Establishing the Most Suitable Storage Conditions for Microencapsulated Allspice Essential Oil Entrapped in Blended Biopolymers Matrices

Abstract

The adsorption isotherms of allspice essential oil microencapsulated in biopolymers blend (whey protein concentrate [WPC], mesquite gum [MG], and maltodextrin DE10 [MD]) in different proportions (WPC17%-MG17%-MD66% w/w and WPC66%-MG17%-MD17% w/w) with wall-to-core material ratios of 4:1 were determined at 25, 35, and 40°C. The isotherms were fitted using the Guggenheim-Anderson-de Boer (GAB) model and the enthalpies and entropies, both differential and integral, were estimated by the Clausius-Clapeyron method. The minimum integral entropy was considered as the point of maximum stability where strong bonds between the adsorbate and adsorbent occurred, and water would be less available and likely to participate in spoilage reactions. The point of maximum stability was found between 13.79 and 15.11 kg H₂O/100 kg d.s. (corresponding to water activity, a _W , of 0.444–0.551) for the microcapsules with WPC17%-MG17%-MD66% w/w as wall material and 18.71–19.63 kg H₂O/100 kg d.s. (a _W  = 0.591–0.713) for the microcapsules with WPC66%-MG17%-MD17% w/w as wall material in the temperature range studied.

Keywords:

• Adsorption isotherms
• Biopolymers blends
• Differential and integral enthalpies and entropies
• Microencapsulated allspice essential oil

ACKNOWLEDGMENT

The authors thank Universidad Autónoma del Estado de México for financing this research through grant 2398/2006.

Notes

Values in the same column with different superscripts are significantly different (p < 0.05). M = microcapsule, WPC = whey protein concentrate, MG = mesquite gum, MD = maltodextrin DE 10.

M = microcapsule, WPC = whey protein concentrate, MG = mesquite gum, MD = maltodextrin DE 10.

Values in the same column with different superscripts are significantly different (p < 0.05) M = microcapsule, WPC = whey protein concentrate, MG = mesquite gum, MD = maltodextrin DE 10.