# High Pressure and Pasteurization Effects on Dairy Cream +
###### Abstract  
Dairy cream, a common ingredient in various dishes and food products, is susceptible to rapid microbial growth due to its high water activity (\(\approx\)0.97) and pH (\(\approx\)6.7). Thus, it requires proper processing conditions to ensure food safety and extend shelf life. High-pressure processing (HPP) has emerged as a nonthermal food pasteurization method, offering an alternative to conventional heat-based techniques to obtain taste, fresh-like, and safe dairy products without undesirable heat-induced alterations. This study assessed the impact of HPP (450 and 600 MPa for 5 and 15 min at 7 \({}^{\circ}\)C) and thermal pasteurization (75 \({}^{\circ}\)C for 15 s) on the microbiological and physicochemical attributes of dairy cream immediately after processing and throughout refrigerated storage (4 \({}^{\circ}\)C). HPP-treated samples remained microbiologically acceptable even on the 51 st day of storage, unlike thermally pasteurized samples. Moreover, HPP decreased inoculated _Escherichia coli_ and _Listeria innocua_ counts by more than 6 log units to undetectable levels (1.00 log CFU/mL). pH, color (maximum variation of \(\Delta\)E\({}^{*}\) up to 8.43), and fatty acid profiles remained relatively stable under varying processing conditions and during storage. However, viscosity exhibited higher values for HPP-treated samples (0.028 \(\pm\) 0.003 Pa-s) compared to thermally processed ones (0.016 \(\pm\) 0.002 Pa-s) by the 28 th day of storage. Furthermore, volatile compounds (VOCs) of all treated samples presented a tendency to increase throughout storage, particularly acids and aliphatic hydrocarbons. These findings show HPP's potential to significantly extend the shelf life of highly perishable dairy cream by at least 15 days compared to thermal pasteurization. dairy cream; fatty acids; food safety; nonthermal and thermal processing; rheological parameters; shelf life; volatile organic compounds +
Footnote †: This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/)]([https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/))). Footnote †: This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/py/4.0/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/licenses/py/4.0/)]([https://creativecommons.org/licenses/py/4.0/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/licenses/py/4.0/))). Footnote †: This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/)]([https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/))). High-pressure processing (HPP) is a common nonthermal method that utilizes elevated hydrostatic pressures (approximately 400-600 MPa) to pasteurize, denature multiple enzymes, and inactivate pathogenic and spoilage vegetative microorganisms, thereby assuring food safety [5]. Unlike thermal pasteurization, HPP does not affect covalent bonds and is able to effectively retain food quality attributes, namely sensorial and nutritional properties [4]. Additionally, as a pasteurization technique, nonthermal HPP does not target bacterial spores, such as those from _Bacillus_ spp., yet it can target some spores from yeasts and molds, with the exception of those from _Byssochlamys_ and _Talaromyces_ spp. and some species of _Zygosaccharomyces_[6]. As such, HPP products are to be kept under refrigeration. Only a few studies have evaluated the effects of HPP on dairy creams [7; 8].