Tangerine peel-derived carbon dots as natural antioxidant and antimicrobial agents for extending the shelf life of precooked baby clam edible portion

• CDs were synthesized from peels of three tangerine cultivars (BM, CK, SNP) • BM-CDs showed the excellent UV-blocking abilities against UV-A and UV-B • SNP-CDs had higher antioxidant and antimicrobial activities than others • CDs could serve as a preservative for precooked baby clam edible portion (PBC-EP) • All CDs delayed lipid oxidation and reduced microbial growth in refrigerated PBC-EP Multi-functional properties of carbon dots (CDs) synthesized from tangerine peels with different cultivars [bangmod (BM-CDs), chokun (CK-CDs) and sai nam pung (SNP-CDs)] and their application in preserving precooked baby clam edible portion (PBC-EP) samples were investigated. The synthesized CDs had nanoscale in sizes ranging from ∼2.24 to 6.83 nm, and SNP-CDs showed the smallest size and most uniform dispersion. All CDs demonstrated strong UV-shielding ability. BM-CDs showed superior UV-A and UV-B blocking performance to others, mainly owing to its π-π* transition. In general, higher radical scavenging activity (RS-A) against ABTS was observed than that toward DPPH, with SNP-CDs displaying the strongest overall antioxidant capacity (P