Changes in the volatile composition and sensory properties of cheeses made with milk from commercial sheep flocks managed indoors, part-time grazing in valley, and extensive mountain grazing

Changes in the volatile composition and sensory profile of cheeses made from the milk of six commercial sheep flocks in different feeding seasons through lactation were studied. The abundance of straight-chain volatile acids, ethyl, propyl, hexyl and isobutyl esters, aldehydes, terpenes and other minor compounds was higher in cheeses made from the milk of mountain grazing sheep (mountain cheeses) than in those made from the milk of indoor feeding and part-time grazing sheep. In contrast, the abundance of 2-butanone and 2-methylpropanoic acid was lower in cheeses made with milk from grazing ewes. Mountain cheeses had lower overall intensity, buttery, toasty and nutty aroma, salty taste, and elasticity and moisture in mouth than cheeses made from milk of indoor feeding ewes. Stepwise discriminant analysis was able to robustly discriminate mountain cheeses from those made with the milk from indoor feeding sheep or those part-time grazing in valley.