Milk fat nanoemulsions stabilized by dairy proteins.

Droplet size, polydispersity, physical and polymorphic stability of milk fat nanoemulsions produced by hot high-pressure homogenization and stabilized by whey protein isolate (WPI pH 4.0 or 7.0) or sodium caseinate (NaCas pH 7.0) were evaluated for 60 days of storage at 25 °C. Smaller droplets were observed for the NaCas pH 7.0 nanoemulsion, which also showed a lower polydispersity index, resulting in a stable emulsified system for 60 days. On the other hand, the nanoemulsion with bigger droplet size (WPI pH 4.0) showed reduced stability, probably due to the pH near the isoelectric point of the whey proteins. The nanostructured milk fat exhibited the same melting behavior as the bulk milk fat, with a balance between liquid and crystallized fat, and crystals in polymorphic form ß'. This could be an advantage concerning the application of the system for delivery of bioactive compounds and improvement of the sensory properties of fat-based food. In summary, nanoemulsions stabilized by NaCas (pH 7.0) showed higher kinetic stability over the storage time, which from a technological application point of view is a very important factor in the food industry.

Characterization of baru nut (Dipteryx alata Vog) flour and its application in reduced-fat cupcakes.

Baru is a native specie from the Brazilian "cerrado" with interesting nutritional and sensory characteristics. The aim of our study was to characterize baru nut flour (BF) and to explore the possibility of producing reduced-fat baru cupcakes. Four different cupcake formulations were produced wheat flour (WF) containing 30% BF with reductions of 50 (F1), 75 (F2) and 100% (F3) margarine, compared to a control with 100% WF and 100% margarine (FC). BF showed 2.76% moisture, 19.2% proteins, 40.8% lipids, 3.05% ash and 18.51% dietary fiber. The substitution of wheat flour with 30% BF increased the mixing tolerance index and resistance to extension in the rheological analyses; however, these changes did not greatly influence cupcake quality. Firmness was the parameter most affected during shelf life, with statistically significant differences between the formulations. The cupcakes prepared with the blend of 70% WF + 30% BF and with fat reductions (F2 and F3) can be considered "light", with the reduction of more than 30% margarine and a significant reduction of trans fatty acids. In the sensory analysis, formulation F2 obtained good acceptance scores.