This study explored the use of fruit- and herb-based powders as fortifying agents in soy- and oat-based beverages. Developed using a New Product Development approach, the powders were derived from underutilized plants rich in bioactives but with limited sensory appeal. Formulations included powders from both widely available fruits, such as apple and pear, chosen for their accessibility and economic relevance, and less commonly consumed fruits, such as Japanese quince, rosehip, and rhubarb, which are often discarded due to sour or astringent flavors. Processing these into powders helped mask undesirable sensory traits and enabled incorporation into beverage matrices. Physicochemical analyses confirmed their technological suitability, while high polyphenol content indicated potential health benefits. Importantly, no process contaminants (furfural, 5-hydroxymethyl--furfural, and acrylamide) were detected, supporting the powders' safety for food use. The integrated application of an electronic tongue and nose enabled objective profiling of taste and aroma. The electronic tongue distinguished taste profiles across formulations, revealing matrix-dependent effects and interactions, particularly with trehalose, that influenced sweetness and bitterness. The electronic nose provided consistent aroma differentiation. Overall, the results highlight the potential of these underutilized plant powders as multifunctional ingredients in plant-based beverage development. They support product innovation aligned with consumer expectations for natural, health-promoting foods. Future work will include sensory validation with consumer panels.