Fungus Puts the Heat in Chili Peppers, Study Says

[Michaelangelica]

I am not sure I believe this.

 

Fungus Puts the Heat in Chili Peppers, Study Says

John Roach

for National Geographic News

August 11, 2008

 

There's a fungus among us chili fans—and some of the spicy peppers evolve their kick to repel it, a new study says.

 

Chili peppers develop piquant chemicals to thwart the harmful microbes long enough to give birds and other animals a chance to disperse the pepper seeds, helping the chilies to procreate, scientists found.

Fungus Puts the Heat in Chili Peppers, Study Says

 

There are so many Chilli peppers with so many different combinations of different capsiacins that this seems very unlikely.

 

So who first discovered that burning your mouth was pleasurable?

[Overdog]

It seems like a reasonable theory to me. I grew up in Alabama, and didn't really like hot peppers, but then I moved to New Mexico.:D

 

I never found eating the hot, spicy chili peppers to be pleasurable, (except maybe in a sadistic sort of way) but after several years of not being able to avoid them in New Mexico resturants, I came to realize I had developed a sort of mild addiction to them. I have been living in Virginia now for the last 10 years (nothing spicy here) but I still crave them. Once a year I still order a case of New Mexico green chili sauce from a company in Albuquerque...

 

The New Mexico chile is a local cultivar of the species, or subspecies otherwise represented as Anaheim peppers. The large, flavorful New Mexican variety gives the region's cuisine much of its distinctive style, and used so extensively that it is known simply as "chile". Green chiles are those that are picked unripe; they are fire-roasted, then peeled before further use. Unlike the ultra-mild canned supermarket green chiles, New Mexico green chiles can range from mild to (occasionally) hotter than jalapeños, and come in grades of spiciness at markets that cater to chile aficionados. The climate of New Mexico tends to increase the capsaicin levels in the chile compared to other areas.

New Mexican cuisine - Wikipedia, the free encyclopedia

 

Try some, you might like it...:evil: 505 Chile: Salsa, Green Chile, New Mexico Southwestern sauces

[freeztar]

I am not sure I believe this.

 

There are so many Chilli peppers with so many different combinations of different capsiacins that this seems very unlikely.

 

Why does it seem unlikely? Here's what the press release had to say about it:

 

One question Levey and his colleagues are still pondering is why any nonhot chilies remain if capsaicin is so beneficial. Their hypothesis is that the production of the chemical comes at a steep price for chili plants.

 

Levey said the plants that produced hot chilies had seeds with very thin coats – a presumed consequence of sacrificing the production of lignin, a complex molecule that makes up the protective seed coat, in favor of the production of capsaicin.

 

This phenomenon represents an interesting tradeoff between chemical and physical seed protection and demonstrates the power of natural selection, Levey said.

 

At higher elevations, where moisture is high and Fusarium fungus is rampant, the scientists found that 100 percent of the plants produced hot chilies. In the drier lowlands, where fungus is less of a problem, only 40 percent of the plants produced fiery fruits. The remainder spent more resources developing thick seed coats, which protect against the devastating ant populations common to lower areas.

 

It makes sense to me. :D

 

So who first discovered that burning your mouth was pleasurable?

The article states that chilis were one of the first cultivated plants. So maybe Adam. :evil:

[mynah]

I remember reading somewhere that chillies evolved their heat and red colour to ensure that they are eaten by birds, rather than mammals. Most mammals do not see red as a distinct colour and they are sensitive to capsaicin, whereas birds have full colour vision and eat chillies without feeling any pain, regardless of the heat. This is an important distinction, considering that the seeds pass unharmed through the digestive tracts of birds, whereas they are damaged by the stomach acids and enzymes of mammals.

[Michaelangelica]

i can't see that higher lattitudes would have more fungus.

Also the testing by

"You can't tell them apart unless you chew on the fruits," he said

is just not scientific as you build up a tolerance to capsaicins the more you eat. There are four (ish) capsaicins and some chillies like the serrano and manzano have diffent blends of these so will taste hotter to someone eating a C. annum variety for example.

Also the Serrano is a high altitude chili- i think- and has a thick flesh so too the manzano, which is avery high altitude plant. Both these chillies have hairy leaves to ATTRACT moisture.

i just don't think their generalisation holds water

The activities of capsaicin (s?) include(Duke)

5-Lipoxygenase-Inhibitor; AAA31:329;

Analgesic; 411;

Anaphylactic; PMP24:118;

Anesthetic; M29;

Antiaggregant; AAA31:338;

Antiarrhythmic; 100 uM; MED95;

Anticolonospasmic; 0.003 ivn gpg; BBE;

Antiinflammatory; AAA31:329;

Antiischemic; 100 uM; MED95;

Antimastalgic; WER;

Antineuralgic; M11;

Antineuritic; WER;

Antinitrosaminic; ABS;

Antinociceptive; TiPS11:333.1990;

Antioxidant; PCF:75;

Antipsoriatic; WER;

Antiseptic; IWU;

Antispasmodic; IWU;

Antitachycardic; 100 uM; MED95;

Antitumor (Lung); NR54:S71;

Antiulcer; TiPS11:333.1990;

Calcium-Antagonist; 100 uM; MED95;

Calcium-Antagonist; 3 uM; K20269;

Cancer-Preventive; 525;

Carcinogenic;

Cardiotonic; FT61:266;

Catabolic; ABS;

Cyclooxygenase-Inhibitor; AAA31:329;

Cytochrome-P450-Inhibitor; PIZ;

Diaphoretic; PJB1(1):170;

Digestive; IWU;

Endocrinactive; 50 mg/kg scu rat; BBE;

FLavor; 0.009-10; ARC;

Hypothermic; 7 mg/kg; JE32:74;

Irritant; M11 RIN;

Neurotoxic; FT61:266.1990;

Pesticide;

Pyrogenic; 6 mg scu rat; PFA366:217;

Repellent;

Respirasensitizer;

Rubefacient; IWU;

Sialogogue; PJB1(1):170;

Thermogenic; 0.7 mg/kg ims rat; JNS34:587;

Vasodilator; IWU;

SoI think the research is baddly controlled and makes useless generalisations that help no one except whoever qwas trying to get his PhD with this.

Where does the Capsicum fit into this research? The chilli with the least heat?

[freeztar]

i can't see that higher lattitudes would have more fungus.

Also the testing by

 

is just not scientific as you build up a tolerance to capsaicins the more you eat. There are four (ish) capsaicins and some chillies like the serrano and manzano have diffent blends of these so will taste hotter to someone eating a C. annum variety for example.

Also the Serrano is a high altitude chili- i think- and has a thick flesh so too the manzano, which is avery high altitude plant. Both these chillies have hairy leaves to ATTRACT moisture.

i just don't think their generalisation holds water

The activities of capsaicin (s?) include(Duke)

5-Lipoxygenase-Inhibitor; AAA31:329;

Analgesic; 411;

Anaphylactic; PMP24:118;

Anesthetic; M29;

Antiaggregant; AAA31:338;

Antiarrhythmic; 100 uM; MED95;

Anticolonospasmic; 0.003 ivn gpg; BBE;

Antiinflammatory; AAA31:329;

Antiischemic; 100 uM; MED95;

Antimastalgic; WER;

Antineuralgic; M11;

Antineuritic; WER;

Antinitrosaminic; ABS;

Antinociceptive; TiPS11:333.1990;

Antioxidant; PCF:75;

Antipsoriatic; WER;

Antiseptic; IWU;

Antispasmodic; IWU;

Antitachycardic; 100 uM; MED95;

Antitumor (Lung); NR54:S71;

Antiulcer; TiPS11:333.1990;

Calcium-Antagonist; 100 uM; MED95;

Calcium-Antagonist; 3 uM; K20269;

Cancer-Preventive; 525;

Carcinogenic;

Cardiotonic; FT61:266;

Catabolic; ABS;

Cyclooxygenase-Inhibitor; AAA31:329;

Cytochrome-P450-Inhibitor; PIZ;

Diaphoretic; PJB1(1):170;

Digestive; IWU;

Endocrinactive; 50 mg/kg scu rat; BBE;

FLavor; 0.009-10; ARC;

Hypothermic; 7 mg/kg; JE32:74;

Irritant; M11 RIN;

Neurotoxic; FT61:266.1990;

Pesticide;

Pyrogenic; 6 mg scu rat; PFA366:217;

Repellent;

Respirasensitizer;

Rubefacient; IWU;

Sialogogue; PJB1(1):170;

Thermogenic; 0.7 mg/kg ims rat; JNS34:587;

Vasodilator; IWU;

SoI think the research is baddly controlled and makes useless generalisations that help no one except whoever qwas trying to get his PhD with this.

Where does the Capsicum fit into this research? The chilli with the least heat?

 

The article says that fungus is more rampant at the higher altitudes, not latitudes.

 

At higher elevations, where moisture is high and Fusarium fungus is rampant, the scientists found that 100 percent of the plants produced hot chilies. In the drier lowlands, where fungus is less of a problem, only 40 percent of the plants produced fiery fruits. The remainder spent more resources developing thick seed coats, which protect against the devastating ant populations common to lower areas.

 

From an ecological and biological standpoint, the quoted text above makes perfect sense.

 

Also the Serrano is a high altitude chili- i think- and has a thick flesh so too the manzano, which is avery high altitude plant.

 

The "flesh" is inconsequential here as the article is describing changes in seed coating, not the fleshy coating of the "seed container". Nonetheless, the serrano pepper's flesh has been described as thin.

 

The serrano is pronounced: suh rah noh. Serrano chile peppers have thin walls. They don't need to be steamed or peeled before using, making it the easiest chile pepper to use for salsas.

Serrano Chiles - Serrano Peppers

 

Also, I'm very curious about the claim of hairy leaves to attract moisture. Can you give me some links for this please? More importantly to this thread, can you give a link that explains how moisture collecting hairs on leaves contributes to more or less fungal infection?

[Michaelangelica]

The article says that fungus is more rampant at the higher altitudes, not latitudes.

Sorry a typo. IMHO Fungus would be more likely to berampant in areas of high humidity ie near the sea.

 

 

 

From an ecological and biological standpoint, the quoted text above makes perfect sense.

It is an assumption not based on fact.

 

 

The "flesh" is inconsequential here as the article is describing changes in seed coating, not the fleshy coating of the "seed container". Nonetheless, the serrano pepper's flesh has been described as thin.

Serrano is not thin compared to most. It is about 1/16- 1/8" thick. manzano is one of the thickest fleshed chillies and is almost exclusive to high altitudes and is bloody hot.

"Changes in seed coating" what's that? Are they talking about the placenta?

Very little structural differences in this among chillies or people.

 

Also, I'm very curious about the claim of hairy leaves to attract moisture. Can you give me some links for this please? More importantly to this thread, can you give a link that explains how moisture collecting hairs on leaves contributes to more or less fungal infection?

Most hairy leaved plants seem to be that way to attract and trap airborne moisture. They usually inhabit areas of low humidity -like high altitudes and deserts.

 

No study was made of the anti fungal properties the leaves. But given that the leaves of Chillies are used in native medicine, they are bound to contain active photochemicals.

 

Testing whether " hairs on leaves contributes to more or less fungal infection" sounds like a good Ph.D . dissertation.

 

Many plants like the "hairy leaved lavender" (yes it exists I'm not kidding) protect themselves with chemicals like essential oils- all of which are anti-fungal.

 

The mere fact that the study used a subjective taste test and not a test of Scoville Heat Units using analytical chemistry makes the whole study a nonsense.

[freeztar]

Sorry a typo. IMHO Fungus would be more likely to berampant in areas of high humidity ie near the sea.

 

Why? This seems to assume that mountains are dry.

 

It is an assumption not based on fact.

Well, it's an assumption that they did not measure humidity levels at both altitudes. My point was that, given their "assumptions", that fungus is more prevalent in moist areas.

 

Serrano is not thin compared to most. It is about 1/16- 1/8" thick. manzano is one of the thickest fleshed chillies and is almost exclusive to high altitudes and is bloody hot.

 

As I consider you knowledgeable about chillies through my years of interaction with you, I'm willing to accept your claims. Nonetheless, it would be beneficial for others if you produced a source that corroborated with your statements above.

 

"Changes in seed coating" what's that? Are they talking about the placenta?

Very little structural differences in this among chillies or people.

Seed coat refers to um...the seed coating.

From the free dictionary:

 

The outer protective covering of a seed. The seed coat develops from the integument of the ovule. Also called testa.

 

I will not even pretend to be able to explain how different plants, in different locales, are able to produce different thickness in seed coats, but that is precisely what this study has observed. In fairness, results may vary in Australia.

 

Most hairy leaved plants seem to be that way to attract and trap airborne moisture. They usually inhabit areas of low humidity -like high altitudes and deserts.

 

No study was made of the anti fungal properties the leaves. But given that the leaves of Chillies are used in native medicine, they are bound to contain active photochemicals.

 

Testing whether " hairs on leaves contributes to more or less fungal infection" sounds like a good Ph.D . dissertation.

 

Many plants like the "hairy leaved lavender" (yes it exists I'm not kidding) protect themselves with chemicals like essential oils- all of which are anti-fungal.

I'm always wanting to learn more about plants, so thanks for sharing that info.

 

The mere fact that the study used a subjective taste test and not a test of Scoville Heat Units using analytical chemistry makes the whole study a nonsense.

 

Not really. Check out this wiki, where they say...

Spice heat is now usually measured by a method using high performance liquid chromatography (HPLC). This identifies and measures the concentration of heat-producing chemicals. They are then used in a mathematical formula in which they are weighted according to their relative capacity to produce a sensation of heat. This method yields results, not in Scoville units, but in American Spice Trade Association (ASTA) pungency units. A measurement of one part capsaicin per million corresponds to about 15 Scoville units, and the published method says that ASTA pungency units can be multiplied by 15 and reported as Scoville units. This conversion is approximate, and spice experts Donna R. Tainter and Anthony T. Grenis say that there is consensus that it gives results about 20–40% lower than the actual Scoville method would have given.[2]

 

Pungency values for any pepper, stated in Scoville units, are imprecise, due to expected variation within a species—easily by a factor of 10 or more—depending on seed lineage, climate (humidity is a big factor for the Naga as the Dorset Naga and the original Naga have quite different ratings), and even soil (this is especially true of habaneros). The inaccuracies described in the measurement methods above also contribute to the imprecision of these values. When interpreting Scoville ratings, this should be kept in mind.[2]

 

What does this have to do with the study's results? Perhaps I missed something.

[Michaelangelica]

Why? This seems to assume that mountains are dry.

Yes

air at higher altitudes is generally drier. Fly in a plane.

 

 

Well, it's an assumption that they did not measure humidity levels at both altitudes. My point was that, given their "assumptions", that fungus is more prevalent in moist areas

.

yes at lower altitudes not high

 

 

 

As I consider you knowledgeable about chillies through my years of interaction with you, I'm willing to accept your claims. Nonetheless, it would be beneficial for others if you produced a source that corroborated with your statements above.

Very good of you.

"said Perry (Who?) oops no Michaelangelica, who is an expert on the domestication of chilies."

 

Seed coat refers to um...the seed coating.

From the free dictionary:

 

I will not even pretend to be able to explain how different plants, in different locales, are able to produce different thickness in seed coats, but that is precisely what this study has observed. In fairness, results may vary in Australia.

the four botanical groups of chillies have remarkably similar "seed coats" Did they measure any? Where are the measurements for each variety and botanic type?

More balderdash. results will not vary because the chilli is grown in adiffent country

 

 

 

 

 

Not really. Check out this wiki, where they say...

Scoville units are still used. I agree a HPLCis probably a better way of going, but generally it is not used or it is than converted to Scoville Units especially where Queen Elizabeth reigns. I wonder how they treat all four capsaicins or do they just measure the one Yanks use in the evil "Pepper (sic) Spray". If so, that measurement is up the spout too.

"wiki is wrong says the expert Australian chilli grower Michaelangelica."

I have grown over 200 varieties of chillies", he said "collected the seed over a number of years and have yet to notice significant variation in so called 'seed coats' in the majority of chillies."

He went on to say, " Soil is unlikely to affect the heat rating of habaneros, but time of harvest may. the first flush of fruit is likely to be hotter than later harvests." he said.

a recent artists sketch of the reclusive Chilli expert from Australia.who is highly critical of American Geographic chilli research.

 

What does this have to do with the study's results? Perhaps I missed something.

THIS

"You can't tell them apart unless you chew on the fruits," he said.

 

Chewing on fruits—tough field work, Tewksbury joked—helped the team to establish a gradient of hotness along a 185-mile-long (300-kilometer-long) sample area in Bolivia.

is subjective balderdash, not science.

 

Capsaiacin levels could go up because of insect attack rather than fungus attack.

Many plants produce toxins when attacked.

What fungus did they observe? I have rarely seen fungus on chillies grown here; in fact never.

 

Heat from chillies will also vary according to the time of harvest.

 

 

The Mayans and others hybridised chillies for at maybe a1,000 years. they were into hybridsation and had huge botanical gardens long before the first one appeared in europe in 15C. It is likely they hybridised chillies that were hotter. Latitude (and/oraltitude) has little to do with it

Two more doubtful assumptions

• The finding, he said, adds weight to a hypothesis that humans first started to eat chilies for their antimicrobial properties.
   
  
• He noted that the majority of people who eat chillies live along the Equator, a region of the world where microbes also flourish and cause a range of intestinal diseases
  

Most anti-microbial action is probably in the leaves!

Perhaps people just liked eating them with their chocolate?

Perhaps people in hot climates like to sweat because it makes them cool?

Perhaps the high Vit C level keeps them healthy?

Perhaps they enhance the flavour of food?

perhaps they werepart of the local cuisine for 1,000-2,000 years or so.

perhaps there are historical reasons like the slave ships using chillies in the muck they fed prisoners.

OR the Brits and french had mostly colonies in equatorial Africal and grew chillies

 

I can make twice as many speculative, unsupported assumptions as the researchers do and don't even get paid for it

Anyway where is the evidence for this Equatorial Chilli Obsession?

The British eat a lot of Chilli,(a region of the world where microbes also flourish and cause a range of intestinal diseases) so too Japan, comparatively very little even in tropical China with the exception of Schezwan.

The people who know how to eat really hot chillies are the people in the Caribbean. They would blow the Bolivians out of the water.

 

Chillies were adopted widely because they were an easy to grow, cheap substitute for pepper. Something else Columbus got wrong and is still perpetuated in the name. Chillies have nothing to do with the Pepper vine.

 

Ihe more I read the study the crankier i get. There is enough stupid folklore about chillies as it is, without a prestigious journal like this adding to it. Perhaps there is more detail somewhere else rather than in this sketchy report?

Next time American Geographic want to send someone on a Bolivian junket/ holiday please put my name forward.

 

So, freeztar are you doing this just to stir me?

[freeztar]

No mate, not trying to stir you just trying to get to the bottom of this. :)

 

I did some researching and found some good info on this.

 

Here's the original press release:

uwnews.org | Bugs put the heat in chili peppers | University of Washington News and Information

 

Here's a link to the journal article:

Evolutionary ecology of pungency in wild chilies ? PNAS

 

Here's more supporting info that describes the methodology:

http://www.pnas.org/content/suppl/2008/08/11/0802691105.DCSupplemental/0802691105SI.pdf

 

If you look at that last link, it's quite clear that the study is scientific.

I really don't find any fault with it. :shrug:

[Michaelangelica]

No mate, not trying to stir you just trying to get to the bottom of this. :lol:

 

I did some researching and found some good info on this.

 

Here's the original press release:

uwnews.org | Bugs put the heat in chili peppers | University of Washington News and Information

 

Here's a link to the journal article:

Evolutionary ecology of pungency in wild chilies ? PNAS

 

Here's more supporting info that describes the methodology:

http://www.pnas.org/content/suppl/2008/08/11/0802691105.DCSupplemental/0802691105SI.pdf

 

If you look at that last link, it's quite clear that the study is scientific.

I really don't find any fault with it. :hyper:

I thought there must be more stuff, but you are easy to please.

My problems with the research,

1. they used only one rare- ish variety, C. chacoense, which uniquely in my experience of chillies produced hot and non-hot varieties-this is unusual " C. chacoense, is naturally polymorphic for the production of capsaicinoids and displays geographic variation in the proportion of individual plants in a population that produce capsaicinoids."

Capsicum chacoense

Believed to be found only in Argentina, Bolivia and Paraguay. A white flowered species. Known to be susceptible to Pepper mild mottle tobamovirus.

Capsicum varieties

Hypersensitivity in Capsicum chacoense to Race 1 of the Bacterial Spot Pathogen of Pepper

Plant Disease 1984 | Hypersensitivity in Capsicum chacoense to Race 1 of the Bacterial Spot Pathogen of Pepper

It has some interesting genetic seed-anti-viral genes too and seems -possibly-a very ancient form of chilli.

 

They did not say which botanical group this chilli belongs to. I assume C. annum.

 

Why test a plant that is naturally polymorphic ? What genetic advantage is there to the 50-60 odd plants we are told are not 'pungent'? How do their germination rates rate? (I found their chart/graph incomprehensible.)

What effect does travelling though the digestive system of a bird (the plant's preferred means of seed dispersal) have on the fungus?

 

2. They tested only 120 plants of this one species only half of which were hot.

A very small sample, for such a big generalisation about ALL chilli plants.

 

3. Their test of "pungency" is still not clear

field determination of pungent to nonpungent ratios

in polymorphic populations is straightforward (1).

1. Tewksbury JJ, Manchego C, Haak DC, Levey DJ (2006) Where did the chili get its spice?

Biogeography of capsaicinoid production in ancestral wild chili species. J Chem Ecol32(3):547– 64.

 

4 This comment is wrong

"By contrast, peppers increase their chemical defense levels, or their heat, as they ripen. This is a very different model and peppers can get away with it because birds don't sense pain when they eat capsaicin," Tewksbury said. "I think a lot of plants would love to come up with this way of stopping fungal growth without inhibiting dispersers. It's just very hard to do."

For example trees eaten by giraffes and elephants on the African savannahs send signals to other plants-or the same species- who increase the bitter/ad or poisonous component in the leaves thus discouraging more foraging. Many other plants increase chemical defence levels when attacked . (Gardeners use this plant mechanism to encourage plant growth when they prune which forces plants to produce more growth hormone & often more flowers or fruit).

 

5. this comment "These results suggest that the pungency in chilies may be an adaptive response to selection by a microbial pathogen, supporting the influence of microbial consumers on fruit chemistry. "

this is

a) a huge generalisation based on one plant species in one spot. and

:) it ignores the hybridising done by the Mayans & Aztecs over hundreds, maybe thousands, of years and

c) the incredible botanical diversity of capsicum species.

 

I would like them to look at the little babyTepin growing in dry, desert (fungus free?) parts of Texas.

A USA chilli expert (Craig Drenman, Redwood City Seed Company) claims it is the hottest chilli ( To be consistent, I disagree with him too:))

 

6. Just about any fungus will affect seed germination rates.

All plant propagation is a race between rooting and rotting.

This is hardly unique to chilli seeds. Even apples produce arsenic around their seeds to protect them and I am sure you could find hundreds of other examples.

 

While their procedures are clear, without access to the full journal article it is hard to marry the procedures with results.