|KRAJNIK, MARTA MIKS - Warmia And Mazury University|
|YOON, YONG-JIN - Nanyang Technological University|
|HYUN, GYUN YUK - National University Of Singapore|
Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2015
Publication Date: 6/28/2016
Citation: Krajnik, M., Yoon, Y., Ukuku, D.O., Hyun, G. 2016. Volatile chemical spoilage indexes of raw Atlantic salmon (salmo salar)stored under aerobic condition in relation to microbiological and sensory shelf lives. Food Microbiology. 53:182-191.
Interpretive Summary: This study was performed to identify and quantify selected volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 degrees C. The volatile organic compounds (VOCs) selected were analyzed with SPME-GC-MS technique. Analysis of samples using modified Gompertz model showed that Pseudomonas spp were suitable for shelf life prediction while H2S producing bacteria and Brochothrix thermospacta determined as part of the specific spoilage organisms (SSOs) were not suitable for shelf life estimation. Also, Pseudomonas spp. and 3Met-1But and aldehydes synthesis, lactic acid bacteria were linked with EtOH, C2 and esters, and B. thermospacta with acetoin formation and therefore can all be used to predict shelf life. Therefore the presence and the level of EtOH, 3Met-1But and aldehydes , C2 and esters, and B. thermospacta within Atlantic salmon (Salmo salar) fillets can be used as volatile spoilage biomarkers for rapid evaluation of quality and shelf life prediction during storage.
Technical Abstract: The purpose of this investigation was to identify and quantify the volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 degrees C in relation to the determined microbial and sensory shelf lives. The volatile organic compounds (VOCs) were analysed with SPME-GC-MS technique. Through multivariate chemometric method, hierarchical cluster analysis (HCA) and Pearson’s correlations, the CSIs: trimethylamine (TMA), ethanol (EtOH), 3-methyl-1-butanol (3Met-1But), acetoin and acetic acid (C2) were selected from the group of 28 detected VOCs. At the moment of microbial shelf life established at total viable count (TVC) of 7.0 log CFU/g, the CSIs achieved level of 11.5, 38.3, 0.3, 24.0 and 90.7 micro g/g of salmon for TMA, EtOH, 3M-1But, acetoin and C2, respectively. Pseudomonas spp. was found as major specific spoilage organism (SSOs), suitable for shelf life prediction using modified Gompertz model. H2S producing bacteria and Brochothrix thermospacta were considered as SSOs, however, they were not suitable for shelf life estimation. Partial least square (PLS) regression revealed possible associations between microorganisms and synthetized VOCs, showing correlations between Pseudomonas spp. and 3Met-1But and aldehydes synthesis, lactic acid bacteria were linked with EtOH, C2 and esters, and B. thermospacta with acetoin formation.