Role of partial dehydration in a naturally ventilated room on the mycobiota, ochratoxins, volatile profile and phenolic composition of Merlot grapes intended for wine production.

Autor: Nievierowski TH; Instituto de Ciência e Tecnologia de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43212, CEP 91501-970 Porto Alegre, Brazil., Veras FF; Instituto de Ciência e Tecnologia de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43212, CEP 91501-970 Porto Alegre, Brazil., Silveira RD; Instituto de Ciência e Tecnologia de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43212, CEP 91501-970 Porto Alegre, Brazil., Dachery B; Instituto de Ciência e Tecnologia de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43212, CEP 91501-970 Porto Alegre, Brazil., Hernandes KC; Instituto de Ciência e Tecnologia de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43212, CEP 91501-970 Porto Alegre, Brazil., Lopes FC; Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43431, CEP 91501-970 Porto Alegre, Brazil., Scortegagna E; Luiz Argenta Vinhos Finos, Av. 25 de Julho, 700, CEP: 95270-000 Flores da Cunha, Brazil; ConceptWine - Escola Profissional de Vinhos, Flores da Cunha, Brazil., Zini CA; Instituto de Química (IQ), UFRGS, Av. Bento Gonçalves, 9500, Prédio 43111, CEP 91501-970 Porto Alegre, Brazil., Welke JE; Instituto de Ciência e Tecnologia de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43212, CEP 91501-970 Porto Alegre, Brazil. Electronic address: juliane.welke@ufrgs.br.
Jazyk: angličtina
Zdroj: Food research international (Ottawa, Ont.) [Food Res Int] 2021 Mar; Vol. 141, pp. 110145. Date of Electronic Publication: 2021 Jan 18.
DOI: 10.1016/j.foodres.2021.110145
Abstrakt: Dehydration of grapes has been used in various regions of the world to produce special wines, aiming to add value to oenological products. Post-harvest dehydration in rooms may be carried out regardless of weather conditions, without the additional cost of a specific infrastructure, in addition to the benefits of protecting the grapes from damages and environmental pollution. The objective of this study was to verify, for the first time, the impact of the dehydration in a naturally ventilated room on the quality of Merlot grapes. Physicochemical characteristics, mycobiota, occurrence of mycotoxins, volatile profile and phenolic composition of grapes were monitored on 7th, 14th and 21st days of dehydration (weight loss of 10, 20 and 27%, respectively). A decrease in aw (6%), pH (4%), and berry hardness (58%), along with an increase in total soluble solid content (15%) were observed during dehydration. The presence of Pestalotiopsis clavispora, Neopestalotiopsis clavispora, Colletotrichum siamense and Alternaria porri was favored during the dehydration process, while a decrease in the occurrence of Aspergillus niger and Phanerochaete sp. was verified. A. niger isolates showed no potential to produce forms of ochratoxins. These toxins were also not found in the grape samples. Regarding the volatile profile, 1-hexanal, 2-hexenal, and 1-octanal gave rise to the corresponding alcohols during dehydration, such as 1-hexanol, 2-hexen-1-ol, and 1-octanol. Acids (hexanoic, decanoic, and 3-hexenoic) resulted in the respective ethyl esters (hexanoate, decanoate, and ethyl 3-hexenoate) during dehydration. Terpenes as limonene, myrcene, and geraniol decreased throughout dehydration, while their biotransformation products (α-terpineol, 6-methyl-5-hepten-2-one, and linalool, respectively) had an increase in concentration. The phenolic content oscillated during dehydration, with an emphasis on increased levels of four hydroxybenzoic acids (ethyl gallate, p-hydroxybenzoic acid, gallic acid-hexose, and gallic acid), two hydroxycinnamic acids (caffeic acid and caftaric acid), two flavonols (kaempeferol galactoside and quercetin) and two anthocyanins (peonidin 3-O-hexoside and delphinidin 3-O-hexoside). Grapes of satisfactory quality were produced by dehydration in a naturally ventilated room. Even small wine producers can be encouraged to implement this procedure for the diversification of oenological products, as it has no costs related to the implementation of chambers/tunnels.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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