Detection of Cheese Batches Exposed to Clostridium Tyrobutyricum Spoilage by near Infrared Spectroscopy

Abstract

Thirty-two batches of semi-hard cheese were produced in a pilot plant in an experimental design with pH, moisture and microbiological contamination as controlled variables. Near infrared reflectance spectra were taken every week during the ripening period of 11 weeks. Sensory properties were evaluated and the cheeses were analysed by chemical and gas chromatographic methods. The data were treated by soft independent modelling of class analogy. Generally it was possible by near infrared spectroscopy to identify cheese batches with developing defects caused by Clostridium tyrobutyricum. These were often identified before defects could be registered by sensory evaluations or by gas chromatographic analyses of free volatile acids.