Fresh-cut iceberg lettuce is an appreciated product by consumers for its nutritive properties, convenience, and ease of use [1]. This product has a natural waxy and edible coating which naturally protects the product from external exposures. However, in the case of freshly cut vegetables, these coatings are damaged, and the surface of the product is exposed to chemical or microbial factors [2]. Indeed, the problem associated with ready-to-use vegetables is their short shelf-life (5–7 days for iceberg lettuce, stored at 4°C). Approximately on the seventh day of storage, these products suffer from loss of freshness, aroma, and quality. To extend their shelf life, they are often stored in modified atmosphere packaging (MAP) [3]. The study of the aromatic profile of these products can give useful information about their quality during the storage time: in fact, some of these volatile compounds are naturally released by horticultural products, but others are produced only during vegetable cutting or from stress-induced metabolic pathways triggered by minimal processing, becoming potential biomarkers of quality changes [4]. In this study, the influence of two storage modalities, passive (air) MAP and active MAP (< 5% O2), on sensory quality parameters and the development of volatile organic compounds (VOCs) at different storage days were evaluated. An untargeted volatolomic approach by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC–MS) is described [5]. More than 400 volatile compounds were found in the lettuce samples and within the class of all the identified aromatic compounds, the most significant VOCs, accurately chosen considering their behavior in function of the storage time, were selected for a semi-quantitative evaluation using the peak area values. Compounds that could represent quality molecular markers were identified by multivariate data analysis (Principal Component Analyses and Partial Least Squares regression), in correlation with the type of MAP applied during the product storage. Finally, two volatile compounds (ethyl alcohol and acetaldehyde, for active and passive MAP, respectively) have been proposed as suitable markers to assess the quality of the product and the shelf-life of fresh-cut iceberg lettuce. References: 1. Caleb, O.J., Mahajan, P.V., Al-Said F.A.J., & Opara U.L., Food Bioprocess Technol. 6 (2013) 303-329. 2. Fan, N., Wang, X., Sun, J., Lv, X., Gu, J., Zhao C. & Wang, D., Macromolecules. 181 (2021) 1003–1009.
UNTARGETED VOLATOLOMICS BY HEADSPACE MICROEXTRACTION GAS CHROMATOGRAPHY-MASS SPECTROMETRY (HS-SPME-GC-MS) FOR THE IDENTIFICATION OF QUALITY MOLECULAR MARKERS IN FRESH-CUT ICEBERG LETTUCE
W. M. V. Marchesiello;G. Spadaccino
;D. Nardiello;M. Quinto
2023-01-01
Abstract
Fresh-cut iceberg lettuce is an appreciated product by consumers for its nutritive properties, convenience, and ease of use [1]. This product has a natural waxy and edible coating which naturally protects the product from external exposures. However, in the case of freshly cut vegetables, these coatings are damaged, and the surface of the product is exposed to chemical or microbial factors [2]. Indeed, the problem associated with ready-to-use vegetables is their short shelf-life (5–7 days for iceberg lettuce, stored at 4°C). Approximately on the seventh day of storage, these products suffer from loss of freshness, aroma, and quality. To extend their shelf life, they are often stored in modified atmosphere packaging (MAP) [3]. The study of the aromatic profile of these products can give useful information about their quality during the storage time: in fact, some of these volatile compounds are naturally released by horticultural products, but others are produced only during vegetable cutting or from stress-induced metabolic pathways triggered by minimal processing, becoming potential biomarkers of quality changes [4]. In this study, the influence of two storage modalities, passive (air) MAP and active MAP (< 5% O2), on sensory quality parameters and the development of volatile organic compounds (VOCs) at different storage days were evaluated. An untargeted volatolomic approach by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC–MS) is described [5]. More than 400 volatile compounds were found in the lettuce samples and within the class of all the identified aromatic compounds, the most significant VOCs, accurately chosen considering their behavior in function of the storage time, were selected for a semi-quantitative evaluation using the peak area values. Compounds that could represent quality molecular markers were identified by multivariate data analysis (Principal Component Analyses and Partial Least Squares regression), in correlation with the type of MAP applied during the product storage. Finally, two volatile compounds (ethyl alcohol and acetaldehyde, for active and passive MAP, respectively) have been proposed as suitable markers to assess the quality of the product and the shelf-life of fresh-cut iceberg lettuce. References: 1. Caleb, O.J., Mahajan, P.V., Al-Said F.A.J., & Opara U.L., Food Bioprocess Technol. 6 (2013) 303-329. 2. Fan, N., Wang, X., Sun, J., Lv, X., Gu, J., Zhao C. & Wang, D., Macromolecules. 181 (2021) 1003–1009.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
