high-brix foods are of course the most nutritious and they also have much more flavor.
For those who do not know much or anything about high v low brix foods these might help................ http://highbrixhome.com/files/BrixChart.pdf
The essence is in selective cultivation in achieving high-brix foods.
Brix is actually a measurement of the percent solids in a given weight of plant sap. It includes the content of sugars, vitamins, minerals, amino acids, proteins, hormones and other solids.
Brix varies directly with quality. For example, a poor, sour-tasting grape from depleted land can test for 8 or less Brix, whereas a full-flavoured delicious grape grown on rich fertile land can test for 24 Brix or higher.
Some voice a concern that high-brix foods have a higher Sugar content (which they do) but this should not be a reason in avoiding them as this will be the naturally occurring complex carbohydrate, as opposed to the refined and very unhealthy kind.
The problem is itís nearly impossible for consumers to distinguish between a nutrient-dense tomato, and a nutrient-
poor tomato on shelves. No financial motivation is provided either for producers to increase levels of nutrients in food.
Buy your own refractometer, but you will probably get kicked-out of Walmart in trying to use it!!!
Good you mentioned Kelp, which as you have said is a good choice for naturally-occurring sodium, plus a host of other nutrients.