Plant sweetness, taste, and fragrance are critical determinants of sensory quality in fruits,flowers, and leaves, influencing ecological interactions, consumer preference, and crop value.These traits emerge from complex biochemical and physiological processes linking primarycarbon assimilation with secondary metabolite biosynthesis and loss. While extensive molecularand biochemical research has elucidated individual pathways involved in sugar accumulation andvolatile organic compound (VOC) synthesis, an integrative systems-level framework capable ofexplaining whole-plant sensory variation across environmental conditions remains limited.This study proposes a phenomenological Plant Sweetness–Taste–Fragrance Energy Framework,grounded in mass balance, absorption–loss dynamics, and metabolic allocation theory. Theframework conceptualizes sweetness, taste, and fragrance as emergent outcomes of absorbedresource supply, effective metabolic conversion capacity, secondary metabolite synthesis, andtranspiration-driven loss. A set of linked equations is introduced to describe (i) resourceabsorption and biomass accumulation, (ii) effective biological mass and absorption–conversioncapacity, (iii) a normalized fragrance energy index, and (iv) a refined rate expression integratingradiation input, stress modifiers, and compound-specific contributions.Importantly, the framework explicitly distinguishes between physical energy (joules) andbiological energy activity indices, avoiding thermodynamic inconsistency while preservingphysiological interpretability. The proposed approach is consistent with established conceptssuch as net primary production, relative growth rate, and aroma retention efficiency, and alignswith extensive empirical evidence from horticultural and crop science. By integrating absorption,metabolic allocation, and loss processes into a single interpretive structure, this work provides ascientifically defensible and flexible tool for understanding why sweetness and fragranceintensify under optimal conditions and fade under stress. Please check the attachment for details