Study of the Phenolic Composition of Shiraz Red Grape Cultivar (Vitis vinifera L.) Cultivated in North-eastern Thailand and its Antioxidant and Antimicrobial Activity

The seed, skin and whole grape extract of the red grape cultivar Shiraz, which is widely cultivated in NortheasternThailand, were investigated. Total phenolic, total flavonoid and total monomeric anthocyanin contentranged from 48.04 to 116.73 g GAE/100g db (dry weight base), 74.82 to 258.69 mg CE/g db, and 5.06 to 55.45mg/100g db, respectively. Dimeric procyanidin (119.56–484.08 mg/100g db), (+)-catechin (52.30–231.92 mg/100gdb), (–)-epicatechin (27.92–174.10 mg/100g db), and gallic acid (4.42–27.80 mg/100g db) were found to be the mainflavanols that were present in the seed. Rutin and trans-resveratrol were present in amounts of between 21.13 and40.05 and 2.85 and 3.60 mg/100g db respectively. All extracts showed remarkable DPPH radical-scavenging activity(EC50), ranging from 0.47 to 2.10 μg/mL. Methanolic extract from the seed and skin were also active against allGram-positive bacteria, but these exerted less of an inhibiting effect on the growth of the tested Gram-negativebacteria. The activity of the methanolic extract of the seed was effective against B. cereus ATCC 11778, B. subtilisATCC 6633 and S. faecalis TISTR 459

Effect of the harvest season on phenolic composition and oenological parameters of grapes and wines cv. Touriga Nacional (Vitis vinifera L.) produced under tropical semi-arid climate, in the state of Pernambuco, Brazil

The northeastern region of São Francisco Valley is the third largest wine producer in Brazil, differentiated by the production of at least two harvests per year, generally in the first and second semesters, respectively. The productive cycle of the vine in the first semester is higher than in the second semester, mainly due to differences in temperature, with maximum and average temperatures of approximately 30 ºC and 26 ºC, respectively. Second semester is characterized by higher temperatures (summer season) and that promote a rapid maturation of the grapes. The objective of this work was to evaluate the phenolic composition, other oenological parameters and the sensorial profile of grapes and wines of cv. 'Touriga Nacional' (Vitis vinifera L.), characterizing grapes and wines from four harvest seasons, two of them referring to the first half of the year and two referring to the second half of the year, using a broad analytical approach. The experimental design consisted of three randomized blocks, with sixty plants marked in different lines and positions (twenty plants in each block at the beginning, middle and end of the vineyard). The results showed that there was a harvesting effect for some of the grape chemical compounds (monomeric anthocyanins, organic acids, condensed tannins and monomeric flavanols, for example) as well as in wines (calcium, monomeric anthocyanins, condensed tannins and monomeric flavanols). Regarding the sensorial profile of the wines, it was possible to observe that higher scores were attributed to floral aroma in wines from the first harvest (first half of the year). Fruity, spice and empyreumatic aromas were higher in wines from second harvest season (second half of the year). For other attributes, there was a tendency for higher variations between the period of study (2014 – 2017) than between the harvest seasonsinfo:eu-repo/semantics/publishedVersio