Optimizing the bioactive potential of wheat bran by processing

Natural polyphenols for drug delivery and tissue engineering construction: A review

Polyphenols, natural compounds rich in phenolic structures, are gaining prominence due to their antioxidant, anti-inflammatory, antibacterial, and anticancer properties, making them valuable in biomedical applications. Through covalent and noncovalent interactions, polyphenols can bind to biomaterials, enhancing their performance and compensating for their shortcomings. Such polyphenol-based biomaterials not only increase the efficacy of polyphenols but also improve drug stability, control release kinetics, and boost the therapeutic effects of drugs. They offer the potential for targeted drug delivery, reducing off-target impacts and enhancing therapeutic outcomes. In tissue engineering, polyphenols promote cell adhesion, proliferation, and differentiation, thus aiding in the formation of functional tissues. Additionally, they offer excellent biocompatibility and mechanical strength, essential in designing scaffolds. This review explores the significant roles of polyphenols in tissue engineering and drug delivery, emphasizing their potential in advancing biomedical research and healthcare.

Rye Bran as a Component in the Diets of Lactating Sows-Effects on Sow and Piglet Performance

From a cost and sustainability perspective, the use of by-products such as rye bran in sow diets is of particular interest. Rye bran has valuable ingredients that have potential benefits for the gut health of sows. The aim of this study was to investigate the effects of including 15% rye bran in the sows' feed on the performance of sows and piglets. The feeding started one week before the farrowing date and ended at weaning. Performance was evaluated by measuring sow (n = 175) and piglet body weight (n = 1372) and sows' backfat thickness (n = 80). These data were additionally used to calculate the colostrum intake of the suckling piglets and the sows' milk production. It was found that there were no differences in the performance parameters between the experimental and control groups. However, this study showed that the piglets with light birth weight (LBW (<1000 g)) and medium birth weight (MBW (1000-1500 g) consumed more colostrum when the sows were fed rye bran (LBW: C/R 203.0 ± 39.2 g/214.3 ± 35.9 g; MBW: 291.3 ± 39.0 g/298.5 ± 36.4 g). It can be concluded that including 15% rye bran in the feed of lactating sows has no obvious negative effects on the performance of sows and piglets. Further studies are needed to evaluate the possible positive effects of rye bran.

Effects of different wheat bran fermentation sources on growth performance, nutrient digestibility, serum antioxidant capacity and fecal microbiota in growing pigs

The present study aimed to evaluate the application of different wheat bran fermentation sources in growing pigs. A total of 320 pigs (43 ± 0.21 kg), were randomly allocated to 5 groups in a 21-d trial. The control group was fed a basal diet (CON) containing raw wheat bran, and the other four treatments were fed the diets in which the raw wheat bran in the basal diet was substituted with Aspergillus niger (WBA), Bacillus licheniformis (WBB), Candida utilis (WBC), and Lactobacillus plantarum (WBL) fermented wheat bran, respectively. The results showed that compared to the CON group, the crude fiber and pH values were decreased (p < 0.05), while the gross energy (GE), crude protein (CP), and lactic acid values were increased (p < 0.05) in all the wheat bran fermented by different strains. Compared with other treatments, feeding B. licheniformis fermented wheat bran had higher final weight, average daily gain, as well as lower feed-to-gain ratio. Compared with CON group, pigs fed with fermented wheat bran diets had higher dry matter, CP, and GE availability, serum total protein, albumin and superoxide dismutase levels, and fecal Lactobacillus counts, as well as lower malondialdehyde level and fecal Escherichia coli count. Collectively, our findings suggested that feeding fermented wheat bran, especially B. licheniformis fermented wheat bran, showed beneficial effects on the growth performance, nutrient digestibility, serum antioxidant capacity, and the gut microbiota structure of growing pigs.

Rye and Rye Bran as Components of Diets in Piglet Production-Effects on Salmonella Prevalence

The nutritional benefits of rye (and therefore rye bran) are mainly due to its high content of fermentable dietary fiber, the non-starch polysaccharides (NSP). Microorganisms in the large intestine are able to convert these into short-chain fatty acids (SCFA), including butyrate. Butyrate strengthens the epithelial barrier function in the colon by nourishing the enterocytes and inhibiting the spread of Salmonella in the intestinal tract. Therefore, the aim of this study was to test under field conditions whether a diet with rye or rye bran as the main ingredient for gilts, sows, and weaned piglets is associated with a lower Salmonella prevalence. Depending on the age groups, between 20-30% rye or between 15-20% rye bran was used in the experimental group. A total of n = 1983 boot swabs, n = 356 fecal samples, and n = 1909 serum samples were examined. The results of this study show that rye or rye bran at the levels used had no apparent effect on the number of positive Salmonella samples. However, the Salmonella OD values in the experimental groups were significantly lower than in the control group. This suggests that the use of rye leads to a lower incidence of infection, but this effect could not be proven from swabs.

Effects of rice bran feruloyl oligosaccharides on gel properties and microstructure of grass carp surimi

Effects of feruloyl oligosaccharides (FOs) from rice bran on the gel properties, microstructure, and sensory properties of grass crap surimi gel were investigated. The results showed that FOs decreased the whiteness of surimi gel, and improved the water-holding capacity and breaking force of surimi gel. According to the texture analysis, the hardness and chewiness of surimi gel significantly increased by adding 0.3% FOs, but had no significant effect on the springiness and cohesiveness. The changes in AFM images indicated that FOs made myofibrillar protein aggregated and uniformly distributed. The SEM micrograph revealed that the 0.3% FOs group had the most compact and ordered network structure. Additionally, sensory characteristics suggested that FOs reduced off-odor from freshwater fish and remained fish delicious taste. This study provides a new prospect for the potential commercial application of FOs as a health gel enhancer in surimi products.

5-Heptadecylresorcinol Regulates the Metabolism of Thermogenic Fat and Improves the Thermogenic Capacity of Aging Mice via a Sirtuin 3-Adenosine Monophosphate-Activated Protein Kinase Pathway

5-Heptadecylresorcinol (AR-C17), a well-known biomarker for whole grain rye consumption, is a primary homolog of alkylresorcinols. In this study, the effects of AR-C17 on the thermogenesis of brown adipocytes and 3T3-L1 adipocytes were investigated. The results showed that AR-C17 increased sirtuin 3 (Sirt3) expression, and the expressions of specific thermogenic genes in adipocytes were increased. Furthermore, AR-C17 increased the mitochondrial functions during the thermogenic activation of adipocytes. In in vivo study, AR-C17 increased the cold tolerance and thermogenic capacity of adipose tissues in aging mice. In addition, Sirt3 activity was required for AR-C17-induced thermogenesis. Meanwhile, AR-C17 increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, and AMPK was involved in the regulation of AR-C17 on thermogenic adipocytes. Mechanically, AR-C17 upregulated a Sirt3-AMPK positive-feedback loop in adipocytes and further increased the expression of uncoupling protein 1 to activate thermogenesis. This study indicated that AR-C17 could be a promising thermogenic activator of adipocytes to alleviate obesity and aging-associated metabolic diseases.

Novel processing strategies to enhance the bioaccessibility and bioavailability of functional components in wheat bran

Dietary fiber, polysaccharides and phenols are the representative functional components in wheat bran, which have important nutritional properties and pharmacological effects. However, the most functional components in wheat bran exist in bound form with low bioaccessibility. This paper reviews these functional components, analyzes modification methods, and focuses on novel solid-state fermentation (SSF) strategies in the release of functional components. Mining efficient microbial resources from traditional fermented foods, exploring the law of material exchange between cell populations, and building a stable self-regulation co-culture system are expected to strengthen the SSF process. In addition, emerging biotechnology such as synthetic biology and genome editing are used to transform the mixed fermentation system. Furthermore, combined with the emerging physical-field pretreatment coupled with SSF strategies applied to the modification of wheat bran, which provides a theoretical basis for the high-value utilization of wheat bran and the development of related functional foods and drugs.

Structural, Physicochemical, and Functional Properties of Wheat Bran Insoluble Dietary Fiber Modified With Probiotic Fermentation

Insoluble dietary fiber (IDF) were isolated from wheat bran (WB) after microbial fermentation with single or mixed strain [Lactobacillus plantarum, Lactobacillus acidophilus, Bacillus subtilis or mixed lactic acid bacteria (L. plantarum and L. acidophilus with ration of 1:1)]. Structure, physicochemical, functional properties, and antioxidant activity of the wheat bran insoluble dietary fiber (W-IDF) modified by fermentation were studied. Fourier transformed infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analysis suggested the successful modification of W-IDF. After fermentation with L. plantarum and mixed lactic acid bacteria, the water retention capacity (WRC), oil retention capacity (ORC), and water swelling capacity (WSC) of W-IDF were improved. The sodium cholate adsorption capacity (SCAC), and cation exchange capacity (CEC) of W-IDF modified with L. acidophilus fermentation were significantly increased. Although the cholesterol adsorption capacity (CAC) of W-IDF decreased after modification with probiotic fermentation, nitrite ion adsorption capacity (NIAC), and total phenolic content (TPC) were enhanced. Additionally, W-IDF modified by fermentation with B. subtilis or mixed lactic acid bacteria exhibited superior antioxidant capacity verified by DPPH, ABTS and total reducing power assays. Results manifested that microbial fermentation is a promising methods to modify the W-IDF to provide high-quality functional IDF for food processing and human health management.

Wheat grain phenolics: a review on composition, bioactivity, and influencing factors

Wheat (Triticum aestivum L.) is a widely cultivated crop and one of the most commonly consumed food grains in the world. It possesses several nutritional elements. Increasing attention to wheat grain phenolics bioactivity is due to the increasing demand for foods with natural antioxidants. To provide a comprehensive understanding of phenolics in wheat grain, this review first summarizes the phenolics' form and distribution and the phenolic components identified in wheat grain. In particular, the biosynthesis path for phenolics is discussed, identifying some candidate genes involved in the biosynthesis of phenolic acids and flavonoids. After discussing the methods for determining antioxidant activity, the effect of genotypes, environmental conditions, and cultivation systems on grain phenolic component content are explored. Finally, the bioavailability of phenolics under different food processing method are reported and discussed. Future research is recommended to increase wheat grain phenolic content by genetic engineering, and to improve its bioavailability through proper food processing. © 2021 Society of Chemical Industry.

A Novel Strategy to Produce a Soluble and Bioactive Wheat Bran Ingredient Rich in Ferulic Acid

Wheat bran (WB) is a byproduct from the milling industry that contains bioactive compounds beneficial to human health. The aim of this work was on the one hand, increasing extractability of antioxidant and anti-inflammatory compounds (specifically ferulic acid, FA), through enzymatic hydrolysis combined with hydrothermal treatment (HT) and high hydrostatic pressure (HHP). On the other hand, enhancing the stability of final ingredient applying spray-drying (SPD) and microencapsulation (MEC). The use of HT increased FA, total phenolics (TP), and antioxidant capacity (AC) in WB hydrolysates, regardless the HT duration. However, the HT tested (30 min, HT30) produced a loss in anti-inflammatory activity (AIA). The combination of HT (15 min, HT15) with HHP increased AIA of the WB. SPD enhanced the TP yield in WB with no significant effect of inlet temperature (up to 140 °C) on phenolic profile mainly composed of trans-FA and smaller amounts of cis-FA and apigenin diglucosides. SPD caused a temperature-dependent increase in AC (160 °C > 140 °C > 130 °C). SPD inlet temperatures affected total solids yield (from 22 to 36%), with the highest values at 140 °C. The use of HHP in combination with HT resulted in >2-fold increase in total solids yield.

Wheat bran, as the resource of dietary fiber: a review

Wheat bran is a major by-product of white flour milling and had been produced in large quantities around the world; it is rich in dietary fiber and had already been used in many products such as whole grain baking or high dietary fiber addition. It has been confirmed that a sufficient intake of dietary fiber in wheat bran with appropriate physiological functions is beneficial to human health. Wheat bran had been considered as the addition with a large potential for improving the nutritional condition of the human body based on the dietary fiber supplement. The present review summarized the available information on wheat bran related to its dietary fiber functions, which may be helpful for further development of wheat bran as dietary fiber resource.

Fermentation of Wheat Bran and Whey Permeate by Mono-Cultures of Lacticaseibacillus rhamnosus Strains and Co-culture With Yeast Enhances Bioactive Properties

The aim of this work was to obtain a bioingredient (BI) with bioactive properties through the solid fermentation of a wheat bran-whey permeate (WB/WP) mixture with three strains of Lacticaseibacillus rhamnosus (R0011, ATCC 9595, and RW-9595M) in mono or co-culture with Saccharomyces cerevisiae. The choice of these strains was based on their capacity to produce the same exopolysaccharide (EPS), but at different yields. The solid fermentation of WB/WP revealed a similar growth pattern, sugar utilization and metabolite production between strains and types of culture. Lactic acid, soluble protein, free amino acid and phenolic compound content in BI were compared to NFWB. Water soluble polysaccharides (including EPS) were significantly increased in co-culture for (44%) ATCC 9595, (40%) R0011 and (27%) RW-9595M. The amount of bound Total Phenolic Content (TPC) as well as the antioxidant activity in BI were higher after fermentation. The free phenolic acid content was higher after fermentation with ATCC 9595 (53-59%), RW-9595M (45-46%), and R0011 (29-39%) compared to non-fermented NFWB. Fermentation by these strains increased the amounts of free caffeic acid and 4-hydroxybenzoic acid in both types of culture. The bound phenolic acid content was enhanced in co-culture for the BI obtained from the highest EPS producer strain RW-9595M which was 30% higher than NFWB. After in vitro digestion, bioaccessibility of free total phenolic acids was improved by more than 40% in BI compared to NFWB. The co-culture increased recovery of TPC (%) and antioxidant activity compared to monoculture for the strains in digested product. In contrast, the recovery of bound total phenolic acids in co-culture was 33 and 38% lower when compared to monoculture for R0011 and RW-9595M. Our findings provide new insights into the impact of LAB/yeast co-culture on the bioactive properties of fermented wheat bran.

Cascade extraction of proteins and feruloylated arabinoxylans from wheat bran

A cascade process for the sequential recovery of proteins and feruloylated arabinoxylan from wheat bran is proposed, involving a protein isolation step, enzymatic destarching and subcritical water extraction. The protein isolation step combining lactic acid fermentation and cold alkaline extraction reduced the recalcitrance of wheat bran, thus improving the total yields of the subsequent subcritical water extraction. The time evolution of subcritical water extraction of feruloylated arabinoxylan was compared at two temperatures (160 °C and 180 °C). Longer residence times enhanced the purity of target feruloylated arabinoxylans, whereas higher temperatures resulted in faster extraction at the expense of significant molar mass reduction. The radical scavenging activity of the extracted feruloylated arabinoxylans was preserved after the initial protein isolation step. This study opens new possibilities for the cascade valorization of wheat bran into enriched protein and non-starch polysaccharide fractions, which show potential to be used as functional food ingredients.

Production performances and antioxidant activities of laying hens fed Aspergillus oryzae and phytase co-fermented wheat bran

OBJECTIVE

Wheat bran (WB) was co-fermented with Aspergillus oryzae and phytase (Phy) to determine whether co-fermentation improve WB phosphorus and fiber utilization in Isa-brown layers.

METHODS

A total of 112 Isa brown layer were randomly divided into 7 treatments with 8 replicates per a treatment and 2 hens per a replicate. The treatments included basal diet (control), basal diet supplemented with 250 unit/kg Phy (control+Phy), diet with 10% WB (10% WB), diet with 5% WB and 250 unit/kg Phy (5% WB+Phy) diet with 10% WB and 250 unit/kg Phy (10% WB+Phy), diet with 5% fermented WB supplemented with molasses and phy (PCFWH) and 125 unit/kg Phy (5% PCFWH), and diet with 10% PCFWH (10% PCFWH). The intestinal microbial population, intestinal morphology, serum antioxidant enzyme activities, and excreta phosphorus content were assessed.

RESULTS

In PCFWH, spore counts, protease activity, xylanase activity, and ferulic acid were 8.50 log/g dry matter (DM), 190 unit/g DM, 120 unit/g DM, and 127 μg/g, respectively. Xylobiose and xylotriose were released in PCFWH, while they were not detectable in WB. Antioxidant capacity was also enhanced in PCFWH compared to WB. The 10% WB+Phy and 10% PCFWH groups produced higher egg mass, but hens fed 5% WB+Phy had the lowest amount of feed intake. Eggs from 10% PCFWH had better eggshell weight, eggshell strength, and eggshell thickness. Birds fed with 10% PCFWH also had higher serum superoxide dismutase and catalase activities. Compare to control, 10% PCFWH significantly reduced excreta phosphorus content.

CONCLUSION

Diet inclusion of 10% PCFWH improved egg quality, antioxidant status, and excreta phosphorus content of laying hens.

Biochemical and functional properties of wheat middlings bioprocessed by lactic acid bacteria

The present study aimed to investigate the bioprocessing of wheat middlings with different lactic acid bacteria (LAB) in order to improve biological activities of this by-product of wheat flour production. The concentration of lactic acid, reducing sugars, and total phenolics, as well as antioxidant, antibrowning, antibacterial and prebiotic activities of fermented samples were analyzed. All LAB strains were capable to growth on wheat middlings, and pH decreased in the medium associated with lactic acid production during cultivation. Samples inoculated with Lactobacillus plantarum DSM20174 presented the maximum growth, lactic acid concentration above 2 mg/ml, and pH values around 3.8. The amount or reducing sugars decreased after 24 hr growth, except for maltose. Bioprocessed wheat middlings exhibited antioxidant, antibrowning, antibacterial, and prebiotic properties, related with the increase of total phenolic content. Highest values for antioxidant activities were obtained for L. plantarum and Streptococcus thermophilus strains, reaching values around 400 and 640 μM Trolox equivalents (TE) ml^-1 for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP) assays, respectively. Bioprocessing techniques using LAB can be an interesting approach to improve the availability of compounds with health-promoting properties from lignocellulosic waste material. PRACTICAL APPLICATIONS: The processing of secondary products from wheat milling can represent an important benefit to the industry. Wheat middlings bioprocessed with LAB showed improved biological activities and may represent an interesting ingredient to be incorporated in food and feed formulations.

The Combination of Whey Protein and Dietary Fiber Does Not Alter Low-Grade Inflammation or Adipose Tissue Gene Expression in Adults with Abdominal Obesity

BACKGROUND

Abdominal obesity is characterized by low-grade inflammation and plays a central role in the development of type 2 diabetes and cardiovascular diseases. Dietary factors can influence low-grade inflammation and affect adipose tissue function.

AIM

To investigate the separate and combined effects of whey protein and cereal fiber on inflammatory markers and adipose tissue gene expression in abdominal obesity.

METHODS

We performed a 12-week, double-blind, randomized controlled dietary intervention in 65 adults with abdominal obesity. The participants were randomized to 4 groups using a 2 × 2 factorial design; they received either 60 g/day of whey protein or maltodextrin in combination with high-fiber wheat bran products (30 g fiber/day) or low-fiber refined wheat products (10 g fiber/day). Plasma concentrations of tumor necrosis factor α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), interleukin 1 receptor antagonist (IL-1Ra), and adiponectin were measured before and after intervention. Changes in gene expression related to inflammation, insulin signaling, and lipid metabolism were measured in abdominal subcutaneous adipose tissue.

RESULTS

After intervention, TNF-α was reduced for both high-fiber groups compared with baseline, but did not significantly differ from the low-fiber groups. There were no differences in fasting or postprandial inflammatory markers between the groups. The relative gene expression of ribosomal protein S6 kinase B1 (S6K1) was increased after whey protein compared with maltodextrin consumption.

CONCLUSION

Intake of whey protein in combination with high cereal fiber content did not differentially affect low-grade inflammation or adipose tissue gene expression compared with maltodextrin and low fiber content in individuals with abdominal obesity.

Solid-State Yeast Fermented Wheat and Oat Bran as A Route for Delivery of Antioxidants

The purpose of our study was to evaluate the potential of solid-state yeast fermentation (SSYF) in improving the phenolic acid content and composition, and the antioxidant activity of commercial wheat bran (WB) and oat bran (OB). The ultrasound-assisted methanolic extracts were compared for their total phenolic content (TPC), phenolics composition, and in vitro antioxidant activity in order to study the effect of fermentation time on the chemical profile and activity of bioactive compounds. The comparative analysis revealed significant differences (p < 0.05) between days of fermentation (0 through 6). The highest TPCs were obtained on day 3 for WB (0.84 ± 0.05 mg of gallic acid equivalents [GAE]/g dry weight [DW]), and on day 4 for OB (0.45 ± 0.02 mg GAE/g DW). The highest relative percentage increase in the phenolics concentration of WB was also registered on day 3 (ferulic acid +56.6%, vanillic acid +259.3%, dihydroxybenzoic acids +161.2%, apigenin-glucoside +15.3%); for OB, this was observed on day 4 (avenanthramide 2f +48.5%, ferulic acid +21.2%). Enhanced antioxidant activities were significantly correlated with the highest TPCs. Our results suggest that SSYF may be a useful procedure for enrichment of antioxidants in cereal bran, considering the design of different functional foods and nutraceuticals.

How Fermentation Affects the Antioxidant Properties of Cereals and Legumes

The major role of antioxidant compounds in preserving food shelf life, as well as providing health promoting benefits, combined with the increasing concern towards synthetic antioxidants, has led the scientific community to focus on natural antioxidants present in food matrices or resulting from microbial metabolism during fermentation. This review aims at providing a comprehensive overview of the effect of fermentation on the antioxidant compounds of vegetables, with emphasis on cereals- and legumes- derived foods. Polyphenols are the main natural antioxidants in food. However, they are often bound to cell wall, glycosylated, or in polymeric forms, which affect their bioaccessibility, yet several metabolic activities are involved in their release or conversion in more active forms. In some cases, the antioxidant properties in vitro, were also confirmed during in vivo studies. Similarly, bioactive peptides resulted from bacterial and fungal proteolysis, were also found to have ex vivo protective effect against oxidation. Fermentation also influenced the bioaccessibility of other compounds, such as vitamins and exopolysaccharides, enabling a further improvement of antioxidant activity in vitro and in vivo. The ability of fermentation to improve food antioxidant properties strictly relies on the metabolic activities of the starter used, and to further demonstrate its potential, more in vivo studies should be carried out.

Innovative Nutritious Biscuits Limit Aflatoxin Contamination

BACKGROUND AND OBJECTIVE

Incorporation of food byproducts in biscuit could increase the safety, nutritional and enhance dough properties. These byproducts were wheat bran (WB), goldenberry fruit (GBF) and goldenberry peel (GBP) contains active ingredients.

MATERIAL AND METHODS

Wheat flour (WF) was partially replaced in biscuit dough. Antioxidant activity, chemical composition and baking quality were evaluated. Anti-aflatoxigenic and antifungal activities of WB, GBF and GBP have estimated also aflatoxin reduction was evaluated.

RESULTS

The results were showed biscuit acceptable sensories. The GBF and GBP exhibited the highest antioxidant and phenolic content explaining its antimicrobial behaviour. The addition of WB, GBF or GBP to fungal media inhibited the growth, however, using 20% GBF in Aspergillus flavus media showed the greatest aflatoxin reduction. The biscuit-specific volume was more pronounced when GBF and GBP were included in the formulation. No great differences were seen for colour, baking quality or texture of biscuit mixes.

CONCLUSION

This novel safe biscuit appears a safer alternative to traditional biscuits.

How Do Arabinoxylan Films Interact with Water and Soil?

Biodegradable materials made from cereal arabinoxylan could provide an alternative source of packaging to replace current nonbiodegradable plastics. The main purpose of this research was to determine how arabinoxylan (AX) films made from wheat bran (WB) AX, maize bran (MB) AX, and dried distillers grain (DDG) AX made with either glycerol or sorbitol at varying levels (10, 25 or 50%) interacts with soil and water. The biodegradability of all films ranged from 49.4% biodegradable (DDG AX with 10% sorbitol) to 67.7% biodegradable (MB AX with 50% glycerol). In addition, the MB AX films with 25% sorbitol had the lowest moisture content at 9.7%, the MB AX films with 10% glycerol had the highest water solubility at 95.6%, and the MB AX films with 50% glycerol had the highest water vapor transmission rate (WVTR) at 90.8 g h^-1 m^-2. Despite these extreme trends in the MB AX films, the WB AX films were the least hydrophilic on average while the DDG AX films were the most hydrophilic on average. The 18 materials developed in this research demonstrate varying affinities for water and biodegradation. These materials can be used for many different packaging materials, based on their unique characteristics.

Fermentation Biotechnology Applied to Cereal Industry By-Products: Nutritional and Functional Insights

Cereals are one of the major food sources in human diet and a large quantity of by-products is generated throughout their processing chain. These by-products mostly consist of the germ and outer layers (bran), deriving from dry and wet milling of grains, brewers' spent grain originating from brewing industry, or others originating during bread-making and starch production. Cereal industry by-products are rich in nutrients, but still they end up as feed, fuel, substrates for biorefinery, or waste. The above uses, however, only provide a partial recycle. Although cereal processing industry side streams can potentially provide essential compounds for the diet, their use in food production is limited by their challenging technological properties. For this reason, the development of innovative biotechnologies is essential to upgrade these by-products, potentially leading to the design of novel and commercially competitive functional foods. Fermentation has been proven as a very feasible option to enhance the technological, sensory, and especially nutritional and functional features of the cereal industry by-products. Through the increase of minerals, phenolics and vitamins bioavailability, proteins digestibility, and the degradation of antinutritional compounds as phytic acid, fermentation can lead to improved nutritional quality of the matrix. In some cases, more compelling benefits have been discovered, such as the synthesis of bioactive compounds acting as antimicrobial, antitumoral, antioxidant agents. When used for baked-goods manufacturing, fermented cereal by-products have enhanced their nutritional profile. The key factor of a successful use of cereal by-products in food applications is the use of a proper bioprocessing technology, including fermentation with selected starters. In the journey toward a more efficient food chain, biotechnological approaches for the valorization of agricultural side streams can be considered a very valuable help.

Whole Grains and Phenolic Acids: A Review on Bioactivity, Functionality, Health Benefits and Bioavailability

Cereal grains represent one of the major sources of human food and nowadays, their production has increased to fulfill the needs of the world's population. Among whole grains, wheat is the most popular and contributes significantly to the human diet. Whole grains possess great nutritional and bioactive properties due to their fractions, bran and germ, that comprise unique health-promoting bioactive components. The evidence of health benefits in human intervention studies, as well as a World Health Organization report for 2012⁻2016, supports the dietary consumption of whole grains and whole-grain foods. The inverse correlation between whole grain consumption and the reduced risk of chronic diseases and metabolic syndromes was underlined by several epidemiological studies. This article focuses on the bioactive components of whole grains and their fractions, namely phenolic acids, starting from their chemical structure, bioactivity and bioavailability. According to the conclusive evaluation of the human intervention studies conducted using cereal bran and whole grains intake, the assumption that the bioactive compounds determine health outcomes is illustrated. In the last part of the work, the functional potential and the health claims related to whole grains and bran intake are discussed, as well as new technologies and strategies to enhance their health potential by an increased bioavailability.

Effect of Extrusion Conditions and the Optimization of Phenolic Compound Content and Antioxidant Activity of Wheat Bran Using Response Surface Methodology

The extrusion process (EP) consists of heat and mechanical treatments under different conditions of moisture, shear, and pressure and rapidly causes structural alterations and changes in the functional properties of the extruded material. The aim of this study was to evaluate the effect of extrusion conditions and optimize the wheat bran extrusion conditions to achieve the greatest content of phenolic compounds and antioxidant activity using response surface methodology. The EP factors evaluated were feed moisture (FM) (25-33.54%) and final extrusion temperature (T) (140-180 °C). The properties evaluated in the extruded material were bound total phenol content (BTPC), total phenolic compounds and antioxidant activity (AOX). Analysis of variance (ANOVA) and response surface methodology were used in the evaluation. The determination coefficients, (FM)² and (T)², very significantly affected the BTPC and bound 2,2-diphenyl-1-picrylhydrazyl content (BDPPHC). The optimization was performed by overlaying two contour plots to predict the best combination regions. The optimized extrusion conditions were the following: FM = 30% and T = 140 °C, which provided BTPC = 3547.01 μgGAE/g (predicted: 3589.3 μgGAE/g) and BDPPHC = 9.5 μmolTE/g (predicted: 10.4 μmolTE/g); and FM = 30% and T = 180 °C, which provided BTPC = 3342.3 μgGAE/g (predicted: 3727.7 μgGAE/g) and BDPPHC = 9.5 μmolTE/g (predicted: 9.3 μmolTE/g). The EP increased the phenolic compounds and AOX, and enhancement of these properties in wheat bran products could make them functional foods.

Effect of Different Extrusion Parameters on Dietary Fiber in Wheat Bran and Rye Bran

Wheat bran and rye bran are mostly used as animal feed today, but their high content of dietary fiber and bioactive components are beneficial to human health. Increased use of bran as food raw material could therefore be desirable. However, bran mainly contains unextractable dietary fiber and deteriorates the sensory properties of products. Processing by extrusion could increase the extractability of dietary fiber and increase the sensory qualities of bran products. Wheat bran and rye bran were therefore extruded at different levels of moisture content, screw speed and temperature, in order to find the optimal setting for increased extractability of dietary fiber and positive sensory properties. A water content of 24% for wheat bran and 30% for rye bran, a screw speed of 400 rpm, and a temperature of 130 °C resulted in the highest extractability of total dietary fiber and arabinoxylan. Arabinoxylan extractability increased from 5.8% in wheat bran to 9.0% in extruded wheat bran at those settings, and from 14.6% to 19.2% for rye bran. Total contents of dietary fiber and arabinoxylan were not affected by extrusion. Content of β-glucan was also maintained during extrusion, while its molecular weight decreased slightly and extractability increased slightly. Extrusion at these settings is therefore a suitable process for increasing the use of wheat bran and rye bran as a food raw material.

Wheat Bran Phenolic Acids: Bioavailability and Stability in Whole Wheat-Based Foods

Wheat bran is generally considered a byproduct of the flour milling industry, but it is a great source of fibers, minerals, and antioxidants that are important for human health. Phenolic acids are a specific class of wheat bran components that may act as antioxidants to prevent heart disease and to lower the incidence of colon cancer. Moreover, phenolic acids have anti-inflammatory properties that are potentially significant for the promotion of gastrointestinal health. Evidence on the beneficial effects of phenolic acids as well as of other wheat bran components is encouraging the use of wheat bran as an ingredient of functional foods. After an overview of the chemistry, function, and bioavailability of wheat phenolic acids, the discussion will focus on how technologies can allow the formulation of new, functional whole wheat products with enhanced health-promoting value and safety without renouncing the good-tasting standards that are required by consumers. Finally, this review summarizes the latest studies about the stability of phenolic acids in wheat foods fortified by the addition of wheat bran, pearled fractions, or wheat bran extracts.

Wheat Bread with Pumpkin (Cucurbita maxima L.) Pulp as a Functional Food Product

In this study, a new application of pumpkin pulp in bread production is shown. The aim of this work is to determine the influence of the addition of fresh pumpkin pulp directly into wheat flour on physical, sensorial and biological properties of bread. The bioaccessibility of active compounds was also studied. An increase in the addition of pumpkin pulp from 5 to 20% (converted to dry matter) caused a decrease of bread volume and increase of crumb hardness and cohesiveness. The sensory characteristics of the bread showed that a partial replacement of wheat flour with up to 10% of pumpkin pulp gave satisfactory results. The taste, aroma and overall acceptability of control bread and bread containing 5 or 10% of pulp had the highest degree of liking. The addition of higher levels of pumpkin pulp caused an unpleasant aroma and taste. Pumpkin pulp is a good material to complement the bread with potentially bioaccessible phenolics (including flavonoids) and, especially, with peptides. The highest antioxidant activity was observed, in most cases, of the samples with added 10 and 15% of pumpkin pulp. The addition of the pulp significantly enriched the bread with potentially bioaccessible angiotensin-converting enzyme (ACE) inhibitors. The highest activity was determined in the bread with 15 and 20% pumpkin pulp. ACE inhibitors from the tested bread were highly bioaccessible in vitro. Pumpkin pulp seems to be a valuable source of active compounds to complement the wheat bread. Adding the pulp directly to the wheat flour gives satisfactory baking results and reduces the cost of production. Additionally, pumpkin pulp is sometimes treated as waste material after the acquisition of seeds, thus using it as bread supplement also has environmental and economic benefits. Key words: pumpkin, bread, texture, antioxidants, bioaccessibility in vitro, angiotensin-converting enzyme (ACE) inhibition.

Bioavailability and metabolism of hydroxycinnamates in rats fed with durum wheat aleurone fractions

A specific wheat aleurone fraction showed potentially interesting ferulic acid improved bioavailability and might be used for the formulation of new wheat based products.

Wheat bran particle size influence on phytochemical extractability and antioxidant properties

It is unknown if particle size plays a role in extracting health promoting compounds in wheat bran because the extraction of antioxidant and phenolic compounds with particle size reduction has not been well documented. In this study, unmilled whole bran (coarse treatment) was compared to whole bran milled to medium and fine treatments from the same wheat bran. Antioxidant properties (capacity, ability, power), carotenoids and phenolic compounds (phenolic acids, flavonoids, anthocyanins) were measured and compared. The ability of whole bran fractions of differing particle size distributions to inhibit free radicals was assessed using four in vitro models, namely, diphenylpicrylhydrazyl radical-scavenging activity, ferric reducing/antioxidant power (FRAP) assay, oxygen radical absorbance capacity (ORAC), and total antioxidant capacity. Significant differences in phytochemical concentrations and antioxidant properties were observed between whole bran fractions of reduced particle size distribution for some assays. The coarse treatment exhibited significantly higher antioxidant properties compared to the fine treatment; except for the ORAC value, in which coarse was significantly lower. For soluble and bound extractions, the coarse treatment was comparatively higher in total antioxidant capacity (426.72 mg ascorbic acid eq./g) and FRAP value (53.04 μmol FeSO4/g) than bran milled to the finer treatment (314.55 ascorbic acid eq./g and 40.84 μmol FeSO4/g, respectively). Likewise, the fine treatment was higher in phenolic acid (7.36 mg FAE/g), flavonoid (206.74 μg catechin/g), anthocyanin (63.0 μg/g), and carotenoid contents (beta carotene, 14.25 μg/100 g; zeaxanthin, 35.21 μg/100 g; lutein 174.59 μg/100 g) as compared to the coarse treatment. An increase of surface area to mass increased the ORAC value by over 80%. With reduction in particle size, there was a significant increase in extracted anthocyanins, carotenoids and ORAC value. Particle size does effect the extraction of phytochemicals.

Bound phytophenols from ready-to-eat cereals: comparison with other plant-based foods

Whole-grain diets are linked to reduced risk of several chronic diseases (heart disease, cancer, diabetes, metabolic syndrome) and all-cause mortality. There is increasing evidence that these benefits are associated with the gut microbiota and that release of fibre-related phenolic metabolites in the gut is a contributing factor. Additional sources of these metabolites include fruits and vegetables, but the evidence for their protective effects is less well established. With respect to the availability of bound phytophenols, ready-to-eat cereals are compared with soft fruits (considered rich in antioxidants) and other commonly consumed fruits and vegetables. The results demonstrated that when compared with an equivalent serving of fruits or vegetables, a recommended portion of whole-grain cereals deliver substantially higher amounts of bound phytophenols, which are available for metabolism in the colon. The increased amount of these phenolic metabolites may, in part, explain the evidence for the protective effects of whole-grain cereals.

Quality and antioxidant properties of breads enriched with dry onion (Allium cepa L.) skin

The aim of the study was to investigate the effect on the antioxidant properties and sensory value of bread of adding ground onion skin (OS). For a determination of bioaccessibility and bioavailability in vitro the human gastrointestinal tract model was used. OS contained mastication-extractable quercetin (4.6 mg/g). Quercetin from OS was highly bioaccessible during in vitro conditions, but only approximately 4% of quercetin released during simulated digestion was bioavailable in vitro. The antioxidant potential of bread with OS was significantly higher than the activity noted in the control. In particular, OS addition significantly fortificated bread with bioaccessible lipid oxidation preventers and compounds with reducing and chelating abilities. The 2-3% OS addition caused significant improvement of antioxidant abilities (further increases in the OS supplement did not increase the activity of bread). Sensory evaluation showed that replacement of wheat flour in bread with up to 3% OS powder gave satisfactory consumer acceptability.