Effect of edible protein-wax coating on post-harvest stability of brussels sprouts stored under simulated commercial storage conditions

Abstract

The washed Brussels sprouts heads were coated through dipping in a coat, i.e. in an aqueous solution of pea protein (10 % w/w), candelilla wax (2 % w/w), and sorbitol (4 % w/w). The coated and uncoated (control) vegetables were stored in the simulated storage conditions (~20 °C in a relative humidity of 50 %) for 10 days. The quality assessment of Brussels sprouts comprised the determination of: mass loss, contents of ascorbic acid, polyphenols and chlorophyll, polyphenol oxidase activity (PPO), colour, texture, and sensory properties. It was evidenced that the coating of Brussels sprouts by protein-wax coating resulted in a significant reduction in mass loss, vitamin C, polyphenols, and firmness during storage, as well as limited the softening of the vegetables. However, the presence of the coating had no effect on the PPO activity and on the content of chlorophyll pigments. The colour measurements proved that during the final stage of storing, the coated vegetables were significantly lighter and more yellow compared with the control samples. A sensory analysis performed on the 4th day of storage showed that the coating of Brussels sprouts favourably impacted their overall appearance, firmness, and gloss, but slightly deteriorated their odour. After 4 days of storage, the sensory quality of Brussels sprouts, both in coated and uncoated samples, decreased below the acceptable level. The results obtained prove that the coating using the emulsion suggested can impact the course of some physiologic and biochemical processes in the Brussels sprouts, which affect their commercial and consumption quality.