Determination of volatile compounds in cider apple juices using a covalently bonded ionic liquid coating as the stationary phase in gas chromatography

Geographical differentiation of apple ciders based on volatile fingerprint

With the globalization of food trade, it's traceability and genuineness becomes increasingly more difficult. Therefore, it is necessary to develop analytical tools to define the authenticity and genuineness of food-derived products. In the current work, headspace solid-phase microextraction followed by gas chromatography-mass spectrometry (HS-SPME/GC-MS) combined with chemometric tools was used to establish the volatile fingerprint of apple ciders produced in different geographical regions of Madeira Island, in order to define their typicity and to identify putative geographical markers. A total of 143 volatile organic compounds (VOCs) belonging to different chemical families have been identified, of which 28 were found in all apple ciders independently of geographical region. Esters, terpenic and furanic compounds presented on average a higher contribution for the total volatile fingerprint in cider produced in northern region of the Island, whereas alcohols, acids, volatile phenols, carbonyl compounds and lactones in cider from southern region. Considering the relative areas of the VOCs, 43 revealed statistically significant differences (p < 0.001) between geographical regions, and 11 between northern and southern regions. A clear differentiation among cider-producing regions was observed on the developed partial least squares-discriminant analysis (PLS-DA) model. Two alcohols (1-hexanol, 1-octanol), 6 esters (methyl acetate, (Z)-3-hexen-1-ol acetate, ethyl hexanoate, ethyl nonanote, ethyl octanoate, isoamyl octanoate) and 1 terpenic compound (limonene), can be considered putative geographic markers due to their discriminatory ability. The results obtained recognize the specific and typical geographical characteristics of the cider, which will allow the forthcoming guarantee for the construction of a sustainable platform for the establishment of the authenticity and typicality of the regional cider.