The aim of this work was to evaluate the effect of process conditions (inlet air temperature, paste flow rate, and whey protein concentration) on the physical and physicochemical characteristics of the powder obtained from spray dried grape skin-whey protein concentrate mixture. The experiments were performed according to the 2³ factorial design, with repetition of the central point. The highest values of anthocyanin retention (> 92%) were obtained with the highest inlet air temperature (190 °C) and the highest whey protein concentration (15% (w/w)). The powder also showed solubility above 78.3%, and low values of moisture content, hygroscopicity and bulk density. Spray drying of grape residues, using whey protein as carrier agent, resulted in a powder with a high level of anthocyanin retention and of good quality, showing a potential application in food products. Therefore, the method indicates a possible alternative to change post-harvesting waste in a natural source of bioactive compounds.

Flaxseed oil is rich in polyunsaturated fatty acids, and its incorporation into food formulations is limited due to its hydrophobic nature and susceptibility to oxidation. The aim of this work was to analyze the effect of wall material mixtures (modified starch Capsul^® and rice and pea protein concentrate) on the efficiency of flaxseed oil encapsulation by freeze-drying, physical characterization, and determining oxidative stability. For the preparation of powders, four emulsions with an oil–wall material ratio of 1:3 were produced and characterized. The mass ratio between rice and pea proteins was fixed at 50–50%. The mass ratio of the protein-Capsul^® mixtures was varied by 0–100%, 10–90%, 20–80%, and 30–70%. Based on the creaming index results, all emulsions showed good stability after 24 h of analysis. The powders showed low moisture content (<3.23%), bulk density (<0.2659 kg/kg), and packed bulk density (<0.4389 kg/kg). Encapsulation efficiency decreased with increasing protein content, ranging from 93.40% (protein-Capsul^® ratio of 0–100%) to 18.26% (protein-Capsul^® ratio of 30–70%). However, the best oxidative stability results (smaller increases in the peroxide index values at the end of the stability experiments) were obtained for the powders containing the highest levels of vegetable proteins (protein-Capsul^® ratio of 20–80% and 30–70%, respectively).

This work investigated the influence of the OSA-modified starch, pea protein, and rice protein combination in the microencapsulation process of a blend of avocado and flaxseed oil (25–75%, w/w) by freeze-drying, focusing on emulsions and powders characteristics and oxidative stability. Four different ratios between the mixture of vegetable proteins (1:1) and the OSA-modified starch were analyzed, using a fixed ratio between the oils blend and the combined encapsulant agents of 1:3. Based on the creaming index, the separation of hydrophilic and hydrophobic phases was not observed. The results demonstrated a tendency to increase the droplet mean diameter with increased protein content (4.71–19.36 μm). An increase in the encapsulation efficiency was verified with the increase in the OSA-modified starch content (51.33–60.32%). Powders presented low moisture content and hygroscopicity, and an oxidative induction time value varying from 0.86 to 1.18 h. The increase in the vegetable protein content increased the powders’ oxidative stability, which could be associated with the antioxidant capacity of rice and pea proteins.