1. Evaluation of safety, quality and shelf-life of agro-food product using non-destructive optical and instrumental-sensory devices
Cristina Malegori
Department of Food, Environmental and Nutritional Sciences
(Università degli Studi di Milano, via Celoria 2, Milan, Italy)
Tutor: Prof. Ernestina Casiraghi; Co-Tutor: Prof Riccardo Guidetti
State of the Art
Visible-Near infrared (vis-NIR) and Near infrared (NIR) spectroscopy has proved to be one of the most efficient and advanced tools for process monitoring and product quality evaluation in food industry (Nicolai et al. 2007). In recent years, the availability of low cost miniaturized spectrophotometers has allowed the use of portable devices directly in field for monitoring the maturity of fruit (Guidetti et al. 2010). The versatility of hyperspectral imaging has built up its wide applications in food inspection and its potential has been successfully proved in the food industry (ElMasry et al., 2011). Concerning the systems and workplace safety, hyperspectral fluorescence imaging methods were utilized to evaluate the potential detection of pathogenic bacteria biofilm formations on different types of food contact surface materials (Jun et al. 2010). E-noses are emerging as an innovative analytical-sensorial tool to characterize the sensory comparison of food in terms of freshness, determination of geographical origin, seasoning (Buratti et al., 2004).
This PhD project will study the possible application of non-destructive optical and instrumental-sensory techniques to evaluate safety, quality and shelf life of agro-food product as well as the sanification of food plants. Spectroscopy, hyperspectral imaging and e-nose could play an important role in the assessment of both quality and safety of foods due to their rapidity, sensitivity and simplicity. These techniques will be used in combination on the same food matrix. A multivariate statistical approach is required, in order to extract information from the signals acquired. The development of simplified, portable devices will be the future of these research project.
Milestones
UNTIL NOW  literature research, development of the experimental plan, NIR and vis-NIR spectra acquisitions focusing on apples, grape and Valerianella fresh-cut. Acquisition of chemometric knowledges (course at UNIMIB, Professor Roberto Todeschini) to be applied to spectroscopy, multispectral and hyperspectral imaging using MATLAB® and its toolboxes (courses in Milan and Copenhagen, Professor Josè Amigo).
EXPERIMENTAL PLAN  non destructive tests on food matrices using multispectral imaging; laboratory testing of fruit and vegetable (quality and safety indices assessment) using traditional chemical methods, IR-spectroscopy, e-nose.
Evaluation of microbial growth (biofilm) on surfaces and identification of species using traditional RGB image analysis and hyperspectral imaging (Sapienza - Università di Roma), joined by microbiological analyses. Wavelength selection algorithm to develop on-line device for quality assessment of agro-food products.
EXPERIENCE ABROAD  a part of the experimental tests and the data processing will be carried out in Brazil (UNICAMP–Universidade Estadual de Campinas; UFPE–Universidade Federal de Pernambuco); during this experience the research project will focus on the evaluation of nutraceutical properties in typical Brazilian fruits using hyperspectral imaging.
Figure1: Gantt diagram
Selected reference:
Buratti S, Benedetti S, Scampicchio M, Pangerod E (2004) Characterization and classification of Italian Barbera wines by using an electronic nose and an amperometric electronic tongue. Anal Chim Acta 525:
ElMasry G, Wang N, Vigneault C (2011) Detecting chilling injury in Red Delicious apple using hyperspectral imaging and neural networks. Postharvest Biology and Technology. 52: 1-8.
Guidetti, R., Beghi, R., Bodria, L. (2010). Evaluation of grape quality parameters by a simple Vis/NIR system. Transactions of the ASABE. 53:
Jun W, Kim MS, Cho BK, Millner P, Chao K, Chan DE (2010) Microbial biofilm detection on food contact surfaces by macro-scale fluorescence imaging. Journal of food Engineering. 99:
Nicolaı BM, Beullens EB, Peirs A, Saeys W, Theron KI, Lammertyna J (2007) Nondestructive measurement of fruit and vegetable quality by means of NIR spectroscopy: A review. Postharvest Biology and Technology. 46(2): 99–118.