**2. Dulce de leche**

DL is a dairy product that is manufactured via heat action concentration. It is produced in small- and medium-sized dairy industries on a large scale throughout South America, particularly in Brazil and Argentina [1].

According to the most recent data from the Annual Industrial Survey (PIA) released by the Brazilian Institute of Geography and Statistics (IBGE), DL production in Brazil represents 345.19 million reais, a sum equivalent to 0.82% of dairy sector production in the country.

In 2009, 50% of Brazil's milk production was concentrated in the state of Minas Gerais, according to the Integrated Development Institute of Minas Gerais [2, 3]. Despite the importance of dulce de leche on the Brazilian market since 2007, the country has maintained a trade balance deficit for the dairy product. Argentina and Uruguay have remained the primary suppliers to Brazil [4, 5].

 In 2015, the Foreign Trade Information Analysis System via Internet (ALICEWeb) determined that 95.46% of Brazil's total DL imports came from Argentina, while 4.54% came from rom Uruguay. As to destination countries for DL in 2015, the United States of America (USA), Bolivia, Paraguay, Costa Rica, United Kingdom, Chile, Uruguay, and the Netherlands accounted for 56.37, 15, 13.92, 9.67, 2.62, 0.99, 0.81, and 0.61%, respectively.

Dulce de leche is defined as a product made from milk or reconstituted milk and added sucrose (either partially substituted or not by monosaccharides and/or other disaccharides), with or without the addition of other food substances, obtained via concentration and heat action at normal or reduced pressure [6].

Regulations require DL to contain milk and/or reconstituted milk and indicate minimum and maximum values for moisture, fat, ash, and protein.

DL may not contain nondairy fat or protein. It is produced by concentration of milk to which sugar, usually sucrose, has been added. In some cases, it is possible to replace part of the sucrose with glucose, which improves the texture and color while simultaneously reducing lactose crystal growth and formation and increasing product viscosity [7].

The heat and the concentration processes during DL processing can lead to a series of product defects, such as protein destabilization, which results in protein precipitation. Acidity reducers can be used to reduce or avoid precipitation, as well as enhance product color. Sodium bicarbonate is one of the most common acidity reducers used in DL production [7].

The DL sensorial characteristics such as flavor and coloring are fundamentally due to the nonenzymatic browning reaction (the Maillard reaction) that occurs during the intense thermal treatment to which the milk and sugar syrup is submitted during manufacturing. Despite the sensory benefits it imparts, this reaction can have adverse effects on the nutritional characteristics of the food, such as reducing the concentration of essential amino acids like lysine [7].

The Technical Regulation of DL classifies products according to fat content and additional ingredients as shown in **Table 1**.

The term DL (dulce de leche) is reserved for products that do not contain fat and/or protein of nondairy origin.


### **Table 1.**

*Dulce de leche (DL) classification for fat content and addition of other food substances.* 

The sales terms for dulce de leche established by the Technical Regulation are as follows:
