Would you like wood chips with that?<\/p>\n
Someday, restaurants will serve wood chips the same way they now serve mashed potatoes and grits. Also on the menu will be corn stems, husks and other unappetizing plant parts. And what\u2019s more, diners will love the stuff.<\/p>\n
That\u2019s what Virginia Tech professor Y.H. Percival Zhang is promising the world.<\/p>\n
Zhang, who studies biological systems engineering at the university\u2019s College of Agriculture and Life Sciences, has developed a process that can transform wood chips, corn stems and other agricultural refuse into edible starches. And he hopes to do it someday in a facility that will look like a giant brewery.<\/p>\n
Plants everywhere consist of cellulose\u2014the substance that makes up plant cell walls and vegetable fibers like cotton. But in its raw form, cellulose is inedible. It\u2019s too coarse, it\u2019s not tasty, and humans can\u2019t digest it properly. But cellulose and starch have the same chemical formula \u2014 they are polysaccharides, which means their molecules are chains of glucose units, or sugars. The only difference is in their chemical bonds.<\/p>\n
\u201cBoth of them are made by sugars, but they use different linkages between the glucose units,\u201d Zhang said in an interview.<\/p>\n
Edible starches such as tapioca and potato consist of glucose units joined by alpha-1,4-glycosidic bonds and alpha-1,6-glycosidic bonds, a type of link between sugar molecules. When we digest those starches, our bodies produce an enzyme, amylase, which breaks the bonds and turns the starches into sugar.<\/p>\n
Inedible cellulose consists of glucose units joined by different links, named beta 1,4-glycosidic bonds. These bonds can be broken down by a different enzyme, cellulase, but our bodies don\u2019t produce it. \u201cThat\u2019s why humans can\u2019t eat cellulose,\u201d Zhang said.<\/p>\n
But here\u2019s good news, bark lovers: Zhang has found the answer.<\/p>\n
If the beta bonds are converted into alpha bonds, the coarse cellulose turns into a soft, powdery substance like corn starch \u2013 and Zhang and his team have developed a process that restructures the bonds to do just that. \u201cOur idea was to use enzymes, which can break down beta 1,4 bonds,\u201d Zhang said, \u201cthen link them again and form new bonds as the alpha ones.\u201d<\/p>\n
Zhang\u2019s process essentially creates a giant stomach. He takes corn stover – a mix of corn stalks, leaves and even weeds and grasses – and stirs different types of enzymes into it.<\/p>\n
\u201cIt\u2019s similar to the human body, which also uses various enzymes, one after another, to break down foods,\u201d he said. The resulting amylose looks and tastes just like a regular starch. \u201cIt tastes a little sweet,\u201d Zhang said, adding that unfortunately, \u201cthere\u2019s no ready recipe for cooking amylose.\u201d<\/p>\n
Well . . . not yet. But there will be.<\/p>\n
Zhang developed the process in his lab bioreactor, a container not much larger than a syringe. But the process is easy to scale. An industrial bioreactor would look like a typical brewery vat used for fermenting beer\u2014only instead of grain, it would use corn stover, and instead of yeast, it would use enzymes.<\/p>\n
\u201cIn our vision, we will produce this starch in a factory called a biorefinery,\u201d Zhang said. He estimates production costs will be very low because enzymes are cheap and reusable, and agricultural refuse is aplenty. \u201cCorn stover is the number one agricultural refuse in the U.S.,\u201d Zhang said. \u201cThe ultimate cost may be nearly zero.\u201d<\/p>\n
In addition to amylose, the other product of the reaction is ethanol, which can be used as biofuel, thus helping solve the world\u2019s fuel problem.<\/p>\n
But Zhang\u2019s method has the potential to solve an even more important global challenge\u2014world hunger. Cellulose is the earth\u2019s most abundant carbohydrate. It makes up the cellular structure of all plants \u2014 crops and weeds, including stalks, stems, branches, leaves, trunks and bark. Plants produce about 40 times more cellulose than edible starch, and a lot of it is wasted.<\/p>\n
\u201cEvery ton of cereals harvested is usually accompanied by the production of two to three tons of cellulose-rich crop residues, most of which are burned or wasted rather than used for cellulosic biorefineries,\u201d Zhang and his colleagues wrote in a recent study published in Proceedings of the National Academy of Sciences.<\/p>\n
With Zhang\u2019s method, any plant material from weed to wood can be turned into food. So far, the team hasn\u2019t found an investor to build the first brewery-like biorefinery, but Zhang hopes countries with large populations like China and India may become interested.<\/p>\n
Amylose is also healthier than the starches used in food production today because it breaks down slowly in the digestive tract. Foods with high amylose content, such as long-grain rice, don\u2019t cause sugar spikes and are diabetic-friendly.<\/p>\n
So if one day, your waiter asks \u201cWould you like wood chips with that?\u201d just say yes. You\u2019ll be eating carbs so healthy you\u2019ll be barking for more.<\/p>\n","protected":false},"excerpt":{"rendered":"
Would you like wood chips with that? Someday, restaurants will serve wood chips the same way they now serve mashed potatoes and grits. Also on the menu will be corn stems, husks and other unappetizing plant parts. And what\u2019s more, diners will love the stuff. That\u2019s what Virginia Tech professor Y.H. Percival Zhang is promising […]<\/p>\n","protected":false},"author":59,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","nova_meta_subtitle":"","footnotes":""},"categories":[5572],"tags":[],"supplier":[1643,656],"class_list":["post-19908","post","type-post","status-publish","format-standard","hentry","category-bio-based","supplier-proceedings-of-the-national-academy-of-sciences-of-the-usa-pnas","supplier-virginia-tech"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/19908","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/59"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=19908"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/19908\/revisions"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=19908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=19908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=19908"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=19908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}