Effect of Ultrasound on the Stability of Turmeric Oleoresin Microencapsulated in Gelatin‐Collagen Matrices

Abstract

This study evaluated the effect of sonication on the stability of turmeric oleoresin microcapsules produced by spray and freeze-drying using blends of gelatin-collagen as encapsulating matrices. Samples prepared with different wall matrix formulations presented solubility between 82.7 and 86.9%, yield above 88% and encapsulation efficiency between 17.41 and 56.21%. The wall matrix composed of 2% gelatin and 28% collagen (C2G28), which presented the highest yield (94.7%) and good encapsulation efficiency (42.83%), was adopted to investigate the effects of ultrasound in the emulsification step (C2G28US), to compare the performance of spray and freeze-drying, as well as to study stability of the microcapsules during storage under incident light. Ultrasound combined with spray drying resulted in the smallest particle size, according to SEM analyses and the highest curcumin retention (342.84 mg/g). Sonication also showed positive effects on product stability, with better curcumin color retention observed for spray-dried microcapsules. PRACTICAL APPLICATIONSEncapsulation of turmeric oleoresin by spray drying in protein matrices composed of gelatin and collagen hydrolysate was enhanced by using ultrasound in the emulsification step, which resulted in the smallest particle size, higher curcumin retention and greater color stability under light incidence. The produced curcumin capsules may be used as a food supplement or as a natural dye.

Turmeric oleoresin encapsulated by spray drying in maltodextrin/gelatin and starch/gelatin blends: storage stability and water sorption

“…In addition to the drying conditions, the composition of the encapsulant material also interferes with the spray drying performance. Zuanon, Malacrida and Telis (2017) found yield of 61.75 -65.07% for turmeric oleoresin encapsulated in gelatin-collagen, Ferreira et al (2016) obtained yield from 9 to 71 % for turmeric oleoresin encapsulated in starch/gelatin using the same spray dryer model and similar drying conditions.…”

“…In spray drying, the high temperature can disrupt the structural organization of the starch granules and facilitate the entry of water resulting in microparticles of high solubility. High values of solubility also were presented in turmeric oleoresin microencapsulated by spray drying using gelatin-collagen (96.8%), maltodextrin/gelatin (84 -98 %) and maltodextrin, gum arabic and modified starch (85.35 -99.25%) (Cano-Higuita, Rudke et al, 2019;Zuanon et al, 2017).…”

“…Other works reported total color difference of 6 (collagen-gelatin), 15.75 (maltodextrin/modified starch), 10.13 (gum arabic) and 7.69 (gum Arabic/maltodextrin/modified starch) in turmeric oleoresin encapsulated by spray drying after 35 days of storage at 25°C + light (Cano-Higuita et al, 2015;Zuanon et al, 2017). Turmeric oleoresin encapsulated by freeze drying using MG and SG showed higher ∆E values after storage of 35 days at -20, 25 + light and 60°C (Malacrida et al, 2013;, demonstrating that spray drying results in more stable capsules to color variation at these temperatures.…”

Ultrasound-Assisted Extraction and the Encapsulation of Bioactive Components for Food Applications

“…Using ultrasonic technology, the microencapsulation of turmeric oleoresin at a frequency of 20 kHz in gelatin-collagen matrices was carried out. The ultrasonication was performed in a double jacketed container with water circulation to keep the temperature at 40 • C [48]. According to the authors, encapsulating turmeric oleoresin with ultrasound technology at a frequency of 20 kHz proved successful.…”