abstract
Apple concentrate juice industry generates a flavored coproduct (apple aroma) recovered in the evaporation process, which is poorly valuated due to the lack of chemical characterization and standardization. In this study, industry apple aroma was characterized, allowing for the identification of 37 compounds, the majority esters (20), alcohols (7), and aldehydes (4). The storage temperature did not affect its volatile composition. Five key compounds were selected and monitored for 10 months of storage, and also compared with other three productions of another season allowing for observation of the same Aroma Index. Apple pomace was also used to produce a hydrodistillate. Contrary to the apple aroma, apple pomace hydrodistillate was unpleasant, reflected in a different volatile composition. Although no additional aroma fraction could be obtained from this wet byproduct, when dried, apple pomace presented 15 volatile compounds with toasted, caramel, sweet, and green notes. The infusions prepared with the dried apple pomace exhibited 25 volatile compounds with a very pleasant (fruity, apple-like, citrus, and spicy notes) and intense aroma. The addition of sugar changed the volatile profile, providing a less intense flavor, with almond, caramel, and sweet notes. These results show that apple aroma and pomace are high-quality flavoring agents with high potential of valuation as food ingredients.
subject category
Chemistry, Multidisciplinary; Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Physics, Applied
authors
Coelho, E; Pinto, M; Bastos, R; Cruz, M; Nunes, C; Rocha, SM; Coimbra, MA
our authors
Cláudia Nunes
Assistant Researcher
Elisabete Verde Martins Coelho
Post-Doc Fellowshipacknowledgements
This research was funded by Project ProfitApple 38162, QREN I&DT in copromotion 2013, FEDER, COMPETE. Thanks are due to the University of Aveiro and FCT-Fundacao para a Ciencia e a Tecnologia/MCT (Portugal) for the financial support for the QOPNA research unit [FCT UID/QUI/00062/2019] and LAQV-REQUIMTE [UIDB/50006/2020] through national funds and, where applicable, co-financed by the FEDER-Fundo Europeu de Desenvolvimento Regional, within the PT2020 Partnership Agreement, and the individual grants of Elisabete Coelho (SFRH/BPD/70589/2010) and Claudia Nunes (SFRH/BPD/100627/2014). Elisabete Coelho (CDL-CTTRI-88-ARH/2018-REF. 049-88-ARH/2018) and Claudia Nunes (CDL-CTTRI-88-ARH/2018-REF. 060-88-ARH/2018) also thank the research contract funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July.