Freshness Assessment of Broccoli using Electronic Nose

Broccoli is one of the nutrient-rich vegetables that can easily be affected by bacteria and consumption of bacterial contaminated fresh products leads to a number of food borne illnesses. A multi-dimensional approach has been adapted to evaluate the freshness of broccoli considering four different mutually supporting techniques namely electronic nose, bacterial culture test, head sampler method with Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infrared (FTIR) spectroscopy. Electronic nose output variations from 0.05 V to 1.5 V and the presence of Staphylococcus, Salmonella and Shigella in the order of Zero, 10(6) and 10(5)-10(7) CFU mL(-1) were observed for fresh, half and completely contaminated broccoli samples. GC-MS data revealed the presence of acetic acid, hexanoic acid, nonanol evolved from half and completely contaminated broccoli samples. In addition, Principle Component Analysis, Centroid-link, and Completely-link cluster analyses were used on electronic nose data in correlation with other techniques for decision making. (C) 2019 Elsevier Ltd. All rights reserved.