I’ve had a few customers ask about the nutrition data for oca, which set me on a search. I was surprised that it is not all that easy to come by, as it seems like a fairly popular crop in New Zealand, but I didn’t turn up much. The main source that I found was a paper titled Nutritional Evaluation of Three Underexploited Andean Tubers: Oxalis tuberosa (Oxalidaceae), Ullucus tuberosus (Basellaceae), and Tropaeolum tuberosus (Tropaeolaceae) by Steven R. King and Stanley N. Gershoff. This paper provides some basic composition data, although little about vitamins and minerals, though I was able to find a little more, particularly about vitamin C content, in other sources. So, I calculated the median where ranges of values were given or where I had more than one source, converted the available numbers from dry weight to wet weight, and whipped up some nutrition labels. Since the main source also covered ulluco and mashua, which we also grow, I produced labels for them as well. (As a side note, the Internet is full of nutrition claims based on the dry weight of the tubers, which are highly misleading.)
These should be used as a gross generalization at best (although that is probably always the case with labels that provide a single number). I have no idea if oca nutrition is similar when grown in lowland New Zealand or the American Pacific Northwest compared to high elevation cultivation in the Andes, but I would guess that there are some significant differences. There may also be differences between oca varieties – the paper that I mentioned above shows very wide ranges for carbohydrate and protein content for oca taken from different areas – up to three or four hundred percent in some cases. But, these are the numbers that are available and they may be better than nothing.
You are welcome to take these images and use them for your own purposes, although it would be a good idea to provide a link to this page in case I update them in the future.
Ulluco (Ullucus tuberosus)
Mashua (Tropaeolum tuberosum)
Oca, ulluco, and mashua are sometimes available in our seed shop.