Some nutritional aspects of Opuntia, with citation.

[Kapidolo Farms]

I'm going to use an extreme abbreviated citation format.

Evaluation of oxalates and Calcium in nopal pads (Opuntia ficus-indica var. redonda) at different maturity stages. Margarita C-Padilla, et al., 2011, Journal of food composition and analysis.

Free download http://www.researchgate.net/profile...ity_stages/links/00b7d5224b0b54c001000000.pdf

The take home message in this paper and how best to use pads is found in Table 1 on page 40, basically when pads are very young and fresh they load up on things (oxalate) that help reduce palatability. As the pad ages and spines grow, the skin thickens, less oxalate is required for a deterrent.

Oxalates get a bad rep from people who panic at the word. Oxalates are so predominate in the plant world the plants that don't have them is the short list. All the produce in the grocery store has them.

Oxalates have roughly fours paths when ingested. 1) they are already bound with some mineral, not exclusively calcium, and they pass right through. 2) They are not bound to any mineral and do so in the GI, and pass through, 3) they are absorbed and serve no purpose and are flushed out through the Kidneys, 4) they are absorbed and serve some metabolic purpose (are degraded so no longer oxalates).

The metabolic purposes are many. There are even bacteria in our gut biome that can among other things degrade oxalates in the gut, freeing up sub-constituents for further digestion. If there is abundant calcium in the gut when oxalates are part of the meal they are bound then and there and go out in feces. GOOD news, opuntia is loaded with calcium, older pads more than younger pads.

I have found PubMed to be a good source on how Opuntia and oxalates can influence humans' nutrition and state of health/ Google scholar is also a good place to look.

Be Calm, Opuntia On.

 

[Kapidolo Farms]

http://www.researchgate.net/profile...US_INDICA)/links/53d7c2480cf2631430bfc278.pdf


Maybe you want to dry your own? Here is a explanation of drying much like I got at CSUFresno when I took coursework for an undergraduate degree in in production agriculture. My emphasis was viticulture (growing grapes) and the fresh fruit and raisins courses were included in the mix of how to grow wine grapes. The raisins courses were also expanded to tree fruit growers and was more comprehensive than just grapes for raisins. Opuntia was not covered in that coursework, but plums/prunes, and dates, as well as many other crops were included.

Drawing water out of plant products can be expensive. The expense is added labor, possible loss of production (mold or insects), and the biggy, energy consumption.

This article, in addition to many formulas and drying curves with equations, shows and explains a dryer built to exploit solar energy, not that converted into electricity with panels, but rather the accumulated heat form the sun. There is a diagram of the dryer they use.

One issue I have with this dryer is the higher temps used. Many studies suggest that protein degradation (denaturing) begins to occur at temps that exceed 45 C (113 F). Lower temps mean longer drying times, but the maintenance of nutrition is sorta important in my opinion. I do not currently have any researched based explanations of how much protein in Opuntia may be lost in drying at higher temps, it could be the protein denaturing standard does not apply to Opuntia, or it is trivial.

I do not use this system as it is designed here for Opuntia that I dry, but have preferred to go with a longer drying time at lower temps.

Be Calm, Opuntia On.

 

[Kapidolo Farms]

http://www.researchgate.net/publica...f_Nopal_Cladodes_at_Different_Maturity_Stages

Here is another paper with a few take home messages regarding Opuntia.

1)Opuntia freeze dried has a higher protein content than Opuntia dried at temps of 50 C or 70 C (corroborates the idea that temperature can denature the protein). The difference is slight but measurable, and we might as well keep all the protein possible. Lower drying temps are better.

2)Older Opuntia has a higher ash (mineral) content, less soluble fiber and more insoluble fiber.*

3)Color as found in the living pad is best maintained by freeze drying applied in the older pads. Again lower drying temp may indeed keep color retention better than higher drying temps.

A little tangent on the color issue and why it is important . . .

I do not yet know this based on carefully quantified studies or observation I have made or found published, but I think the non photosynthesis pigments (green) that are in Opuntia which are the betalains (red, purples yellows) are what draws tortoises to them. I see that when my tortoises defecate after having eaten beets, their feces are NOT red. So those betalains are being used somehow in their digestive system. Betalains are very abundant in the Opuntia fruit as bright red. I believe tortoises can see the insignificant quantity of betalains in the green pad, that we do not see. I believe they get some nutritional benefit from betalains , as they don't defecate them out like we do (that's why you have an impulse to see a doctor when you eat beets then look back into the toilet and see all that red), then you remember "oooh, I ate beets" and relax. Some studies of betalains have been prompted by the false observation positive they give for blood in the bowels. The red in the toilet matter.

I think the pads look red-ish to tortoises, and the betalains have nutritional benefit that they can use.

Here is a paper that goes on about 'pigments' but does not talk about their role in nutrition. It describes how anthocyanins are mutually exclusive to betalains, and how all 'pigments' are used in plants.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2008.03447.x/full

Here is a not so scientific expression of what betalains do in human bodies.
http://www.gracebisbikosrmt.com/blog/2012/05/28/The-Power-of-Betalains.aspx

*Soluble fiber, which dissolves in water, is readily fermented in the colon into gases and physiologically active byproducts, and can be prebiotic and viscous.
Insoluble fiber, which does not dissolve in water, is metabolically inert and provides bulking, or it can be prebiotic and metabolically ferment in the large intestine. Bulking fibers absorb water as they move through the digestive system, easing defecation.

 

[Kapidolo Farms]

This paper talks about many aspects of Opuntia, it is a review of other papers.

The take home here is mention in @DeanS thread about a species named in a different genera here, but is what DeanS has in his thread, as a variegated varietal. I suspect the low oxalate compounds might carry to the varietal of this species, but don't know that.


Also know as Nopalea cochenillifera and mentioned on page 181, top left.

 

[Yvonne G]

It was interesting to note my Mee and opuntia yesterday. I had been using the newer pads, but recently switched to the older, tougher pads. I cut a large pad in fourths top to bottom, making four 'strips' about 2" wide. I fed the Manouria emys emys their mixture of fruits, vegetables and meat protein, and placed the opuntia strips on top of the pile. At the end of the day the cactus was still there, with a few bites off the edges. But by the end of the following day (no food this day), they were all gone.

 

[tinkerbell1189]

Do you guys cut the spiky bits off? I tried feeding it and he took one look at the prickles, pulled a face and left it. By the next day he had trampled all over it and I just ended up throwing it out

 

[AnimalLady]

The kind that grows in my yard doesnt really have spines, I guess thats good.

I give the big pads because their easier for me to pick, i did not know there was a difference from the younger pads and the older pads.. thanks for the read, very informative

 

[Kapidolo Farms]

An example of how to use fresh or dried opuntia.

http://www.tortoiseforum.org/thread...chips-lower-cost-better-functionality.149062/

Remember all techniques that use heat above 112F will denature (destroy protein) and freezing can result in mush. Low temp drying is optimal.