Characterization of oligosaccharides during the production process (WP2)

ESTEBAN GERBINO

Workshop; Workshop - Process eco-design: application on lactic acid bacteria preservation; 2019

PREMIUM European Union's Horizon 2020-INRA

Fructo and galacto-oligosaccharides(FOS and GOS, respectively) are attracting increasing interest as prebiotic functionalfood ingredients as they may confer health benefits on the host, mainly associatedwith the modulation of microbiota. However, their benefits go beyond theirprebiotic properties, as they are low caloric sweeteners, give a feeling ofsatiety, contribute to body weight control, relieve constipation, have a lowglycemic index and are not cariogenic. Therefore, GOS and FOS are increasinglyused in the formulation of dairy products, beverages, bakery products, and somesweets, converting them in functional foods. Moreover, they are extensivelyemployed in infant formula to stimulate the development of newborns microbiota.FOS are small chainoligosaccharides composed of fructose units linked by (2→1)-β-glycosidic bonds and a singleD-glucosyl unit at the non-reducing end. In most cases, FOS are mixtures ofshort chain oligosaccharides, namely 1-kestose [degree of polymerization (DP)equal to 3], nystose (DP4) and 1F-fructofuranosylnystose (DP5).GOS are then composedof a variable number of galactose units linked to a glucose unit. Thecomposition of GOS can vary quite markedly with respect to their degree ofpolymerization, which can range from two to eight monomeric units. The maincomponents of GOS are disaccharides other than lactose, trisaccharides (DP3) andtetrasaccharides (DP4), with higher-molecular-weight oligosaccharides in muchlesser proportions.As FOS and GOS can be incorporatedinto many products, their demand has exponentially increased worldwide overtime. From a technological point of view, these prebiotics can be produced eitherby enzymatic synthesis (by fructosyltransferase or β-galactosidaseenzymes) using disaccharides or other substrates as raw materials or by extractionand hydrolysis (hydrothermal process) from different natural sources mainlyfrom roots (of chicory, artichoke, yacon, dahlia or agave) and legume seeds (suchas soybean, lupin, lentil, chickpea, pea and cowpea). To the best of our knowledge, no environmentalstudy has been published with special focus on the environmental footprints ofdifferent production schemes of FOS and GOS.In this work, the assessment of theenvironmental impacts associated to the enzymatic synthesis and hydrolyticproduction of FOS and GOS was performed. To this aim, a Life Cycle Assessment(LCA)1 was undertaken toanalyse two scenarios based on different extraction routes considering sucrose,lactose, yacon potato and chickpea seeds as raw materials. On the basis ofexperimental results carried out at laboratory scale, the environmentalhotspots responsible of the largest environmental impacts were identified.This environmental methodologyconsiders all the resources (mass and energy balances) required to make aproduct, the wastes generated, as well as the environmental burdens associatedwith the product. In addition, this methodology can provide useful informationto stakeholders and policy makers on decision making of processes underdevelopment. The principles established by ISO standards (ISO 14040, 2006)were followed in this research study.