PLUMS AND PRUNES
Plums come in many color varieties, from yellow to red to blue, and we also have the dried plums (prunes) that are black. The sweet and slightly acidic flavor of plums is contained within a soft meshy flesh. They belong to the stone fruit family that also includes apricots, cherries, and nectarines. The season of the plums coincides with that of the other stone fruits, and for the temperate climate countries falls between May and September, but can be extended in the warmer countries. Plums, as the other stone fruits, contain a good amount of vitamins A and C, as well as some dietary fibers, potassium and vitamin B2. They are also low on calories and can also be used (consciously or not!) as a laxative since their high content of sorbitol - a sweet alcohol that is also used as an artificial sweetener.
Nutritionally speaking, the combination of the strong antioxidants in plums is good to prevent cancer, cardiovascular diseases, and macular degeneration (bad eye vision), just to mention a few benefits. In addition, plums also contain phenolic antioxidants in pretty impressive amounts, especially when it comes to prunes (where the quantity becomes concentrated with water loss). The high amount of antioxidants in prunes also leads to a good preservative effect, and prunes can be stored as they are, without any additional chemicals. Lastly, as mentioned above, plums and prunes carry massive amounts of the laxative sorbitol and should therefore be eaten in moderate amounts.
There are many variants of plums available. Usually it's simplest to divide them into the European and Asian subgroups. Within the European group we have the French and the Italian plums, Reine Claude, the yellow-egg, as well as a number of other types. Common to them all is that they are often dried into prunes, although they can naturally be eaten fresh. The Asian plum varieties include Santa Rosa and elephant heart, although there are several other types on the market. Asian plums are normally not dried but eaten as they are. What is common to all plums is their ability to ripen after being harvested in their pre-ripeness stage. With ripening, the flavors within the plums develop and their flesh becomes soft.
When you buy plums, first of all try to do that when they are in season, that is from May to September. Look for soft fruits with an even softer tip. They should not be overly soft of course, because then they are overripened. As an alternative, you can go and look for pre-ripened fruits and ripen them at home. In this case, look for the more firm plums (although not too hard) and put them on the table to allow them to ripen over a course of a few days. And, in general, it is good to select the plums that have nice rich colors, are unblemished, and possibly have a little white "bloom" (a sign of good quality!).
Just a short note about oxalates: plums contain a substantial amount of the kidney stone-forming oxalates, which means that if you have troubles with kidney stones, then you should not consume too many plums. You can enjoy them from time to time though, unless your condition is really grave.