RELATIONSHIP BETWEEN BED MORPHOLOGY AND TECHNOLOGICAL PROPERTIES OF POWDERS: AN EVALUATION OF GRUMIXAMA (Eugenia brasiliensis Lamarck) SAMPLES OBTAINED BY FOAM-MAT DRYING

Foam-mat drying (FMD) is a technique applied to raw materials such as fruits, aiming to reduce perishability and expand commercialization/distribution possibilities. Grumixama (Eugenia brasiliensis Lamarck) is a native fruit that is highly perishable due to its high moisture content (≥86%), which makes FMD a promising alternative for obtaining stable ingredients. The principle of the technique involves preparing foams incorporated with foaming/stabilizing agents, which are then subjected to drying. Among the advantages of the technique, the reduction of processing time and the ease of reconstitution of the powders stand out, both associated with the formation of porous structures. In this context, the objective of this study was to apply FMD to grumixama and to evaluate the relationship between bed morphology and the technological properties of the obtained powders. For the foam formulation, 100 g of the edible fraction of grumixama, 0.5 g of carboxymethylcellulose, and 33 g of water were used. The mixture was homogenized with a mixer (500W/1min), added with 1.0% (w/w) soybean protein isolate solution, homogenized, and beaten in a hand mixer (500W/7min). The foams were spread on trays (20×20 cm/thickness: 0.7cm) and subjected to convective hot-air drying in an oven with air renewal (v: 0.53 ms⁻¹): S50 (50 °C/180 min), S60 (60 °C/140 min), and S70 (70 °C/90 min). The dehydrated beds were evaluated by Scanning Electron Microscopy (SEM). The powders obtained after grinding and standardization (0.5 mm) were characterized for Water/Oil Holding Capacity (WHC and OHC) and Water Solubility Index (WSI). The micrographs indicated that S50 and S60 exhibited smaller, more defined pores with fissures, whereas in S70, larger pores predominated, due to the higher drying rate. The WHC was higher than the OHC for all samples, indicating a hydrophilic character. The OHC ranged from 1.62–1.84 g oil/g dry solids, with no significant difference (p< 0.05). The WHC was highest in S60 (6.71 g water/g dry solids), followed by S50 (6.55) and S70 (5.90). The results for S70 were associated with pore morphology, which may have hindered water retention. However, the WSI was higher for S70 (42%), whereas S50 and S60 had WSI values between 36–37%, with no significant differences, indicating that faster drying resulted in more soluble materials. The results evidenced that bed morphology can directly influence the technological properties of the powders obtained by FMD, and different processing conditions can generate specific applications, thus enhancing the value of grumixama as a functional ingredient.