The 19th Gums & Stabilisers for the Food Industry Conference: Hydrocolloid MultifunctionalityHybrid gels are biphasic systems formed by conjugating hydrogels and oleogels. The mixture
of water-based and oil-based gels provides distinct and unique characteristics to hybrid gels,
and based on the structurant molecules and mixture ratio used during their production,
different textural and rheological properties can be obtained. Hybrid gels remain a very
recent topic concerning pharmaceutical and food applications and despite recent studies on
the use of hybrid gels for controlled delivery of compounds (pharmaceutical applications)
these structures are still under-studied in regard to their food application possibilities [1, 2].
To improve knowledge and expanding ways to use these systems, it is important to
understand how these gels behave regarding textural and rheological properties. Also, the
knowledge on their micro and nanostructure allows tailoring their properties and thus
maximizing their applicability in foodstuffs. We report on how the combination of a beeswaxbased
oleogel and a sodium alginate-based hydrogel influences the gel structural properties
at macroscopic (rheological and textural), microscopic (optical microscopy) and molecular (Xray
diffraction) levels. Different ratios of both hydrogel and oleogel were used in order to
evaluate the hybrid gels’ behaviour in terms of morphological, textural, rheological and
polymorphic properties. Differences regarding oleogel particles distribution in the hydrogel
matrix were noticed with the increase of oleogel fraction. A more disarranged distribution of
oleogel particles was observable for the 50:50 ratios of hydrogel and oleogel. X-ray
diffraction data unveiled that once polycrystallinity is reached (in hybrid gels) these patterns
remain persistent for all tested ratios. Oleogel showed d-spacings in the range of 3.74 to 8.04
Å. Hybrid gel samples (and hydrogel control) are semi-crystalline, displaying spacings
ranging in intervals of d (001) 6.99 – 7.18 Å; d (002) 3.09 – 3.23 Å and d (003) 2.45 – 2.46 Å,
respectively. The samples with increasing oleogel ratio revealed a firmness decrease and a
consequent reduction of spreadability values. Consequently, is observed less adhesivity for
these samples, due to a more pronounced disaggregated structure. For all hybrid gels a gellike
behaviour (G´ > G´´) was observed. Results showed that it is possible to modify the
hybrid gels’ rheological and textural behaviour by a controlled mixture ratio of oleogels and
hydrogels. This opens the possibilities of food applications for this kind of systems.info:eu-repo/semantics/publishedVersio
