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The use of carotenoids in foods is limited due to their poor solubility in water-rich matrices, and the nanoencapsulation emerges as an alternative to allowing the solubilization and to protect the carotenoids against degradation. The aims of this study were to produce, by the interfacial deposition of the preformed polymer, to characterize, and evaluate the stability of nanocapsules obtained from a blend of β-carotene, α-carotene, and lutein (BALNs) and nanocapsules of synthetic β-carotene (BNs). The encapsulation efficiency, transmission electron microscopy, and the logarithm of the distribution of the coefficient of the BALNs and BNs, with 26 μg/mL of carotenoids, were performed after preparation. During 100 days of storage (4°C) for the BALNs and BNs, the carotenoids retention, hydrogen potential, color, particle diameter, and the zeta potential were analyzed. The z-average and zeta potential after 100 days of storage for the BALNs and BNs were, respectively, 166.53 ± 4.71 nm/−18.37 ± 2.06 mV and 190.90 ± 7.87 nm/−9.08 ± 1.23 mV. At the end of storage, the β-carotene content was 67.62 ± 7.77 % (BALNs) and 11.69 ± 1.65 % (BNs). The βcarotene retention in the BALNs was higher than in the BNs probably due to the synergism that occurs among the compounds. Regardless of the decrease in the pH values and the b* coordinate, the formulations of the BALNs and BNs were considered physically stable during the storage. Nevertheless, beyond the physical stability, the BALNs presented a satisfactory carotenoid retention at end of storage.

Lipid-core nanocapsules loaded with ␤-carotene and ␣-carotene, and lutein (NCs) were produced with monomodal particle size distribution. Their mean diameter was 151.33 ± 5.03 nm (D 4,3) and 180.30 ± 0.70 nm (z-average), zeta potential was −22.63 ± 0.52 mV, and pH was 3.21 ± 0.04. The stability of NCs was studied under different simulated industrial treatments, such as thermal and ultraviolet (UV)-visible light treatment. Regardless of the temperature and incubation time of the samples, higher carotenoids retention (%) was observed in NCs than ethanol extract (EE) (under UV-vis light treatment) and higher carotenoids retention (%) was observed in NCs compared to EE and data already published on the stability of non-encapsulated carotenoids (under thermal treatment). In addition, NCs when exposed to UV-vis light treatment had higher activation energy and lower constant rate (k) than EE. In conclusion, nanoencapsulation offers greater stability to the ␤-carotene, ␣-carotene, and lutein upon exposure to conditions similar to those used in the food processing (heat) and storage (UV-vis light).

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Background: Ultraviolet B (UV-B) radiation is a promising and environmentally friendly technique, which in a low flow rate, can induce bioactive compound synthesis. This work aimed at evaluating the effectiveness of post-harvest UV-B treatment in order to improve carotenoid content in climacteric fruits like persimmon and guava fruits. Methods: The fruits were harvested at commercial maturity and placed into climatic chambers equipped with UV-B lamps. For control treatment, the UV-B lamps were covered by a benzophenone film, known to block the radiation. This radiation was applied during 48 hours and fruits were sampled at 25, 30 and 48 hours of each treatment. HPLC analysis was performed to separate and identify carotenoid compounds from fruit skin after a saponification process. Results: Fruit from 30 hours treatment began to present a carotenoid accumulation since the majority of analyzed compounds exhibited its synthesis stimulated from this time on. In persimmon skin, it was observed that the maximum content was reached after 48 hours of UV-B treatment. Conclusion: These results suggest that this post-harvest UV-B treatment can be an innovative and a viable method to induce beneficial effects on guava and mainly on persimmon fruit.

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