Technological properties of arabinoxylans as baking additives
Technological properties of arabinoxylans as baking additives
Arabinoxylans are soluble fibres extracted from cereal grains, such as the wheat endosperm. Due to the physicochemical and technological properties of these molecules, arabinoxylans can be used as a baking additive to improve dough consistency, increase loaf volumes, improve crumb structure and decrease bread staling. Arabinoxylans are palatable and arabinoxylan-rich foods are well accepted by consumers.
What are arabinoxylans?
Arabinoxylans are soluble fibres extractable from cereal grains. Arabinoxylans have been identified in all major cereal grains, including wheat, barley, oats, rye, rice, sorghum, maize, and millet.
In cereal grains, arabinoxylans are localized mainly in the cell walls of starchy endosperm and the aleurone layer, in the bran tissues, and in the husk of some cereals.
Arabinoxylans can be used as a dietary supplement due to their beneficial effects on gut health, glycaemic control and immune health.
Depending on the genus and species, the amount and structure of arabinoxylans in a particular tissue may vary. For instance, in wheat, there is more arabinoxylan in the walls surrounding the cells of starchy endosperm than in those of aleurone.
Not all arabinoxylans are the same. They vary on the degree of polymerization, which represents the length of the arabinoxylan chains, and on the soluble arabinoxylan content, among others.
Arabinoxylans as technologically functional food ingredients
The role of arabinoxylans in the bread-making processes and their effects on the final bread product have been widely studied. Soluble arabinoxylans, such as those found in the wheat endosperm, have positive effects on dough consistency, loaf volumes, crumb structure and bread staling.
All these characteristics contribute to their utility not only in the bread-making process, but also as neutraceuticals incorporated into functional foods. Arabinoxylans are palatable and arabinoxylan-rich foods are well accepted by consumers. Arabinoxylans have been successfully added to bread, porridge or biscuits, among others.
• Dough consistency
A clear distinction needs to be made between soluble and insoluble arabinoxylans. When added to wheat flour, soluble arabinoxylans, compete for water with other flour constituents. As a consequence, dough consistency is increased.
In opposition, insoluble arabinoxylans can form physical barriers for the gluten network during dough development. The resulting gluten has lower extensibility, which decreases dough consistency.
• Loaf volumes
Soluble arabinoxylans increase the viscosity of the dough’s aqueous phase and, thus, have a positive effect both on dough structure and stability, especially during the early baking processes.
This increased stability surrounding the gas cells is very useful in prolonging oven rise, which leads to an increased loaf volume.
Insoluble arabinoxylans, on the other hand, destabilize dough structure and have a negative effect on loaf volume. They also absorb a large amount of water, leaving less available water for proper gluten development and film formation, resulting in a lower loaf volume.
• Crumb structure
As mentioned, soluble arabinoxylans increase the viscosity of the dough’s aqueous phase, leading to greater dough stability. This increased stability surrounding the gas cells also leads to an improved crumb structure.
• Bread staling
Another functional property of arabinoxylans is associated with their role in bread staling. Bread staling is a complex phenomenon involving loss of aroma, deterioration of crust characteristics and increase in crumb firmness. Stale bread is dry and hard.
Over a 7-day storage period, arabinoxylan-fortified bread exhibits lower crumb hardness than the controls without added arabinoxylans. This is attributed to the higher moisture content in the bread fortified with arabinoxylans, as well as to the plasticizing effects of water. [1]
The bottom line
Due to the physicochemical and technological properties (e.g. water-binding capacity, gelation) of soluble arabinoxylans, such as those found in the wheat endosperm, these molecules can be used as a baking additive to improve dough consistency, increase loaf volumes, improve crumb structure and decrease bread staling. Arabinoxylans are palatable and arabinoxylan-rich foods are well accepted by consumers.
WEBINAR - Brain Fitness
WEBINAR – Brain Fitness
Join us for a deep-dive webinar into Brain Fitness dedicated to the professionals operating in the nutraceutical industry. Together with our expert speakers, we will explore different facets of this “hot topic”, connecting the trends, clinical research and innovation.
Connecting trends, clinical research and innovation for nutraceuticals.
The human brain is our command centre and enables thoughts, memory, movement and emotions by a complex function. Maintaining a fit brain during one’s life is the uppermost goal in pursuing health and wellbeing.
Consumers are increasingly looking to improve Brain Fitness and focus. Nootropic ingredients have been on the rise due to more people looking to enhance their brain performance. Moreover, working remotely with many distractions further accelerated the popularity of such ingredients, which have become a must-have for many individuals.
Therefore, it is essential for professionals in the sector to understand what Brain Fitness really is, the consumers’ segmentation and key insights about this trend, and how the clinical research is performed to evaluate the potential of new nutraceuticals solutions.
Watch the webinar and find out more!
Meet the Speakers:
What are you going to learn during this webinar?
The Brain Fitness trends & consumer insights
Who are these consumers and what are they looking for? Presentation by Marit Veenstra – Trends and consumers insights specialist, who will provide insights into the consumer trends driving the brain health product positioning of the nutraceutical and functional foods market.
Duration: 10 minutes
Clinical Research
How do you research Brain Fitness? Presentation by Sanne Ahles – Clinical researcher, who will dive into the science, explaining the relevant endpoints, tools and biomarkers, currently used in clinical research.
Duration: 10 minutes
Innovation
Brainberry®: Aronia melanocarpa extract to help consumers reach their Brain Fitness goals. Presentation by Cosimo Cisternino – Marketing & Account manager at BioActor, who will introduce the health ingredient Brainberry® – A natural, clinically validated Aronia berry extract targeting cognition.
Duration: 10 minutes
Q&A session
Duration: 10 minutes
What are the health benefits of wheat arabinoxylans?
What are the health benefits of wheat arabinoxylans?
Wheat arabinoxylans are a type of non-starch polysaccharide found in the cell walls of wheat grains. The interest in these molecules has been increasing over time due to their proven health benefits. The consumption of wheat arabinoxylans results in a strong prebiotic effect, enhancement in overall gut health and immunity, and improvement in metabolic parameters such as blood glucose and insulin levels.
What are arabinoxylans?
Arabinoxylans are a type of non-starch polysaccharide found in the cell walls of cereal grains. Arabinoxylans have been identified in all major cereal grains, including wheat, barley, oats, rye, rice, sorghum, maize, and millet. They are localized mainly in the cell walls of starchy endosperm and the aleurone layer, in the bran, and in the husk.
Not all arabinoxylans are the same. Depending on the cereal, the amount and structure of arabinoxylans in a particular tissue may vary. Wheat arabinoxylans are formed by side chains linked by α-(1→2) and/or α-(1→3) bonds along the xylan backbone, and xyloses are most commonly mono-substituted.
The molecular structure of arabinoxylans is also dependent on the extraction method applied. Arabinoxylans can be extracted using chemical, enzymatic, or physical treatments. The different extraction techniques results in differences in the degree of polymerization (which represents the length of the arabinoxylan chains), and the content of soluble arabinoxylan.
As with all dietary fibres, their physicochemical characteristics affect the degree to which they are utilised by the gut microbiota. Higher degrees of polymerization and concentrations of soluble fibre are related to greater bifidogenic effects. [1]
Wheat arabinoxylans can be used as a dietary supplement due to their beneficial effects on gut health, glycaemic control and immune health.
Moreover, due to the physicochemical and technological properties of these molecules (e.g. water-binding capacity, gelation), wheat arabinoxylans can also be used as a baking additive to improve dough consistency, increase loaf volumes and improve crumb structure.
The health benefits of wheat arabinoxylans
Research around wheat arabinoxylans has suggested that these compounds, as part of dietary fibre, have many beneficial physiological effects along the entire human gastrointestinal tract.
These effects are dependent on a complex mixture of molecular and physical properties of arabinoxylan preparations, as well as on the site, rate and extent of their digestion and fermentation in the gut.
Wheat arabinoxylans have strong prebiotic properties
Arabinoxylans have strong prebiotic properties, by selectively stimulating the growth of beneficial bacteria in the colon, such as Bifidobacterium and Bacteroides species. [2,3]
This change in the microbiota is associated with positive health outcomes, such as improved overall health, decreased gut infections and enhanced mineral absorption.
Additionally, the fermentation of prebiotics by intestinal bacteria results in the production of short-chain fatty acids (SCFAs), which have numerous favourable effects.
These effects include the inhibition of harmful bacteria, colon cancer prevention or improvement of glucose tolerance, among others. [4]
Wheat arabinoxylans improve glycaemic control and insulin sensitivity
Evidence suggests that arabinoxylans from wheat improve metabolic control in people with impaired glucose tolerance and with Diabetes type 2, by improving blood glucose and insulin levels.
The short-chain fatty acids (SCFAs) formed from the metabolization of arabinoxylans by the gut microbiota are mainly butyrate, acetate and propionate. Acetate and propionate can bind to a specific protein receptor called GPCR43 in the colon.
After binding, the secretion of two peptides (PYY and GLP-1) is increased. This leads to lowered intestinal motility and a decrease in the levels of a hunger hormone called ghrelin. These processes are key to improving glucose handling. [5,6]
The European Food Safety Authority (EFSA) concluded that there is sufficient scientific evidence to substantiate the health claim that the consumption of arabinoxylans produced from wheat endosperm contributes to a reduction of the glucose rise after a meal. [7]
Some other soluble fibres have also been associated with this health benefit; however, one of the advantages of arabinoxylans lies in their higher palatability.
Wheat arabinoxylans boost immune health
Arabinoxylans have immunomodulatory properties. Specifically, they may enhance adaptive immunity, innate immunity and gut barrier integrity:
1. Adaptive immunity. Arabinoxylans may enhance vaccination efficacy against influenza, resulting in fewer adverse events, fewer respiratory tract infections and an improved seroprotection rate. [8]
2. Innate immunity. As mentioned, arabinoxylans may promote a beneficial short-chain fatty acid (SCFA) profile. This leads to increased cytokine production, improved monocytes recruitment capacity, and activation of regulatory T-cells, resulting in increased immune system vigilance. All these cells are involved in keeping the immune system in check by making sure that it returns to a stable state after invaders have been successfully cleaned up. [9,10]
3. Gut barrier integrity. The short-chain fatty acid (SCFA) butyrate provides additional energy to the gut cells and strengthens the mucus layer. Arabinoxylans further induce the upregulation of tight junction proteins, protecting the human body against foreign invaders and strengthening the immune system. [11,12]
How can you add wheat arabinoxylans to your diet?
Though in small concentrations, wheat arabinoxylans are naturally found in wheat-based products. However, if you want to increase the intake of these compounds in your diet, dietary supplements or enriched functional foods are also available. They can be found in capsule form, in powder blends, bars and even products such as enriched bread, pasta, and a variety of other snacks.
Generally, 1 to 5 grams of arabinoxylans daily are enough to benefit from their prebiotic effect. Regarding EFSA’s health claim on glycaemic control, at least 8% of arabinoxylan-rich fibre produced from wheat endosperm per unit of available carbohydrates should be consumed.
Wheat arabinoxylans are generally considered safe and well tolerated by the gut, meaning that they do not cause intestinal discomfort. [13,14]
What are postbiotics? Let's find out!
What are postbiotics? Let’s find out!
Probiotics and prebiotics are very popular nowadays for their positive effects on gut health. Most recently, postbiotics, which are products or metabolites released from microbial fermentation, have also gained attention due to their health benefits. However, they are still unknown to the majority of consumers.
What are postbiotics?
Postbiotics are defined as a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host”. In other words, they are the bacterial products or metabolites released from microbial fermentation.
For this reason, postbiotics include several types of compounds, such as short-chain fatty acids (that have several health benefits), microbial cell fragments, functional proteins, extracellular polysaccharides, cell lysates or teichoic acid.
Unlike probiotics, postbiotics do not need to be alive to be beneficial, so they are more stable than the living bacteria they are derived from. [1]
Why postbiotics?
Why postbiotics when I can already take probiotics and prebiotics? This may be a question that comes up.
It is important to understand that gut microbiota composition varies between individuals. This means that the degree to which different components are metabolized may be different among persons.
As a result, probiotics and prebiotics may have different health effects between individuals. Moreover, temporal changes in our gut microbiota composition could also influence the effects of these compounds.
On the other hand, many positive health effects of probiotics and prebiotics are due to the production of components such as short-chain fatty acids, microbial fragments, functional proteins or teichoic acid.
As mentioned before, these components are postbiotics, which means that when postbiotics are taken, these components are directly ingested.
If you want to know more about prebiotics, check this article. Or if you are familiar with prebiotics, this article about synbiotics might be for you!
What are the health benefits of postbiotics?
Research suggests that postbiotics may have several health benefits. These include the following:
• Modulation of the microbiota. Postbiotics components such as butyrate, a short-chain fatty acid, are beneficial for gut health. [2]
• Modulation of the immune system. Butyrate can stimulate the production of T cells in the intestine, which helps control immune responses. Other components such as microbial cell wall fragments can increase the production of cytokines, which are chemical messengers that help reduce inflammation and boost immune responses. [2,3]
• Modulation of the metabolism. Propionate, a short-chain fatty acid, can help improve insulin sensitivity and glucose tolerance. On the other hand, butyrate can stimulate the production of an antioxidant called glutathione. [1,2]
• Weight loss aid. Short-chain fatty acids may help weight loss through the modification of eating behaviours. This is due to the release of hormones that increase satiety. [1]
• Reduction of irritable bowel syndrome (IBS) symptoms. A study in 443 individuals with IBS involving orally administered, heat-inactivated Bifidobacterium bifidum, found that the postbiotic substantially alleviated symptoms associated with IBS, such as abdominal pain or discomfort, abdominal bloating and abnormal bowel habits. [4]
• Other potential benefits. Orally administered, inactivated lactic acid bacteria may help eradicate Helicobacter pylori infection, chronic unexplained diarrhoea and the abrogation of the negative effects of stress. [1]
How can I add postbiotics to my diet?
Postbiotics are not as easy to find as probiotics and prebiotics, but they can be purchased in health food stores and online. They are generally considered safe and well-tolerated.
As postbiotics are generated from fermentation by the bacteria in your gut, you can increase postbiotics production by eating foods rich in probiotics and prebiotics. Probiotics can be found in fermented foods and drinks, such as yoghurt, kefir, tempeh or kombucha. Prebiotics can be found in high fibre foods, such as vegetables and whole-grain products.
