Draining and salting as responsible key steps in the generation of the acid-forming potential of cheese: Application to a soft blue-veined cheese

Many of us enjoy a cheese platter or a cheese and wine evening. However, the consequences shortly thereafter may not be as pleasant. This is due to the fact that cheeses have a high acid-forming potential when ingested, which in the long run is associated with deleterious effects on consumers health. Dr Gore and colleagues are addressing this problem and in the cited paper below they aimed to characterize the acid-forming potential of a blue-veined cheese during manufacturing to identify the main steps of the processes involved. The paper was published in the Journal of Dairy Science, Volume 99 of 2016, pages 6927 to 6936, with the title: Draining and salting as responsible key steps in the generation of the acid-forming potential of cheese: Application to a soft blue-veined cheese

In the study the authors sampled three batches at 10 steps of the cheese-making process: at reception of the raw milk, after pasteurization, following maturation, during coagulation, when stirring, during draining of the curds and at four ripening stages, respectively at 21, 28, 42 and 56 days. The acid-forming potential of each sample was evaluated by (1) the calculation of the potential renal acid load (PRAL) index (in the process considering protein, Cl, P, Na, K, Mg and Ca contents), and (2) its organic anion content (lactate and citrate), considered as alkalinizing elements. 

Draining and salting were identified as the main steps responsible for generation of the acid-forming potential of cheese. The draining process induced an increase in the PRAL index from 1.2 milli-equivalent (mEq) per100 gram in milk to 10.4 mEq per100 gram in drained curds due to the increase in dry matter and the loss of alkaline minerals into the whey. The increase in PRAL value of 20.3 mEq per 100 gram recorded at day 56 following salting resulted from an imbalance between the strong acid-inducing elements (Cl, P and proteins) and the main alkalinizing ones (Na and Ca). Particularly, Cl had a major effect on the PRAL value. Regarding organic anions, draining induced a loss of 93% of the citrate content of the  initial milk. The lactate content increased as fermentation occurred (1298 milligram per 100 gram in the drained curds) and then decreased during ripening (519.3 milligram per 100 gram at day 56). This lactate level probably helps moderate the acidifying potential of the end products. The authors concluded that alteration of the processes followed and new technologies may limit the acid-forming potential of cheeses and these should be explored in future research, also to evaluate their nutritional influences.