Comparative impact of thermal and high isostatic pressure inactivation of gram-negative microorganisms on the endotoxic potential of reconstituted powder milk

• Published in: Food science & technology Vol. 106; pp. 78 - 82
• Main Authors: Aires Machado, Karla Idelça, Roquetto, Aline Rissetti, Moura, Carolina Soares, de Souza Lopes, Aline, Cristianini, Marcelo, Amaya-Farfan, Jaime
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2019
• Subjects: Food safety; Long-term toxicity; Pasteurization; Sterilization; Wholesome; Food safety; Wholesome; Long-term toxicity; Pasteurization; Sterilization
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2019.02.064

Foods are a primary source of exogenous microorganisms and chemical motifs thereof that act as endotoxins because they trigger systemic inflammation in the body. One of the main accomplishments of food processing has been to prevent spoilage and protect human health by killing pathogenic microorganisms, but secondary consequences compel us to give more importance to the presence of the toxic chemical motifs that remain behind because they can cause systemic inflammation. To test if the type of inactivation affects the amounts of remnants, the concentrations of such toxic compounds were measured after microbial inactivation by classical thermal treatment and high-pressure processing of cow's milk. Three gram-negative bacteria were individually inoculated in reconstituted powder milk: Escherichia coli ATCC 11229, Pseudomonas fluorescens IB 2312 and Enterobacter aerogenes ATCC 13048, and the endotoxic potential estimated by determining the levels of the toxic chemical motifs known as lipopolysaccharides (LPS). The results indicated that the inactivation of these three microorganisms in cow's milk by classical heat treatment or by high pressure have the general tendency to increase the amounts of LPS, but not to a great extent. Additionally, the increases appeared to be a combination of both the type of microbe and the process.
•Microbial inactivation leaves behind endotoxins in reconstituted powdered milk.•Microbial inactivation of foods tends to increase potentially harmful LPS.•LPS levels tend to increase with either thermal or high pressure processing.•LPS levels may be the combined result of the type of microbe and the type of process.