Title : Aromatic and fatty acid profile of Fontina PDO cheese produced in Aosta Valley during summer alpine pasture
Abstract:
Fontina is an Italian semi-hard and semi-cooked cheese, labelled PDO, typically produced in Aosta Valley made from raw cow milk from Valdostana breed and ripened for at least 3 months in natural caves. In the summer this cheese is directly manufactured in alpine farms located in different valleys and where cows are grazed and moved progressively to higher altitudes. As is well known, there is a close correlation between the aromatic and fatty acids profiles with the cattle diet in environments with different forage species. This is found both in milk and in its processed such as Fontina PDO cheese. The aim of this work was to support the practice of seasonal migration of livestock in high mountains to produce typical cheeses with high nutritional value and having unique organoleptic characteristics. For this purpose, analysis have been carried out on Fontina cheese produced in three mountain pastures (A1, A2, A3), located up to 2300 m above sea level, over three consecutive summer seasons. The samples were collected three per season at 90 days of ripening and analysed in duplicate or triple depending on the type of determination. The analysis of fatty acid composition via GC/MS and GC/FID was carried out according to Jiang et al. (1996) and FIL-IDF: 182-1999 for the extraction of the lipid component and to Cadiddu et al. (2009) for the qualitative and quantitative determination of the fatty acids methyl ester extracted. The qualitative and semi-quantitative evaluation of the volatile organic compounds profile, on the other hand, was carried out using SPME-GC/MS, referring to Bergamaschi and Bittante (2017), with some modifications.
Results obtained, considering only the statistically significant differences (p< 0.05 HSD Tukey test), allow us to say that the alpine Fontina PDO cheese reflects the high nutritional characteristics of summer milk, large amount of PUFA, CLA and a good ω6/ω3 ratio, confirming what has already been reported in the past by other authors. Among all, the Fontina PDO cheese of the A1 pasture was the richest in CLA (90% CLA 9c,11t) which are equal to 2.00 g/100 g fat (mean value) and with the best ratio ω6/ω3 that is around 1.50 (mean value). Regarding mountain Fontina PDO cheese aromatic profile, it is known that altitude and botanical composition of pasture are factors determining the sensory quality of cheeses. In fact, results show that cheese, especially those from the A3 mountain pasture, was rich in compounds such as alcohols (ethanol and 3-methylbutanol), esters (ethylacetate) and terpenes (α-pinene), which notoriously produce an aroma rich in fruity notes. This study confirms that a strictly correlation exists between the aromatic and fatty acids composition of diet and of dairy products. Therefore, it is necessary to promote maintenance and enhancement of the biodiversity typical of the alpine pastures and transhumance in order to produce high quality standards Fontina PDO cheese very appreciated by consumers.
Audience Take Away Notes:
- The audience will know Fontina PDO alpine cheese both from a point of view of organoleptic and nutritional qualities
- The audience can learn typical analytical techniques for the analysis of fatty acids and volatile aromatic compounds in cheese
- This study can be a stimulus to develop innovative and sustainable agronomic practices for the enhancement of alpine turf
- The results show that it is necessary to support the alpine transhumance both for the maintenance of the alpine territory biodiversity and for the production of cheeses with high nutritional and organoleptic value
