HIGH PRESSURE HOMOGENIZATION ENHANCES PHYSICOCHEMICAL AND FUNCTIONAL PROPERTIES OF A PLANT-BASED BEVERAGE FROM PUMPKIN SEED AND PEA PROTEINS

The growing demand for plant-based foods has driven the development of beverages targeting consumers with dietary restrictions, such as dairy allergies or lactose intolerance, as well as those seeking sustainable and ethical alternatives to animal-derived products. Among plant proteins, pea protein is widely studied due to its favorable nutritional and functional properties. However, diversifying protein sources is crucial to enhance sustainability and valorize agro-industrial by-products. In this regard, pumpkin seed protein emerges as a promising option, being a nutrient-rich by-product also containing bioactive compounds. This study aimed to evaluate the effect of high pressure homogenization (HPH) on the physicochemical and functional properties of a plant-based beverage formulated with a blend of pumpkin seed and pea proteins, including its antioxidant activity, over storage. The beverage was sterilized for microbiological stability (121°C/15min) and subjected to homogenization at 30 MPa (conventional process) and 150 MPa (HPH). A non-homogenized sample (control) was prepared for comparative evaluation. After processing, the beverages were stored at 25°C for 60 days. pH, titratable acidity, color (CIELAB parameters), soluble protein content (Lowry method), and antioxidant activity (DPPH assay) were evaluated following standard procedures. pH (7.4) and titratable acidity (0.13% lactic acid) remained stable during 60 days of storage. At time zero, no significant color differences were observed between treatments. However, after 60 days, the non-homogenized sample exhibited greater ∆E compared to the homogenized samples (P<0.05). Soluble protein content increased in the sample processed at 150 MPa (up to 11.5 %) at time zero but declined over storage in all treatments (P<0.05). Antioxidant activity increased from 30.8% DPPH inhibition in the control sample to 40.4% in the 150 MPa treatment at time zero (P<0.05), likely due to the release of phenolics and bioactive peptides. Despite a decrease in antioxidant activity among all treatments after 60 days, the 150 MPa sample maintained the same activity as the non-homogenized sample at time zero (P>0.05). In summary, while homogenization at 30 MPa did not result in significant changes in the beverage’s physicochemical properties, high-pressure homogenization at 150 MPa probably reduced particle size, promoted the release of bioactive compounds and enhanced antioxidant activity. Furthermore, the increase of soluble proteins content may have contributed to greater physical stability of the beverage by enhancing protein-water interactions, which may help reduce sedimentation in plant-based beverages.