Evaluation of PTR-MS analysis as rapid and non invasive tool for quality control in agroindustry: the effect of storage and packaging on anhydrous milk fat

The growing awareness of consumers for food quality posed new challenges to the quality control (QC) programs of agroindustry. The reliability in sensory and performance experiences of a product has been recognized as an important feature of product quality [1]. Thus, assuring the quality of products on a sensory basis is a fundamental corporate goal. However, sensory analysis, due to its high costs in terms of both time and resources, is not always feasible and adaptable to the high number of samples and fast decision times required by industry [2]. To answer to these needs, new rapid and non-invasive instrumental methods have been developed in the last years. Among the different approaches, analyzing the volatile organic compounds (VOCs) of the different matrixes seems the most promising since VOCs have a key-role in defining food flavor and aroma [3]. For long time gas chromatography (GC) has been the reference method but in the last years, new direct injection mass spectrometry methods have been developed in order to improve time resolution leading to high sensitive and faster analysis. Proton-transfer reaction mass spectrometry (PTR-MS) is one of these techniques. Based on proton transfer from a protonated reagent, usually H3O+, it implements efficiently a soft chemical ionization that makes this technique suitable for rapid characterization of food products [3]. PTR-MS and other techniques have been widely used in different researchers to investigate the different flavors and off-flavors originating from dairy ingredients leading to the identification of more than 230 VOCs [4-6]. The aim of this research was to evaluate PTR-MS as a rapid tool for the quality control of anhydrous milk fat (AMF). AMF usage in pastry, confectionery and ice-cream industry, is rapidly increasing due to its convenient features. The effect of different type of packaging – Bag-in-Box (BIB) and cardboard packages with a layer of plastic film (CT) – on the volatile profile and the quality of AMF has been investigated during a shelf life of 8 months at refrigerated storage (4°C). AMFs were valuated both during shelf life and accelerated shelf life (ASL) where AMF was exposed at 50°C for a total of 11 days.