Lactose, lactic acid and mineral equilibria in Cheddar cheese manufacture

Abstract

SummaryIn experimental small-scale manufacture of Cheddar cheese a study was made of the movement of lactose, lactic acid, calcium and phosphorus between curd and whey, and of the effect of high acidity developed in the curd before whey separation, on the pH and physical properties of the cheese. It was found that while the curd particles remain in contact with the whey, the lactose fermented in the curd is replaced by lactose diffusing from the whey. Lactic acid produced in the curd diffuses into the whey rather slowly.When a high lactic acid level is attained rapidly the curd does not cheddar well, the pH of the cheese is low, the flavour is sour and bitter, the body is crumbly and the cheese is bleached. When a high lactic acid level is reached slowly, the curd also does not cheddar properly but the pH of the cheese may be within normal limits up to 3 weeks, at which age its body is coherent and its colour is normal. However, on maturing, the cheese becomes acid, the body crumbly and liquid separation occurs even at 2 months of age. This points to a risk in grading cheese at an early age.It is suggested that the abnormal behaviour in cheddaring of ‘high-acid’ curds is connected with an excessive loss of calcium. When high acidity is developed over an extended time in the whey, the curd retains more lactose but loses more phosphorus so that its buffering capacity is reduced. Cheese made from such curd becomes highly acid at maturity and this leads to the development of a bitter flavour.It is, therefore, concluded that both the rate of development of acidity, and the time the curd is in the whey, are critical factors in controlling the quality of Cheddar cheese.

Effect of cook temperature on starter and non-starter lactic acid bacteria viability, cheese composition and ripening indices of a semi-hard cheese manufactured using thermophilic cultures

“…As discussed below, the pH after brining was significantly lower in the cheeses cooked to 47 1C than in those cooked to 50 or 53 1C. This lower pH may have increased the degree of solubilisation of micellar calcium phosphate (Van Hooydonk, Hagedoorn, & Boerrigter, 1986) permitting increased soluble calcium to be lost from the curds during whey drainage (Czulak, Conochie, Sutherland, & van Leeuwen, 1969).…”

Influence of processing and ripening parameters on starter, non-starter and propionic acid bacteria and on the ripening characteristics of semi-hard cheeses

“…However, the pH at 2 d of the MSC cheeses was similar to that of the ST cheeses and significantly higher than that of the SC cheeses. These significant differences between the SC and MSC were attributed to the use of a curd-washing step during manufacture, which reduced lactose content and regulated acidification (Czulak et al, 1969;Huffman & Kristoffersen, 1984;Shakeel-Ur-Rehman et al, 2004). There was no significant difference at 2 d between the pH of the MST and SC cheeses, however the pH of the ST cheeses was higher than that of the MST cheeses.…”

“…Cheese pH controls the rate of growth and metabolism of PAB (Kurtz, Hupfer, Corbin, Hargrove, & Walter, 1959;Turner, Morris, & Martley, 1983) and a higher inocula is required for cheeses with a lower cheese pH (Frö hlich-Wyder & Bachmann, 2004). Curd washing enables regulation of acid production and thus pH during cheese manufacture and ripening (Czulak, Conochie, Sutherland, & van Leeuwen, 1969;Huffman & Kristoffersen, 1984;Shakeel-UrRehman, Waldron, & Fox, 2004).…”

Effect of curd washing on composition, lactose metabolism, pH, and the growth of non-starter lactic acid bacteria in full-fat Cheddar cheese

“…Similarly, analysis of data from previous studies (Czulak, Conochie, Sutherland, & van Leeuwen, 1969;Guinee, Kilcawley, & Beresford, 2008;Huffman & Kristoffersen, 1984;Martley & Crow, 1993;Rynne et al, 2007;Turner & Thomas, 1980) indicated that the reported concentrations of LLAMc (3.4e4.6%, w/w) for Cheddar cheese are lower than those expected (w4.3e5.2%, w/w) based on the seasonal variations in the concentration of lactose milk of (w4.0e4.8%, w/w) (O'Brien et al, 1999). The lower levels of LLAMc compared with that of LIMm may reflect a more rapid diffusion rate of lactic acid from the moisture phase of the curd particle (where lactose is being fermented to lactic acid by the starter culture) than that of lactose from the whey into curd particle because of the lower molecular mass of the former compared with the latter (w90 and 342 Da, respectively) and the higher concentration of lactate in the curd particle moisture.…”