This dissertation explores the emerging field of food-derived carbon nanodots (CNDs), focusing on their synthesis, detection, occurrence in foods, and applications within the food and agricultural sectors. CNDs are fluorescent nanomaterials generated during thermal processing, yet their pathways of formation, dietary prevalence, and analytical detection have remained largely underexplored. By integrating model systems, real food matrices, advanced analytical tools, and sustainable valorization strategies, this work provides a comprehensive understanding of CNDs in the context of food science and nanotechnology. The first part of the research addressed the sustainable synthesis and characterization of CNDs from food-grade precursors. Screening six amino acids reacting with sucrose under Maillard conditions revealed excitation-dependent emission behavior, with glycine identified as the optimal nitrogen precursor yielding the highest fluorescence intensity. Gly-S-CNDs were thoroughly characterized as ~4 nm spherical, nitrogen-doped nanodots with blue fluorescence and abundant surface functionalities contributing to solubility and stability across a wide pH and ionic strength range. A second focus was the development and validation of robust detection methods for quantifying CNDs in complex food matrices. A fluorescence spectroscopy method was validated with excellent linearity and sensitivity (LOD ~0.14 mg/kg), confirming that CNDs are absent in raw dough but accumulate during baking, with markedly higher concentrations in bread crust than in breadcrumb. To further enhance selectivity, an HPLC-SEC-FD platform was established, enabling reliable discrimination of CNDs from overlapping fluorescent compounds such as melanoidins. This method achieved superior sensitivity, accuracy, and robustness, providing a practically superior tool for selective CNDs monitoring in complex food matrices. The third part of the study investigated the occurrence and formation mechanisms of CNDs in real food systems. CNDs were detected across major food categories including bakery products, beverages, chocolates, spices, cereals, and processed black foods, with concentrations ranging from several tens of mg/kg to approximately 3,860 mg/kg in coffee, depending on food type and processing intensity. A case study on coffee brewing demonstrated that processing parameters significantly affect CNDs yield, and that fluorescence is inversely correlated with caffeine content, suggesting caffeine-induced quenching. Controlled breadmaking experiments confirmed the influence of temperature and exposure time on CNDs accumulation. By synthesizing model CNDs from different precursor combinations, a unified formation framework was proposed, in which Maillard reactions, caramelization, pyrolysis, and wet-heat brewing all contribute to CNDs formation in foods. The fourth part systematically screened ten food-waste categories as CNDs precursors, finding that protein- and polyphenol-rich wastes produced the highest fluorescence yields, while citric acid co-treatment strongly enhanced CNDs formation. This established practical guidelines for maximizing CNDs production from food waste. Finally, this work demonstrated practical applications of food-derived CNDs. Gly-S CNDs were employed as a fluorescent probe for rapid, selective caffeine sensing in beverages, achieving a detection limit of 36.5 nM with good agreement with HPLC, outperforming reported CNDs-based caffeine sensors and confirming suitability for real world applications. Banana peel valorization was optimized using Central Composite Design and machine learning, identifying urea as the superior co-precursor and achieving a quantum yield of 40%. Mass ratio and temperature were identified as dominant factors, while predictive modeling significantly reduced experimental workload. In conclusion, this dissertation advances the fundamental understanding of food-derived CNDs, establishes reliable detection methods, and demonstrates their practical applications in sensing and waste valorization. It provides the first systematic quantification of CNDs across diverse food categories, confirms their formation through multiple thermal processing pathways, and highlights their potential as safe, functional nanomaterials. The findings contribute to both food safety research and green nanotechnology, aligning with principles of sustainable development and the circular bioeconomy.