In an article recently published in the journal Dr foodResearchers have developed a new type of breaded gluten-free sourdough with a pseudocereal formulation Moringa Oleifera, An unconventional crop that promotes health.
Study: Development of functional gluten-free sourdough bread with pseudocereals and enriched with Moringa oleifera. Image credit: Created with assistance from DALL·E 3
The rise of gluten-free alternatives
Bread is a dietary staple that is widely consumed throughout the world. Although most people can eat wheat-based bread, people with celiac disease cannot. Others avoid gluten for lifestyle reasons and gluten sensitivity, which has increased the market for gluten-free products in recent years. As a result, pseudocereals, such as buckwheat, quinoa and amaranth, which are naturally gluten-free, have also attracted much attention.
Why Moringa and Sour?
Researchers hypothesize that moringa plant leaf extract added to bread may be safe for consumption in both healthy and celiac populations. Additionally, sourdough fermentation can enhance protein digestibility, total phenolic compound (TPC) content, antioxidant properties, micronutrient availability and functional properties of bread.
How bread was made and tested
In the current study, researchers evaluated whether gluten-free sourdough bread made with pseudocereals is enriching Moringa oleifera Leaf powder increases its nutritional value, especially protein, amino acids, soluble fiber and essential minerals.
They developed six gluten-free bread formulations, three of which were control breads, containing quinoa, amaranth, or brown rice sourdough, abbreviated as Q, A, and BR. The other three breads were quinoa, amaranth and brown rice sourdough but had moringa. oleifera Extract at 6% concentration in flour, abbreviated as QM, AM, and BRM.
All six types of gluten-free sourdough bread were compared with gluten-free commercial bread (COM) on various parameters.
To make bread, the researchers performed a spontaneous fermentation every 24 h for five days at 25–26°C, where they added water and flour in a 50:50 ratio following Tomic et al. method
Nutritional breakdown: protein, fat and more
During analysis, they determine the composition of moisture, protein, total fat, ash, total dietary, soluble and insoluble fiber (in grams per 100 grams of bread) using the standard methods described by the Association of Official Analytical Chemists (Association of Official Analytical Chemists). AOAC) and their pH, total titratable acidity (TTA), lactic and acetic acid content.
Further, they evaluated the colorimetric parameters of bread, including lightness, yellowness, and redness coordinates (L*, b*, and a*), saturation (C*), and tone (h*). The antioxidant activity of breads was determined using four different assays.
The Folin−Ciocalteu method described by Singleton and Ross was used to determine TPC in breads and their sucrose, maltose, d-glucose and d-fructose (total sugar content) were also analyzed. Similarly, they used Minekus et al. Method to assess mineral bioaccessibility of whole bread samples. Further, the team determined the bread’s fatty acid and amino acid profile and folate content.
Taste testing and consumer acceptance
A total of 35 panelists performed sensory analysis of all types of bread using hedonic tasting, evaluating their color, appearance, aroma, juiciness, texture, taste, general acceptability and purchase intention. They rated each bread sample on a scale of 1–5, with scores of one and five indicating that they did not like the bread and liked it very much, respectively.
During the statistical analysis, a two-way ANOVA test helped to examine differences in amino acid, fatty acid, proximate composition, mineral bioaccessibility, antioxidant capacity, folate and TPC content across all bread samples studied. The post-hoc HSD Tukey test was used to compare least mean squares, where P <0.05 was considered statistically significant.
Among the control breads, Cu bread had the highest protein content and the lowest BR. Since quinoa and Moringa oleifera Both protein and sour fermentation increase protein digestibility, with QM bread achieving the highest protein content, equivalent to 6.76 g/100 g.
Even quinoa’s fat content is higher than brown rice and amaranth and increases it with moringa leaves. Thus, both Q and QM breads are high in total fat (6.07 g/100 g); However, they were lower than COM bread, which had a total fat equivalent of 3.25 g/100 g.
QM bread had the highest total, insoluble and soluble dietary fiber content, whereas COM bread had the lowest. The high fiber content of moringa leaf powder further increases this (24.97 g/100 g).
Moringa oleifera The ash content of reformed bread also increased significantly, especially in QM bread (2.33 g/100 g), while COM bread had a much lower ash content (0.01 g/100 g).
The carbohydrate content of bread depends on moisture, ash, fat, fiber and protein content. As breads enriched with moringa leaves had higher lipid, ash, fiber and protein content, they had lower carbohydrate content, with the lowest level observed in AM bread (36.27 g/100 g). Overall, bread A had the highest carbohydrate content, equivalent to 48.98 g/100 g.
BR bread had the highest pH; However, in general, bread enriched with moringa leaves, due to its high mineral content, had significantly lower pH values (P <0.05) than control bread.
Moringa leaf addition significantly reduced the lightness coordinate (L*) and tone (h*) parameters; But, conversely, it significantly increased the redness coordinate (a*). Moreover, it slightly reduced the saturation (C*) and yellowness coordinate (b*) values.
The darkening of the color after the addition of moringa leaves can be considered a positive point, as gluten-free bread usually has a poor color. It also improved aroma and texture but did not increase acceptance among consumers, who preferred the sensory attributes contributed by pseudocereals alone.
Furthermore, the addition of Moringa leaves significantly increased the TPC and antioxidant activity of bread by 64.54%, 96.37% and 71.15% in QM, AM and BRM, respectively. The increase in TPC of all six formulated gluten-free breads compared to COM bread was statistically significant (P<0.05).
Notably, AM bread had the highest total folate content, antioxidant capacity, and TPC with high amounts of moringa compounds, equivalent to 32.90 mg GAE/g DW, and amaranth bioactive compounds, such as p-hydroxybenzoic acid, vanillic, rutin, and gallic acid.
Regarding mineral bioaccessibility, the bread was high in iron (Fe) and calcium (Ca) minerals, which is especially important for celiac patients who are deficient in these micronutrients. BR bread achieves greater mineral bioaccessibility mainly due to lower phytic acid content. Sourned control bread had higher bioaccessibility of most minerals including Fe, Ca, Mn (manganese), Zn (zinc), Sr (strontium), S (sulfur) and B (boron).
All pseudocereals, quinoa, buckwheat and amaranth, are rich sources of amino acids. Thus, Q, A, and BR breads contained higher amounts of methionine, phenylalanine, cysteine, and hydroxyproline, equivalent to 66.79, 213.73, 69.04, and 0.26 g/100 g, respectively. Because of the high content of all folate-monoglutamate, BRM bread can be great for celiac patients who are generally deficient in folate.
In sensory evaluation, QM bread achieved the highest score on aroma and texture attributes, while A bread emerged as the winner in appearance, taste, color and acceptability. BRM bread scored lowest in terms of aroma, taste and overall acceptability.
Ultimate health benefits and future prospects
According to the authors, this is the first time a gluten-free sourdough bread pseudocereal has been fortified. Moringa Oleifera, A drought-resistant and high-yielding crop with several health benefits.
The inclusion of moringa significantly increased the nutritional richness, especially in terms of protein, amino acids and essential minerals. Also, it increases the level of soluble dietary fiber in the bread, which has health benefits. Accordingly, bread fortified with moringa leaves had higher antioxidant capacity, TPC, folate content, phenylalanine and cysteine amino acid content, total sugars and fatty acids such as docosahexaenoic acid (DHA).
Furthermore, a panel of tasters found this novel formulation acceptable and agreed that it met the requirements for labeling as a functional food.
Overall, reformulated gluten-free sourdough breads with pseudocereals and fortified with moringa can improve the health of all people. They may be most beneficial for people with celiac disease who lack nutrients due to their reliance on gluten-free bread.