Quality of frozen semi-finished products from pear fruit for the application of edible coating

The article presents the results of studies of the quality of frozen semi-finished products from pears with edible pectin coating depending on the concentration of the pectin solution and the storage time. Frozen semi-finished products were produced from Duchesne pear fruits according to the generally accepted technological instructions by cutting the fruits into 20x20 mm particles, followed by blanching in a 0.1 % citric acid solution at 85 °C for 2–5 minutes and drying. The prepared pear particles were immersed in a pectin solution with a concentration of 1, 2, 3, 4, 5 % for 1 min, followed by drying. Semifinished pear products were frozen at a temperature of minus 30 ± 1 °C, packed in plastic film bags weighing up to 0.5 kg and stored for six months at minus 18 °C. The quality of the products was assessed by changes in physical and organoleptic parameters. The cryoresistance of frozen semi-finished pear products ranged from 93.5 % to 95.7 %. A reliable dependence of the cryoresistance of frozen semifinished products on the concentration of pectin solution and the duration of storage was established, with the maximum value of the studied indicator in samples coated with a 5 % pectin solution and its decrease during storage. The weight loss of semi-finished products during freezing amounted to 1.5–2.1 % by weight, with maximum losses in uncoated semi-finished products, and during storage – 0.5–0.6 %. The dependence of semi-finished products weight loss on the presence of a coating was proved, with maximum losses in the control during freezing. A significant effect of the coating on the organoleptic quality indicators of semi-finished products was found, in particular, improvement of appearance, consistency and color with a maximum score of 4.4 points in samples coated in a 5 % pectin solution. The application of edible pectin coating on pear semi-finished products before freezing contributed to an increase in their cryo-resistance by 0.5–2.5 %, and the overall organoleptic score by 0.2–0.6 points with 0.1–0.6 % lower weight loss. Key words: edible coating, freezing, semifinished products, quality, cryo-resistance, weight loss.