To advance carbon emission reduction in agricultural product processing and achieve low-carbon synergistic development between agriculture and the food industry, this study conducts full-chain carbon footprint accounting and emission reduction hotspot identification for concentrated citrus juice products. Against the backdrop of China's "double carbon" strategy, which targets peaking emissions by 2030 and carbon neutrality by 2060, the agricultural product processing sector faces unprecedented pressure to quantify and mitigate greenhouse gas emissions in operations. However, systematic carbon accounting for fruit juice products remains limited in existing literature, hindering evidence-based decarbonization policymaking and industrial transformation. This research aims to fill this critical knowledge gap by establishing a robust carbon footprint assessment framework tailored for concentrated citrus juice, identifying key emission hotspots distributed across the entire supply chain, and providing scientific support for developing precise agricultural carbon accounting systems and low-carbon production standards. The study employs the life cycle assessment (LCA) methodology in strict accordance with ISO 14040/14044 international standards for environmental management. The functional unit (FU) is defined as a standard 330 mL glass bottle of concentrated citrus juice ready for retail consumption. A comprehensive "gate-to-gate" system boundary is established, encompassing three sequential production stages: raw material preparation, juice processing, and finished product delivery to storage facilities. The global warming potential (GWP) is quantified using the professional eFootprint platform combined with the CML2016 impact assessment method, which enables comprehensive characterization of greenhouse gas emissions across all life cycle stages and material flows. To ensure result reliability and statistical confidence, the error propagation method is rigorously applied for uncertainty assessment, accounting for inherent variabilities in inventory data, emission factors, and process parameters across the production chain. This integrated methodological approach ensures both methodological rigor in scientific assessment and practical applicability for industrial carbon management decision-making. The results demonstrate that the carbon footprint of a single 330 mL bottle of concentrated citrus juice amounts to 1.01 kgCO₂e. From a detailed production process perspective, the blended juice processing stage emerges as the dominant GWP hotspot, contributing 55.53% of total emissions across the entire supply chain. Further upstream analysis reveals that high-fructose corn syrup production represents the second-largest driving factor, accounting for 28.25% of the total carbon footprint and highlighting the significant impact of raw sweetener ingredients. These findings indicate that emissions are heavily concentrated in two critical nodes: the energy-intensive mechanical and thermal processing phase and the agricultural supply chain of key sweetening ingredients. The uncertainty analysis confirms the robustness of these hotspot identifications despite minor fluctuations in underlying inventory data and parameter assumptions. Carbon emission reduction strategies for juice products should prioritize three key directions: clean energy substitution in processing facilities, low-carbon optimization of high-fructose corn syrup supply chains, and circular economy-based lightweight packaging solutions. This study provides a scientific foundation and methodological reference for constructing precise agricultural product carbon accounting systems. The findings can guide food enterprises in formulating targeted decarbonization roadmaps and support policymakers in developing science-based carbon labeling schemes and emission reduction regulations for the agricultural processing sector.