Spruce galactoglucomannans inhibit the lipid oxidation in rapeseed oil-in-water emulsions

Authors: LEHTONEN, MARI - University Of Helsinki; TERASLAHTI, SUVI - University Of Helsinki; XU, CHUNLIN - Abo Akademi University; Yadav, Madhav; LAMPI, ANNA-MAIJA - University Of Helsinki; MIKKONEN, KIRSI - University Of Helsinki

Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2016
Publication Date: 3/5/2016
Publication URL: http://handle.nal.usda.gov/10113/62211
Citation: Lehtonen, M., Teraslahti, S., Xu, C., Yadav, M.P., Lampi, A., Mikkonen, K.S. 2016. Spruce galactoglucomannans inhibit the lipid oxidation in rapeseed oil-in-water emulsions. Food Hydrocolloids Journal. 58:255-266.

Interpretive Summary: The need to add value to low value by-products obtained from agricultural products processing and mechanical pulping of wood has prompted us to develop flavor stabilizers for soft drinks. Some natural flavors in soft drinks are derived from essential oils, and they are susceptible to oxidation during long term storage to form undesirable products. This lipid (oil) oxidation leads to the development of off-flavor (rancidity), which are not acceptable to consumers. Two new flavor stabilizers were identified in this study. Both are polymers with the amazing property to bind oil flavor and keep their tiny droplets dispersed in the drink. During the stabilization of oil-droplets, they also prevent their oxidation and avoid the development of off-flavor during long term storage. Our studies have clearly shown that the developed flavor stabilizers have remarkably slowed the amount of hydroxyperoxides (oxidation product of oil) during 8 days storage. The amount of volatile oxidation products was also negligible until 11 days storage in the beverage emulsions studied. These two polymers: arabinoxylan and galactoglucomannan are prepared from the low value by-products of corn wet milling process and spruce mechanical pulping respectively. Thus these findings will be useful for commercial manufactures who are trying to develop new commercial products based on corn fiber and waste obtained from spruce pulp milling industries. Commercialization of these materials will provide new uses for agricultural by-products and more revenue for farmers, processors and manufacturers of agricultural materials.

Technical Abstract: Oil-in-water emulsions are functional and industrially valuable systems, whose large interfacial area makes them prone to deterioration, due in part to as the oxidation and oligomerization of polyunsaturated fatty acids. Spruce galactoglucomannans (GGM), wood biomacromolecules abundantly available from the by-product of emerging future forestry biorefineries, were characterized as novel, bio-based and sustainable stabilizers against lipid oxidation in rapeseed oil-in-water emulsions. The formation of hydroperoxides, volatile oxidation products, and lipid oligomers were followed in emulsions during accelerated storage at 40 degrees C for two weeks. The free and bound phenolic residues associated with plant polysaccharides were quantified to evaluate the oxidation pathways of emulsions stabilized with GGM and their carboxymethyl derivatives (CMGGM), in comparison with the “gold standard” food stabilizer, gum Arabic (GA) and its promising replacement, corn fiber gum (CFG). GGM and CMGGM efficiently inhibited and altered the pathways of lipid oxidation of rapeseed oil. GGM showed exceptional capacity to inhibit the lipid oxidation and act as multifunctional stabilizer, enhancing both the physical and chemical stability of emulsions.