Thursday, April 26, 2018

A Remarkable New Technology That Will Diminish A Global Cancer Threat


We in the rich societies of the world don’t hear a lot about aflatoxin. It is probably one of the single largest causes of cancer in the developing world – particularly in Africa. Around a half a billion people are at risk from this toxin in their diet. At high doses it can cause acute poisoning and death. It also causes cognitive stunting in children exposed to it. Aflatoxin is a natural chemical that is made by a fungus called Aspergillus that can infect crops like corn, peanuts and tree nuts particularly when there is damage by insects and/or stress from drought. People like Americans are well protected from this threat by farmers who exercise control measures for the insects and disease, by an advanced food system that monitors for the issue in the harvested crops, uses proper storage conditions, and excludes it from what is sold to us. For instance the EU standard for maize is that it must have less than five parts per billion of aflatoxin.  Unfortunately only 20% of the normal maize supply in Kenya meets that standard.

For high value crops like almonds and peanuts, there are not only concerted efforts to prevent this sort of contamination, there are also mechanisms to literally check each individual nut for the presence of the fungus and reject those that are suspect. That kind of detailed scrutiny has never been feasible for a lower value crop like corn (or Maize). But recently, a Swiss, family-owned grain handling equipment company called Bühler has cooperated with Microsoft to develop a system which can process corn at a rate of 15 metric tons per hour and reject any of the kernels that are contaminated with the nasty chemical aflatoxin. That is both amazing and very cool.

The sorting machine in high speed process

This remarkable system relies on very high speed imaging technology using LED lights to look for the florescence that suggests the presence of the fungus. It is applied to every single corn kernel even at that high rate of grain flow. The system uses Microsoft technology to pass all relevant data to the Azure cloud, where visualization of the data, tracking, and reporting are possible in real time. Bühler can also tap into Azure’s massive cloud infrastructure, available in 140 countries, to scale the solution globally.  A puff of air is used to knock the suspect grain out of the main flow and can achieve a 90% or better degree of contamination reduction with something like a 5% level of grain rejection.

In the Buhler applications lab

This technology will have immediate applications in the feed grain industry in the developed world because instead of rejecting entire loads that have some contaminated grain, it will be possible to protect the animals that eat the grain while still using as much of the yield as possible – a food waste reduction success. Also, since aflatoxin can come through to milk, dairy product consumers will also get an even higher level of protection.
Moving this sort of technology into key areas like Africa will require some creative public/private partnership approaches particularly in areas where there are not really any sort of commercial grain handling systems at, say, a village level. The grain equipment company behind this, Bühler has been doing business in Africa for 100 years and runs a milling school in Nairobi, so they are positioned to find creative solutions to the implementation of this advance.

As revolutionary as this technology promises to be, it is a good thing that it isn’t the sole solution. One way to reduce the infection/contamination issue is to intentionally spread a strain of the culprit fungus that does not happen to make aflatoxin. It’s a biological control strategy that was first developed by USDA researchers and commercialized in the U.S., but which has since been re-developed in Africa. Insect resistant, “GMO” maize also significantly reduces the incidence of the problematic infections. There is also a “gene silencing” strategy proven by an Arizona State researchers that would prevent the fungus from making its toxin even if it was able to infect the plant.

There has also been a very creative, to design an enzyme that breaks down aflatoxin into harmless bits that was actually facilitated by an on-line, crowdsourced game effort led by a researcher at UC Davis with support from Mars, Inc. Such an enzyme might be able to turn the rejected, contaminated grain from this new sorting mechanism into more food/feed or feedstock for bio-based materials. The most robust and resilient anti-cancer strategy would be to combine all of these methods and finish off with the high speed sorting technology.
So there is new hope for the mental development status of African children and for a lower incidence of cancer there and elsewhere. I guess I just have to say that technology can achieve some really cool results and I hope that non-profits and governmental entities will join Bühler in extending this to the poorest and most vulnerable populations.

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Tuesday, April 3, 2018

A Food Waste Solution You Might Not Know You Are Already Using

The Food Waste Solution That You Might Not Know You Are Using

Some of the bagged bread options in a local grocery store

Do you buy bagged bread in the grocery store?  There are usually several options including bread made with whole grains or containing several different kinds of grain. You have probably noticed that such breads stay nice and soft for quite a while.  Some people are even suspicious about that imagining that the bread might be “loaded with preservatives.”  They are not.  If you buy the freshly “baked in the store” options like baguettes, or get those at a bakery, they are really tasty, but they rather quickly become stale.  They become candidates for making French Toast or maybe croutons.  That kind of short-lived bread is amajor source of food waste and some have even found creative ways to collect stale bread from bakeries and turn it into beer. 

Fresh bread from in-store bakery

The bagged bread on the other hand can remain good and usable for a week or more.  If you don’t get through using the loaf for a long time it might get moldy, but in general each loaf can keep a family fed with morning toast or lunch sandwiches for quite a while. That didn’t used to be the case.  Back in the 1960s the bread aisle was restocked almost every day and you could buy “Day Old Bread” at a discount - but it wasn’t very good. 

So what changed?  It’s an interesting story that involves crystals and enzymes.  We think of stale bread as being “dried out,” but that isn’t the real issue. Staling occurs when the starch changes to a crystalline form in the finished bread. The solution to the food waste problem of stale bread is a type of enzyme called “amylase” that can modify the bread’s starches during baking and keep that crystalline structure from forming after the bread is baked. To unpack that, I’ll go into some background on enzymes and on starch.

OK, flash back to high school biology class.  Do you remember learning about enzymes?  Those are proteins and if you do the 23andme analysis of your DNA, a good deal of it codes for the enzymes that make your body function.  These very cool proteins “catalyze” chemical reactions, serving functions like digesting our food, or turning it into the energy that keeps us going.  There are also enzymes in our liver that protect of from certain toxins.

Bread is made from mostly wheat grains that contain starch.  Starch is a really big molecule that is a long and branched chain built from many units of the simple sugar glucose linked together. The reason that a wheat plant makes starch is so the germinating seed can use it as a source of energy to start growing a new wheat plant.  About 10,000 years ago, we humans started growing wheat as a crop and it has been a major source of our food since then.  We get both energy and protein from eating wheat.

When we eat bread, there is an enzyme in our saliva called amylase that starts breaking the starch into simple sugars and the process continues in our digestive system.  There is a similar enzyme in the wheat itself because that seed needs to be able to tap into the energy stored in the kernel when it starts to grow.  The yeast we add to make bread also has various enzymes including amylase and there are even more enzymes from various organisms in something like sourdough bread.  Bread “rises” because the wheat and yeast amylase enzymes make some of the starch into simple sugars that the yeast then ferments to grow.  In the process the yeast makes carbon dioxide gas that makes bubbles in the dough that make the bread rise.  So in the enjoyment of bread there are already three different kinds of amylase enzymes involved- from the wheat, from the yeast and later from ourselves.

But after the bread is baked, the starch that is still mostly undigested can “re-crystalize” into forms that make the bread taste “stale” to us.  We think of it as “dry” but that isn’t really the issue. It’s a texture thing based on those starch crystals. What the baking industry discovered in 1990 is that they could add a different kind of amylase enzyme to the dough that would control the starch in baked bread and slow down the formation of the crystalline structure that makes the bread taste/feel stale. 

So if you look at the ingredient list of the bread in the store, it could list “enzymes.”  The one that keeps the starch from crystallizing is an amylase. Not only does that reduce the amount of bread waste generated by stores and in customer’s homes, it also has dramatically reduced the number of trips that bread trucks need to make from the bakeries to the stores, thereby reducing the amount of CO2 released into the atmosphere

Note the Enzymes" in this bread ingredient label
When we eat the bread, that tiny amount of enzyme is just a protein that our own digestive enzymes easily break down into the amino acids that we need as a part of our diet. 

So the next time that you pull a loaf of supermarket bread out of your breadbox and find it still soft and tasty, you can appreciate this robust, enzyme solution to the food waste issue of stale bread!

(Note: I am writing this article as part of a partnership with the enzyme producing company, Novozymes. This gives me the time to delve into the technical details about specific enzymes and then try to explain those in ways that make sense to as many readers as possible)