Search

Oleoresins are natural extracts obtained from plants and spices. Cinnamaldehyde and carotenoids are the main compounds found in cinnamon and paprika oleoresins, respectively, and exhibit pronounced antimicrobial and antioxidant potential. The coencapsulation of the two oleoresins can promote greater stability and synergism between them. Microencapsulation by spray chilling generates solid lipid microparticles when the atomized matrix crystallizes in contact with the cold chamber. This technique allows greater trapping of volatile compounds as they are more soluble in lipid materials. This work's main objective was to evaluate the synergistic antifungal effect between cinnamon and paprika oleoresins and their coencapsulation by spray chilling. Cinnamon:paprika (1:1 and 2:1) mixture showed a synergistic effect against Penicillium paneum and Aspergillus niger. The extracts also prevented the growth of microorganisms without direct contact with the agar. The microparticles showed a spherical surface and polymorphic β′-characteristic. Particles containing paprika oleoresin presented orange color, while samples with only cinnamon were off-white. The size distribution was multimodal with (D0.5) ranging from 13.6 μm for samples containing only cinnamon to 1152.7 μm for samples containing only paprika oleoresin. The storage temperature (5 and 25 °C) affected the release of cinnamaldehyde from the microparticles. Regarding the first 14 days, samples stored at 5 °C released more cinnamaldehyde compared to that stored at 25 °C. The concentration of carotenoids in the particles remained constant throughout the 49 days of storage for both temperatures. The coencapsulation of oleoresin from paprika and cinnamon made it possible to obtain a lipid coloring powder that has antimicrobial properties. [ABSTRACT FROM AUTHOR]

Moisture sorption isotherms and glass transition temperature ( T) of paprika oleoresin microcapsules were evaluated. Microcapsules were produced by spray drying using modified starch (Capsul) as encapsulating agent. The differential and integral thermodynamic functions of enthalpy and entropy were estimated from the sorption data for paprika oleoresin microcapsules. T of microcapsules conditioned at various water activities ( a's) were determined by modulated differential scanning calorimetry. The critical water content or water activity (RHc) was estimated from T values. Both a and T were used to determine the critical conditions for microcapsules storage. The GAB model provided a good fit to the experimental data. The point of maximum stability according to the minimum integral entropy (Δ S) was found at a = 0.241 at 35 °C, and at this point the system was within the glassy state. RHc was founded at a = 0.789 at 35 °C; all microcapsules stored at a's ≤ 0.627 were able to maintain their structural integrity without caking and stickiness occurring. The lowest carotenoid degradation of microcapsules during storage at 35 °C proceeded at a = 0.742, which was near to RHc; however, microcapsules stored at this a showed incipient caking and agglomeration. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]