Discrimination of Spanish-Style Green Olives Inoculated with Undesirable Microbiota Using E-Nose, Chemometrics and...

Area of Science:

• Food Science
• Microbiology
• Analytical Chemistry

Background:

• Table olives are susceptible to bacterial spoilage, impacting quality and safety.
• Traditional spoilage detection methods can be time-consuming and destructive.

Purpose of the Study:

• To evaluate the efficacy of electronic nose (E-nose) technology for detecting bacterial spoilage in Spanish-style green table olives.
• To correlate E-nose data with microbial, physicochemical, and sensory changes during spoilage.

Main Methods:

• Olives were inoculated with different bacterial strains (e.g., Bacillus cereus, Escherichia coli).
• Microbial growth, physicochemical properties, sensory attributes, and volatile organic compounds (VOCs) were analyzed.
• E-nose data was analyzed using Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA).

Main Results:

• Bacterial strains exhibited strain-dependent survival and induced significant changes in olive properties.
• Sensory evaluation revealed defects like rancid and woody aromas in spoiled olives.
• VOC profiles showed strain-specific alterations, with increased aldehydes and phenols.
• E-nose analysis successfully distinguished spoiled from non-spoiled olives with 90.4% accuracy using PLS-DA.

Conclusions:

• E-nose technology is a promising rapid, non-destructive tool for detecting bacterial spoilage in table olives.
• This technology can aid in quality control and early detection of spoilage in the olive industry.