Relationships between the sensory characteristics, neutral volatile composition and gross composition of ten cheese varieties

Abstract

-Relationships between the odour, flavour and texture sensory attributes and the neutral volatile composition and gross composition of ten varieties of cheese were determined. Sensory evaluation was carried out by fifteen trained assessors who used a vocabulary of nine odour, twenty-one flavour and ten texture terms. Volatile compounds were isolated in a bench top purge and trap model system, trapped on Tenax-TA and analysed using gas chromatography coupled with mass spectrometry. Gross composition was measured using standard methods. Results of Principal Components Analysis on the sensory data showed that the first seven Principal Components significantly discriminated between cheeses and accounted for 86% of the variation. Partial Least Squares regression was used to determine the relationship between significant sensory attributes and thirty identified volatile compounds and the gross compositional data. Six odour and eleven flavour attributes were positively correlated with subsets of volatile compounds and gross compositional data. Seven texture attributes were shown to be correlated to subsets of gross compositional measurements. Overall, the present study illustrated that individual cheese flavour and texture attributes are the result of complex interactions of specific volatile compounds and compositional variables. évaluation sensorielle a été réalisée par quinze sujets entraînés avec un vocabulaire de neuf descripteurs pour l'odeur, vingt et un pour le goût et dix pour la texture. Les composés volatils ont été isolés à l'aide d'un système de concentration des effluves sur polymère Tenax-TA et ont ensuite été analysés par chromatographie en phase gazeuse couplée à la spectrométrie de masse. Les principaux paramè-tres de composition ont été déterminés à l'aide de méthodes standards. Les analyses en composantes principales des données sensorielles ont montré que les sept premières composantes principales significativement discriminantes comptaient pour 86 % de la variation totale. Une méthode statistique de régression multidimensionnelle a été utilisée pour déterminer les corrélations entre les données sensorielles, trente composés volatils des différents fromages et leur composition. Six descripteurs d'odeur et onze de goût ont été positivement corrélés avec des groupes de composés d'arômes et certains paramètres de composition. Sept descripteurs concernant la texture ont été corrélés à des paramètres de composition. Cette étude a montré que l'arôme et la texture d'un fromage résultent d'interactions complexes entre la fraction volatile et les principaux paramètres de composition.caractéristique sensorielle / fraction volatile neutre / composition / fromage / régression type PLS

Esters and their biosynthesis in fermented dairy products: a review

“…This is because the concentration of esters is not always positively associated with fruitiness and can be correlated with other flavour attributes. For example, whereas esters are positively associated with the sweet odour of Swiss-type cheeses, esters are also positively correlated with acidic, peppery, salty and silage-like flavours in other cheese types (Lawlor et al, 2001). Also, the nutty flavour of Emmental cheese is found to be positively correlated with the concentration of ethyl acetate, whereas the sweet flavour of Dubliner cheese is negatively correlated with the concentration of ethyl hexanoate (Lawlor, Delahunty, Wilkinson, & Sheehan, 2002).…”

“…Esters are positively associated with the sweet odour of Swiss-type cheeses (Lawlor, Delahunty, Wilkinson, & Sheehan, 2001). The unique esters in Swiss-type cheeses and their appearance in dairy fermentations where only propionibacteria are present (Liu, Holland, & Crow, unpublished data) indicate that the role of propionibacterial esterases/ lipases should be investigated further (see Section 5.6).…”

“…As stated by Lawlor et al (2001), 'associative' is not necessarily 'causative' and a statistical correlationship between variables (sensory, volatile and compositional) does not imply a cause-andeffect situation. Clearly, information gained from such correlation studies must be interpreted with caution.…”

Influence of a bacteriocin-producing lactic culture on the volatile compounds, odour and aroma of Hispánico cheese

“…Hexanal originates from b-oxidation of unsaturated fatty acids, with the formation of an intermediate hydroperoxide (Engels, Dekker, De Jong, Neeter, & Visser, 1997). This aldehyde has been positively correlated with a caramel and creamy odour in a study carried out on ten European cheese varieties representing a range of flavour types (Lawlor, Delahunty, Wilkinson, & Sheehan, 2001). Levels of hexanal were higher in experimental cheese than in control cheese after 25 and 75 days of ripening (Table 1), in agreement with Garde et al (2002), who also found a higher level of hexanal in cheese made with a bacteriocin-producing adjunct culture after 75 days.…”

Propionibacterium freudenreichii strains quantitatively affect production of volatile compounds in Swiss cheese

“…Esters are responsible for fruity flavours that can be considered as a flavour defect or contribute positively to cheese flavour [28]. In Swiss cheese, esters are though to contribute to the fruity note [33,34], and their presence has also been associated with the sweet odour of this cheese [27]. Numerous BC compounds were detected at a higher concentration in cheeses made using PAB than in the controls (Tab.…”