Evolution of volatile compounds and physical, chemical and sensory characteristics of Toscano PDO ham from fresh to dry-cured product

Francesco Sirtori,Riccardo Bozzi,Corrado Dimauro,Oreste Franci,Chiara Aquilani,Luca Calamai,Carolina Pugliese,Antonio Pezzati

doi:10.1007/s00217-019-03410-0

Francesco Sirtori, Riccardo Bozzi + Show 6 more

Open Access

https://doi.org/10.1007/s00217-019-03410-0

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Abstract

Physical and chemical changes in Toscano ham lean were evaluated according to three different seasoning time (14, 16 and 18 months). Moreover, on Semimembranosus muscle, the volatile profile at 0, 1, 3, 6, 12, 14, 16 and 18 months of seasoning was determined by SPME–GC–MS. Eventually, a quantitative-descriptive sensory evaluation was performed. Longer seasoning times led to a decrease of Chroma in Biceps femoris, and also protein and proteolysis index decreased as the seasoning time increased. A total of 97 volatile compounds (VOCs) belonging to seven chemical families (29 aldehydes, 16 esters, 14 alcohols, 13 hydrocarbons, 12 ketones, 10 acids, 2 furans and 1 nitrogenous compound) were identified. Sensory evaluation outlined the major differences between 18th months ham and the other two classes, with the former being harder and with a slight presence of off flavor and off odor. The VOCs evolution during curing was studied and a multivariate approach was performed to test the feasibility of using the VOCs profile to predict the curing stage of Toscano ham. The discriminant analysis successfully managed to separate the samples of 0–6 months from the ones of 12–18 months using 26 of the identified VOCs. Among them, pentane 2,3-dimethyl, acetophenone and 9-decenoic acid were strong discriminants for 0–6 months hams, while dodecanoic, benzeneacetaldehyde, 3-octen-2-one and pentanoic acid ethylester were linked to 12–18 months hams. Within the high maturing classes (12, 14, 16, 18 months of seasoning), the 17 discriminating compounds identified successfully allocated only 12 and 18 months samples. The main VOCs associated with the “12 months” class were nonanal, 1,5-diphenyl-3-methylthio-1,2,4-triazole and 6-methoxy 2-hexanone. The “18 months” seasoning class, instead, was identified by 1,5-diphenyl-3-methylthio-1,2,4-triazole, phenol and l,2-butoxy ethanol.

Highlights

In the last decades, the analysis of volatile compounds (VOCs) was widely performed to characterize the dry-cured products and, in particular, the dry-cured ham [1,2,3,4]
Moisture showed a light tendency to decrease from 14- to 18-month hams, in line with what is generally observed in dry-cured ham [19,20,21]
As the curing process advances, Toscano ham was the one that showed the greater decrease in lightness during the last seasoning phases

Summary

Introduction

The analysis of volatile compounds (VOCs) was widely performed to characterize the dry-cured products and, in particular, the dry-cured ham [1,2,3,4]. The modification in VOCs composition, linked to the change of some discriminant factors (curing time, salt reduction, etc.), is generally due to a quantitative difference among compounds rather than the presence of a “marker compound”; the entire pool of VOCs can be used as an element of characterization (a kind of aromatic fingerprint) generated by processing data through appropriate statistical tests. Several authors [9, 11, 12] have already used a multivariate approach, such as the principal component analysis (PCA), to explore VOCs data. Alternative statistical approaches, such as the canonical discriminant analysis (CDA) and the discriminant analysis (DA), were preferred to PCA to analyze data. The DA is useful to classify objects into groups

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