Starch Pros

May 25^th 2022

Researchers use CRISPR technology to modify starches in potatoes.

Humble potatoes are a rich source not only of dietary carbohydrates for humans, but also of starches for numerous industrial applications. Texas A&M AgriLife scientists are learning how to alter the ratio of potatoes’ two starch molecules — amylose and amylopectin — to increase both culinary and industrial applications.

For example, waxy potatoes, which are high in amylopectin content, have applications in the production of bioplastics, food additives, adhesives and alcohol.
Two articles recently published in the International Journal of Molecular Sciences and the Plant Cell, Tissue and Organ Culture journals outline how CRISPR technology can advance the uses of the world’s largest vegetable crop.
Both papers include the work done by Stephany Toinga, Ph.D., who was a graduate student in the lab of Keerti Rathore, Ph.D., AgriLife Research plant biotechnologist in the Texas A&M Institute for Plant Genomics and Biotechnology and Department of Soil and Crop Sciences. Also co-authoring both papers was Isabel Vales, Ph.D., an AgriLife Research potato breeder in the Texas A&M Department of Horticultural Sciences. Toinga is now a Texas A&M AgriLife Research postdoctoral associate with Vales.
“The information and knowledge we gained from these two studies will help us introduce other desirable traits in this very important crop,” Rathore said.

Potatoes are the No. 1 vegetable crop worldwide and the third most important human food crop, only behind rice and wheat in global production. Potatoes are grown in over 160 countries on 40.8 million acres and serve as a staple food for more than a billion people.
With a medium-size potato supplying approximately 160 calories, mostly derived from starch, the tubers constitute an important energy source for many people worldwide, Rathore said. Potatoes also provide other necessary nutrients, including vitamins and minerals.
Potatoes are a cool-season crop that is relatively sensitive to heat and drought stress. The crop also suffers from pests such as Colorado beetle, aphids and nematodes, as well as diseases including early and late blight, zebra chip, Fusarium dry rot and a number of viral diseases. Late blight was the cause of the Irish potato famine.

The amount of starch in potato tubers is the main factor that determines a potato’s use. High-starch potatoes are often used to make processed foods such as french fries, chips and dehydrated potatoes, Vales said.
Potatoes with low to medium starch levels are frequently used for the fresh or table stock market, she said. For the fresh market, additional important considerations are tuber appearance, including skin texture, skin color, flesh color and tuber shape. Recently, specialty potato types with different shapes, such as fingerlings; smaller sizes; and red, purple or yellow skin and flesh colors are becoming popular because of their convenience in cooking and increased nutritional value.Potato tuber shape is less important for industrial purposes than it is for human consumption, Vales said. Potato tubers with external deformities caused by heat or drought stress or other factors can be re-directed to myriad uses, including food for dogs and cattle. In addition, potato starch can produce ethanol for fuel or in beverages like vodka; a biodegradable substitute for plastics; or adhesives, binders, texture agents and fillers for the pharmaceutical, textile, wood and paper industries, and other sectors.
For industrial applications, the amount and type of starch in a potato are important considerations. Toinga said starches higher in amylopectin are desirable for processed food and other industrial applications due o their unique functional properties. For example, such starches are the preferred form for use as a stabilizer and thickener in food products and as an emulsifier in salad dressings. Because of its freeze-thaw stability, amylopectin starch is used in frozen foods. Additionally, potatoes rich in amylopectin starch yield higher ethanol levels compared to those with other starches.

Developing potato cultivars with modified starch could open new opportunities, Toinga said. Potatoes with high amylopectin and low amylose, like the gene-edited Yukon Gold strain she described in the International Journal of Molecular Sciences, have industrial applications beyond traditional uses.
In contrast, potatoes with high amylose levels and low amylopectin would be desirable for human consumption, Vales said. The amylose acts like fiber and does not liberate glucose as easily as amylopectin, thus resulting in a lower glycemic index and making potatoes more acceptable for people with diabetes.

CRISPR/Cas9 technology has expanded the toolset available to breeders, Vales said, and it represents a more direct, faster means to incorporate desired traits into popular commercial crop varieties. Conventional breeding is a lengthy process that can take 10-15 years.
In addition, she said, due to the complex nature of the potato genome, generating new cultivars with the right complement of desirable traits is challenging for conventional breeding. Molecular breeding has enhanced breeding efficiencies, and gene-editing using the CRISPR/Cas9 technology adds another level of sophistication.
“We utilized the Agrobacterium method to deliver the CRISPR reagents into potatoes because it is reliable, efficient and least expensive compared to all other delivery methods,” Rathore said.
In the first study, highlighted in the Plant Cell, Tissue and Organ Culture article, a potato line containing four copies of gfp, a jellyfish gene that allows a fluorescence-based visualization of the gene’s activity, was targeted for mutation using the CRISPR/Cas9 system, Toinga said.
In essence, this project provided an easy-to-see trait that enabled researchers to optimize the methodology. “Loss of the characteristic green fluorescence and sequencing of the gfp gene following CRISPR treatment indicated that it is possible to disrupt all four copies of the gfp gene, thus confirming that it should be possible to mutate all four alleles of a native gene in the tetraploid potato,” Rathore said.

Among the various potato cultivars evaluated in the first study, the Yukon Gold strain regenerated the best, and so it was used for the second study. In the second knockout study, described in the International Journal of Molecular Sciences, the native gene gbss in the tetraploid Yukon Gold strain was targeted to effectively eliminate amylose. The result was a potato with starch rich in amylopectin and low in amylose.
“One of the knockout events, T2-7, showed normal growth and yield characteristics but was completely devoid of amylose,” Toinga said. That tuber starch, T2-7, could find industrial applications in the paper and textile sectors as adhesives/binders, bioplastics and ethanol industries. Tuber starch from this experimental strain, because of its freeze-thaw stability without the need for chemical modifications, should also be useful in producing frozen foods. Potatoes with amylopectin as the exclusive form of starch should also yield more ethanol for industrial use or to create alcoholic beverages.
As the next step for these studies, the T2-7 strain has been self-pollinated and crossed with the Yukon Gold strain donor and other potato clones to eliminate the transgenic elements.

Source: https://www.mdpi.com/1422-0067/23/9/4640

May 12^th 2022

ADM continues evolution of carbohydrate solutions business with significant expansion of starch production in Marshall, Minnesota.

Food commodities giant ADM will invest substantially in expanding its starch production facility in the US to meet the rising demand from F&B sectors and industrial customers for plant-based ingredients. The Minnesota-based project is expected to be complete by the third quarter of 2023.

The envisioned capacity will propel the company’s BioSolutions platform and grow its carbohydrates solutions business. BioSolutions delivered US$100 million in annualized revenue in 2021 with a continued swift expansion of US$55 million in new sales growth in 2022, according to ADM.

The financial details of the current investment have not been released.

“Three years ago, we announced that we would be phasing out production of high-fructose corn syrup at Marshall and expanding starch production to support increasing demand for products like sustainable packaging,” says Chris Cuddy, president, carbohydrate solutions business, ADM.

“In the short time since then, demand has continued to expand, both for food and beverage customers and the broad array of plant-based products that make up our fast-growing BioSolutions platform,” he highlights.

“This significant capacity expansion will help ensure we can continue to meet our customers’ needs across this broad portfolio.”

ADM’s BioSolutions platform focuses on meeting the demand for more sustainable products and solutions across various applications, including F&B, packaging and personal care.

Finite materials and the production of physical waste are a big concern for consumers. A key R&D focus of the platform is plant-based materials and processing practices that reduce waste and energy use from development to disposal.

“We’re continuing to expand the frontier of what is possible to meet the demand for sustainable, plant-based products and solutions,” Cuddy continues.

“From our bioplastics agreement with LG Chem to our work with NET Power and 8 Rivers to build a zero-emissions power plant in Decatur, to our advancement of the decarbonization of our footprint, we’re powering growth and living our purpose with the continued evolution of our carbohydrates solutions business,” he outlines.

Source: https://www.adm.com/en-us/news/news-releases/2022/5/adm-continues-evolution-of-carbohydrate-solutions-business-with-significant-expansion-of-starch-production-in-marshall-minnesota/

April 30^th 2022

Hybrid electro-biosystem upcycles carbon dioxide into energy-rich long-chain compounds.

Artificial upcycling of carbon dioxide (CO2) into value-added products in a sustainable manner represents an opportunity to tackle environmental issues and realize a circular economy.

However, compared with facilely available C1/C2 products, efficient and sustainable synthesis of energy-rich long-chain compounds from CO2 still remains a huge challenge.

A joint research team led by Prof. XIA Chuan from the University of Electronic Science and Technology of China, Prof. YU Tao from the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, and Prof. ZENG Jie from the University of Science and Technology of China, has developed a hybrid electro-biosystem, coupling spatially separate CO2 electrolysis with yeast fermentation, which efficiently converted CO2 to glucose.

The results were published in Nature Catalysis on April 28.

The proposed spatially decoupled electro-biosystem includes CO2 electrolysis and yeast fermentation. It can convert CO2 to glucose or fatty acids with both high titer and high yield.

“Acetic acid is not only the main component of vinegar, but also one of the excellent biosynthetic carbon sources. It can be transformed into other substances in life, such as glucose. Acetic acid can be obtained by direct electrolysis of CO2, but with ultra-low efficiency. We thus propose a two-step strategy to convert CO2 into acetic acid, with CO as the intermediate,” said Prof. ZENG.

Accordingly, the researchers first converted CO2 into CO in a membrane electrode assembly using a Ni–N–C single-atom catalyst, and then developed a grain-boundary-rich Cu (GB_Cu) catalyst for acetate production from electrochemical CO reduction.

GB_Cu exhibited a high acetate Faradaic efficiency up to 52% at -0.67 V versus a reversible hydrogen electrode in a typical three-electrode flow cell reactor using 1.0 M KOH aqueous electrolyte.

“However, the acetate produced by conventional electrocatalytic devices is always mixed with electrolyte salts which cannot be directly used for biological fermentation,” said Prof. XIA.

To tackle this challenge, the researchers developed a porous solid electrolyte reactor equipment with thick anion exchange membranes for pure acetic acid solution separation and purification. It continuously and stably worked for 140 hours under a current density of -250 mA cm-2, which achieved an ultrapure acetic acid solution with a relative purity of ~97% wt.%.

In the following microbial fermentation, the researchers deleted all defined hexokinase genes (glk1, hxk1, hxk2, YLR446W and emi2) in Saccharomyces cerevisiae to enable microbe growth on pure acetic acid and the efficient release of glucose in vitro.

The overexpression of heterologous glucose-1-phosphatase further improved the glucose titer. S. cerevisiae was fed with titrated acetate from electrolysis, obtaining an average glucose titer of 1.81 ± 0.14 g·L-1, equivalent to a high yield of 8.9 μmol per gram of yeast per hour. Similar results were observed in S. cerevisiae fed pure acetic acid.

In addition, an engineered S. cerevisiae for free fatty acids production was fed via titrating acetate from electrolysis, with a total free fatty acids (C8~C18) titer of 500 mg·L-1.

Pure and concentrated acetic acid from electrochemical CO2 reduction served as the carbon source for S. cerevisiae fermentation. Such a platform for long-chain products is promising for large-scale practical use.

“This demonstration is a starting point for realizing light-reaction-free artificial synthesis of important organic products from CO2,” said Prof. YU.

Source: https://english.cas.cn/newsroom/research_news/chem/202204/t20220429_304775.shtml

March 28^th 2022

Lantmännen introduces gluten-free wheat starch to counter effects of celiac disease.

In response to the growing number of gluten-intolerance diagnoses, Lantmännen Biorefineries has launched its gluten-free wheat starch from autumn wheat harvested in Sweden. The market for gluten-free products is also growing due to more consumers adopting a gluten-free diet for lifestyle and health reasons.

“After several years of development, we can now offer the market a gluten-free ingredient with good baking properties that do not affect the final product’s taste. In addition, it is the first Swedish alternative in this fast-growing market,” according to Lars Franzén, head of food ingredients, Lantmännen Biorefineries.

Wheat starch has many functional properties in baked goods compared to other starches. It stabilizes bread crumb structure and texture, creating a loaf of bread with an even crumb. When baking gluten-free, the stabilizing and binding function of gluten must be reached via the addition of other ingredients, for example, hydrocolloids and fibers.

Gluten-free wheat starch is a fine white powder with a neutral taste. When cooled down, it forms consistent and firm gels and contains less than 0.35% protein. It is also non-soluble in cold water and hot swelling. Lantmännen Biorefineries has launched a gluten-free wheat starch for bakery goods.

According to European directives, the product has been approved as gluten-free and will be launched initially in the Nordics and in northern Europe, where demand is very high.

The diagnosis of celiac disease (gluten intolerance) has increased significantly, affecting approximately 2% of the regional population. Gluten-free wheat starch allows bakers to create various products in the same formulations they are used to, without gluten.

Lantmännen Unibake acquired the production assets from French Bakery Company AS, a Norwegian bakery located close to Drammen, in 2020. The acquisition was a critical step in providing sustainable products and bakery solutions in Norway and meeting consumer demand for locally produced bakery products. The acquisition included the take-over of French Bakery Company’s production equipment.

Source: https://www.lantmannenreppe.com/products/gluten-free-wheat-starch/

March 24^th 2022

Study: Preparation and Properties of Pea Starch/ε-Polylysine Composite Films.

In this study, the authors examined the composite films made of ε-polylysine (PL) and pea starch (St), where St and PL were utilized as the matrix and sodium alginate and glycerol were used as the plasticizers. The composite films’ mechanical, rheological, spectroscopic, water vapor permeability (WVP) and oil permeability, thermogravimetry (TGA), microstructure, and antibacterial characteristics were investigated. The proposed five solutions of the film were made up of various pseudoplastic fluids.

The team explored the effects of blends with various proportions of St and PL on film-forming ability and microbial inhibition were explored. The apparent viscosity shear rate curves of the five composite film solutions were measured by using a rheometer. The average value of five points on a film measured with a micrometer caliper was used to calculate the thickness of each composite film. A physical property tester was used to determine the films’ tensile strength (TS) and fracture elongation (E).

The researchers used the quasi-cup method to determine the WVP of the composite films. The thermal stability of the powder samples was investigated with a thermal analyzer employing TGA and differential thermogravimetric analysis (DTG). A scanning electron microscope was used to examine the morphology of the composite films. To investigate the antibacterial characteristics of the composite films, Escherichia coli (ATCC 25312), yeast (Saccharomyces cerevisiae, ATCC 204508), and Bacillus subtilis (ATCC 23857) were used.

Source: Yu, Z., Gong, D., Han, C., Preparation and Properties of Pea Starch/ε-Polylysine Composite Films. Materials 15(6) 2327 (2022).

Link: https://www.mdpi.com/1996-1944/15/6/2327

March 03^rd 2022

Green flexible electronics based on starch.

Abstract.

Flexible electronics (FEs) with excellent flexibility or foldability may find widespread applications in the wearable devices, artificial intelligence (AI), Internet of Things (IoT), and other areas. However, the widely utilization may also bring the concerning for the fast accumulation of electronic waste. Green FEs with good degradability might supply a way to overcome this problem. Starch, as one of the most abundant natural polymers, has been exhibiting great potentials in the development of environmental-friendly FEs due to its inexpensiveness, good processability, and biodegradability. Lots of remarks were made this field but no summary was found. In this review, we discussed the preparation and applications of starch-based FEs, highlighting the role played by the starch in such FEs and the impacts on the properties. Finally, the challenge was discussed and the outlook for the further development was also presented.

Source: https://www.nature.com/articles/s41528-022-00147-x

February 08^th 2022

Inspired by the always immaculate lotus leaf, researchers have developed a self-cleaning bioplastic that is sturdy, sustainable and compostable.

Inspired by the pristine lotus leaf, Australian scientists have engineered a quickly biodegradable yet self-cleaning plastic they say is ideal for packaging fresh and takeaway foods.

If successfully commercialised, the wholly compostable product would help reduce the almost 80 per cent of plastic waste left to accumulate as landfill or sloughed off as a litter.

Like the foliage of the Nelumbo nucifera blossom, the synthetically-engineered substance repels liquids and dirt, making it suitable to meet hygiene standards.

Once discarded, it then breaks down rapidly in the soil.

Lead author of the RMIT University project, PhD candidate Mehran Ghasemlou, says the bioplastic was created with mass production in mind.

“Plastic waste is one of our biggest environmental challenges but the alternatives we develop need to be both eco-friendly and cost-effective to have a chance of widespread use,” he said.

“We designed this new bioplastic with large-scale fabrication in mind, ensuring it was simple to make and could easily be integrated with industrial manufacturing processes.”

Although strong, the product is made from cheap and widely-available starch and cellulose to keep production costs low and support biodegradability.

Unlike other compostable plastics, its fabrication doesn’t require heating or industrial processing and would be simple to upscale to a roll-to-roll production line, Mr Ghasemlou says.

Neither does the new plastic need industrial intervention to biodegrade, with trials showing it breaks down naturally and quickly once exposed to bacteria and bugs in the soil.

“Our ultimate aim is to deliver packaging that could be added to backyard compost or thrown into a green bin alongside other organic waste,” Mr Ghasemlou said.

“The food waste can be composted together with the container it came in, to help prevent … contamination of recycling.”

Lotus leaves are known to have some of the most water-repellent surfaces on Earth and are almost impossible to get dirty.

The secret lies in the leaf’s surface structure, which is composed of tiny pillars topped with a waxy layer.

Water that lands on the leaf remains as droplets that roll off with the help of gravity or wind. They also sweep up dirt as they slide.

To emulate the effect, the RMIT team imprinted the surface of the plastic with a pattern that mimics the structure and coated with it a protective layer of PDMS, a silicon-based organic polymer.

Tests show it not only repels liquids and dirt effectively, it retains its self-cleaning properties after being scratched with abrasives and exposed to heat, acid and ethanol.

Co-author of the research Professor Benu Adhikari says the design overcomes the key challenges of starch-based materials.

“Starch is one of the most promising and versatile natural polymers but it is relatively fragile and highly susceptible to moisture,” he said.

“Through our bio-inspired engineering that mimics the ‘lotus effect’, we have delivered a highly-effective starch-based biodegradable plastic.”

Source: https://www.rmit.edu.au/news/all-news/2022/feb/self-cleaning-bioplastic

February 02^nd 2022

Łódź scientists create revolutionary ‘heavy-duty’ biodegradable materials from modified starch.

Scientists from Łódź have solved a ‘long-standing problem’ after engineering an innovative new biodegradable, heavy-duty foil made from modified starch.

Although the use of starch in recycled materials is not new, previous attempts to apply it created materials that were weak and susceptible to tears.

But now the revolutionary development means that for the first time a starch material that is both biodegradable and durable can be used in the form of a thin foil for the production of bags, sachets and foil packaging for foodstuffs or cosmetics packed on trays.

It can also be used to make disposable single use trays and plates.

Team leader Professor Grażyna Budryn from the Łódź University of Technology said: “We were able, to a substantial degree, to overcome the defects thanks to the addition of an extra ingredient to the starch, an organic acid present in many grains, which in this case cause the cross-linking of the starch.

“This leads to a reduction in water absorption, gas permeability and tearing susceptibility of the foil modified in this way.”

In addition, the material also possesses anti-microbial properties, obtained through the addition of a natural substance, a chicory root extract.

The team are now working on an additional hydrophobic layer for their biodegradable foil which will make it useful also as a packaging for moist products.

Professor Budryn said: “The hydrophilic nature of the foil ensures that it can be easily and quickly biodegraded, however the applications of such a foil for the packaging of moist products is limited.

“Here natural hydrophobic layers based on lipids, can be useful…We plan to develop a variant of the foil with a hydrophobic layer, which will also be biodegradable.”

The team also included Professor Agnieszka Nowak and Dr Andrzej Jaśkiewicz.

Source: https://p.lodz.pl/en/about-tul/news/patent-biodegradable-foil-lodz-university-technology

January 31^st 2022

Plantcarb, spin out, start up for starch with 100% amylose.

Plantcarb ApS is a plant biotechnological spin out from Aarhus University and University of Copenhagen established by (among others) two scientists who – as the only ones in the world – have developed a method for producing agricultural crops whose starch consists of 100% amylose. Starch is composed of two kinds of molecules. One type branches off and is called amylopectin (~ 75%). The other does not branch out and is called amylose. The two forms have very different properties. Unlike amylopectin, amylose does not dissolve in the stomach for sugar. Amylose therefore prevents type-2 diabetes. And unlike amylopectin, amylose is an excellent raw material for compostable bioplastics. Plantcarb focuses on both food and industry. For food, a 100% amylose crop (HIAMBA®) is developed to be used for flour for bread. For industrial use, a variant of 100% amylose maize is bred.

See also: https://plantcarb.com/#home .

Source: https://international.au.dk/collaboration/technology-transfer/spin-outs/plantcarb

December 20^th 2021

How starch makes its way through your body and its effect on health.

Starch digestion is a complex process that begins in the mouth and ends in the guts, all the while releasing glucose that provides energy for all tissues and organs and nutrients for vital gut bacteria.
Starch, known in some circles as a controversial carb, is often labelled as either good or bad. It turns out, the way starch is digested determines its nutritional qualities and its effect on our health.

The importance of starch to humans dates back to the Palaeolithic era. Researchers believe starchy foods from roots and tubers might have had a crucial role in the evolution of modern humans (Homo sapiens) from their early hominin ancestors.

Around one million years ago, humans began to consume starchy plant foods regularly, possibly thanks to the discovery of the cooking process. Around the same time, genetic variation equipped humans with multiple copies of the salivary amylase gene (AMY1), which initiates the digestion of starch in the mouth.

University of Sydney researchers hypothesis that the increased availability of dietary starch led to an expansion of the human brain.

Today, starch is found in many staple foods and is the main glycaemic (glucose-releasing) carbohydrate in human diets, contributing to 50 to 70% of dietary energy.

Raw starch is poorly digested.

“We need to cook our food to be able to eat it,” said Professor Emeritus Les Copeland AM, an agricultural chemist who has studied starch for 40 years at the University of Sydney.

The application of heat and absorption of water disrupts, at least partially, the starch structure, making it more digestible. But not all starch is digested the same way.

Starch is a polymeric carbohydrate consisting of numerous glucose molecules joined by glycosidic bonds. Some starch molecules are linear, and others have a more complex, tree-like structure.

The way these two are combined makes some starches less digestible than others, so they take longer to go through the body.

Rapidly digested starch (RDS) is found in highly processed foods such as many breakfast cereals and white bread. It’s digested chiefly within 20 to 30 minutes, releasing glucose and setting off rapid insulin response.

“Over time, exposing yourself to this sort of rapid release of glucose increases the risk of health issues such as diabetes and obesity,” Emeritus Professor Copeland said.

Foods can contain either rapidly digested starch (RDS) or slowly digested starch (SDS).

That does not mean we should be avoiding RDS altogether.

Glucose is an essential energy source for all tissues, especially the brain, kidneys, red blood cells and reproductive tissues. The brain alone uses about 25% of the total energy expenditure even though it accounts for less than 10% of body weight.

Glucose is also the primary energy source for foetal growth, and higher starch intake during pregnancy and nursing is essential.

Slowly digested starch (SDS) takes longer to break down and moves from the stomach to the small intestine, largely intact. This type of starch is found in whole grains, legumes and starchy nuts.

SDS digestion results in a slower release of glucose and consequently a moderated insulin response. Also, emerging evidence suggests that remnants of SDS that reach the ileum – the junction between the small intestine and the colon – trigger the release of hormones that make us feel fuller.

Emeritus Professor Copeland, who in 2020 received the F B Guthrie Grain Science Medal, which recognises outstanding scientific achievement and contribution to knowledge in the field of grain science, said an active area of research focuses on resistant starch.

This is found in starchy raw food like green bananas, some nuts and seeds, or that has been refrigerated after cooking like potatoes.

Resistant starch granules are often encapsulated into bulky structural material, which renders them hardly digestible.

Researchers have discovered that resistant starch has a vital role in human health because it reaches the colon – the last section of our intestine – and becomes food for gut bacteria.

“The gut has a colony made up of thousands of different species of bacteria that work in a collaborative way to break down resistant starch and draw nutriment from it,” said Emeritus Professor Copeland.

“They grow and proliferate. The health and richness of this community of bacteria are vital, and when that balance is lost, that is associated with illness.”

Emeritus Professor Copeland said what we eat has a profound effect on our health, but “if something is good for you, it doesn’t mean that more is better for you”.

Instead, he said it is crucial to find balance in our diet of different foods that contribute to body health and functions.

“We eat meals, not food.”

Source: https://www.sydney.edu.au/science/news-and-events/2021/12/20/nutritional-qualities-of-starch-depend-on-the-way-it-is-digested.html