Evaluation of the effects of mild heat in bovine milk by time resolved fluorescence

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2019-08, Vol.219, p.457-462
• Main Authors: Brandao, Mariana P., Neto, Marina Gouvea, dos Anjos, Virgílio de Carvalho, Bell, Maria José V.
• Format: Article
• Language: English
• Subjects: Lifetimes; Milk; Temperature; Time-resolved fluorescence
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2019.04.079

Heat treatment of milk and dairy products are indispensable for the dairy industry. This thermal processing intends to extend shelf life, improve quality of the milk and minimize the health risks associated with milk and dairy products. The use of time-resolved fluorescence techniques to identify conformation and structure changes ok milk fat and proteins could help understand the temperature effects in bovine milk. This study aimed to use fluorescence lifetimes to evaluate the effects of heating fresh cow milk up to 85 °C. We observed different tendencies for fluorescence lifetimes submitted to different heating temperatures. The longer lifetime values decreased for temperatures higher than room temperature until it reached a minimum value near 40 °C and it slowly increased again for temperatures higher than 40 °C, indicating two distinct processes. These results indicate that time-resolved fluorescence can assist on the analysis of heating effects in fluid milk. [Display omitted] •We propose a novel method for evaluation of effects on milk mild heating.•Fluorescence lifetime decreases linearly from room temperature until 40 °C.•Fluorescence lifetime increases slowly for temperatures higher than 40 °C.•Time-resolved fluorescence can assist on the analysis of mild heating effects on milk.•Vitamin A's fluorescence lifetime is correlated to milk's mild heating.