Food Irradiation

[jsolomon]

Heck, in Nebraska where the climate is not quite as extreme, we would use the thing just as much. Unfortunately, I am very certain that the licensing for any sort of radiative source be it gamma or electron would be prohibitively expensive or paperwork heavy.

[slkinsey]

i specifically asked for educated opinions, and most of what Ive read has been bleeding heart, and back in the day, nonsense. Dont get me wrong you are entitled to your opinion, just not in an EDUCATED forum.

I find this a puzzling statement on your part, as you seem to have rejected out of hand statements from the one person in this discussion with a PhD relevant to the topic subject and years of relevant experience in a highly applicable area. If there is one person on this thread who can claim to have education as well as professional experience and knowledge as to the effects of irradiation on biological material, it is bkinsey. And, of course, andiesenji appears to be the only person with actual experience tasting irradiated and not-irradiated foods side-by-side, but that's not acceptable either, for some reason.

I'm not sure what you were expecting. Someone who works in a lab doing food irradiation experiments? I think you can see the full spectrum of responses on this thread: some pro some con; some grounded in scientific experience/education, some in personal experience, and some in politics and philosophy.

[cdh]

It seems that ChefS's thesis is that irradiation is bad... and he's looking for data to back that up.

I imagine that there are downsides to it... can we come up with a bunch of them?

I've never really played with any food I know to have been irradiated, so I can't comment directly myself... but drawing from the earlier conversation the list might start like this:

1. Irradiation allows unscrupulous businessfolk to operate dirty facilities and rely on last minute irradiation to keep their customers from getting ill.

2. Irradiation is energy inefficient, taking more power to irradiate than to just run a clean operation. [this claim seems intuitive, but I don't have any data to back it up]

...

Anybody able to think of any others?

[slkinsey]

It seems that ChefS's thesis is that irradiation is bad... and he's looking for data to back that up.

Well, that's the problem with real science and real information and real situations. Sometimes the data doesn't back you up and you don't find what you're looking for. And the situation is always more complicated than you thought it would be.

I would suggest, by the way, that it is not particularly productive to come up with strawman arguments for why irradiation might be "bad."

[andiesenji]

I didn't realize that the question was meant to produce a response that supported a particular bias.

I am sorry that I bothered to answer as apparently my experience is not "expert" enough. Sorry to have wasted my time and any others who bothered to read my posts.

[cdh]

I would suggest, by the way, that it is not particularly productive to come up with strawman arguments for why irradiation might be "bad."

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I don't know about that... it serves everybody best if both sides of an argument are clearly set forth. Somebody has to take the anti side... so why not help them build as strong a case as possible. Then when the argument plays out, both sides can feel that they have been treated fairly.

This thread is not the argument (or shouldn't be) it is prep for one side of the argument.

Edited April 6, 2005 by cdh (log)

[fifi]

Well, andie, I consider your opinion in the expert category. That is particularly true of anything involving equipment.

The problem here is that you can't remove the water (humidity) from the environment in any practical manner. In a desert situation, if you have water available you can really control your conditions by adding water at will. I am speculating but I think that is why relatively arid conditions with water available via irrigation or springs (think oases) can be some of the most productive agricultural land on the planet.

When I was a kid, we moved to a house that had a big grapefruit tree in the back yard. It produced excellent grapefruit. We left them on the tree to ripen. For the period that this was going on, every couple of days we had to pick the grapefruit and process them right away, mostly into juice for the freezer. We quickly learned not to delay even a day since they would start to mold. Then we got the house air conditioned and that at least meant that we could collect them and have a processing party on the weekend. At least I didn't have to look forward to juicing grapefruit almost every day after school. If I had known such a thing as an irradiator was available, I would have killed for one.

BTW . . . I know that having an irradiator isn't practical due to all of the licensing and such. (I used to handle that for some equipment at FDA.) But, I can dream, can't I?

Does anyone know if nuts are irradiated? Again back to my FDA days, we analyzed tons of pecans for E. coli and aflatoxin. The E. coli comes in because in a commercial operation (or, actually, non-commercial as well) the pecans are picked up from the ground where cows are typically stomping around. Then the nut meats as well are particularly susceptible to the Aspergillus mold species that produces aflatoxin, a particularly nasty actor. This seems like a natural application. Finding the nasties was not at all uncommon back then.

[ivan]

Sorry to have wasted my time and any others who bothered to read my posts.

←

Far from it. It's now apparent that ChefSwartz' intent in starting this thread was to get someone to do his homework for him, rather than have a discussion. Nonetheless, this has turned out to be a most informative thread. My own thinking on the topic has crystalized. This was not a waste of anyone's time. Well, except for the good Chef's, maybe.

[ChefSwartz]

ivan, i wish not to be rude.

Taste is 98% smell according to wolke, mcgee, and any number of other scientists. I will bite my tongue if this info is incorrect. and to be honest you only "sense", sweet,sour,salty,bitter,msg with your tongue. all other components are sensed by the olfactory receptors in your nasal cavity. they work together to form "taste".

I am not a bad guy here and maybe I come off the wrong way but lets just say that my thesis started with that irradiation was bad and i wanted to prove such. However upon scrupulous research I have found out otherwise. except for the effects on flavor, nutrient levels, and texture. These are facts indisputable from mounds of scientific data. (e.g. My HOMEWORK!)

i set to find out how much these deplete in the process. flavor and texture are most important to me(as a cook). Are they enough to warrant me slamming the process? Slamming ignorance ( ivan, your last 3 comments) however, i will with great vigilance and furious anger.

Tasting one or two is not enough evidence for me to make a decent opinion on it, maybe for others, but not myself.

i set out to find as much negative press as i could because I am a simplist and purist cook who loves organics, and freshness as much as anyone. But on what i have found the process is "no more dangerous to us or our enviroment than the invention of electricity itself"(wolke).

I want everyone to know your inputs are greatly appreciated, and I am sorry for discrediting anyone in my mind who feels they are knowledgable.

Edited April 6, 2005 by ChefSwartz (log)

[slkinsey]

Taste is 98% smell according to wolke, mcgee, and any number of other scientists. I will bite my tongue if this info is incorrect. and to be honest you only "sense", sweet,sour,salty,bitter,msg with your tongue. all other components are sensed by the olfactory receptors in your nasal cavity. they work together to form "taste".

I don't think anyone is challenging the notion that odor is the most important contributor to flavor (flavor and odor are not the same thing)*. It's the 98% part that is problematic. First, I have never seen that number cited by any reliable source. And second, it seems too high a percentage. I know people sometimes say "98%" to mean "mostly," and perhaps that is what you mean to say. But, for now, let us agree that smell is the most significant sensory contributor to the perception of flavor and leave it at that.

The new edition of McGee's On Food and Cooking has this to say:

(Page 387) Flavor is a composite quality, a combination of sensations from the taste buds in our mouth and the odor receptors in the upper reaches of our nose. . . There are only a handful of different tastes -- sweet, sour, salty, bitter and savory or umami, while there are many thousands of different odors.  It's odor molecules that make an apple "taste" like an apple, not like a pear or radish. . . So most of what we experience as flavor is odor, or aroma.

(Page 591) . . . Recent research has shown that taste sensations affect our smell sensations.  In a sweet food, the presence of sugar enhances our perception of aromas, and in savory foods, the presence of salt has the same effect.

As I think these two extracts demonstrate, while smell is the central component, it's considerably more complex than simply saying "98%."

I have found out otherwise. except for the effects on flavor, nutrient levels, and texture. These are facts indisputable from mounds of scientific data. (e.g. My HOMEWORK!)

I would be delighted if you could share some of this scientific data with us, including the sources.

i set out to find as much negative press as i could because I am a simplist and purist cook who loves organics, and freshness as much as anyone. But on what i have found the process is "no more dangerous to us or our enviroment than the invention of electricity itself"(wolke).

Thank you. It is always good to see someone be open to the influence of new evidence to the extent that they change their mind.

I've made the point before, but it bears repeating: I don't think anyone here is arguing in favor of tasteless factory farmed mealy tomatoes. We'd all prefer to have organic sustainable heirloom tomatoes just picked off the vine and conveyed directly to our plates. For many of is, this is simply not possible, and so we make do with the closest we can come to that ideal. And the fact is that there are certain circumstances where the judicious use of irradiation can actually help in this direction. Here we have evidence from someone who had tomatoes from her own garden irradiated, and she says that they stayed in condition better and longer than the not-irradiated tomatoes! The only other way she would have been able to keep her tomatoes for that length of time without irradiation would have been to freeze, dry or can them -- and I think you will agree that either one of these processes would have far greater effect on the flavor, texture and nutrient levels than simple irradiation. I, for one, would love to be able to go to the Greenmarket and buy heirloom tomatoes from a local farmer (something I do religiously anyway) that had been irradiated. I could buy more of them, because they would keep longer. The farmer would have less spoilage, and would make a better profit. What customer doesn't want to have more heirloom tomatoes? What farmer doesn't want to sell more of them? This would be a win-win situation. What about cheeses? A young raw milk cheese could be aged to absolute perfection and then irradiated. This would not only preserve the deliciously funky raw flavor at its peak, but would also render meaningless all the safety concerns that restrict the (legal) sale of these cheeses in the US.

All this is to say that sustainable, fresh, pure, slocal, seasonal, organic food and irradiation are not mutually exclusive. They could work very well together.

* Taste is the sensation produced by the activation of taste buds in the mouth and throat area by certain chemicals. Smell is the sensation produced by the activation of olfactory receptors by certain chemicals. There is another chemosensory mechanism called the "common chemical sense" through which various nerve endings (especially prevalent in the naturally moist/membrane areas of the body) react to certain chemicals to create sensations such as the burn of capsaicin, the sting of ammonia, etc. These senses combine with other sensed elements such as texture and temperature to produce the impression that we call "flavor." As many people understand, smell is perhaps the most important contributor to the perception of flavor.

[ChefSwartz]

sources:

"To zap or not to zap?" kevin keener dept. of food science NCSU

Public Citizen.org "FAQ'S about food irradiation: Registered Dietitian, Karen Graham answers some question"

"effect of electron beam irradiation on the bacterial load and sensorial quality of sliced canteloupe" Journal of Food Science Vol.69 Nr.9 2004.

The NY times "Questions on irradiated food" Oct 15, 2003 pgF6

"The olfactory receptors in our noses can differentiate among thousands of different odors and contribute to an estimated 80% of flavor" Wolke,robert "What einstein told his cook"

I have read an estimation of "98%" on at least 2 occasions and I will quote them when I run back across my library.

Edited April 7, 2005 by ChefSwartz (log)

[ivan]

I've seen all sorts of numbers -- 65%, 70%, 75%, 80%... Usually preceded by the words "up to". But in fact, there is no real way to arrive at a number, because it varries from individual to individual and from food item to food item. Some ingredients like herbs are sensed practically 100% by the olfactory nerves, whereas in the case of salt or sugar, only a small part of their flavor is conveyed through scent. You can come up with a ballpark estimate that illustrates a general pattern, but there is no one number that is always correct.

The 98% figure is not a feasible numeric model because it reduces the role of actual taste to almost nothing. Such a number can be arrived at by comparing the total possible flavors detected by the tongue with the total possible scents detected by the nose (the latter being thousands of times greater than the former), but what use is such a number? Common sense alone tells us that removing salt, sweet, sour, bitter and umami sensations from a flavor profile leave it substantially depleted of flavor, no matter how good it smells.

[slkinsey]

Chef,

I would respectfully suggest that Karen Graham is not a very scientifically reliable source. Here are some sources you might consider in addition to those you cite:

The Centers for Disease Control and Prevention's Frequently Asked Questions about Food Irradiation and presentation on Food Safety and Irradiation.

Iowa State's Food Irradiation Site, including the Consumer Questions document referenced by bkinsey upthread. This document directly refutes many of Karen Graham's assertions.

The The Foundation for Food Irradiation Education's Information Website.

Some Food Irradiation Links from the National Agricultural Library.

An interesting PDF from Kansas State that lists the maximum dosages allowed for the various applications of irradiation.

Some of the documents you find will be out of date. Even something as recent as 2000 may not reflect the most recent methods.

[ChefSwartz]

Such a number can be arrived at by comparing the total possible flavors detected by the tongue with the total possible scents detected by the nose (the latter being thousands of times greater than the former)

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exactly, couldn't have put it better myself. I guess it comes to roughly 98%?

Lets also define the reasearch as a whole to "limited" on this matter. i dont think they have exactly cracked the code on this one.

Thanks for the links sl.

Edited April 7, 2005 by ChefSwartz (log)

[ivan]

Such a number can be arrived at by comparing the total possible flavors detected by the tongue with the total possible scents detected by the nose (the latter being thousands of times greater than the former)

←

exactly, couldn't have put it better myself. I guess it comes to roughly 98%?

Lets also define the reasearch as a whole to "limited" on this matter. i dont think they have exactly cracked the code on this one.

Thanks for the links sl.

←

No, if we use the all-possible-sensations approach, the number would be more like 99.9375% aroma and 0.00625% taste. Which is meaningless.

The only meaningful way to look at it is simply this: flavor is an aggregate of sensations transmitted through taste, aroma and touch. The contributions of these senses vary from individual to individual and from food to food. Even for one individual, there are days when taste is hightened or suppressed, when the sense of smell is acute or diminished. To say that any one source of flavor has a consistent share in contributing to flavor is just not true.

With regards to the relative importance of these senses, I ask myself the question: if I had to lose any two of my senses, which one would I keep: smell, taste or feel? I have periods when I completely lose my sense of smell; also, I remember what it is like to have no taste and feel (through the administration of novocaine). I would most certainly prefer to keep taste at the expense of feel and smell. As an illustration of this value judgement, compare a glass of strawberry juice with a glass of mineral water embued with strawberry essence.

There is a tendency in the last 20-30 years to emphasize the role of the olfactory system in the perception of flavor. I believe this is because science has had a series of revelations: our perception of flavor has changed dramatically. However, just because our sense of smell is more discerning and versatile does not mean it is more important in perceiving flavor. Of the two, taste is the less atavistic, more advanced sense. Humans' sense of smell is in evolutionary decline; we rely on it less and less to survive. Taste, however, is in evolutionary ascension: our ancestors had very little need for taste as a survival mechanism, whereas for modern man the development and refinement of taste is part of human mental growth.

I'm not an expert on the science of flavor, only an enthusiast. Janet Zimmerman (eGullet's own JAZ), however, is an expert. Last year, she posted a fascinating rundown on this subject (click here). Notice that JAZ does not attempt to evaluate the relative contributions of our senses to the perception of flavor. That is the only valid scientific approach, since quantifying the importance of any one sense is purely subjective.

One thing I would like to restress is the tendency of recent scientific study to dwell on the olfactory component at the expense of taste. I think taste has been foolishly dismissed as a known, finite quantity. But it is not. Just ten or twenty years ago, only four tastes were recognized: sweet, sour, bitter, salty. In other words, science was telling us that we perceive only 4 tastes, and any other tastes are a combination of those 4. I think we all know that is simply not true. Recently, a fifth taste has been admitted to the list: savory, or umami, or MSG. But please -- that is still not enough. JAZ notes in her article,

Some would also argue that "metallic" and "alkaline" (or soapy) count as basic tastes; however, since ideally those two tastes do not occur in our foods, I'm going to ignore them here.

I must respectfully but emphatically disagree. Metallic taste is very prevalent in spring water, and is a delicious component of the flavor of tea or coffee brewed with this water (just as one example). Anise has a distinct soapy component. And I dare say we can go further yet in defining basic tastes. I think, for instance, the "green" taste of grass or lettuce is basic, and serves as a component in many flavors.

After getting all excited about the role of smell in flavor, I predict that science will now begin to find an ever-increasing universe of taste.