Electronic Nose Based on Metal Oxide Semiconductor Sensors as an Alternative Technique for the Spoilage Classification of Red Meat.

Noureddine El Barbri,Xavier Correig,Benachir Bouchikhi,Eduard Llobet,Nezha El Bari

doi:10.3390/s8010142

Abstract

The aim of the present study was to develop an electronic nose for the quality control of red meat. Electronic nose and bacteriological measurements are performed to analyse samples of beef and sheep meat stored at 4°C for up to 15 days. Principal component analysis (PCA) and support vector machine (SVM) based classification techniques are used to investigate the performance of the electronic nose system in the spoilage classification of red meats. The bacteriological method was selected as the reference method to consistently train the electronic nose system. The SVM models built classified meat samples based on the total microbial population into "unspoiled" (microbial counts < 6 log10 cfu/g) and "spoiled" (microbial counts ≥ 6 log10 cfu/g). The preliminary results obtained by the bacteria total viable counts (TVC) show that the shelf-life of beef and sheep meats stored at 4 °C are 7 and 5 days, respectively. The electronic nose system coupled to SVM could discriminate between unspoiled/ spoiled beef or sheep meats with a success rate of 98.81 or 96.43 %, respectively. To investigate whether the results of the electronic nose correlated well with the results of the bacteriological analysis, partial least squares (PLS) calibration models were built and validated. Good correlation coefficients between the electronic nose signals and bacteriological data were obtained, a clear indication that the electronic nose system can become a simple and rapid technique for the quality control of red meats.

Highlights

The evaluation of quality in red meat products is needed because producers, agents of the logistic chain and vendors need to ensure that they offer products that meet the quality expectations of customers
It was decided that a quality criterion corresponding to a 106 cfu/g for total viable counts (TVC) should be applied to discriminate between unspoiled and spoiled samples in this study, because this is the general microbiological safety guideline applied for food quality [13, 23, 24]
A bacterial analysis was used as a complementary method to develop a simple and rapid electronic nose technique for the spoilage classification of red meat

Summary

Introduction

The evaluation of quality in red meat products is needed because producers, agents of the logistic chain and vendors need to ensure that they offer products that meet the quality expectations of customers. The spoilage of meat is a sensorial quality and may consist in the occurrence of off-odours and off-flavours or discoloration [13]. The off-odours resulting from bacterial activity determine their shelf-life. Since sensory analysis is very expensive and not always possible, developing automated sensing techniques able to ensure the safety and quality of meat products is a priority task and would benefit both producers and consumers. This is why many efforts are underway or have been conducted to develop different types of sensors for meat quality or safety applications [6]

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