The Profile and Bioaccessibility of Phenolic Compounds in Cereals Influenced by Improved Extrusion Cooking Treatment

Unraveling the Bioactive Potential of Camellia japonica Edible Flowers: Profiling Antioxidant Substances and In Vitro Bioactivity Assessment

In recent years, the search for novel natural-based ingredients by food and related industries has sparked extensive research aimed at discovering new sources of functional molecules. Camellia japonica, traditionally known as an ornamental plant, has gained attention due to its diverse array of bioactive compounds with potential industrial applications. Although C. japonica flowers are edible, their phytochemical profile has not been thoroughly investigated. In this study, a phenolic profile screening through an HPLC-ESI-QQQ-MS/MS approach was applied to C. japonica flower extracts, revealing a total of 36 compounds, including anthocyanins, curcuminoids, dihydrochalcones, dihydroflavonols, flavonols, flavones, hydroxybenzoic acids, hydroxycinnamic acids, isoflavonoids, stilbenes, and tyrosols. Following extract profiling, their bioactivity was assessed by means of in vitro antioxidant, antimicrobial, cytotoxic, and neuroprotective activities. The results showed a multifaceted high correlation of phenolic compounds with all the tested bioactivities according to Pearson's correlation analysis, unraveling the potential of C. japonica flowers as promising sources of nutraceuticals. Overall, these findings provide insight into the valorization of C. japonica flowers from different unexplored cultivars thus diversifying their industrial outcome.

Grains in a Modern Time: A Comprehensive Review of Compositions and Understanding Their Role in Type 2 Diabetes and Cancer

Globally, type 2 diabetes (T2D) and Cancer are the major causes of morbidity and mortality worldwide and are considered to be two of the most significant public health concerns of the 21st century. Over the next two decades, the global burden is expected to increase by approximately 60%. Several observational studies as well as clinical trials have demonstrated the health benefits of consuming whole grains to lower the risk of several chronic non-communicable diseases including T2D and cancer. Cereals grains are the primary source of energy in the human diet. The most widely consumed pseudo cereals include (quinoa, amaranth, and buckwheat) and cereals (wheat, rice, and corn). From a nutritional perspective, both pseudo cereals and cereals are recognized for their complete protein, essential amino acids, dietary fibers, and phenolic acids. The bran layer of the seed contains the majority of these components. Greater intake of whole grains rather than refined grains has been consistently linked to a lower risk of T2D and cancer. Due to their superior nutritional compositions, whole grains make them a preferred choice over refined grains. The modulatory effects of whole grains on T2D and cancer are also likely to be influenced by several mechanisms; some of these effects may be direct while others involve altering the composition of gut microbiota, increasing the abundance of beneficial bacteria, and lowering harmful bacteria, increasing insulin sensitivity, lowering solubility of free bile acids, breaking protein down into peptides and amino acids, producing short-chain fatty acids (SCFAs), and other beneficial metabolites that promote the proliferation in the colon which modulate the antidiabetic and anticancer pathway. Thus, the present review had two aims. First, it summarized the recent knowledge about the nutritional composition and bioactive acids in pseudo cereals (quinoa, amaranth, and buckwheat) and cereals (wheat, rice, and corn); the second section summarized and discussed the progress in recent human studies, such as observational (cross-sectional studies, case-control studies, and cohort studies) and intervention studies to understand their role in T2D and cancer including the potential mechanism. Overall, according to the scientific data, whole grain consumption may reduce the incidence of T2D and cancer. Future studies should carry out randomized controlled trials to validate observational results and establish causality. In addition, the current manuscript encourages researchers to investigate the specific mechanisms by which whole grains exert their beneficial effects on health by examining the effects of different types of specific protein, dietary fibers, and phenolic acids that might help to prevent or treat T2D and cancer.

Composition of Whole Grain Dietary Fiber and Phenolics and Their Impact on Markers of Inflammation

Inflammation is an important biological response to any tissue injury. The immune system responds to any stimulus, such as irritation, damage, or infection, by releasing pro-inflammatory cytokines. The overproduction of pro-inflammatory cytokines can lead to several diseases, e.g., cardiovascular diseases, joint disorders, cancer, and allergies. Emerging science suggests that whole grains may lower the markers of inflammation. Whole grains are a significant source of dietary fiber and phenolic acids, which have an inverse association with the risk of inflammation. Both cereals and pseudo-cereals are rich in dietary fiber, e.g., arabinoxylan and β-glucan, and phenolic acids, e.g., hydroxycinnamic acids and hydroxybenzoic acids, which are predominantly present in the bran layer. However, the biological mechanisms underlying the widely reported association between whole grain consumption and a lower risk of disease are not fully understood. The modulatory effects of whole grains on inflammation are likely to be influenced by several mechanisms including the effect of dietary fiber and phenolic acids. While some of these effects are direct, others involve the gut microbiota, which transforms important bioactive substances into more beneficial metabolites that modulate the inflammatory signaling pathways. Therefore, the purpose of this review is twofold: first, it discusses whole grain dietary fiber and phenolic acids and highlights their potential; second, it examines the health benefits of these components and their impacts on subclinical inflammation markers, including the role of the gut microbiota. Overall, while there is promising evidence for the anti-inflammatory properties of whole grains, further research is needed to understand their effects fully.

Effect of Sprouting on Biomolecular and Antioxidant Features of Common Buckwheat (Fagopyrum esculentum)

Buckwheat is a pseudo-cereal widely grown and consumed throughout the world. Buckwheat is recognized as a good source of nutrients and, in combination with other health-promoting components, is receiving increasing attention as a potential functional food. Despite the high nutritional value of buckwheat, a variety of anti-nutritional features makes it difficult to exploit its full potential. In this framework, sprouting (or germination) may represent a process capable of improving the macromolecular profile, including reducing anti-nutritional factors and/or synthesizing or releasing bioactives. This study addressed changes in the biomolecular profile and composition of buckwheat that was sprouted for 48 and 72 h. Sprouting increased the content of peptides and free-phenolic compounds and the antioxidant activity, caused a marked decline in the concentration of several anti-nutritional components, and affected the metabolomic profile with an overall improvement in the nutritional characteristics. These results further confirm sprouting as a process suitable for improving the compositional traits of cereals and pseudo-cereals, and are further steps towards the exploitation of sprouted buckwheat as a high-quality ingredient in innovative products of industrial interest.

The Phenolic Compounds' Role in Beer from Various Adjuncts

BACKGROUND

The present article considers the influence of malt with various adjuncts on beer organic compounds and taste profile composition, with more attention paid to the phenol complex change. The topic under consideration is relevant since it studies the interactions of phenolic compounds with other biomolecules, and expands the understanding of the adjuncts organic compounds contribution and their joint effect on beer quality.

METHODS

Samples of beer were analyzed at a pilot brewery using barley and wheat malts, barley, rice, corn and wheat, and then fermented. The beer samples were assessed by industry-accepted methods and using instrumental analysis methods (high-performance liquid chromatography methods-HPLC). The obtained statistical data were processed by the Statistics program (Microsoft Corporation, Redmond, WA, USA, 2006).

RESULTS

The study showed that at the stage of hopped wort organic compounds structure formation, there is a clear correlation between the content of organic compounds and dry substances, including phenolic compounds (quercetin, catechins), as well as isomerized hop bitter resines. It is shown that the riboflavin content increases in all adjunct wort samples, and mostly with the use of rice-up to 4.33 mg/L, which is 9.4 times higher than the vitamin levels in malt wort. The melanoidin content in the samples was in the range of 125-225 mg/L and its levels in the wort with additives exceeded the malt wort. Changes in β-glucan and nitrogen with thiol groups during fermentation occurred with different dynamics and depending on the adjunct's proteome. The greatest decrease in non-starch polysaccharide content was observed in wheat beer and nitrogen with thiol groups content-in all other beer samples. The change in iso-α-humulone in all samples at the beginning of fermentation correlated with a decrease in original extract, and in the finished beer there was no correlation. The behavior of catechins, quercetin, and iso-α-humulone has been shown to correlate with nitrogen with thiol groups during fermentation. A strong correlation was shown between the change in iso-α-humulone and catechins, as well as riboflavin and quercetin. It was established that various phenolic compounds were involved in the formation of taste, structure, and antioxidant properties of beer in accordance with the structure of various grains, depending on the structure of its proteome.

CONCLUSIONS

The obtained experimental and mathematical dependences make it possible to expand the understanding of intermolecular interactions of beer organic compounds and take a step toward predicting the quality of beer at the stage of using adjuncts.

Polyphenolic compounds from rapeseeds (Brassica napus L.): The major types, biofunctional roles, bioavailability, and the influences of rapeseed oil processing technologies on the content

The rapeseed (Brassica napus L.) are the important oil bearing material worldwide, which contain wide variety of bioactive components with polyphenolic compounds considered the most typical. The rapeseed polyphenols encompass different structural variants, and have been considered to have many bioactive functions, which are beneficial for the human health. Whereas, the rapeseed oil processing technologies affect their content and the biofunctional activities. The present review of the literature highlighted the major types of the rapeseed polyphenols, and summarized their biofunctional roles. The influences of rapeseed oil processing technologies on these polyphenols were also elucidated. Furthermore, the directions of the future studies for producing nutritional rapeseed oils preserved higher level of polyphenols were prospected. The rapeseed polyphenols are divided into the phenolic acids and polyphenolic tannins, both of which contained different subtypes. They are reported to have multiple biofunctional roles, thus showing outstanding health improvement effects. The rapeseed oil processing technologies have significant effects on both of the polyphenol content and activity. Some novel processing technologies, such as aqueous enzymatic extraction (AEE), subcritical or supercritical extraction showed advantages for producing rapeseed oil with higher level of polyphenols. The oil refining process involved heat or strong acid and alkali conditions affected their stability and activity, leading to the loss of polyphenols of the final products. Future efforts are encouraged to provide more clinic evidence for the practical applications of the rapeseed polyphenols, as well as optimizing the processing technologies for the green manufacturing of rapeseed oils.

In Vitro Digestion and Colonic Fermentation of UHT Treated Faba Protein Emulsions: Effects of Enzymatic Hydrolysis and Thermal Processing on Proteins and Phenolics

Faba bean (Vicia faba L.) protein is a new plant protein alternative source with high nutrient content especially protein and phenolic compounds. The present study investigated physicochemical properties, phenolic content, antioxidant potential, and short chain fatty acids (SCFAs) production during in vitro digestion and colonic fermentation of faba bean hydrolysates and oil-in-water (O/W) emulsions. Results indicate that the enzymic hydrolysates of faba proteins exhibited higher protein solubility, increased electronegativity, and decreased surface hydrophobicity than native faba protein. O/W emulsions showed improved colloidal stability for the faba protein hydrolysates after ultra-high temperature processing (UHT). Furthermore, UHT processing preserved total phenolic content, DPPH and ABTS radical scavenging abilities while decreasing total flavonoid content and ferric reducing power. Besides, the release of phenolic compounds in faba bean hydrolysates (FBH) and emulsions (FBE) improved after intestinal digestion by 0.44 mg GAE/g and 0.55 mg GAE/g, respectively. For colonic fermentation, FBH demonstrated an approximately 10 mg TE/g higher ABTS value than FBE (106.45 mg TE/g). Total SCFAs production of both FBH and FBE was only 0.03 mM. The treatment of FBH with 30 min enzymatic hydrolysis displayed relatively higher antioxidant capacities and SCFAs production, indicating its potential to bring more benefits to gut health. Overall, this study showed that enzymic hydrolysis of faba proteins not only improved the colloidal emulsion stability, but also released antioxidant capacity during in vitro digestibility and colonic fermentation. Colonic fermentation metabolites (SCFAs) were related to the degree of hydrolysis for both FBH and FBE. Additional studies are required to further elucidate and differentiate the role of phenolics during faba protein processing and digestion stages in comparison to contributions of peptides, amino acids and microelements to digestion rates, antioxidant capacities and colonial SCFA production.

Targeted and Untargeted Metabolomic Analyses Reveal Organ Specificity of Specialized Metabolites in the Model Grass Brachypodium distachyon

Brachypodium distachyon, because of its fully sequenced genome, is frequently used as a model grass species. However, its metabolome, which constitutes an indispensable element of complex biological systems, remains poorly characterized. In this study, we conducted comprehensive, liquid chromatography-mass spectrometry (LC-MS)-based metabolomic examination of roots, leaves and spikes of Brachypodium Bd21 and Bd3-1 lines. Our pathway enrichment analysis emphasised the accumulation of specialized metabolites representing the flavonoid biosynthetic pathway in parallel with processes related to nucleotide, sugar and amino acid metabolism. Similarities in metabolite profiles between both lines were relatively high in roots and leaves while spikes showed higher metabolic variance within both accessions. In roots, differences between Bd21 and Bd3-1 lines were manifested primarily in diterpenoid metabolism, while differences within spikes and leaves concerned nucleotide metabolism and nitrogen management. Additionally, sulphate-containing metabolites differentiated Bd21 and Bd3-1 lines in spikes. Structural analysis based on MS fragmentation spectra enabled identification of 93 specialized metabolites. Among them phenylpropanoids and flavonoids derivatives were mainly determined. As compared with closely related barley and wheat species, metabolic profile of Brachypodium is characterized with presence of threonate derivatives of hydroxycinnamic acids.

Simulated Gastrointestinal Digestion of Bioprocessed Spelt Seeds: Bioaccessibility and Bioactivity of Phenolics

The goal of this research was to evaluate the impact of different bioprocessing techniques on improved bioaccessibility of phenolics from spelt seeds. Despite the negative influence of gastrointestinal digestion, fermentation of germinated seeds significantly increased the bioaccessibility of total phenolics and their antioxidant activity compared to digested raw seeds. Enzymatic treated fermented seeds showed the highest relative bioaccessibility of p-coumaric and trans-ferulic acids, while their absolute contents were significantly higher in “germinated + fermented” seeds. Our research suggests that pretreatment of spelt seeds with hydrolytic enzymes improves access of fermenting microorganisms to structural elements, resulting in an increased content of extractable and bound trans-ferulic acid. Significantly higher biostability of phenolics was observed in raw seeds. Some major quality changes in the composition of extracts were observed under simulated in vitro digestion, since antioxidants of the same extract showed a different relative decrease in DPPH• and ABTS•+ scavenging activities compared to the raw seeds or their corresponding undigested counterparts. It is therefore important to increase the content of extractable antioxidants in seeds by bioprocessing, since they are strongly diminished during digestion.

In Vitro Digestibility and Bioaccessibility of Nutrients and Non-Nutrients Composing Extruded Brewers' Spent Grain

This study aimed to evaluate the effect of the extrusion process on the bioaccessibility of brewers’ spent grain (BSG) nutrients (carbohydrates and proteins) and non-nutrients (bioactive compounds). BSG and extruded BSG (EBSG) were digested in vitro simulating human oral-gastro-intestinal digestion and colonic fermentation. The duodenal bioaccessibility of glucose, amino acids and phenolic compounds was analyzed. The fermentability of the dietary fiber was assessed by analysis of short-chain fatty acids. Additionally, assessment of the bioaccessibility of phenolic compounds after colonic fermentation was undertaken. The antioxidant, anti-inflammatory and antidiabetic properties of the bioaccessible compounds were studied. Extrusion caused no change in the digestibility of gluten and glucose bioaccessibility (p > 0.05). Moreover, the bioaccessibility of amino acids and phenolic compounds significantly increased (p < 0.05) due to extrusion. However, higher short-chain fatty acid content was formed in colonic fermentation of BSG (p < 0.05) compared to EBSG. The latter inhibited intracellular ROS formation in IEC-6 cells and showed anti-inflammatory properties in RAW264.7 cells. With respect to antidiabetic properties, glucose absorption was lower, and the inhibition of carbohydrases higher (p < 0.05), in the presence of EBSG compared to BSG. The effects of EBSG and BSG digests on glucose transporters were not significantly different (p > 0.05). In conclusion, extrusion positively affected the nutritional value and health-promoting properties of BSG.

Effect of Flaking and Precooking Procedures on Antioxidant Potential of Selected Ancient Cereal and Legume Flours

Consumption of cereals (and particularly ancient cereals) is considered the base of a healthy diet, and all current dietary guidelines have cereals at the bottom of the nutrition pyramid. Together with cereals, legumes are an excellent source of nutrients and nutraceuticals. The effects of agroindustrial pretreatments (flaking and precooking processes) on the antioxidant potential of flours from ancient cereals and legumes were studied. The extraction of free hydrophilic phenolic compounds was carried out in a hydroalcoholic solvent mixture via an ultrasound-assisted process. Furthermore, the solid residue was successively hydrolyzed by an alkaline solution to extract the bound phenolic fraction. Both free and bound extracted fractions were then quantitatively characterized for total polyphenolic and flavonoid contents, and the antioxidant potential was determined by carrying out the ABTS and DPPH radical scavenging assays, expressing the results (in both cases) as the Trolox equivalent antioxidant capacity (TEAC/ABTS and TEAC/DPPH, respectively). The samples were also extracted in organic apolar solvents (acetone or water-saturated iso-butanol) to quantitatively characterize lipophilic antioxidant compounds and pigments. A discussion on the comparison of these analytical parameters of flours obtained from raw, flaked, and precooked cereals and legumes is reported revealing that (i) phenolic compounds are mainly present in the post-hydrolysis extract (bound fraction), (ii) the precooking process significantly reduced the concentration of antioxidants, (iii) the flaking process slightly increased the phenolic content, (iv) legumes were less influenced by pretreatments, suggesting the possibility of using legumes to enrich cereal foods.

In Vitro Bioaccessibility of Bioactive Compounds from Rosehip-Enriched Corn Extrudates

The rosehip (Rosa canina L.) fruit has gained researchers′ attention due to its rich chemical composition in vitamin C, phenols, carotenoids, and high antioxidant activity; meanwhile, polymers such as pea protein are generally recognized as exhibiting a protection role against the extrusion process. Corn snacks extrudates obtained by replacing corn flour with 10% R. canina powder (R) and 10% R. canina with pea protein (RPP) were evaluated for the physicochemical, textural, optical, and nutritional characteristics. A sample manufactured without R. canina powder was used as a control. Hardness, crispiness, chewiness, and solubility index (WSI) of the final extrudates were improved by addition of R. canina and pea protein powder (PP); meanwhile, b* (yellow/blue coordinate), C (chroma), and h* (tone) optical parameters were significantly different from the control sample (p < 0.05). Extrusion highlighted a negative impact on total phenols, carotenoids, vitamin C, and antioxidant activity extrudates, while PP exhibited a good protection against the extrusion process. In vitro digestion increased the bioaccessibility of vitamin C, folate, antioxidant activity, total phenols, and total carotenoids mainly on RPP extrudates.

A review of extrusion-modified underutilized cereal flour: chemical composition, functionality, and its modulation on starchy food quality

Compared with three major cereals, underutilized cereals (UCs) are those with less use but having abundant bioactive components and better functionalities after proper processing. As a productive and energy-efficient technology, extrusion has been used for UC modification to improve its technological and nutritional quality. Extrusion could induce structural and quantitative changes in chemical components of UC flour, the degree of which is affected by extrusion intensity. Based on the predominant component (starch), functionalities of extruded underutilized cereal flour (EUCF) and potential mechanisms are reviewed. Considering bioactive compounds, it also summarizes the physiological functions of EUCF. EUCF incorporation could modulate the dough rheological behavior and starchy foods quality. Controlling extrusion intensity or incorporation level of EUCF is vital to achieve sensory-appealing and nutritious products. This paper gives comprehensive information of EUCF to promote its utilization in novel staple foods.

Effect of Extrusion or Fermentation on Physicochemical and Digestive Properties of Barley Powder

In this work, the effect of extrusion and fermentation on the physicochemical and digestive properties of barley powder was studied. The results showed that the contents of phenolics, β-glucan, protein, and lipid decreased after extrusion. The contents of nutrients (except lipid) increased after fermentation. Both extrusion and fermentation of barley can lead to the darkening of the color and effectively optimize the palatability by reducing the viscosity. In vitro digestion of starch showed that the content of as rapidly digestible starch increased after extrusion and fermentation. The contents of ferulic acid, 2-hydroxybenzoic acid, and caffeic acid decreased after extrusion, while the contents of chlorogenic acid, p-coumaric acid, and ferulic acid increased after fermentation. Basically, the content of all the phenolic showed an increasing trend after digestion. The antioxidant activity decreased after extrusion and increased after fermentation. Therefore, the nutritional composition and properties of barley powder were changed under the two processing methods.

Impact of oats in the prevention/management of hypertension

Oats are a rich source of a soluble fibre, beta-glucan, phenolic compounds, as well as functional lipid and protein components that could potentially aid in preventing and managing hypertension. Processing techniques commonly used to manufacture oat based foods have been shown to improve its physiological efficacy. Hypertension is a common condition that is a risk factor for cardiovascular disease, a primary cause of mortality worldwide. Though exercise and pharmacological interventions are often used in the management of hypertension, diet is an incredibly important factor. One preclinical study and a handful of clinical studies have shown that oat components/products are effective in lowering blood pressure. However, research in this area is limited and more studies are needed to elucidate the anti-hypertensive potential of oats.

Food Processing Technologies to Develop Functional Foods With Enriched Bioactive Phenolic Compounds in Cereals

Cereal grains and products provide calories globally. The health benefits of cereals attributed to their diverse phenolic constituents have not been systematically explored. Post-harvest processing, such as drying, storing, and milling cereals, can alter the phenolic concentration and influence the antioxidant activity. Furthermore, cooking has been shown to degrade thermo-labile compounds. This review covers several methods for retaining and enhancing the phenolic content of cereals to develop functional foods. These include using bioprocesses such as germination, enzymatic, and fermentation treatments designed to enhance the phenolics in cereals. In addition, physical processes like extrusion, nixtamalization, and parboiling are discussed to improve the bioavailability of phenolics. Recent technologies utilizing ultrasound, micro- or nano-capsule polymers, and infrared utilizing processes are also evaluated for their effectiveness in improving the phenolics content and bio-accessibility. We also present contemporary products made from pigmented cereals that contain phenolics.

Influence of extrusion process on the release of phenolic compounds from mango (Mangifera indica L.) bagasse-added confections and evaluation of their bioaccessibility, intestinal permeability, and antioxidant capacity

Extruded polyphenol-rich by-products like mango bagasse (MB) could be used to manufacture functional confections. However, few reports have assessed the extrusion impact on MB polyphenols within a food matrix. This research aimed to evaluate the impact of extrusion on the bioaccessibility, intestinal permeability, and antioxidant capacity of phenolic compounds (PC) from non-extruded and extruded MB-added confections (EMBC and MBC, respectively). The inhibition of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radicals and in silico approaches were used to evaluate the antioxidant capacity. MBC displayed the highest gastric bioaccessibility (%) of xanthones and flavonoids, whereas selective release of gallic acid, mangiferin, and quercetin glucoside was shown for EMBC. Lower PC' apparent permeability coefficients were found in EMBC compared to MB (0.11 to 0.44-fold change, p < 0.05). EMBC displayed the highest antioxidant capacity by the DPPH method for the non-digestible fraction, being mangiferin the highest in silico contributor (-4 kcal/mol). Our results showed that the extrusion process helps release selective phenolics from MBC, which increases their bioaccessibility and intestinal permeability.

Changes in Phenolics during Cooking Extrusion: A Review

In this paper, significant attention is paid to the retention of phenolics in extrudates and their health effects. Due to the large number of recent articles devoted to total phenolic content (TPC) of input mixtures and extrudates, the technological changes are only presented for basic raw materials and the originating extrudates, and only the composites identified has having the highest amounts of TPC are referred to. The paper is also devoted to the changes in individual phenolics during extrusion (phenolic acids, flavonoids, flavonols, proanthocyanidins, flavanones, flavones, isoflavons, and 3-deoxyanthocyanidins). These changes are related to the choice or raw materials, the configuration of the extruder, and the setting the technological parameters. The results found in this study, presented in the form of tables, also indicate whether a single-screw or twin-screw extruder was used for the experiments. To design an extrusion process, other physico-chemical changes in the input material must also be taken into account, such as gelatinization of starch; denaturation of protein and formation of starch, lipids, and protein complexes; formation of soluble dietary fiber; destruction of antinutritional factors and contaminating microorganisms; and lipid oxidation reduction. The chemical changes also include starch depolymerization, the Maillard reaction, and decomposition of vitamins.

The Bioaccessibility of Phenolics, Flavonoids, Carotenoids, and Capsaicinoid Compounds: A Comparative Study of Cooked Potato Cultivars Mixed with Roasted Pepper Varieties

An in vitro method was used to assess the bioaccessibility of phenolics, flavonoids, carotenoids, and capsaicinoid compounds in different cooked potatoes mixed with roasted peppers (Capsicum annuum), Joe Parker (JP, hot), and Sweet Delilah (SD, sweet). The present study identified differences in the bioaccessibility of bioactive compounds among the potato cultivars (Solanum tuberosum) Purple Majesty (PM; purple flesh), Yukon Gold (YG; yellow flesh), Rio Grande Russet (RG; white flesh) and a numbered selection (CO 97226-2R/R (R/R; red flesh)). The bioactive compounds and capsaicinoid compounds in potatoes and peppers were estimated before and after in vitro digestion. Before digestion, the total phenolic content of potato cultivars mixed with JP was in the following order: R/R > PM > YG > RG. The highest levels of carotenoids were 194.34 µg/g in YG and 42.92 µg/g in the RG cultivar when mixed with roasted JP. The results indicate that the amount of bioaccessible phenolics ranged from 485 to 252 µg/g in potato cultivars mixed with roasted JP. The bioaccessibility of flavonoids ranged from 185.1 to 59.25 µg/g. The results indicate that the YG cultivar mixed with JP and SD showed the highest phenolic and carotenoid bioaccessibility. In contrast, the PM mixed with JP and SD contained the lowest phenolic and carotenoid bioaccessibility. Our results indicate that the highest flavonoid bioaccessibility occurred in R/R mixed with roasted JP and SD. The lowest flavonoids bioaccessibility occurred in PM and the RG. The maximum bioaccessible amount of capsaicin was observed in YG mixed with JP, while the minimum bioaccessibility was observed with PM.

Bioaccessibility and Bioactivity of Cereal Polyphenols: A Review

Cereal bioactive compounds, especially polyphenols, are known to possess a wide range of disease preventive properties that are attributed to their antioxidant and anti-inflammatory activity. However, due to their low plasma concentrations after oral intake, there is controversy regarding their therapeutic benefits in vivo. Within the gastrointestinal tract, some cereal polyphenols are absorbed in the small intestine, with the majority accumulating and metabolised by the colonic microbiota. Chemical and enzymatic processes occurring during gastrointestinal digestion modulate the bioactivity and bioaccessibility of phenolic compounds. The interactions between the cereal polyphenols and the intestinal epithelium allow the modulation of intestinal barrier function through antioxidant, anti-inflammatory activity and mucin production thereby improving intestinal health. The intestinal microbiota is believed to have a reciprocal interaction with polyphenols, wherein the microbiome produces bioactive and bioaccessible phenolic metabolites and the phenolic compound, in turn, modifies the microbiome composition favourably. Thus, the microbiome presents a key link between polyphenol consumption and the health benefits observed in metabolic conditions in numerous studies. This review will explore the therapeutic value of cereal polyphenols in conjunction with their bioaccessibility, impact on intestinal barrier function and interaction with the microbiome coupled with plasma anti-inflammatory effects.

Development and Optimisation of Solid-Phase Extraction of Extractable and Bound Phenolic Acids in Spelt (Triticum spelta L.) Seeds

A solid-phase extraction (SPE) technique was developed and optimised for isolation and concentration of extractable and bound phenolic acids from germinated spelt seeds, for analysis by liquid chromatography–mass spectrometry. Samples initially underwent solvent extraction under different conditions to maximise the yield of phenolic antioxidants. Optimal extraction conditions for extractable phenolics were absolute methanol as solvent, sample-to-methanol ratio 1:9, and reconstitution in non-acidified water. The bound phenolics were extracted from sample pellets using hydrolysis with 2 M NaOH, acidification of the hydrolysate with formic acid, and simultaneous isolation and purification using Strata X polymeric RP tubes. Compared to liquid-liquid extraction, this direct SPE protocol has significant advantages in terms of higher extraction efficiencies of total and individual phenolics and their antioxidant activities. These data suggest that direct SPE represents a rapid and reliable method for quantitative analysis of both the extractable and the commonly overlooked bound phenolics in Triticum spelta seeds.

Statistical Approach to Potentially Enhance the Postbiotication of Gluten-Free Sourdough

Fermented products are permanently under the attention of scientists and consumers, both due to nutritional importance and health promoting effects. The fermented functional foods contribute to a more balanced diet and increase the immune responses (among many other health effects) with positive implications for quality of life. In this sense, improving the sourdough’s fermentation to boost the biotic (postbiotic and paraprobiotic) properties of the sourdough-based products has positive impacts on the nutritional and functional properties of the final baked products. These enhanced sourdoughs can be obtained in controlled fermentation conditions and used as sourdough bread improvers or novel bioingredients. In this context, our work aimed to optimize, using statistical tools, a gluten-free sourdough based on chickpea, quinoa, and buckwheat fermentation with selected lactic acid bacteria (LAB) to enhance its postbiotic properties. The most important biotechnological parameters were selected by Plackett–Burman Design (PBD) and then Response Surface Methodology (RSM) was applied to evaluate the interactions between the selected factors to maximize the gluten-free sourdough’s properties. As a result, the optimized fermented sourdough had antimicrobial activity with inhibition ratios between 71 and 100% against the Aspergillus niger, Aspergillus flavus, Penicillium spp. molds and against the Bacillus spp endospore-forming Gram-positive rods. The optimized variant showed a total titratable acidity (TTA) of 40.2 mL NaOH 0.1N. Finally, the high-performance liquid chromatography (HPLC) analysis highlighted a heterofermentative profile for the organic acids from the optimized sourdough. Among flavonoids and polyphenols, the level of caffeic and vanillic acids increased after lactic acid fermentation. The comparison between the optimized sourdough and the control evidenced significant differences in the metabolite profiles, thus highlighting its potential postbiotication effect.

Bioaccessibility of phenolic acids in Canadian hulless barley varieties

In order to gain understanding of bioaccessibility of phenolic acids in food-grade barley, an investigation was conducted using four cooked whole-grain, hulless, barley varieties. An in vitro digestion model was used to mimic human upper gastrointestinal digestion. Boiling enhanced the extractability of bound phenolic acids while digestion increased the level of free phenolic acids. The high bioaccessibilities observed were likely due to the release of bound phenolic acids during cooking and digestion. The major bioaccessible phenolics were ferulic and p-coumaric acids with bioaccessibility ranging from 131 to 173% and 51-135%, respectively. Peru-35 had significantly greater bioaccessibility of ferulic acid compared to other varieties. A hydroxycinnamic acid amide not reported before in boiled barley, N¹, N⁸- dicaffeoyl spermidine, was identified in free phenolic extracts with relatively high abundance compared to the phenolic acids. It may provide additional anti-inflammatory and antioxidant functions. These cooked whole-grain, hulless barley varieties are sources of bioaccessible phenolic acids.

High-amylose corn in gluten-free pasta: Strategies to deliver nutritional benefits ensuring the overall quality

High-amylose corn alone or in combination (25% and 50%) with conventional corn was used to produce gluten-free pasta. Flour pre-gelatinization in a tank (process A) or on a conveyor belt (process B) were tested. Resistant starch (RS), soluble (SPAs) and cell-wall bound phenolic acids (CWBPAs) and antioxidant capacity were significantly higher in high-amylose corn pasta. Cooked pasta from process B showed a higher SPA concentration, likely due to the lower cooking loss. The structure of pasta prepared with process B was more homogeneous, whereas it was more compact in the case of process A, as shown by a lower starch susceptibility to α-amylase hydrolysis, higher beginning of gelatinization temperature and lower water absorption. 25% HA represents a good compromise between high RS (4.2%) and good cooking behavior. At higher HA levels, process B is more suitable to obtain pasta with a better cooking quality.

The effect of the amylose content and milling fractions on the physico-chemical features of co-extruded snacks from corn

The suitability of corn fractions (break meal: 250-500 µm; flour: < 150 µm) from hybrids with different amylose contents (conventional: 18%; high-amylose: 42%; waxy: 2%) and their blends, to produce co-extruded snacks was assessed. Corn flour exhibited a higher content in total soluble phenolic acids (+34%) than break meal. The high-amylose hybrid maintained a higher antioxidant capacity and phenolic acid content (+52% for soluble and + 54% for cell-wall bound phenolic acids), even after extrusion, than the conventional one. Because of its gelatinization properties (high pasting and peak temperatures; low maximum viscosity), the high-amylose hybrid produced co-extruded snacks characterized by low section areas and large inner areas. The blends led to snacks whose features (sections and inner areas, porosity and hardness) did not follow a linear trend with the amylose content, suggesting the need for further studies to better understand the starch interactions that take place among the various hybrids.

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.

Health Promoting Bioactive Properties of Novel Hairless Canary Seed Flour after In Vitro Gastrointestinal Digestion

The bioactive properties and health-promoting effects of two novel yellow (C09052, C05041) and two brown (Calvi, Bastia) hairless canary seed (Phalaris canariensis L.) cultivars were investigated in comparison to two common cereal grains (wheat and oat). The cereal flours were digested using the standardized INFOGEST in vitro human gastrointestinal digestion model. The three-kilo dalton molecular weight cutoff (3 kDa MWCO) permeate of the generated digestates was assessed in vitro for their antioxidant, chelating, antihypertensive and antidiabetic activities. The results showed no significant differences in studied bioactivities between yellow and brown canary seed cultivars, except for antioxidant activity by the DPPH and chelating Fe2+ assays, where brown cultivars had higher activities. Canary seeds had superior or equivalent antioxidant activity than those from oat and wheat. The anti-hypertensive activity (Angiotensin-converting enzyme (ACE) inhibition) in yellow canary seed cultivars was significantly higher than that of oat and wheat, particularly for C09052 and Calvi varieties. Peptides exhibiting the highest antihypertensive activity from the permeate of the C09052 canary seed variety were further fractionated and identified by mass spectrometry. Forty-six peptides were identified belonging to 18 proteins from the Pooideae subfamily. Fourteen of the parent proteins were homologous to barley proteins. Peptides were analyzed in silico to determine potential bioactivity based on their amino acid composition. All 46 peptides had potential anti-hypertensive and anti-diabetic activities and 20 had potential antioxidant activity, thereby validating the in vitro assay data. Canary seed peptides also exhibited potential antiamnestic, antithrombotic, immunostimulating, opioid and neuro-activity, demonstrating important potential for health promoting effects, particularly against cardiovascular disease.

Effects of different industrial processes on the phenolic composition of white and brown teff (Eragrostis tef (Zucc.) Trotter)

Teff is currently being incorporated into a range of foodstuffs, especially gluten-free flakes and extruded products. The main objective of this work was to assess the effects of different treatments (industrial milling, formation of flakes and extrusion) on the phenolic composition of two types of teff grains differing in their colour (white and brown). Fifty-nine phenolic compounds were detected by HPLC-DAD-MSⁿ. C-glycosyl flavones accounted for more than 90% of the total phenolic contents in both teff types. White teff mostly contained apigenin-derived flavones (86-92%), whereas luteolin derivatives prevailed in brown teff (91-94%). The industrial processes, mainly flaking and extrusion, caused marked changes in the phenolic composition, some of which were dependent on the teff type. In both teff types, processing changed the phenolic profiles similarly by increasing C-monoglycosyl flavones and decreasing acylated derivatives. However, the total content was increased in flakes and extruded products made only from brown teff grains.

Phenolic Compounds and Bioaccessibility Thereof in Functional Pasta

Consumption of food products rich in phenolic compounds has been associated to reduced risk of chronic disease onset. Daily consumed cereal-based products, such as bread and pasta, are not carriers of phenolic compounds, since they are produced with refined flour or semolina. Novel formulations of pasta have been thus proposed, in order to obtain functional products contributing to the increase in phenolic compound dietary intake. This paper aims to review the strategies used so far to formulate functional pasta, both gluten-containing and gluten-free, and compare their effect on phenolic compound content, and bioaccessibility and bioavailability thereof. It emerged that whole grain, legume and composite flours are the main substituents of durum wheat semolina in the formulation of functional pasta. Plant by-products from industrial food wastes have been also used as functional ingredients. In addition, pre-processing technologies on raw materials such as sprouting, or the modulation of extrusion/extrusion-cooking conditions, are valuable approaches to increase phenolic content in pasta. Few studies on phenolic compound bioaccessibility and bioavailability in pasta have been performed so far; however, they contribute to evaluating the usefulness of strategies used in the formulation of functional pasta.

Comparative study of conventional steam cooking and microwave cooking on cooked pigmented rice texture and their phenolic antioxidant

The impact of two different cooking processes (microwave and steaming) on cooked rice quality (i.e., texture), and changes in the bioactive compounds (total phenolic content [TPC] and total anthocyanin content [TAC]) and antioxidant activities (DPPH and FRAP assays) of black and red (nonwaxy) and purple (waxy) pigmented rice were investigated. No significant difference in the firmness between microwave-cooked rice and steam-cooked rice was found, except for cooked purple rice. However, microwave cooking promoted an increase in the cooked rice adhesiveness, which approximately higher 2- ~ 3-fold than that of steam cooking with varying among rice cultivars. Microwave cooking also exhibited significantly higher TPC (1.2- ~ 2.0-fold), TAC (2.0- ~ 3.2-fold), DPPH (1.3- ~ 2.5-fold), and FRAP (1.5- ~ 2.4-fold) than steam cooking for black and purple rice cultivars. There was a strong positive correlation among these bioactive compounds and the antioxidant activities (p < .01). Our study indicated that the TPC, TAC, DPPH, and FRAP of all rice examined were remarkably decreased after cooking, and the extent of the decrease depended on the rice cultivar and cooking method.

Phenolic compounds and biological activities of rye (Secale cereale L.) grains

The rye flour is, together with the wheat flour, the basic ingredient used in traditional bread baking. The rye grain contains many compounds with significant impacts on the consumer. Considering that, various biologically active phytochemicals were determined in extracts from mature grains of 19 rye genotypes (Secale cereale L.). The content of total phenols, flavonoids, phenolic acids and thiols, as well as antioxidant activities and inhibitory activities against trypsin, thrombin, and urokinase were analyzed by spectrophotometric methods. The vanillic acid, vanillin, p-coumaric acid, and t-ferulic acid were analyzed in particular by high performance liquid chromatography (HPLC). The observed differences in the amounts and activities between rye genotypes reflected variations in their genetic background. Rye grain is a remarkable source of specific phytochemicals. Genetic diversity in rye makes it possible to identify individual genotypes that have a unique content and biological activity of compounds deposited in mature grains. One subgroup of rye genotypes had higher values of antioxidant properties and concentrations of polyphenols. Other sub-group had higher proteinase inhibitory activities and contents of polyphenols. The third sub-group contained as though the universal genotypes, i.e. genotypes with average values in nearly all the measured parameters.

Composition and content of phenolic acids and avenanthramides in commercial oat products: Are oats an important polyphenol source for consumers?

Oats contain a range of phenolic acids and avenanthramides which may have health benefits. Analysis of 22 commercial oat products (oat bran concentrate, oat bran, flaked oats, rolled oats and oatcakes) using HPLC-DAD detected eleven bound and thirteen free + conjugated phenolic acids and avenanthramides. The oat products (excluding concentrate) provided between 15.79 and 25.05 mg total phenolic acids (9.9-19.33 mg bound, 4.96-5.72 mg free + conjugated) and between 1.1 and 2 mg of avenanthramides in a 40 g portion while an 11 g portion of oat concentrate provided 16.7 mg of total phenolic acids (15.17 mg bound, 1.53 mg free + conjugated) and 1.2 mg of avenanthramides. The compositions and concentrations of the components in the different products were broadly similar, with the major component being ferulic acid (58-78.1%). The results show that commercial oat products are a source of phenolic acids and avenanthramides for consumers.

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.

In vitro digestibility, free and bound phenolic profiles and antioxidant activity of thermally treated Eragrostis tef L

BACKGROUND

Total phenolic content, phenolic profile and antioxidant activity were determined in free and bound phenolic fractions of thermally treated brown and white teff grains.

RESULTS

Phenolic content in raw brown and white teff (1540 and 992 mg gallic acid equivalent kg^-1 ) as well as antioxidant activity (6.3 and 5.5 mmol trolox equivalent kg^-1 ) were higher in free phenolic fractions. The most significant decrease in total phenolics was observed after application of the sous-vide method (35% for brown teff and 11% for white teff). Main free phenolics of heat-treated teff were ferulic, protocatechuic, p-coumaric and ellagic acids, rutin and epigallocatechin. Main bound phenolics were ferulic, gallic, sinapic and ellagic acids, catechin and epigallocatechin. The detrimental effect on free and bound quercetin and bound cinnamic acid concentrations was also examined during heat treatment. Thermally treated brown teff showed a high level of in vitro organic matter digestibility if water cooking and rice cooker (both 99.5%) and sous-vide (96.5%) methods were applied.

CONCLUSION

The sous-vide method may be recommended as the most suitable hydrothermal treatment for grains of teff when compared with water cooking and rice cooker methods. © 2017 Society of Chemical Industry.

Identification and Quantification of Avenanthramides and Free and Bound Phenolic Acids in Eight Cultivars of Husked Oat ( Avena sativa L) from Finland

Finland is the second largest oat producer in Europe. Despite the existing knowledge of phenolics in oat, there is little information on the phenolic composition of oats from Finland. The aim of the study was to investigate the concentrations of free and bound phenolic acids, as well as avenanthramides in eight Finnish cultivars of husked oat ( Avena sativa L.). Seven phenolic acids and one phenolic aldehyde were identified, including, in decreasing order of abundance: p-coumaric, ferulic, cinnamic, syringic, vanillic, 2,4-dihydroxybenzoic, and o-coumaric acids and syringaldehyde. Phenolic acids were mostly found as bound compounds. Significant varietal differences ( p < 0.05) were observed in the cumulative content of phenolic acids, with the lowest level found in cv. 'Viviana' (1202 ± 52.9 mg kg^-1) and the highest in cv. 'Akseli' (1687 ± 80.2 mg kg^-1). Avenanthramides (AVNs) 2a, 2p, and 2f were the most abundant. Total AVNs levels ranged from 26.7 ± 1.44 to 185 ± 12.5 mg kg^-1 in cv. 'Avetron' and 'Viviana', respectively.

Processing of oat: the impact on oat's cholesterol lowering effect

Epidemiological and interventional studies have clearly demonstrated the beneficial impact of consuming oat and oat-based products on serum cholesterol and other markers of cardiovascular disease. The cholesterol-lowering effect of oat is thought to be associated with the β-glucan it contains. However, not all food products containing β-glucan seem to lead to the same health outcome. Overall, highly processed β-glucan sources (where the oat tissue is highly disrupted) appear to be less effective at reducing serum cholesterol, but the reasons are not well understood. Therefore, the mechanisms involved still need further clarification. The purpose of this paper is to review current evidence of the cholesterol-lowering effect of oat in the context of the structure and complexity of the oat matrix. The possibility of a synergistic action and interaction between the oat constituents promoting hypocholesterolaemia is also discussed. A review of the literature suggested that for a similar dose of β-glucan, (1) liquid oat-based foods seem to give more consistent, but moderate reductions in cholesterol than semi-solid or solid foods where the results are more variable; (2) the quantity of β-glucan and the molecular weight at expected consumption levels (∼3 g day-1) play a role in cholesterol reduction; and (3) unrefined β-glucan-rich oat-based foods (where some of the plant tissue remains intact) often appear more efficient at lowering cholesterol than purified β-glucan added as an ingredient.