FEA researchers reduce content by 25%, preserving flavor, aroma and texture
Although cheese consumption contributes little to daily sodium intake, there is interest among certain consumer segments in developing products in which its content is reduced. Evaluating the effects of reducing salt on the physical-chemical characteristics of cheese – whose consumption in Brazil is surpassed only by mozzarella and cream cheese – was the focus of the research developed during the master's degree in food technology by food engineer Débora Parra Baptista. The study emphasized maturation, which is the transformation of cheese compounds, such as the breakdown of proteins (proteolysis) that occurs continuously through the action of enzymes added and produced by microorganisms, leading to the formation of the typical characteristics of matured cheeses. , such as flavor, aroma and texture that affect the sensory acceptance of the product by the consumer.
It is known that salt plays an important role in defining the characteristics of cheeses, making its reduction a technological challenge. In addition to giving cheeses the desirable salty taste, salt exerts control over microbial and enzymatic activities during their maturation and, together with pH and calcium content, affects the hydration of the cheese protein (casein), important in the development of characteristics of the final product.
Carried out at the Laboratory and pilot plant of milk and dairy products, of the Department of Food Technology, of the Faculty of Food Engineering (FEA) of Unicamp and guided by professor Mirna Lúcia Gigante, the work focused on determining the level of reduction of salt that would not affect the physical-chemical and sensorial characteristics of the cheese, so that it would be equally accepted by consumers when compared to cheeses available on the market. According to the author, different strategies can be used to reduce the salt content of industrialized products. But research must begin by determining the minimum salt content required to achieve the desirable characteristics of each product.
The importance of the work is highlighted when it is known that excessive sodium consumption is associated with increased blood pressure, the development of cardiovascular diseases and the occurrence of strokes. Its reduction in processed foods has mobilized regulatory bodies, producers and academic areas towards solutions that simultaneously enable the reduction of salt and the maintenance of product quality and safety. In 2013, the Ministry of Health and the Brazilian Food Industry Association signed an agreement to reduce sodium in meat and dairy products, in line with the World Health Organization, which recommends a maximum intake of 2000 mg of sodium per day.
The study was developed in partnership with professor Marcos Nogueira Eberlin, from the ThoMSon Mass Spectrometry Laboratory, from the Institute of Chemistry (IQ) at Unicamp, and had the collaboration of researcher Francisca Diana da Silva Araújo.
Two phrases
The work consisted of two distinct phases. In the first, ten brands of cheese were analyzed sold in Campinas, but coming from various regions of the country. These cheeses were evaluated regarding their composition (moisture, fat, protein and salt content) and their peptide profile, which are the fragments obtained after the breakdown of proteins or proteolysis. Corroborating data already published by Anvisa, the results indicated a very large variation in the amount of salt, which ranged from 1,09% to 3,77%, highlighting a lack of standardization of cheeses. For the author, “the analyzes showed that these commercial cheeses, produced with different raw materials and processing conditions, presented very similar peptide profiles when evaluated at the molecular level and that the results suggest that salt reduction is perfectly possible, a since products with such different salt contents are accepted by consumers”. These conclusions were published in Journal of Food Science under the title A survey of the peptide profile in dish cheese as measured by MALDI-MS and Capillary Electrophoresis (Evaluation of the peptide profile of Prato cheese by MALDI-MS and Capillary Electrophoresis).
The second part of the research evaluated the effect of reducing salt (25% and 50%) on the proteolysis, firmness and sensory acceptance of Prato cheese during 60 days of maturation. For this second phase, the author produced, using the conventional industrial process, but on a smaller scale, plate cheeses with three salt levels: control cheeses, with 1,7% salt, which corresponds to the average value found in commercial cheeses; and cheeses with a 25% and 50% reduction in salt compared to the control cheese, that is, with levels of 1,23% and 0,84% respectively.
Cheeses with 50% salt reduction were of lower quality than control cheese and were not well accepted by consumers as they were less firm and more acidic. On the other hand, cheeses produced with 25% salt reduction showed the same proteolysis profile and had similar characteristics to the control cheese. In the sensory evaluation, control cheeses and those with 25% salt reduction received the same scores in relation to overall acceptance, which includes appearance, aroma, flavor and texture. These results were published in International Dairy Journal under the title Reduction of 25% salt in dish cheese does not affect proteolysis and sensory acceptance (25% reduction in salt in cheese does not affect proteolysis and sensory acceptance).
Professor Mirna highlights that the most important transformation during maturation is proteolysis, which is characterized by the breakdown of protein chains through enzymatic action, determining the texture and flavor of the cheeses. She concludes: “In the cheese dish, with up to 60 days, the period in which we stayed, we obtained very tasty cheeses with a 25% reduction in salt, without compromising the functional and sensorial characteristics desired by the consumer. The same did not happen when the salt reduction was 50%.”
For the researchers, a 25% reduction in the salt content in Prato cheese, in relation to the average value present in the commercial products examined, is possible without compromising the development of maturation and its physical-chemical and sensorial qualities, indicating the possibility of manufacturing of a healthier product.