Investigation of the effect of the amount of film-forming coatings based on natural biopolymers on the quality characteristics of grape berries

¹ Federal State Budget Scientific Institution «North Caucasian Federal Scientific Center of Horticulture, Viticulture, Wine-making», 39 str. 40 Let Pobedy, Krasnodar, 350901, Russia
² Krasnodar Research Institute of Agricultural Products Storage and Processing – branch of FSBSO “North-Caucasian Federal Scientific Center of Horticulture & Viniculture”, st. Topolinaya alleya, 2, Krasnodar, 350072, Russia

^* Corresponding author: yakovleva_yy@mail.ru

Abstract

Post-harvest losses of grapes during prolonged storage in refrigerated chambers are mainly associated with dehydration and darkening of stems, wilting of berries and the development of mold. As a result of the physiological processes in the berries, a sufficiently humid environment is created, which contributes to the development of microbiological spoilage. To combat this phenomenon, it is recommended to use natural biodegradable polymers, which prevent the deterioration of quality characteristics by creating a semi-permeable protective barrier. In this regard, the purpose of the study was to determine the optimal dosage of film-forming solutions for treatment of grapes. For this, samples of grapes of the Kishmish Luchistyi variety were prepared with an applied to the surface coating layer of two types: potato starch/gelatin/glycerin/ natamycin and chitosan/sodium alginate/glycerin/natamycin at a biopolymer ratio of 50/50%, with the addition of 1.3% glycerin and 0.3% natamycin. Based on the identified dependence of the weight loss and the value of the resistance of berries to the pressure force on the storage time and the amount of film-forming coating, the optimal amount of film-forming coating required to treat 1000 grams of berries is substantiated – 50 ml.