FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Effect of edible protein-wax coating on quality of cold-stored broccoli


In the production of minimally processed fruits and vegetables (MPFV), the raw material is trimmed, peeled, washed, and cut. Therefore, no pre-treatment of fruits and vegetables at home is necessary and it is possible to quickly prepare a highly nutritionally valuable meal. However, tissue damage occurring during the processing of raw materials is the cause of high perishability of MPFV. To ensure the adequate quality and safety of minimally processed foods, it is required to maintain the highest standards of hygiene in food production and to keep products under the refrigeration conditions. It is also necessary to use additional methods of food preservation. The objective of this study was to investigate the possibility of using protein-wax coating to protect the quality of minimally processed broccoli. The broccoli heads were washed, cut in small parts, and coated through double dipping in an aqueous solution of the pea protein (10 % w/w), candelilla wax (2 % w/w), and sorbitol (5 % w/w). The coated and uncoated (control) vegetables were stored at 4 ºC in a relative humidity of ≈90 % for 21 days. The quality assessment of broccoli comprised the measurements of mass loss, content of ascorbic acid and chlorophyll, titratable acidity, pH, colour (CIE L*a*b*), and texture. It was evidenced that the coating of broccoli heads made it possible to significantly reduce the rate of loss of vitamin C, to cut the increase in acidity, and to limit a firmness loss in inflorescences during storage. However, the edible coating had no effect on reducing the mass loss and chlorophyll content. After the coating process completed, the colour of the surface of broccoli florets became darker. During the final stage of storing, the coated vegetables were significantly less yellow compared with the control samples. It was proved that the coating impacted some physiological and biochemical processes appearing allimportant regarding the commercial and consumption quality of broccoli. The ineffectiveness of coating in preventing loss results, most probably, from storing those vegetables under the conditions of high relative air humidity.


broccoli, edible coatings, pea proteins, candellila wax, cool storage quality