P3-117 Prediction of Microbial Shelf Life of Raw Chicken Breast under Aerobic Storage Conditions Using Volatile Spoilage Biomarkers

Wednesday, August 6, 2014
Exhibit Hall D (Indiana Convention Center)
Marta Mikš-Krajnik, National University of Singapore, Singapore, Singapore
Hyun-Jung Chung, Inha University, Incheon, South Korea
Yong-Jin Yoon, Nanyang Technological University, Singapore, Singapore
Hyun-Gyun Yuk, National University of Singapore, Singapore, Singapore
Introduction: Fresh, raw chicken breast is a highly perishable food, of great importance, characterized by complex microbial ecosystem. Microorganisms responsible for spoilage are known as specific spoilage organisms (SSOs), and their activity is commonly manifested as off-odors caused by the presence of volatile organic compounds (VOCs) produced as a result of bacterial metabolism.

Purpose: The aims of this investigation were to find unique VOCs as possible spoilage biomarkers to predict microbiological spoilage of raw chicken breast stored aerobically under different temperature conditions and to characterize SSOs growth dynamics.

Methods: The growth of total viable count (TVC) and six SSOs including: psychotropic bacteria, Pseudomonas spp., coliforms, lactic acid bacteria (LAB), Brochothrix thermosphacta and H2S producing bacteria were investigated. The VOCs profiles were determined by HS-SPME-GC-MS. Chicken breast samples were stored at 4 and 10°C for 14 days and 21°C for 3 days. The growth curves were fitted to the modified Gompertz model. The predicted shelf life was defined by the time, when TVC reached 7.0 log CFU/g. Maximum concentration level coefficients (M values) for the growth of SSOs were designated. The results were statistically analyzed by ANOVA followed by Tukey’s significant difference test.

Results: Regardless of the temperature, predominant SSOs (highest M values) in naturally spoiled chicken breast were: psychrotrophs, probably represented mostly by Pseudomonas spp., followed by LAB. The predicted shelf lives of chicken breasts were 1.95, 1.20 and 0.29 days for storage at 4, 10 and 21°C, respectively. The significant (P < 0.05) and high correlations between TVC and SSOs, and selected VOCs (ethanol, 1-butanol-3-methyl and acetic acid) were observed in all studied conditions. 

Significance: This study suggests that the identified VOCs could be used as the most promising volatile spoilage biomarkers for chicken breast.