Sensory properties of mozzarella cheese as affected by starter cultures and preservation liquid

Industrial manufacturing of pasta filata cheeses with commercial starter cultures, despite a qualitative standardisation, may cause flavour flattening. In order to improve the sensory profile of mozzarella cheese, we used two starters: ST051 (commercial) vs CL13A (natural milk culture) and two preservation liquids: TL (0.4% NaCl brine) vs IL (0.4% NaCl, 0.67% CaCl2, 0.51% lactose, 1% Lact. lactis + Leuc. mesenteroides). Sensory analyses were performed on four products (two starters x two liquids) by a 10- member panel (7 females and 3 males) in triplicate, whereas 82 consumers evaluated product acceptability. ST051 products had higher brightness, colour uniformity, eye number (P<0.001) and buttermilk release (P<0.05). CL13A cheeses showed higher milk flavour, and higher tenderness (P<0.05) and grainy (P<0.001) mouth feel intensities, whereas sourness (P<0.01), bitterness (P<0.05) flavours and mouth feel of residual (P<0.01) were lower. IL products had a lower eye number (P<0.001), buttermilk release (P<0.05) in terms of aspect, lower fruity and bitterness flavours (P<0.001), increased butter flavour (P<0.05), and increased shear strength (P<0.01), moisture (P<0.05) and grainy (P<0.001) mouth feel. Consumers expressed higher overall and taste/flavour liking for CL13A (P<0.01), whereas IL products were preferred in terms of taste/flavour liking (P<0.05). The PLS regression of 82 judges on 23 sensory variables (38% and 33% of Y variance explained by the first and second component, respectively) allowed to cluster four groups representing 5, 28, 37 and 21% of the consumers, respectively (Fig. 1). Group I preferred ST051 cheese preserved in IL liquid, with high surface uniformity, shear strength and butter flavour. Group II preferred both CL13A products with high milk and sweetness taste/flavour and grainy and tenderness textural attributes. Group III did not express a preference for a particular product, albeit showing a preference for attributes such as fruity flavour and colour intensity, while Cluster IV favoured ST051TL cheeses, characterized by brightness, eye number, and uniformity, in terms of aspect, bitterness, sourness and yogurt taste/flavour, and residual and oily mouth feel. The identification and selection of suitable cheese making technologies, involving the use of adjunct cultures or flavouring preservation liquid may be useful to the industry for product differentiation.