Development of a Plant-Based Beverage with Tarwi (<i>Lupinus mutabilis</i>) Milk, Polysaccharides from Cushuro (<i>Nostoc sphaericum</i>), and Blueberry Extract

Plant-based milk alternatives are a rapidly growing niche in functional beverages, driven by demand from vegans and lactose-intolerant consumers. However, commercial options often have low protein content (<1.5%) and contain additives. Tarwi, native to the Andes, is rich in protein (45%), oils, and essential nutrients, while blueberries offer flavor and health benefits. Cushuro (<i>Nostoc sphaericum</i>), is an Andean microalga and contains high protein content and polysaccharides (42%). The objective of this research was to develop a plant-based beverage (PBB) with tarwi (<i>Lupinus mutabilis</i>), polysaccharides from cushuro (PC) and blueberry extract (<i>Vaccinium corymbosum</i>)(BE), compared with a control sample with carboxymethyl cellulose (CMC), a commercial thickening agent. The beverage was optimized and characterized using a design of rotatable central composite of surface methodology with nine formulations and four replicates in the center point. The effects of three independent variables were examined: tarwi milk (45% to 55%) and polysaccharides from cushuro (0.05% to 0.2%). The variable blueberry extract content was used as the differential factor between these two conditions. The response variables were protein (%) content and viscosity coefficient (mPa·s). The optimized beverage showed high protein (2.72%) content, viscosity coefficient (23.05 mPa·s), °Brix (2.5), pH (4.49), and acceptable sensory attributes using a 1-to-9-point hedonic scale with 67% positive acceptance. This powdered beverage complied with the Peruvian normative NTP 203.111.2021. Thereby, the plant-based beverage could be a nutritious alternative to functional plant-based beverages.