Ultrasound-assisted gelation of β-carotene enriched oleogels based on candelilla wax-nut oils: Physical properties and in-vitro digestion analysis

This study investigated the effects of high-intensity ultrasound (HIU, 95 W, 10 s) on the physical properties, stability and in vitro digestion of beta-carotene enriched oleogels. Candelilla wax (3 wt%) and nut oils (peanut, pine nut and walnut oil) with or without beta-carotene were used to form oleogels. HIU improved the storage modules (G') of peanut, pine nut and walnut oleogels without p-carotene from 11048.43 +/- 728.85 Pa, 38111.67 +/- 11663.98 Pa and 21921.13 +/- 1011.55 Pa to 13502.40 +/- 646.54 Pa, 75322.47 +/- 9715.25 Pa and 48480.97 +/- 4109.64 Pa, respectively. Moreover, HIU reduced oil loss of peanut, pine nut and walnut oleogels without beta-carotene from 23.98 +/- 2.58%, 17.14 +/- 0.69% and 24.66 +/- 1.57% to 17.60 +/- 1.10%, 13.84 +/- 0.74% and 18.72 +/- 3.47%, respectively. X-ray diffraction patterns showed that HIU did not change the form of the crystal (beta-polymorphic and (beta'-polymorphic) but increased the crystal intensity. Polarized light microscope images indicated that all oleogels showed more visible crystals after HIU. After 120 d of storage, HIU decreased the degradation of p-carotene for peanut oil and walnut oil samples (the contents of beta-carotene in peanut and walnut oleogels without HIU after 120 d of storage were 897 +/- 2 mu g/g and 780 +/- 1 mu g/g, respectively, and those of sonicated samples were 1070 +/- 4 mu g/g and 932 +/- 1 mu g/g, respectively). Furthermore, HIU reduced the release of beta-carotene in intestinal digestion. In conclusion, HIU could improve the functional properties of wax-nut oils oleogels and their beta-carotene enriched oleogels.

Automated summary

The study showed that high-intensity ultrasound treatment can improve the physical properties, stability, and beta-carotene enrichment of wax-nut oil oleogels. Ultrasound increased the storage modulus and crystal intensity, decreased oil loss and beta-carotene degradation, and reduced the release of beta-carotene during intestinal digestion.