Agro-ecological and Technological Quality of Some Apples

Abstract

The aim of the study is to investigate cloudy apple juices, produced from 83 apple varieties, grown by the Institute of Agriculture in town of Kyustendil, Bulgaria for their main ecological and technological parameters, in view of their safety for the population and the possibilities for their use as raw material in the food industry. The study found, that the apples are environmentally friendly for the studied parameters. Technologically, there are varieties with the highest juice yields (over 70%) - Defloga, Ginger Gold, Gold Rush, Granny Smith, and Melrose. The most tasty and colored juices of fresh fruit and fruit flour are separated from the Florina, Free Redstar, Ginger Gold, Gold Rush, Golden Delicious, and Granny Smith. Some practically do not give juice and material for fruit flour with the applied method 100% cold-pressed apple juice, but they produce puree with high quality as the Belgolden, Braeburn, Charden, and Red Delicious. There were observed very stable approximate ratios between Conductivity, Total Dissolved Solids, and Salt content in the juices as follows: Cond./TDS=1.5, TDS/Salt=1.3, Cond./Salt=2. Retio between Total Sugar Content and Total Acidity - Brix/pH = 3-5, as the most tasty and with good color juices have ratio Brix/pH=4.

Agrogeological and mineralogical characteristics of the soil from experimental fields of the Institute of Agriculture-Kyustendil, Bulgaria

“…This particular adhesion of magnetite with carbonates marks secondary mineralization due to adsorption processes in the soil and speaks of the participation of magnetite in cation exchange processes in the soil. The mineral magnetite is also related to the microbial composition of the soil (Sotirov et al, 2020).…”