The present study investigated the effect of salt (NaCl) on the flavor and texture of Cheddar cheese with the particular aim to elucidate consequences of, and strategies for, reducing the salt concentration. Descriptive sensory analysis and physicochemical mapping of 9-mo-old Cheddar cheeses containing 0.9, 1.3, 1.7, and 2.3% salt and an equal level of moisture (37.6 ± 0.1%) were undertaken. Moisture regulation during manufacture resulted in slightly higher calcium retention (158 to 169 mmol/kg) with decreasing NaCl concentration. Lactose was depleted only at 0.9 and 1.3% salt, resulting in concomitantly higher levels of lactate. Lower levels of casein components and free amino acids were observed with decreasing NaCl concentration, whereas levels of pH 4.6-soluble peptides were higher. Key taste-active compounds, including small hydrophobic peptides, lactose, lactate, and free amino acids, covaried positively with bitter, sweet, sour, and umami flavor intensities, respectively. An additional direct effect of salt due to taste-taste enhancement and suppression was noted. Sensory flavor profiles spanned a principal component dimension of palatability projecting true flavor compensation of salt into the space between cheeses containing 1.7 and 2.3% salt. This space was characterized by salt, umami, sweet, and a range of sapid flavors, and was contrasted by bitter and other off-flavors. Rheological and sensory measurements of texture were highly correlated. Cheeses made with 2.3% salt had a longer and slightly softer texture than cheeses containing 0.9, 1.3, and 1.7% salt, which all shared similar textural properties. Moisture regulation contributed to restoring the textural properties upon a 50% reduction in salt, but other factors were also important. On the other hand, significant flavor deterioration occurred inevitably. We discuss the potential of engineering a favorable basic taste profile to restore full palatability of Cheddar with a 50% reduction in salt.

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Reduction of salt in ripened cheese presents an industry challenge due to its profound role in flavour and texture development. This study investigated the biochemical impact of varying the salt concentration in Cheddar cheese while maintaining the moisture content constant, with particular emphasis on proteolysis. Cheeses containing 0.9, 1.3, 1.8 and 2.4 % (w/w) salt and 37.7±0.2 % (w/w) moisture were manufactured by parallel adjustment of the curd grain size, cooking temperature and time, cheddaring, curd chip size and rate of salting and analysed over the course of 270 days ripening. Salt reduction affected chymosin and starter lactocepin activities to accelerate casein degradation and accumulate derived peptides at rates correlating positively or (mostly) inversely with salt concentration. The kinetics of α S1 -CN (f1-23) and N-terminal peptides produced thereof and of β-CN(f193-209) were studied in detail. Plasmin activity was affected by cooking treatment and (small) pH differences during ripening but appeared limited overall, due to low levels of pH. Starter lysis showed a strong positive dependency on the salt concentration, and resultant lower contents of free amino acids upon salt reduction were evident. In essence, salt reduction caused a marked decrease in the ratio of peptidase to proteinase activity. Remedies to counterbalance this ratio were discussed in order to avoid excessive accumulation of bitter peptides and promote the stage of maturity. Salt

Part-skim Mozzarella cheese was manufactured from milk hydrolyzed with fungal phospholipase A1 prior to renneting. The phospholipase treatment reduced fat losses in whey and cooking water and increased cheese yield as a result of improved fat and moisture retention in the cheese curd. The amount of phospholipids in the whey was reduced because of improved retention of lysophospholipids in the cheese curd. Water binding in the fresh curds and young cheeses up to 3 wk of storage was investigated by a 1H nuclear magnetic resonance spin-spin relaxation technique. In the fresh curds, 2 dominant water fractions were present, characterized by average spin-spin relaxation times (T2) of 14 and 86 to 89 ms, respectively. These 2 fractions of low- and high-molecular-mobility water were similar in all cheeses and presumed to represent water associated with the casein matrix and water present in the pores. A few hours after manufacture, cheeses made with phospholipase showed decreased T2 of the high-mobility fraction, indicating improved water-holding capacity. It is suggested that lysophospholipids released from the fat globule membranes act as surface-active agents in the cheese curd, helping emulsification of water and fat during processing and reducing syneresis. During 3 wk of storage after manufacture, the mobility of both water fractions increased in all cheeses, but was highest in the cheeses made with phospholipase. The increase in mobility during the first weeks of storage has earlier been ascribed to structural changes in the protein matrix, which in principle could be accelerated because of the higher moisture content. However, the microstructure of phospholipase-treated cheese was investigated by confocal laser scanning microscopy and found to be very similar to the control cheese during processing and up to 28 d of storage. In addition, flowability, stretchability, and browning were acceptable and similar in all the manufactured cheeses. Thus, phospholipase hydrolysis of cheese milk improved the cheese yield without changing the cheese microstructure, and resulted in cheese with functional properties that were identical to traditional Mozzarella cheese.

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