Gas chromatography-mass spectrometry-based electronic nose, glycosidically bound volatile, and alcohol-acyltransferase activity profiles of Okinawan pineapple

A recent increase in the demand for pineapple necessitates the development of new varieties with superior flavour quality. In this study, we characterised the volatile profiles of three new Okinawan pineapple breeding lines using gas chromatography (GC)-mass spectrometry (MS)-based electronic nose (e-nose), glycosylated volatiles, and alcohol-acyltransferase (AAT) activity measurements. The volatile profiles of the fruits were selected using the GC-MS-e-nose and visualised using multivariate statistical plots. The glycosidically bound compounds were collected by solid-phase extraction and hydrolysed by beta-glucosidase. In total, 12 hydroxyl-group substances, including chavicol (medicinal-herbal aroma), geraniol (floral-sweet), and linalool (floral-citrus), were released from these glycosides. Crude enzymes containing AAT were extracted, and their in vitro activities in 2-methylbutyl acetate production were highly related to their contents. These results provide information regarding volatile profiles and bounded-aroma resources, as well as the esterification potential of new Okinawan pineapple breeding lines for use in the agro-food industry. The volatile characteristics of three Okinawan pineapple breeding lines were assessed. A GC-MS-e-nose was used to screen the ripened fruits with comparable volatile profiles. The breeding lines differed in the amount and composition of free and glycosidically bound aroma compounds, and ester levels in the fruits were affected by the enzymatic ester-forming potential, i.e., alcohol-acyltransferase activity. image