Background and objectives
Plant industrial by‐products are relatively low cost and rich in organic material. Although these by‐products are a good source of various nutritional compounds, they represent the main disposal problem for the food industry. Wheat bran, one of the main by‐products of the wheat milling industry, contains more than 15% high‐quality proteins. However, these proteins are present in a form which is poorly digested as they are enclosed within a matrix of cell wall polysaccharides. About 15.5 million tonnes of usable protein could be recovered from bran if a commercial extraction process can be made viable. The purpose of this work was to extract protein from durum wheat bran using an alkaline acid method to study its nutritional and functional properties with the goal of using it as a fortifying material in cereal‐based foods such as pasta and bread.
Findings
Durum wheat bran protein concentrate (WBPC) was prepared by using an alkaline extraction method (pH 9.5 for two hours) followed by isoelectric precipitation (pH 4.2). Chemical, nutritional, and functional properties of WBPC were obtained. WBPC had a protein content of ~61% (protein yield 20.5%–24.8%), containing also lipids, fiber, and small quantities of starch. WBPC was enriched in phytosterols compared to wheat bran (11.59 vs. 5.14 mg/g) with β‐sitosterol the predominant (4.37 mg/g). WBPC was also enriched in all the amino acids compared to bran, especially lysine and threonine. WBPC retained some phenolic acids, but at an eightfold lower quantity than in bran and retained about half the antioxidant activity (DPPH) of bran. WBPC showed excellent functional properties in terms of high solubility over a wide range in pH and good water and fat absorption capacity. The main protein components were albumin and globulin proteins.
Conclusion
The extraction method used produced a protein concentrate in reasonable yield with high protein content enriched in essential amino acids and phytosterols compared to wheat bran with good functional properties and phenolic acids and antioxidant potential.
Significance and novelty
The nutritional and functional properties of WBPC make it a promising ingredient for various food products such as cereal and baked foods, processed meat, and beverages.
Wheat bran is a conventional by-product of the wheat milling industry mainly used for animal feed. It is a rich and inexpensive source of phytonutrients, so is in demand for fibre-rich food products but creates quality issues when incorporated into bread. The purpose of this study was to characterize the physicochemical properties and phytochemical composition of different size durum bran fractions and show how they impact bread quality. Durum wheat (Triticum durum Desf.) was milled to create a coarse bran fraction (CB), which was further ground into a finer fraction (FB) which was sieved using four screens with apertures 425, 315, 250, 180, and <180 µm to create a particle size range of 1497 to 115 µm. All fractions contained phytosterol with highest in the 180 and FB, while total phenolic acids and antioxidant capacity was highest in CB and 425. Use of the fractions in a leavened common wheat (T. aestivum L.) bread formula at 10% incorporation negatively impacted bread loaf volume, colour, and texture compared to standard loaves, with CB having the least impact. Results suggest that to combine the highest phytochemical content with minimal impact on bread quality, bran particle size should be considered, with CB being the best choice.
Background and objectives
Wheat bran is commonly used in pasta products and is an excellent source of phytochemicals, but it creates various processing and consumer acceptability issues. Proteins extracted from bran (WBPC) have potential to improve the protein content and protein quality of pasta, but their contribution to the phytochemical content of pasta is unknown.
Findings
In this study, WBPC was added to a spaghetti formulae at 0, 1%, 5%, 10%, and 20% (w/w). The dried uncooked spaghetti were characterized for quali‐quantitative composition of phytosterols and phenolic acids. Also, both the uncooked and cooked samples were evaluated for total soluble phenolics (TSP) and antioxidant activity (AO). Results showed that pasta with 20%WBPC increased total phytosterol content (~55%), and phenolic acids content (~57%), with ferulic acid being the main component. Cooked spaghetti had reduced TSP and AO compared to the uncooked. However, cooked 20%WBPC spaghetti had significantly higher contents of both TSP (~37%) and AO (~93%) compared to 100% durum semolina spaghetti. The in vitro starch digestion of pasta was not affected by WBPC at these levels.
Conclusion
Spaghetti enriched with WBPC has improved phytochemical content without negative changes on pasta in vitro starch digestion.
Significance and novelty
WBPC is a suitable ingredient to enhance the phytochemical content of regular spaghetti with potential health benefits.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.