Comparing PTR-MS profile of milk inoculated with pure or mixed cultures of spoilage bacteria. (June 2017)

• Record Type: Journal Article
• Authors: Alothman, Mohammad; Lusk, Karen A.; Silcock, Patrick; Bremer, Phil J.
• Is Part Of: Food microbiology. Volume 64(2017:Jun.)
• Page Start: 155
• Page End: 163
• Publication Date: 2017-06
• Subjects: Microbial interaction -- PTR-MS -- VOC composition -- Milk -- Pseudomonas -- Chryseobacterium -- Inoculation; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2017.01.001
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: The volatile organic compounds (VOCs) associated with UHT milk ( n =8) inoculated with either pure inoculums of Pseudomonas fluorescens (two strains tested) or Chryseobacterium sp., or with mixed cultures of 2 or all 3 of the bacterial strains, and held at 4.5 °C for up to 26 days was measured using proton transfer reaction – mass spectrometry (PTR-MS). The VOCs evolved included a range of carbonyl compounds, alcohols, esters, and acids and had significant qualitative and quantitative differences between the inoculums. Milks inoculated with paired (mixed) bacterial cultures attained patterns similar to the VOC composition of one of the pure inoculums, which could be attributed to the domination of these bacteria within the mixed inoculum. This study will help to characterize the spoilage of milk and provide important insights into understanding the factors that limit the shelf life of milk. Highlights: Volatile organic compounds (VOCs) in inoculated UHT milk were assessed using PTR-MS. VOC's produced included a range of carbonyl compounds, alcohols, esters, and acids. VOC composition differed between single and mixed isolate cultures. Different combinations of the same isolates gave different VOC profiles.