Starch Pros

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

December 16^th 2021

Healthier tapioca starch is on the way.

Researchers at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan have recently created a healthier form of starch in the cassava plant. Published in the scientiêc journal Plant Molecular Biology, the study shows how reducing levels of starch branching enzymes (SBEs) in cassava plants changes the composition of tapioca starch, making it more resistant to digestion and healthier for us to eat. Most of the starch we eat comes from cereal crops like rice, corn, and wheat or tuber crops like potato and cassava. Starch contains two molecules—amylose and amylopectin. The diéerence between them is that amylose is a straight chain of glucose molecules connected end to end, while in amylopectin the chains branch out like a tree. The crops we eat diéer in their relative amounts of amylose and amylopectin. For example, rice starch contains about 35% amylose (65% amylopectin), while cassava starch, commonly called tapioca, contains only about 17% amylose (82% amylopectin). Normal starch that includes branching amylopectin is easily digested by enzymes in saliva. That sounds good, but actually amylose and lessbranched amylopectin are healthier because their structures can resist digestion. Instead of giving us unhealthy blood sugar spikes, resistant starch travels to our gut where it becomes food for all the good bacteria that live there and keep us healthy.

The RIKEN CSRS team focused on the cassava plant because it is often overlooked, even though it is one of most import crops in tropical and subtropical regions. “By suppressing multiple genes one by one, we were able to increase the amount of resistant tapioca by about 63%.” says lead researcher Yoshinori Utsumi. “Not only will this starch improve intestinal function, but it will also improve blood sugar and insulin responsiveness.”

Resistant starch has two characteristics. The êrst is amylopectin with fewer branches and longer chains, making is harder to digest. The second is a lower percentage of amylopectin overall. To generate resistant starch, the researchers focused on the enzyme that helps create the branches in amylopectin. To create a branch, one chain of amylose must attach to the middle of another chain of amylose. Creating this bond requires starch branching enzymes (SBEs). The team reasoned that reducing this enzyme’s activity would be a way to generate resistant starch. Therefore, the êrst step was to identify the SBE genes in the cassava genome. Analysis revealed three SBE genes, with a few subtypes. SBE1 and SBE2a appear to be involved in making amylopectin in cassava leaves and roots, while SBE2c is only in the roots.

Next, the researchers created several lines of transgenic cassava to compare with unmodiêed wildtype cassava. The most successful transgenic lines were those in which both SBE1 and SBE2 expression were reduced to about 10% of wildtype expression. Looking at the factors that increase starch resistance, the researchers found that although wildtype cassava contained about 17% amylose, the roots of two transgenic lines in which both SBE1 and SBE2 were reduced contained about 40% amylose. These lines also produced root amylopectin with fewer branches and longer chains. Overall, the percent of resistant tapioca starch rose from 0.4% to about 25%, a whopping increase of about 6300%, although the total amount of starch did decrease a little.

“In addition to advancing cassava molecular breeding, we hope that our êndings will lead to more functional foods that improve human health,” says Utsumi. “Now that we have identiêed the cassava genes for molecularly more resistant starch, the next step will be to verify the eéectiveness of these plants and the tapioca starch they produce.”

Reference: Utsumi et al (2021) Suppressed expression of starch branching enzyme 1 and 2 increases resistant starch and amylose content and modiêes amylopectin structure in cassava. Plant Mol Biol. doi: 10.1007/s11103-021-01209-w

Source: https://phys.org/news/2021-12-healthier-tapioca-starch.html

December 15^th 2021

Natural titanium dioxide substitute: wheat starch component improves the appearance of pet food.

Declaration-friendly alternative from Trigea offers high levels of whiteness and functionality.

The European Food Safety Authority (EFSA) no longer considers the white pigment titanium dioxide (E 171) to be a safe additive in animal feed.1 Trigovit® Starch 1104 ND native small-grain starch has a naturally high degree of whiteness and visually brightens various pet food applications. This starch component from Trigea, a specialist in wheat-based functional ingredients, is not chemically modified, is completely harmless to health and has no E number.

Trigovit® Starch has a whiteness (brightness) of 98.17 on the scale of 0 (black) to 100 (white). In pet food applications, it provides a clear brightening effect and, in snack applications for example, can be used to create offset optical highlights. Now that EFSA’s assessment has already led to a ban on titanium dioxide as a food additive from next year, a similar decision is expected for feed production. For manufacturers who now want to reformulate their products, Trigea offers a natural alternative as well as advice and targeted assistance.

Trigovit® Starch is a native wheat starch produced by physical separation. The size of the starch granules is very small (less than 10 μm), so that ten times more particles are contained in the same volume compared with conventional corn or wheat starch. The starch distributes homogenously in the end product without sedimenting. It is also free-flowing and dispersible, neutral in taste and easily digestible.

Maximilian Hegge, Sales Manager at Trigea, comments: “Demand for a natural substitute for titanium dioxide has increased enormously since the EFSA notification and the ban in the food sector. We frequently encounter this topic at trade fairs and customer meetings. With our native wheat starch, we help manufacturers to prepare for potential changes in the law and ensure that they can make their product as visually appealing as before — with a natural, renewable raw material.”

Source: Source: https://crespeldeitersgroup.com/news/natuerlicher-titandioxid-ersatz/