Recent explorations into cinnamaldehyde (CIN) have identified its potential as a natural preservative, particularly when incorporated into active packaging to enhance the shelf-life of fruits and vegetables. This study explores the use of cellulose nanofiber (CNF)-stabilized Pickering emulsions as a novel delivery system for essential oils, demonstrating broad applicability in food preservation strategies. We employ CNF as Pickering stabilizers to effectively emulsify and encapsulate CIN, investigating the influence of tannic acid (TA) concentrations on the stability of these emulsions. Results reveal that a TA concentration of 0.05 % significantly improves emulsion stability against centrifugation, freeze-thaw cycles, and thermal stresses. This enhanced stability is attributed to hydrogen bonding between TA and CNF, which fosters a uniform and robust network structure. Moreover, the incorporation of TA markedly boosts both the antioxidant properties and the bacteriostatic effectiveness of the CIN Pickering emulsion. Notably, DPPH radical scavenging efficacy escalated from 31.96 % to 93.82 %, and ABTS radical scavenging increased from 22.0 % to 86.31 %. We developed a functional coating by integrating carboxymethyl chitosan (CMCS) with the CIN Pickering emulsions. Application of this coating on mangoes under ambient conditions proved effective in minimizing weight loss, retarding senescence, inhibiting enzymatic activities, and consequently extending the fruit's shelf life.