Encapsulation of Sorghum Leaf Red Dye: Biological and Physicochemical Properties and Effect on Stability.

The encapsulation of the 3-deoxyanthocyanidins (3-DXA) red dye, extracted from sorghum (Sorghum bicolor L.) leaves, was explored for food application. The extracts showed antioxidant activity at concentrations ranging from 803 to 1210 µg mL-1 and did not reveal anti-inflammatory or cytotoxic properties, indicating their potential for food application. Encapsulation was performed with two carrier agents (maltodextrin and Arabic gum) in different proportions (1:1, 2:1 and 1.5:2.5 (w/w)). The microparticles produced by freeze-drying and spray-drying were studied according to the concentration of the dye, the encapsulation efficiency, the process yield, the solubility and the colour of the powders. The dye extracts are released from the microparticles at different pHs. The variation in ratio composition of the 3-DXA encapsulation was assessed by principal component analysis (PCA) using data from ten physicochemical parameters. The results indicated that the maltodextrin at the 2:1 ratio had a higher dye concentration and total phenolic content (TPC) at pH 6. This ratio was selected to produce the microparticles by freeze-drying and spray-drying, and the particles were used in the temperature stability tests at pH 6. The results suggest that the freeze-drying process offers better protection to 3-DXA, with a degradation percentage of 22% during the heating period (80 °C for 18 h), compared to the non-encapsulated dye (48%). However, there were no significant differences between the two polymeric agents. The non-encapsulated 3-DXA was evaluated as control and lost 48% of the total colour with the same treatment. Red dyes from sorghum leaf by-products may constitute promising ingredients for the food industry and increase the value of this crop.

Strategies to reduce sodium levels in European seabass sausages.

Considering the increasing demand towards "ready-to-cook" processed seafood products, recognised as being potential contributors to high sodium (Na) intake by consumers, this study aimed to assess the effect of sodium chloride (NaCl) reduction on physicochemical, microbiological and sensory properties of European seabass (Dicentrarchus labrax) sausages stored in chilling conditions during 5 weeks. Three formulations were tested in comparison with a control (100% NaCl, CTR): (i) 50% NaCl+50% ME (oleoresins microcapsules) (F1); (ii) 50% NaCl+50% KCl (F2); and (iii) only 50% NaCl (F3). The NaCl reduction mainly affected the texture and the salty taste, resulting in softer and perceived as less salty sausages after processing. However, hardness differences disappeared after 5 weeks. It seems that an antioxidant protection was obtained in sausages formulated with oleoresins microcapsules. No or low growth of psychrotrophic and mesophilic bacteria was observed (≤2.40 log CFU/g). Decreasing NaCl content and/or partially replacing it (50%) by KCl or oleoresins microcapsules seem to be suitable solutions to reduce Na (30.9-36.3%) levels, while maintaining the chilled sausages quality for 5 weeks. The partial replacement of NaCl by KCl also allows obtaining a product richer in K (997.2 mg/100 g), which ingestion may contribute for a cardiovascular protective effect.

Encapsulation of oleoresins for salt reduction in food.

BACKGROUND: In our study, oleoresins were explored for their ability to replace the original ground spice and herbs with a standardized taste and aroma, and mask the salt reduction. In order to protect taste and aroma oleoresins from high temperature, and to improve their solubility in food matrices, encapsulation with inulin and maltodextrin was carried out from two mixtures of oleoresins using two drying processes (spray and freeze drying), thus allowing it to be used as an additive to reduce salt for convenience in the food industry. METHODS: The oleoresins experiment was conducted with two mixtures to apply to meat and fish. Oleoresins were obtained by solvent extraction, and the solvent was removed by evaporation, encapsulated into inulin and maltodextrin microcapsules, and powdered by spray and freeze drying. Physicochemical analyses were carried out using several methods (drying yields, water activity, solubility, hygroscopicity, color, encapsulation efficiency), and characterization of the microcapsules was done by scanning electron microscopy. The total phenolic compounds were quantified using the Folin-Ciocalteau method, and the chemical compounds present in the microcapsules were elucidated by high resolution mass spectrometry. RESULTS: Freeze and spray drying the microcapsules presented good quality products with high yields, high encapsulation efficiency and good solubility. The spray drying process can offer better applications for the food industry due to the more regular shape of the microcapsules. In addition, inulin microcapsules obtained by spray drying showed a more protective effect for flavonoid compounds in fish oleoresins, while maltodextrin microcapsules offered more protection for hydroxycinnamic acids in meat oleoresins. CONCLUSIONS: The present study shows an attractive encapsulation system for non-volatile compounds from oleoresins, which results in standardized taste and aroma products that can reduce salt in food systems with different compositions.