USE OF NEAR INFRARED SPECTROSCOPY TO MONITOR THE EFFICIENCY OF OLIGOSACCHARIDES AS CRYOPROTECTANTS

M.I. SANTOS; C. ARAUJO-ANDRADE; E. E. TYMCZYNSZYN; A. GÓMEZ-ZAVAGLIA

Oxford

Congreso; XV European Conference on Biological Molecular Spectroscopy. Oxford. 25-30/8/2013.; 2013

Monitoring industrial bioprocesses requires methodologies able to provide complete information in a fast way, and if possible in real time. In this context, the potentiality of near infrared spectroscopy (NIR) has been deeply explored in the last fifteen years. The role of polyhydroxylated compounds as cryoprotectants is well known [1]. Among them, trehalose, sucrose and more recently prebiotics (i.e. galactooligosaccharides) have been reported as efficient cryoprotectants [2,3]. The aim of this work was to set up an experimental and analytical methodology to evaluate the feasibility of developing simple, accurate and quantitative models based on NIR and multivariate analysis [Principal Component Analysis (PCA) and PLS] to monitor the evolution of viable, damaged and/or dead bacteria along with the kinetics of growth of Lactobacillus delbrueckii subsp. bulgaricus subjected to dehydration using three different prebiotics (polyhydroxylated compounds) as protectants. The differences observed in the NIR spectra could be correlated with the bacterial stage of growth, and with the efficiency of each prebiotic as protectant. It was observed that prebiotics containing tri and tetra saccharides were more efficient than prebiotics with lower degree of polymerization and than disaccharide prebiotics. These results support the use of NIR to monitor fermentations in real time. This relevant tool is particularly valuable at an industrial level, where the safe of time represents an added value.