Caracterização e avaliação de indicadores físico-químicos, tecnológicos e de tratamento térmico em doces de leite

Abstract

The “dulce de leche” (DL) is traditionally obtained by concentrating heat milk plus sugar and has significant production and commercialization in Latin America. The standardization of the characteristics of this product and the adequacy recommended by the Technical Regulation Identity and Quality of “Dulce de Leche” become hampered by cultural diversity, technological changes, and different ingredients used in manufacturing. This food has characteristic flavor, aroma and color mainly due to the Maillard Reaction (MR) triggered during heating. This study aimed to verify the quality and uniformity through physical-chemical and compositional analysis of the products marketed in the city of Juiz de Fora - Minas Gerais (MG) and in DL manufactured experimentally. In addition, the study sought to determine the 5-hydroxymethylfurfural content (HMF) in commercial DL and along the manufacture of experimental DL in order to understand how different formulations influence the formation of this index. Nine different trademarks and twelve experimental formulations were submitted to determination of moisture, lipid, protein, ash, carbohydrates, water activity (Aw) and soluble solids. It was held the determination of free HMF and total HMF by spectrophotometry at 443 nm using thiobarbituric acid. The descriptive statistic of the results for the physico-chemical and compositional properties, and the free HMF and total HMF index of the comercial DL show high variability between samples with non standardization and not complete compliance with current legislation. Regarding the experimental samples, the descriptive statistic found low variability for the physical-chemical and compositional attributes indicating greater cohesion with the limits established by Technical Regulation Identity and Quality of “Dulce de Leche”. The analysis of the results of HMF for the experimental dulces showed elevated levels of free HMF and total HMF along the manufacturing. It is concluded that the addition of glucose and the use of higher concentrations of sodium bicarbonate were decisive factors for increasing the index of HMF. The results of this study expand scientific knowledge about dulce de leche favoring the dairy industry and the scientific community, as well as highlight the importance of standardization and control during the manufacture of “dulce de leche”.