutathione-enriched Inactive dry yeast preparations (g-IDYs) on the stability of some typical wine terpenes (linalool, α-terpineol, ß-citronellol, and nerol) stored under accelerated oxidative conditions was evaluated in model wines. Additionally, the effects of a second type of IDY preparation with a different claim (fermentative nutrient) and the sole addition of commercial glutathione into the model wines were also assessed. Model wines were spiked with the low molecular weight fraction (<3 kDa permeate) isolated from the IDYs, avoiding the interaction of aroma compounds with other yeast components. An exhaustive chemical characterization of both IDY permeates was carried out by using targeted and nontargeted metabolomics approaches using CE-MS and FT-ICR-MS analytical platforms. The findings suggest that the addition of <3 kDa permeate isolated from any of the IDYs employed decreases the loss of typical wine terpenes in model wines submitted to accelerated aging conditions. The g-IDY preparation did indeed release reduced GSH into the model wines, although this compound did not seem exclusively related to the protective effect on some aroma compounds determined in both model wines. The presence of other sulfur-containing compounds from yeast origin in g-IDY, and also the presence of small yeast peptides, such as methionine/tryptophan/tyrosine-containing tripeptide in both types of IDYs, seemed to be related to the antioxidant activity determined in the two permeates and to the minor loss of some terpenes in the model wines spiked with them.

Assessment of the impact of the addition of antimicrobial plant extracts to wine: volatile and phenolic composition.

BACKGROUND: Antimicrobial plant phenolic-rich extracts have been proposed as alternative to sulfites in the control of the malolactic fermentation (MLF) during winemaking. This addition may affect wine organoleptic properties. In this paper, we have investigated the changes in wine volatile and phenolic composition, after MLF, of a red wine treated with antimicrobial extracts from eucalyptus leaves and almond skins. RESULTS: Although addition of both extracts led to statistically significant changes (P < 0.05) in the concentration of several esters, alcohols, C13 nor-isoprenoids and volatile phenols, only few of these volatile compounds showed values of odour activity > 1 aroma unit; that is to say, whose concentrations were higher than their corresponding odour thresholds. With regard to phenolic compounds, the addition of both extracts did not significantly modify the content of anthocyanins, which predicts minor changes in wine colour. However, the content of non-anthocyanin phenolics was significantly higher in the wines treated with antimicrobial extracts, especially for flavonols, being the dose-over-taste factor for these wines significantly higher. Finally, principal component analysis showed that wines were mainly differentiated on the basis of whether MLF was conducted or not, and its method of performance (inoculated/spontaneous). CONCLUSION: Addition of antimicrobial extracts leads to some compositional changes in the wine, whose relevance needs to be addressed in future experiments, including wine sensorial analysis.

Assessment of the effect of the non-volatile wine matrix on the volatility of typical wine aroma compounds by headspace solid phase microextraction/gas chromatography analysis.

BACKGROUND: The aim of this study was to evaluate the effect of the whole non-volatile wine matrix composition on the volatility of typical wine aroma compounds by comparing the slopes of regression lines of five deodorised and reconstituted wines with the slopes calculated for the same compounds in a control wine with no matrix effect. RESULTS: The main effect observed was a reduction in the slopes, or a retention effect, that was largest for the reconstituted sparkling wine, which showed between 11 and 69% lower slopes than the control wine. In addition, an increase in the slopes, or a 'salting-out' effect, in the most compositionally complex reconstituted aged-red and sweet wines was also noticed for some volatiles with a very low boiling point or a low hydrophobic constant value. CONCLUSION: This study has shown that the non-volatile composition of wines strongly affects the volatility of wine aroma compounds. In addition, the aroma chemical class, in particular its physicochemical properties (volatility and hydrophobicity), strongly influences this behaviour. On the basis of these results, many odour threshold values calculated in simple hydroalcoholic solutions and usually employed to evaluate the odour importance of specific volatile compounds may have been over- or underestimated.

A comparison of laboratory and pilot-scale fermentations in winemaking conditions.

We investigated the influence of the fermenter size on alcoholic fermentation. Experiments were carried out at pilot scale, in 100-L fermenters, and at laboratory scale, in stirred and static 1-L fermenters. Two musts, Grenache blanc and Sauvignon, were fermented with and without the addition of solid particles from grape musts. Highly clarified must fermentation kinetics was strongly affected by the scale of the experiment, with slower fermentation occurring in the 100-L fermenter. Alcohol, ester, and thiol synthesis in clarified sauvignon must fermentation was also strongly correlated with the fermentation scale. Addition of solid particles from grape tended to reduce the effects on kinetics associated with increasing the scale of the fermentation, by increasing the maximum rate of CO(2) production, and by shortening the duration of fermentation. The addition of such particles also decreased the effects of scaling up the fermentation on the concentration of some volatile compounds, i.e., isoamyl acetate, ethyl octanoate, but did not decrease this effect for other compounds, such as isobutyl acetate, isobutanol, and 3-mercaptohexanol.

Volatile compounds of red wines macerated with Spanish, American, and French oak chips.

The volatile composition of a red wine aged for 2 months with three different Spanish oak chips (Quercus pyrenaica and Quercus petraea) from different regions of Castilla y León was compared with that of wines aged with American and French chips. In general, the extraction kinetics showed that the maximum concentration of the volatile compounds extracted from wood can be reached in only 1 month. In the final wines, the levels of furanic aldehydes and eugenol were higher in the wines macerated with Spanish chips, whereas cis-whiskey-lactone, vanillin, and methyl vanillate showed higher levels in wines treated with American chips. Among the wines treated with the different Spanish chips, the differences observed in the volatile composition were more related to the geographical origin of the forest than to the botanical species. In general, the wines macerated with Spanish chips showed levels of oak-related volatile compounds that were more similar to those macerated with French chips than to those macerated with American chips.

Improved method to quantitatively determine powerful odorant volatile thiols in wine by headspace solid-phase microextraction after derivatization.

A solid-phase microextraction (SMPE) method coupled to a gas chromatography-mass spectrometry analysis was optimized to analyze the pentafluorobenzyl bromide (PFBBr) derivatives of the volatile thiols 4-methyl-4-mercapto-2-pentanone (4MMP), 3-mercaptohexyl acetate (3MHA) and 3-mercaptohexanol (3MH) in wine. This method used deuterated analogue compounds as internal standards. It allowed us to significantly reduce the matrix effect, resulted in good repeatability for all the compounds (RDS<9.5% for 4MMP; <6% for 3MH and <4.1% for 3MHA) with limits of detection below their odour thresholds. The method was validated using white, rosé and red wines. When applied to analyze different wines, quantities closed to the odour threshold were determined.