Effect of the botanical composition of hay and casein genetic variants on the chemical and sensory characteristics of ripened saint-nectaire type cheeses

Abstract

Forty-two multiparous dairy cows of 3 different breeds (Holstein, Montbéliarde and Tarentaise) were divided into 2 groups (A and B) according to β-and κ-casein genetic variants, and were fed 3 floristically different types of hay (cocksfoot, rye-grass-rich and native mountain grassland hay) according to a 3 × 3 Latin-square design. The milk produced by these cows was used to make Saint-Nectaire-type cheese, using identical and controlled cheesemaking techniques. The cheeses made from cocksfoot diet milk had higher pH (P < 0.01), lower fat in dry matter (P < 0.05), more elastic texture and a strong cellar odour (P < 0.1). The cheeses produced from the milk of cows fed native mountain grassland hay exhibited a slightly gritty and yellower body, and had a pronounced vinegar and cabbage odour. Rheological analysis confirmed the beneficial effect of the B variant of β-and κ-caseins on milk rennet clotting ability. This effect did not seem to affect the cheeses because they could not be distinguished by any of their sensory characteristics.