Controlled ethylene-releasing from V-type starch coated with sodium alginate for banana ripening via changing the humidity of environment

摘要

A carrier of storing and releasing ethylene was prepared using V-type starch (VS) or cross-linked VS as core and sodium alginate (SA) as shell. Fourier Transform InfraRed spectra revealed that the VS was successfully crosslinked and its stability in water was enhanced. Scanning electron microscopy (SEM) images confirmed that ethylene was encapsulated into VS or cross-linked VS and then coated with SA-Ca2+ matrix to form close-knit beads. The SA beads contained 0.48-0.67 mol ethylene per Kg starch and maintained a very slow ethylenereleasing rate at 4 degrees C for 7 d in a dry storage condition. SA shell absorbed the water from the air and swelled after being exposed to an environment with certain humidity, triggering a stable release of ethylene within 7 h. In the ripening process, banana treated with 30 mg ethylene carriers in a 2.5 L container had a delayed maturation compared to the pure ethylene treatment along, and finally, ripening effect of carriers was equal to 10 nmol L-1 ethylene gas. This carrier can accomplish stability gas storage in dry condition, precisely controlled and targeted applications of ethylene under humidity ambience for agricultural applications.

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