A microbiological perspective of raw milk preserved at room temperature using hyperbaric storage compared to refrigerated storage. (June 2022)

• Record Type: Journal Article
• Authors: Duarte, Ricardo V.; Pinto, Carlos A.; Gomes, Ana M.; Delgadillo, Ivonne; Saraiva, Jorge A.
• Is Part Of: Innovative food science & emerging technologies. Volume 78(2022)
• Publication Date: 2022-06
• Subjects: Hyperbaric storage -- Raw milk -- Microbiology -- Refrigeration -- Endospores; Food -- Biotechnology -- Periodicals; Food industry and trade -- Technological innovations -- Periodicals; Aliments -- Biotechnologie -- Périodiques; Food -- Biotechnology; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.ifset.2022.103019
• Languages: English
• ISSNs: 1466-8564

Abstract

Abstract: The effects of hyperbaric storage (HS, 50–100 MPa) at room temperature (RT) on endogenous and inoculated pathogenic surrogate vegetative bacteria ( Escherichia coli, Listeria innocua ), pathogenic Salmonella enterica and bacterial spores ( Bacillus subtilis ) were assessed and compared with conventional refrigeration at atmospheric pressure for 60 days. Milk stored at atmospheric pressure and refrigeration quickly surpassed the acceptable microbiological limit within 7 days of storage, regarding endogenous microbiota, yet 50 MPa/RT slowed down microbial growth, resulting in raw milk spoilage after 28 days, while a significant microbial inactivation occurred under 75–100 MPa (around 4 log units), to counts below 1 log CFU/mL throughout storage, similar to what was observed for B. subtilis endospores. While inoculated microorganisms had a gradually counts reduction in all HS conditions. Results indicate that HS can not only result in the extension of milk shelf-life but is also able to enhance its safety and subsequent quality. Industrial relevance: This new preservation methodology could be implemented in the dairy farm storage tanks, or during milk transportation for further processing, allowing a better microbial control, than refrigeration. This methodology is very promising, and can improve food products shelf-life with a considerable lower carbon foot-print than refrigeration. Highlights: Hyperbaric storage (HS) restrained raw milk endogenous microbiota during storage. HS inactivated ca 4 logs of inoculated surrogate and pathogenic microorganisms. HS (≥75 MPa) reduced B. subtilis endospores from 5.59 logs to undetectable counts. HS microbial inactivation along storage enhanced its safety vs refrigeration (RF). HS increased raw milk shelf-life up to at least 60 days vs only 14 days at RF.