Some embodiments of food preservatives, methods of preparation thereof, and methods of room-temperature preservation, in the technical field of food preservation, are disclosed. In some embodiments, the food preservative includes chitosan, Chinese prickly ash oil, and astaxanthin. In other embodiments, the food preservative includes glycerol, acetic acid, and water. In further embodiments, the glycerol, the acetic acid, and the water are at a volume ratio of 5-30:5-25:915-985, and the chitosan and the water are at a mass-volume ratio of 5-20 g:915-985 mL. In some embodiments, the Chinese prickly ash oil, the chitosan, and the astaxanthin are at a volume-mass-mass ratio of 5-30 mL:5-20 g:0.01-0.06 g.

Lime-incorporated chitosan (LCh) beads are a non-toxic, environmentally friendly, and efficient preservative for food products, showcasing their superiority in microbial control, alcohol inhibition, color retention, and maintenance of physicochemical parameters. The all-natural LCh beads described here exhibit an on-par preservation performance with synthetic sodium benzoate at its maximum permissible limit in fruit juices. Additionally, the LCh beads offer the unique advantage of reusability, maintaining their preservation efficacy over multiple fruit juice preservation cycles, contributing to economic and environmental sustainability. The all-natural and biodegradable LCh beads exhibit comparable or superior preservation performance to synthetic preservatives like sodium benzoate at its maximum permissible limit in fruit juices. In light of the growing concerns about the harmful effects of synthetic preservatives, LCh beads present an eco-friendly and biocompatible solution, aligning with the increasing consumer demand for fresh and safe foods without chemically synthesized additives.