Influence of foam mat drying on the nutritional and technological potential of fruits - a review.

The consumption of fruits and vegetables is strongly encouraged in the nutritional recommendations presented in national and international guidelines, which strongly advise the intake of these elements as part of a healthy diet. However, this type of food matrix has a low post-harvest durability, making it necessary to apply techniques that extend its shelf life. Among the methods that can be applied, drying acts as a unitary operation of wide use, presenting low operational cost, ease of handling and wide variation of procedural techniques. However, it still remains a methodology seen as "critical" in the food sector, especially when the maximum focus of efforts is to obtain a material of high quality, nutritional and sensorial. In this context, foam layer drying has gained recognition as an effective and low-cost technique, where foam porosity and higher surface area-volume ratio provide high heat and mass transfer rates, reducing process time and improving the physical-chemical quality of the final product. We provide information capable of elucidating that drying requires a large amount of energy for the operation, and that many studies are still needed in order to optimize the process and guarantee the economic, nutritional and functional viability of the final product.

Inclusion complexes of yellow bell pepper pigments with ß-cyclodextrin: preparation, characterisation and application as food natural colorant.

BACKGROUND: This work aimed to prepare inclusion complexes using yellow bell pepper pigments and ß-cyclodextrin by two different procedures (method A, ultrasonic homogenisation; method B, kneading), to characterise them and evaluate their colour stability in an isotonic beverage model. The extract/ß-cyclodextrin ratio was 1:2 for both inclusion methodologies evaluated. The formed extract-ß-cyclodextrin complexes and a physical mixture of extract and ß-cyclodextrin were evaluated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). RESULTS: Both methodologies resulted in good complex yield and inclusion efficiency. The colour indices L* (lightness), a* (green/red) and b* (blue/yellow) of isotonic drinks added with the complexes were measured during storage under irradiance (1400 lx) and in the absence of light at temperatures between 25 and 31 °C for 21 days. CONCLUSION: The complex obtained by inclusion method B promoted better colour protection for the beverage compared with the use of the crude extract, showing that the molecular inclusion of yellow bell pepper carotenoids can provide good results for that purpose. © 2017 Society of Chemical Industry.

Foam mat drying of Tommy Atkins mango: Effects of air temperature and concentrations of soy lecithin and carboxymethylcellulose on phenolic composition, mangiferin, and antioxidant capacity.

In this study, foam mat drying was applied to Tommy Atkins mango. Using a multifactorial design, the effect of soy lecithin (L) and carboxymethylcellulose (CMC) used as foam stabilizers (0-1.50g/100g), as well as temperature (T) (53-87°C), on phenolic content and antioxidant capacity of mango were evaluated. Mango pulp contains antioxidant, such as mangiferin, that can be utilized in foods to enhance their functional properties. Our results indicated that L and T had negative effects (p<0.05) on the phenolic content and antioxidant capacity, whereas CMC had a positive effect (p<0.05). Increasing the total amount of phenolic compounds present in dried mango contributed to the higher antioxidant capacity after the drying process. This study concluded that a drying T of 80°C, and a concentration of 0.30g/100g of CMC and L are optimal for increased retention of phenolic compounds and antioxidant capacity.