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The objective of this study was to compare the effect of traditional sun-drying method (TM) with four alternative dehydration methods [(a) multiple horizontal wires (MHW), (b) multiple vertical pallets (MVP), (c) low greenhouse (LGH) and (d) hot-air dryer treatment (HAD)] on phenolic composition, oenological parameters, aroma potential and browning compounds of musts obtained from dehydrated grapes ( Vitis vinifera cv. ‘Xynisteri’). Dehydrated grapes of the examined cultivar are being used to produce ‘Commandaria’ dessert wine, a protected designation of origin product in Cyprus. LGH and HAD treatments led to a significant reduction of the dehydration period. Soluble solid contents were used to monitor the progress of dehydration process; no changes among the examined dehydration methods in reducing sugar composition were found. Notably, HAD led to a dramatic rise (3.2-fold) of titratable acidity that was obviously not related only to the concentration effect. Furthermore, all dehydration methods concentrated total bound volatiles and induced the formation of brown pigments. Based on the Folin-Ciocalteu index, only HAD and LGH induced a significant increase in total phenolic content in dehydrated grape musts. Subsequently, forty phenolic compounds were identified and quantified by LC-DAD-qTOF-MS. Results showed a significant effect of dehydration methods that vary according to the different groups of phenolic compounds considered. Similarly to Folin-Ciocalteu index, HAD and LGH methods increased significantly the phenolic content in grape musts, whereas MHW and MVP methods increased it slightly higher than the concentration factor. Flavonols, flavan-3-ols and flavanonols were the most affected polyphenolic groups. A significant increment of hydroxybenzoic and hydroxycinnamic acids, the predominant groups of phenolic compounds found in ‘Xynisteri’ grapes, was monitored. Taking into consideration that HAD cannot be exploited under the existing legal framework, LGH showed the greatest potential for the production of high quality dehydrated ‘Xynisteri’ grape must. [ABSTRACT FROM AUTHOR]

Grapes's sun-dried process is one of the most critical steps in the production of ‘Commandaria’, a dessert wine product that is exclusively produced in Cyprus and derived from must obtained from two indigenous grape cultivars, namely ‘Mavro’ and ‘Xynisteri’. Despite its significant economic importance, no data regarding the primary and secondary metabolites of the aforementioned cultivars exist. Thus, in the current study, the effect of sun drying process on the qualitative attributes and phenolic profile of ‘Mavro’ and ‘Xynisteri’ musts was dissected. Musts were analyzed at harvest and at the end of the sun-drying process that corresponds to ca. 30–40% water loss. Results highlighted significant differences in chemical composition of the must before and after the sun-drying process. Except for the increase of soluble solids content, a significant increment in glucose, fructose, total acidity, total phenols and total flavonoids contents was monitored. Subsequently, forty-two phenolic compounds were identified by LC-DAD-qTOF-MS revealing the polyphenolic fingerprint of the two cultivars. Results also indicated that changes in the phenolic composition of the obtained must are not only correlated with the dehydration effect, but both synthesis or degradation reactions occurred. In particular, the increases in the concentration of hydroxybenzoic acids were higher than the concentration effect for both cultivars. Regarding to hydroxycinnamates, dehydration caused a six-fold increase of hydroxycinnamic acid content in both cultivars. Intriguingly, the concentration of some hydroxycinnamic acids such as caffeic acid dihexoside and fertaric acid isomer went descending. Although the degradation of the internal side of the skin facilitate improved extractability from the skins to the grape pulp and therefore to the grape must, the sun-drying process may also induced stilbene and lignans synthesis production. A significant effect of dehydration on the postharvest biosynthesis of three groups of flavonoids (flavonols, flavan-3-ols, flavanonols), was also observed. This study sheds some light in the substantial changes that occur in specific metabolites during the sun drying process; such metabolites can be considered as potential factors that may determine organoleptic characteristics and biological properties of the end-product. [ABSTRACT FROM AUTHOR]

Highlights: [•] Quinoa is a good source of saponins and phenolic compounds. [•] A pearling degree of 30% was necessary to obtain sweet quinoa. [•] Pearling process is a promising sustainable method to obtain sweet quinoa. [Copyright &y& Elsevier]

Abstract: The phenolic compounds present in seven samples of olive fruits were analysed by a rapid and resolutive LC–ESI-TOF MS method. All samples were collected during the normal picking period for olive oil production, in central and south Tunisia, and were obtained from the Oueslati variety cultivated in different olive growing areas. In the Tunisian samples, 22 compounds have been characterised by LC–ESI-TOF MS analysis. Results showed no qualitative differences in the phenolic fractions between virgin olive oils from different geographical region. However, significant quantitative differences were observed in a wide number of phenolic compounds. These results permit to use the phenolic fractions as an indicator of each region. [Copyright &y& Elsevier]

The present study aimed to examine how different oils (extra virgin olive oil (EVOO), refined olive oil, high oleic sunflower oil (HOSO), and refined sunflower oil (RSO)) and intermittent deep-frying could influence the levels of glycidols (GD), monochloropropanediols (MCPDs) and acrylamide (AA) in pre-fried French fries. Time and type of oil affected the content of MCPDs, GD, and AA. The migration of MCPDs and glycidols in French fries during the frying was confirmed, but a new formation was also noticed. Extra virgin olive oil showed the lowest MCPDs and GD content (3-MCPD: 0.016–0.27 mg/kg, 2-MCPD < limit of detection (LOD)-0.04 mg/kg, and GD: 0.05–0.14 mg/kg). The 22% of the samples analyzed showed an AA content higher than 500 μg/kg (the limit recommended by the EFSA), 18% corresponded to samples deep-fried with EVOO, and 4% to samples deep-fried with RSO. Moreover, the lowest AA level was found when using HOSO (121.2–250.8 mg/kg). The overall analysis of these results suggests that HOSO could be used as a deep-frying oil, furnishing a good compromise between MCPD accumulation and AA formation. • Intermittent frying contributes to improve the formation of AA, GD and MCPDs. • MCPD and glycidols were transferred from oil to fried potatoes. • High oleic sunflower oil showed the best performance. [ABSTRACT FROM AUTHOR]