Enzyme cross-linked pectin microgel particles for use in foods

Injectable Microporous Annealed Particle Hydrogel Based on Guest–Host‐Interlinked Polyethylene Glycol Maleimide Microgels

“…The relationship among the hydrogel ultimate tensile strength, shear force, and particle size has been systematically investigated by others for pectin and agarose gels. [31,32] They show that particle size is dictated by the balance between shear force and ultimate tensile strength. This explains why smaller microgels were only able to be generated by emulsion: the shear force is applied before the hydrogel has completed crosslinking.…”

Emulsifying properties of sugar beet pectin microgels

“…Subsequently, 5 ml laccase was combined with 25 ml SBP stock solution via vortex mixing to give a final enzyme concentration of 0.1 mg ml − 1 laccase. When the two solutions were visibly well mixed, 'parent' hydrogels were allowed to develop quiescently in sealed containers for a minimum of 12 h by incubation at 25 • C. The elasticity of SBP hydrogels depends strongly on the SBP concentration in the gel (C GEL ) (Stubley et al, 2021). In this work, we have chosen to refer to the hydrogels, plus the microgels derived from them, as 'soft' when C GEL = 2.4 wt% and 'firm' when C GEL = 4 wt%.…”

“…In this work, we have chosen to refer to the hydrogels, plus the microgels derived from them, as 'soft' when C GEL = 2.4 wt% and 'firm' when C GEL = 4 wt%. The development and rheology of these gels has been described in detail earlier (Stubley et al, 2021) and these designations of soft and firm are based on yield stress and strain values of 84% and 460 Pa for C GEL = 2.4 wt% and corresponding values of 63% and 853 Pa for C GEL = 4 wt%. (These values were obtained in strain amplitude sweep tests at an angular frequency of 3.14 rad s − 1 , performed as described in section 2.9 below, i.e., as for measurements on emulsions).…”

“…Another interesting use of oxidative crosslinking of SBP is in the preparation of chemical hydrogels (Thibault et al, 1987) which are thermally irreversible (Khalighi, Berger, & Ersoy, 2020) and resist dissolution when placed in excess solvent (Stubley, Cayre, Murray, Torres, & Farrés, 2021). We recently exploited this technique to prepare sugar beet pectin microgels (SBPM), by homogenizing bulk SBP hydrogels (cross-linked via laccase) in the presence of excess solvent (water) to produce aqueous suspensions of microgel particles (Stubley, Cayre, Murray, & Torres, 2022;Stubley et al, 2021). Microgels are solvent swollen polymer networks of finite dimensions, a type of soft colloid demonstrating the properties of both polymers and particles (Dickinson, 2016;Lyon & Fernandez-Nieves, 2012).…”

“…Microgels are solvent swollen polymer networks of finite dimensions, a type of soft colloid demonstrating the properties of both polymers and particles (Dickinson, 2016;Lyon & Fernandez-Nieves, 2012). In general, microgel suspensions appear to be very promising for bulk rheology modification, as an alternative to polymer solutions (Adams, Frith, & Stokes, 2004;Stubley et al, 2022;Stubley et al, 2021). However, since SBP is surface active, it might be expected that SBPM would also be surface active and testing the ability of SBPM to stabilize O/W emulsions is the main topic that this paper seeks to address.…”