Application of spray drying, spray chilling and the combination of both methods to produce tucumã oil microparticles: characterization, stability, and ß-carotene bioaccessibility.

The aim of this work was to produce tucumã oil (PO) microparticles using different encapsulation methods, and to evaluate their properties, storage stability and bioaccessibility of the encapsulated ß-carotene. Gum Arabic was used as carrier for spray drying (SD), while vegetable fat was the wall material for spray chilling (SC) and the combination of the methods (SDC). Powders were yellow (hue angle around 80°) and presented particles with small mean diameters (1.57-2.30 µm). PO and the microparticles possess high ß-carotene contents (∼0.35-22 mg/g). However, some carotenoid loss was observed in the particles after encapsulation by SD and SDC (around 20%). After 90 days of storage, SDC particles presented the lowest degradation of total carotenoids (∼5%), while SD samples showed the highest loss (∼21%). Yet, the latter had the lowest contents of conjugated dienes (4.1-5.3 µmol/g) among treatments. At the end of simulated digestion, PO and the microparticles provided low ß-carotene bioaccessibility (<10%), and only SC increased this parameter compared to the pure oil. In conclusion, carotenoid-rich microparticles with attractive color were obtained through microencapsulation of PO by SD, SC and SDC, revealing their potential as natural additives for the development of food products with improved nutritional properties. The SC method stood out for providing microparticles with high carotenoid content and retention, high oxidative stability, and improved ß-carotene bioaccessibility.

Investigation on brewer's spent yeast as a bio-vehicle for encapsulation of natural colorants from pumpkin (Cucurbita moschata) peels.

Brewer's spent yeast (BSY) Saccharomyces cerevisiae has been explored as a bio-vehicle for the encapsulation of bioactive compounds and as a delivery system. The main objectives of this work were to encapsulate carotenoids from pumpkin peel extract using BSY as an encapsulating agent and to evaluate the influence of ultrasound treatment on the carotenoid incorporation, stability and release. The powders produced by atomization of the suspension of BSY in the extract from pumpkin peels showed physical and microbiological stability during storage, presenting low values of water activity (<0.406), moisture content (<7.0%) and hygroscopicity (<6.8 g per 100 g), characteristics of greatest importance for powder formulations. Regarding the chemical stability of the incorporated carotenoids, there was a decline in carotenoid content in the first 30 days (p ≤ 0.01), although stabilization was achieved up to the 75th day. The best retention of carotenoids (273.3 µg g-1 of particles) was obtained by applying ultrasound treatment before atomization, which probably led to the adsorption of carotenoids onto yeasts. Ultrasound also showed a positive effect on the color protection of powders during storage and on the protection of compounds under simulated gastrointestinal digestion. BSY released the carotenoids gradually during the digestion and higher carotenoid release occurred in the intestinal phase with bioaccessibility values of 26.9 and 30.3%. Yeasts are a suitable carrier material and show promising characteristics for technological application.

Microencapsulation of carotenoid-rich materials: A review.

Carotenoids are natural pigments that present several bioactive properties, including antioxidant, anticarcinogenic and provitamin A activities. However, these compounds are susceptible to degradation when exposed to a number of conditions (e.g. light, heat, oxygen), leading to loss of benefits and hampering their application in food products. Their hydrophobicity also makes incorporation into water-based foods more difficult. Microencapsulation techniques have been applied for decades to provide stability to carotenoid-rich extracts under typical conditions of processing and storage of foods, besides offering several other advantages to the use and application of these materials. This work reviews the recent advances in the microencapsulation of carotenoid-rich extracts, oils and oleoresins from varying sources, evidencing the technologies applied to encapsulate these materials, the effects of encapsulation on the obtained particles, and the impact of such processes on the bioaccessibility and release profile of carotenoids from microparticles. Moreover, recent applications of carotenoid-rich microparticles in food products are discussed. Most of the applied processes were effective in improving different aspects of the encapsulated materials, especially the stability of carotenoids during storage, resulting in microparticles with promising properties for future applications in food products. However, the lack of information about the effects of microencapsulation on carotenoids during processing of model foods, the sensory acceptance of enriched food products and the bioaccessibility and bioavailability of microencapsulated carotenoids reveals gaps that should be explored in the future.

Endogenous antioxidant properties of curcuminoids from Curcuma longa L. obtained by a single-step extraction/nanoencapsulation approach.

Curcuminoids found in turmeric have attracted attention due to their remarkable biological activity. Nanoencapsulation may improve their technological properties, but extraction and encapsulation procedures could be time-consuming and expensive when carried out separately. This work aimed to combine extraction and nanoencapsulation steps to obtain curcuminoids-polyvinylpyrrolidone (PVP) nanoparticles directly from plant rhizomes. This single-step procedure was evaluated by a Rotatable Central Composite Design (RCCD) and optimized using desirability functions, resulting in the optimal conditions of temperature (29.9°C), ethanol (99%), and PVP (15.38 mg). Nanoencapsulation allowed curcuminoids to exert scavenging activity against superoxide anions donors and hydrogen peroxide in an aqueous medium, despite their poor water solubility. Curcuminoids-PVP nanoparticles could be used to formulate nutraceutical foods as an adjuvant to the endogenous antioxidant defense systems protecting against cellular damage. PRACTICAL APPLICATION: Simultaneous extraction and nanoencapsulation of curcuminoids from turmeric (Curcuma longa L.) was studied in this work. The combination of two processes in one single step reduces production time and costs, enhancing the feasibility of curcuminoids microparticles application into foodstuff. Moreover, since most foodstuff presents water in their composition, increase of curcuminoids water dispersibility could facilitate their incorporation into food matrices and improve the use of their health benefits, as results from this research demonstrated that encapsulated curcuminoids were able to scavenge reactive oxygen species in aqueous medium, even though they are lipophilic compounds.

Evaluation of the in vivo acute antiinflammatory response of curcumin-loaded nanoparticles.

Curcumin is the main curcuminoid found in turmeric rhizomes and is a strong candidate to formulate foodstuff with specific properties. Among various bioactive properties of curcumin, its antiinflammatory activity is remarkable; on the other hand, its low water solubility leads to low absorption. Thus, new formulations need to be developed to improve its efficacy, and encapsulation is a promising alternative strategy in this regard. The objective of the present study was to obtain curcumin-loaded polyvinylpyrrolidone (PVP) nanoparticles and evaluate their acute in vivo antiinflammatory activity. Nanoparticles were obtained by complexation using the solid dispersion technique, and the characterization of nanoparticles showed that curcumin and PVP formed an amorphous solid solution. Encapsulated curcumin was colloidally stable in distilled water; this was attributed to the formation of hydrogen bonds between curcumin hydroxyl and PVP carbonyl groups. Rats were treated orally with single doses of curcumin and curcumin-loaded PVP nanoparticles, and antiinflammatory activity was evaluated by an experimental model of carrageenan-induced paw edema, myeloperoxidase (MPO) activity, and microcirculation in situ. Treatment with nanoparticles at 12.5 mg kg-1 significantly reduced the intensity of edema and MPO activity, whereas pure curcumin only presented a significant effect at 400 mg kg-1. Curcumin inhibited cell migration since rolling and adherent leukocytes were significantly reduced using nanoparticles at 50 mg kg-1 and curcumin at 400 mg kg-1. Compared to free curcumin, encapsulated curcumin was effective at lower doses; this might be due to the improved water affinity and colloidal stability of curcumin nanoparticles.

Production and characterization of curcumin microcrystals and evaluation of the antimicrobial and sensory aspects in minimally processed carrots.

Nontoxic conserving agents are in demand by the food industry due to consumers concern about synthetic conservatives, especially in minimally processed food. The antimicrobial activity of curcumin, a natural phenolic compound, has been extensively investigated but hydrophobicity is an issue when applying curcumin to foodstuff. The objective of this work was to evaluate curcumin microcrystals as an antimicrobial agent in minimally processed carrots. The antimicrobial activity of curcumin microcrystals was evaluated in vitro against Gram-positive (Bacillus cereus and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) microorganisms, showing a statistically significant (p < 0.05) decrease in the minimum inhibitory concentration compared to in natura, pristine curcumin. Curcumin microcrystals were effective in inhibiting psychrotrophic and mesophile microorganisms in minimally processed carrots. Sensory analyses were carried out showing no significant difference (p < 0.05) between curcumin microcrystal-treated carrots and non-treated carrots in triangular and tetrahedral discriminative tests. Sensory tests also showed that curcumin microcrystals could be added as a natural preservative in minimally processed carrots without causing noticeable differences that could be detected by the consumer. One may conclude that the analyses of the minimally processed carrots demonstrated that curcumin microcrystals are a suitable natural compound to inhibit the natural microbiota of carrots from a statistical point of view.