What is more important, garden cress wasn't affected at all by pests.
This is the yield of ~3m^2 of cress, more than a Kg of seeds:
Recovery of seeds is easy and pretty efficient: step over the plants with thick socks, remove the stalks and use a sieve to separate seeds from most chaff. The rest can be blown away by winnowing.
They are pretty nutritious, but their greatest value I think lies in the oil content, up to 22% in weight. The oil composition in term of fatty acids is mostly oleic acid (~30.6%) and linolenic acid (~29.3%), erucic acid is present and can be used for lighting and cooking. Gamma and delta tocopherols are present at ~1422ppm and ~356ppm respectively (relatively high concentrations).
Another source (http://cat.inist.fr/?aModele=afficheN&cpsidt=22574870) shows this:
alpha linolenic acid 34%
oleic acid ~22%
linoleic acid ~11.8%
eicosanoic acid ~12%
palmitic acid ~10%
erucic acid acid ~4.4%
arachidic acid ~3.4%
stearic acid ~2.9%
The oil is described as being fairly stable and with a high alpha linolenic acid content.
Sounds good. After the oil has been extracted you are left with starches, proteins and a fine mustard flavour.
Of course I don't plan to extract the oil only for food and lighting, its main purpose is lubrication of machines and engines.
On a side note, just pressing the seeds is not enough, the seed actually has to be crushed to efficiently extract the oil.
These seeds, by the way, will be sown again next year on a larger scale;
by july they will be ready.
