# Differentiation of Fresh and Processed Fruit Juices Using Volatile Composition  
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1 CQM-Centro de Quimica da Madeira, Universidade da Madeira, Campus da Penteada, 9020-105 Funchal, Portugal; [EMAIL_ADDRESS] (C.S. ); [PERSON]L_ADDRESS]m (P.S. ); [EMAIL_ADDRESS] (S.M.) Departamento de Quimica, Faculdade de Ciencias Exatas e Engenharia, Universidade da Madeira; Campus da Penteada, 9020-105 Funchal, Campus da Penteada, 9020-105 Funchal, Portugal  
1 CQM-Centro de Quimica da Madeira, Universidade da Madeira, Campus da Penteada, 9020-105 Funchal, Portugal; [EMAIL_ADDRESS] (C.S. ); [PERSON]L_ADDRESS]m (P.S. ); [PERSON]AIL_ADDRESS] (P.S. ); [PERSON]AIL_ADDRESS] (P.S.) Departamento de Quimica, Faculdade de Ciencias Exatas e Engenharia, Universidade da Madeira; Campus da Penteada, 9020-105 Funchal, Campus da Penteada, 9020-105 Funchal, Portugal  
1 CQM-Centro de Quimica da Madeira, Universidade da Madeira, Campus da Penteada, 9020-105 Funchal, Portugal; [EMAIL_ADDRESS] (C.S. ); [PERSON]L_ADDRESS]m (P.S.) Departamento de Quimica, Faculdade de Ciencias Exatas e Engenharia, Universidade da Madeira; Campus da Penteada, 9020-1 most important esters contributing to the characteristic apple aroma [6; 7; 8; 9]. In pear fruit, esters were also the most significant contributors to aroma [10], being methyl and hexyl esters of decadienoate, the character imparting compounds of the European pear [11]. Other esters, such as hexyl acetate, 2-methylpropyl acetate, butyl acetate, and pentyl acetate, as well as butyl butanoate, ethyl hexanoate possessed strong pear-like odors [12]. In addition, hexanal, 2-methylpropyl acetate, ethyl acetate, hexyl acetate, 3-methylbutyl-2-methyl butanoate, ethyl butanoate, and butanol were identified as impact volatiles in Conference pears (_Pyrus communis_ L.) [13]. Orange is a large cultivated fruit and studied worldwide. A total of 58 VOCs, including esters, terpenoids, carbonyl compounds, alcohols, and acids were identified and quantified in Dortyloyl perli orange juice. Terpenoids were the most representative chemical group, limoneene being the predominant VOC, followed by valencene, linalo, terpinen-4-ol, and \(\alpha\)-terpineol [14]. On the other hand, grapes (_Vitis vinifera_ L.) volatiles include a great number of VOCs, namely monoterpenoids, sesquiterpenoids, carbonyl compounds, alcohols, C\({}_{13}\) norisoprenoids, and acids [15]. Linalool, geraniol, citronellol, nerol, dienol I and II were the most abundant terpenoids in Muscat grape [16]. Other monoterpenes potentially contributing to Muscat aroma were rose oxide, citral, geraniol, nerol, and citronellol [17]. The evolution of terpenic compounds was evaluated during ripening of four _V. vinifera_ L. grape varieties, Bual, Malvasia, Sercial (white grapes), and Tinta Negra (red grapes). Linalool, citronellol, geraniol, \(\alpha\)-ylangene, bicyclogermacrene, \(\beta\)-ciclocitral, \(\beta\)-damascenone are common to all grape varieties studied and were detected in all ripening stages, whereas others were found only in some ripening stages and in some varieties (e.g., \(\beta\)-ocimene isomer, \(\beta\)-gurjunene, \(\gamma\)-elemene). In addition, for all _V. vinifera_ L. grapes studied, the maximum potential of mono-, sesquiterpene, and norisoprenoid compounds was achieved at maturity date, which was established based on the maximum sugar content and minimum tittatable acidity [18]. Even at low levels, these VOCs may have a significant impact on the overall flavor of fruits and their corresponding juices due to their lower odor threshold (OT). The levels of these VOCs are frequently low (typically \(\upmu\)g/L) and are influenced by a number of agronomic (e.g., variety, climatological conditions, ripening stage) [19] and technological factors (e.g., harvest, post-harvest treatments, storage and processing conditions) [20]. During fruit juice processing, the volatile signature is affected by the addition of additives, preservatives, and chemical or processing treatments that change the volatile profile of fresh juices [21].