From Crop Service International: http://www.cropservicesintl.com/ld_nutrient_dense.php
The goal of Nontoxic, Sustainable, Biological farming is to grow high Brix, high nutrient crops. Brix is a refractometer reading indicating the level of dissolved solids (mostly sugars and carbohydrates) contained in the juice being measured. The higher the brix reading the higher the sugars, mineral levels, specific gravity and true protein levels. This adds up to a sweeter tasting, more minerally nutritious food/feed with a lower nitrate and water content and better storage characteristics (less rotting). High Brix crops will produce more animal contentment and be more resistant to insects and diseases, resulting in decreased insecticide usage. Crops with a higher sugar content/brix reading will have a lower freezing point and be less prone to frost
damage. A bite of a 16 brix Bell pepper from a PA grower tasted sweet, almost like eating an apple. A bite from a 4 Brix bell pepper tastes somewhat bitter. Four brix string beans need sugar added to make them taste good enough for kids to eat yet four to five Brix vegetables are typical at your local supermarket.