Mozzarella and stretched-curd cheeses are presented as such, in labeling and advertising, without distinguishing between products coagulated with natural whey starter or with citric acid (1) nor those made with fresh milk rather than with ‘purchase curds,’ perhaps even frozen.
Our previous market survey of two dozen mozzarellas allowed us to distinguish-through examination of the ingredient lists on the label-the presence of citric and/or lactic acid, as well as the use of raw materials (milk and/or curd) of foreign origin. (2)
However, there remains unacceptable omertà about the use of curds that come from other factories, outside the guarantees offered in PDO mozzarellas. Therefore, it is worth delving into the production processes and the EU rules to be applied to ensure correct information to consumers.
Curd, a semi-processed ingredient or cheese
‘Curd’ is defined as the semi-solid product obtained from the coagulation of milk after separation of the whey. Its ingredients are milk, rennet and salt, to which milk enzymes or citric acid (additive, acidity corrector) may be added. Coagulation of milk proteins can occur by thermal, acid-thermal, acidic or enzymatic means.
The curd obtained after draining the whey and after any stewing may constitute:
– A compound ingredient, (3) semi-finished product of cheese making, to be subjected to subsequent unit operations (pressing, salting, curing, etc.), viz.
– A cheese, finished product. This is the case for most fresh high-moisture dairy products, e.g., first salt, which do not require curing and are therefore ready for consumption at or shortly after the end of the manufacturing process. (4)
Curd mozzarella
Pasta filata cheeses, fresh and aged, can be made by subjecting ripe curd (that is, which has reached the right level of demineralization, by fermentation or chemistry) to a characteristic thermo-mechanical operation, spinning.
Spinning, using hot water or steam, can plasticize the curd and make it take on a new structure that is maintained and consolidated after cooling. Packaging in the preserving liquid and any subsequent cooling complete the process of making fresh mozzarella in preserving liquid.
Other curd cheeses from curds
Other stretched-curd che eses such as scamorze or provolette-although they have a lower moisture content than mozzarella and thus greater durability-qualify in turn as fresh cheeses because they are not aged. Provolettes are often paraffin-embedded before packaging, while scamorzas are mostly vacuum-packed or packaged in a protective atmosphere.
Provolas, provolones, caciocavalli and other semi-hard or hard pasta filate, on the other hand, must wait for maturation periods, longer or shorter depending on the size, in order to develop the organoleptic characteristics peculiar to each cheese before it is released on the market.
PDO mozzarellas, quality guaranteed
The production specifications for mozzarellas with GIs(Geographical Indications) recognized, certified and protected in the EU – Mozzarella di Bufala Campana PDO and Mozzarella di Gioia del Colle PDO – require that all stages of the manufacturing process be carried out in a continuous cycle in the same factory.
This constraint serves to distinguish authentic premium mozzarella, made directly from raw milk from the production area, from those made in whole or in part with purchased curds, almost always of foreign origin and/or foreign milk.
Purchase curds and ‘citric mozzarella’
So-called purchase curds are produced in countries with high milk production, where milk generally has lower prices, using plants for the production of pressed, semi-hard cheeses. They have a moisture content of 43-45%, a fat on dry matter of 45-48% and a pH value of 5.4-5.6 normally obtained by fermentation (lactic curd).
‘Citric mozzarellas’ (i.e., subject to coagulation with citric acid) are usually made from ad hoc, non-pressed, chemically demineralized curds that are refrigerated or frozen. The latter have a shelf life of up to 12 months and are used to produce both pasta filata and processed (spreadable or stringy) cheeses. (5) The curds themselves are then actual cheeses, sometimes left to ripen in the cold for a few weeks to improve the spinning performance of the stringy melt (e.g., “The curds are not a cheese but a cheese”). ‘stringy dough’ or pizza cheese). (5)
Purchasing curds in string cheese, conveniences and limitations
The use of purchase curds in the production of pasta filata is dictated primarily by economic convenience but also sometimes by the scarcity of raw material. They effectively act as substitutes for milk of purchase, with the advantages of being concentrated, having greater durability and lower logistical costs. On the other hand, in Italy the use-or even the storage, in the dairy- of powdered or otherwise concentrated milk is not permitted (Law 138/1974).
The inherent difficulty of purchase curds to absorb moisture in spinning obviously affects the quality of mozzarella. It therefore turns out to be necessary to use them only pro-rata, in addition to fresh curd (e.g., 30% purchased curd and 70% fresh curd). Provolas, scamorzas and stringy spindles, on the other hand, can easily be made with only the purchase curd, 100 percent. Without informing consumers about the characteristics and composition of the products. (6)
How to identify the presence of curds in cheeses
Identifying the presence of curds by laboratory analysis is very simple. Thanks to an analytical method developed in 2014 by Professors Michele Faccia and Aldo Di Luccia – full professors of Food Science and Technology at the Universities of Bari and Foggia, respectively – that allows the addition of purchase curds to be revealed based on the highest level of degradation of their caseins. (7)
Magnetic resonance imaging to field cycle (Fast-Field Cycling Nuclear Magnetic Resonance, FFC NMR) – an innovative technique for analyzing the molecular dynamics of matrices – has itself been successfully tested by Professor Pellegrino Conte of the University of Palermo on Parmigiano Reggiano and Fiore Sardo DOP. (8) And it may also be used on pasta filata cheeses.
Outlaw labels
Labels of stretched-curd cheeses made from purchased curds-that is, curds not made within the same dairy where further processing takes place-must include in the ingredient list, the name of the compound ingredient, ‘curd,’ followed in parentheses by its ingredients.
‘A compound ingredientmay appear in the list of ingredients under its designation, to the extent that it is provided for by regulation or fixed by use, in relation to its overall weight, and must be immediately followed by the list of its ingredients‘ (reg. EU 1169/11. Annex VII, Part E, point 1).
Rightful transparency
The Food Information Regulation allows no exceptions and applies-in its identical text, in the 24 official languages-in all member states of the European Union. And no ‘interpretation of convenience’ can be allowed at the national level.
Consumers therefore have the inviolable right to distinguish mozzarella and other cheeses made even in part with purchased curd (of foreign, or otherwise external, origin) from those made from milk.
Dario Dongo
Notes
(1) Dario Dongo, Michele Polignieri. Mozzarella cheese, here’s why to be wary of citric acid. GIFT(Great Italian Food Trade). 6.11.20, https://www.greatitalianfoodtrade.it/etichette/mozzarella-ecco-perché-diffidare-dell-acido-citrico
(2) Marta Strinati. Mozzarella unsuitable for vegetarians or as a hasty starter. 25 products compared to choose well. GIFT (Great Italian Food Trade). 14.11.20, https://www.greatitalianfoodtrade.it/consum-attori/mozzarelle-inadatte-ai-vegetariani-o-da-starter-sbrigativo-25-prodotti-a-confronto-per-scegliere-bene
(3) Dario Dongo. Compound ingredients and QUID on labels, widespread deceptions. GIFT(Great Italian Food Trade). 1.6.19, https://www.greatitalianfoodtrade.it/etichette/ingredienti-composti-e-quid-in-etichetta-inganni-diffusi
(4) In fact, curd corresponds to the Codex Alimentarius definition of cheese.
‘2.1 Cheese is the ripened or unripened soft, semi-hard, hard, or extra-hard product, which may be coated, and in which the whey protein/casein ratio does not exceed that of milk, obtained by:
(a) coagulating wholly or partly the protein of milk, skimmed milk, partly skimmed milk, cream, whey cream or buttermilk, or any combination of these materials, through the action of rennet or other suitable coagulating agents, and by partially draining the whey resulting from the coagulation, while respecting the principle that cheese-making results in a concentration of milk protein (in particular, the casein portion), and that consequently, the protein content of the cheese will be distinctly higher than the protein level of the blend of the above milk materials from which the cheese was made; and/or
(b) processing techniques involving coagulation of the protein of milk and/or products obtained from milk which give an end-product with similar physical, chemical and organoleptic characteristics as the product defined under (a).
2.1.1 Ripened cheese is cheese which is not ready for consumption shortly after manufacture but which must be held for such time, at such temperature, and under such other conditions as will result in the necessary biochemical and physical changes characterizing the cheese in question.
2.1.2 Mould ripened cheese is a ripened cheese in which the ripening has been accomplished primarily by the development of characteristic mold growth throughout the interior and/or on the surface of the cheese.
2.1.3 Unripened cheese including fresh cheese is cheese which is ready for consumption shortly after manufacture‘ (CODEX STAN 283-1978, updated 2008)
(5) ‘Pasta filante’ instead of mozzarella cheese in pizzerias? Lawyer Dario Dongo answers.. FARE(Food and Agriculture Requirements). 2/23/17, https://www.foodagriculturerequirements.com/archivio-notizie/domande-e-risposte/pasta-filante-al-posto-della-mozzarella-in-pizzeria-risponde-l-avvocato-dario-dongo
(6) The prohibition against misleading consumers about the essential characteristics of foods-including composition and manufacturing method-is expressly provided for in Reg. EU 1169/11, Article 7.1.a. Its violation may integrate at the same time an unfair business practice, in violation of the Consumer Code (Legislative Decree 206/2005), therefore also subject to the supervision of the Antitrust Authority (AGCM, so-called Antitrust)
(7) Michele Faccia, Antonio Trani, Pasqua Loizzo, R. Gagliardi, Barbara Gatta, Aldo Di Luccia. (2014). Detection of αs1-I casein in mozzarella Fiordilatte: A possible tool to reveal the use of stored curd in cheesemaking. Food Control. doi: 10.1016/j.foodcont.2014.01.044
(8) Dario Dongo. Fast-Field Cycling RNM, an innovative analysis to verify food authenticity. GIFT(Great Italian Food Trade). 4.5.21, https://www.greatitalianfoodtrade.it/innovazione/fast-field-cycling-rnm-un-analisi-innovativa-per-verificare-l-autenticità-degli-alimenti
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
