Relationship between total microbial numbers, volatile organic compound composition, and the sensory characteristics of whole fresh chilled pasteurized milk. (March 2018)

• Record Type: Journal Article
• Authors: Alothman, Mohammad; Lusk, Karen A.; Silcock, Patrick J.; Bremer, Phil J.
• Is Part Of: Food packaging and shelf life. Volume 15(2018)
• Page Start: 69
• Page End: 75
• Publication Date: 2018-03
• Subjects: (W)FCPM (Whole) fresh chilled pasteurized milk -- VOCs Volatile organic compounds -- DA sensory descriptive analysis -- PTR-MS Proton transfer reaction – mass spectrometry -- HDPE High-density polyethylene -- PPM Part per million -- TMN Total microbial numbers -- CFU Colony forming unit -- sccm Standard cubic centimetre per minute -- n-cps Normalized counts per second -- GLM General linear model -- MFA Multiple factor analysis -- PPC Post-pasteurization contamination -- m/z Mass-to-charge ratio; Total microbial numbers -- Descriptive sensory analysis -- Post-pasteurization contamination -- PTR-MS -- Shelf life; Food -- Packaging -- Periodicals; Food -- Preservation -- Periodicals; Food -- Packaging; Periodicals; 664.0905
• DOI: 10.1016/j.fpsl.2017.11.005
• Languages: English
• ISSNs: 2214-2894

Abstract

Highlights: We monitored microbial numbers sensory properties and volatile composition of milk. We used PTR-MS and descriptive sensory panel to study changes in the milk over time. High microbial numbers did not cause spoilage with a detectable threshold. Weak relationship existed between microbial numbers, sensory properties & volatiles. This was due to differences in the spoilage potential of the microorganisms. Abstract: Total microbial numbers (TMN*) is a widely used, yet broad indicator of the quality of fresh chilled pasteurized milk (FCPM). Changes in the sensory characteristics (trained panel, n = 9), volatile organic compounds (VOC) composition (proton transfer reaction mass spectrometry, PTR-MS), and TMN were assessed for FCPM stored at 4.5 °C ± 0.5 for up to 26 days (12 days past the stated shelf life). Significant differences ( p ≤ 0.05) in its VOC composition ( m / z 41, 43, 45, and 47) and the sensory characteristics (10 out of 17 attributes) occurred at various TMN levels over this time. However, owing to differences in the spoilage potential of the microorganisms present there was only a weak relationship between TMN, VOC composition, and the sensory characteristics, which indicates that both the nature of the microorganisms present as well as the numbers present play a critical role in determining the shelf-life of FCPM.