Pigmented sorghum polyphenols as potential inhibitors of starch digestibility: An in vitro study combining starch digestion and untargeted metabolomics

Sorghum starch review: Structural properties, interactions with proteins and polyphenols, and modification of physicochemical properties

Sorghum, a gluten-free carbohydrate source with high antioxidants and resistant starch, contains anti-nutrients like phytic acid, tannin, and kafirin. Interactions with starch and proteins result in polyphenol-starch, starch-kafirin, and tannin-protein complexes. These interactions yield responses such as V-type amylose inclusion complexes, increased hydrophobic residues, and enzyme resistance, reducing nutrient availability and elevating resistant starch levels. Factors influencing these interactions include starch composition, structure, and Chain Length Distribution (CLD). Starch structure is impacted by enzymes like ADP-glucose pyrophosphorylase, starch synthases, and debranching enzymes, leading to varied chain lengths and distributions. CLD differences significantly affect crystallinity and physicochemical properties of sorghum starch. Despite its potential, the minimal utilization of sorghum starch in food is attributed to anti-nutrient interactions. Various modification approaches, either direct or indirect, offer diverse physicochemical changes with distinct advantages and disadvantages, presenting opportunities to enhance sorghum starch applications in the food industry.

Impact of heat and high-moisture pH treatments on starch digestibility, phenolic composition, and cell bioactivity in sorghum (Sorghum bicolor L. Moench) flour

Sorghum (Sorghum bicolor L. Moench), characterized by substantial genetic diversity, encompasses some lines rich in health-promoting polyphenols. Laboratory studies have demonstrated anticancer properties of sorghum phenolics; however, their presence may impact nutritional factors, such as digestible starch. The objective of this study was to determine the effects of pH and high-moisture heating on starch digestibility, phenolic profile, and anticancer activity in sorghum. High Phenolic sorghum flour line SC84 was combined with buffer solutions (pH 3, 4, 5, 7, and 8) and heated for 0, 10, 30, 60, or 120 min. Starch digestibility was assessed using the K-DSTRS kit from Megazyme. Changes in phenolic composition were analyzed using total phenolic content (TPC) and condensed tannin content (CTC) assays coupled with reversed phase high performance liquid chromatography (RP-HPLC) analysis. Anticancer potential against human colorectal cancer cells (HCT116 and SW480) was determined though cell viability assay. Results indicated a significant increase in total starch digestibility of sample after heating. Heating samples for 10 min did not significantly reduce TPC of samples. However, CTC was significantly reduced with heating time, while pH exhibited no significant effect on CTC. The measured 3-deoxyanthocyanidins experienced a significant decrease (p < 0.0001), while certain flavonoids increased significantly (p < 0.05) after heating for 30 min or longer. Notably, the 10 min heating duration minimally affected anticancer activity, whereas longer heat times diminished extract efficacy against human colorectal cancer cells. Alkaline pH levels significantly decreased anticancer activity, regardless of heating time. Importantly, heating sorghum for 10 min improved starch digestibility with minimal compromise to potential health benefits. These findings suggest promising implications for the development of high-phenolic sorghum products, and provide valuable insights to guide forthcoming animal and clinical studies. The demonstrated impact of wet-heating on increased starch digestibility, coupled with the preservation of phenolic content and bioactivity, underscores the potential of incorporating high-phenolic sorghum lines in future functional food formulations.

In vitro gastrointestinal digestion methods of carbohydrate-rich foods

The trend toward healthier food products has led to an increase in the research of in vitro gastrointestinal digestion methods. Among the most used models, static models are the simplest. Most static models have three stages: oral, gastric, and intestinal, simulating the enzymatic, electrolyte, pH, temperature, and bile salt conditions. The studies that have taken the most notice are those related to antioxidant activity, followed by those dealing with proteins and carbohydrates using most of them static in vitro digestion models. The number of these studies has increased over the years, passing from 45 to 415 in a 10-year period (2012-2023) and showing an interest in knowing the impact of food on human health. Nevertheless, published papers report different methodologies and analytical approaches. This review discusses the similarities and differences between the published static in vitro gastrointestinal digestion methods, with a focus on carbohydrates, finding that the most used protocol is Infogest, but with differences, mainly in the type of enzymes and their activity. Regarding in vitro gastrointestinal digestion of carbohydrates, many of the published studies are related to food and biomacromolecules, being the oral phase the most omitted, while the intestinal phase in the most diverse. Other methodologies to study the intestinal phase have been recommended, but the number of in vitro digestion studies using these methodologies (RSIE and BBMV) is still scarce but could represent a good alternative to analyze carbohydrates foods when combining with Infogest. More studies are required in this area.

Development of an Ultrasound-Assisted Extraction Procedure for the Simultaneous Determination of Anthocyanins and Phenolic Acids in Black Beans

Beans are an essential source of nutritional components such as plant proteins, minerals and dietary fiber, as well as of antioxidants such as phenolic compounds. Phenolic compounds are praised for their biological activities and possible benefits on human health. Since no official methods are available for phenolic compound extraction, the optimization of extraction parameters via Response Surface Methodology (RSM) has become a commonly used methodological approach for reliable determinations. This study aimed to apply RSM to optimize the ultrasound-assisted extraction procedure of phenolic compounds, including anthocyanins, from black beans. A Generally Recognized As Safe solvent (ethanol) was used. Solvent concentration, extraction time, and solvent/sample ratio were optimized to maximize two responses: Total Anthocyanin Content (TAC) and Total Phenolic Content (TPC). An ethanol concentration of 64%, 30 min extraction time, and a 50 mL/g solvent/sample ratio were identified as the optimal extraction conditions. The TAC was 71.45 ± 1.96 mg cyanidin-3-O-glucoside equivalents 100 g-1 dm, and the TPC was 60.14 ± 0.89 mg gallic acid equivalents 100 g-1 dm. Among the pigmented phenolic compounds, cyanidin-3-O-glucoside and peonidin-3-O-glucoside were identified in the extracts. Regarding phenolic acids, caffeic, sinapic, and t-ferulic acids were detected.

Effect of proanthocyanidins from different sources on the digestibility, physicochemical properties and structure of gelatinized maize starch

The effect of proanthocyanidins (PAs) from Chinese bayberry leaves (BLPs), grape seeds (GSPs), peanut skins (PSPs) and pine barks (PBPs) on physicochemical properties, structure and in-vitro digestibility of gelatinized maize starch was investigated. The results showed that all PAs remarkably retarded starch digestibility, meanwhile, BLPs highlighted superiority in increasing resistant starch content from 31.29 ± 1.12 % to 68.61 ± 1.15 %. The iodine-binding affinity analysis confirmed the interaction between PAs and starch, especially the stronger binding of BLPs to amylose, which was driven by non-covalent bonds supported by XRD and FT-IR analysis. Further, we found that PAs altered the rheological properties, thermal properties and morphology structure of starch. In brief, PAs induced larger consistency, poorer flow ability, lower gelatinization temperatures and melting enthalpy change (ΔH) of starch paste. SEM and CLSM observation demonstrated that PAs facilitated starch aggregation. Our results indicated that PAs especially BLPs could be considered as potential additives to modify starch in food industry.

Mining nutri-dense accessions from rice landraces of Assam, India

The Indian subcontinent is the primary center of origin of rice where huge diversity is found in the Indian rice gene pool, including landraces. North Eastern States of India are home to thousands of rice landraces which are highly diverse and good sources of nutritional traits, but most of them remain nutritionally uncharacterized. Hence, nutritional profiling of 395 Assam landraces was done for total starch, amylose content (AC), total dietary fiber (TDF), total protein content (TPC), oil, phenol, and total phytic acid (TPA) using official AOAC and standard methods, where the mean content for the estimated traits were found to be 75.2 g/100g, 22.2 g/100g, 4.67 g/100g, 9.8 g/100g, 5.26%, 0.40 GAE g/100g, and 0.34 g/100g for respectively. The glycaemic index (GI) was estimated in 24 selected accessions, out of which 17 accessions were found to have low GI (<55). Among different traits, significant correlations were found that can facilitate the direct and indirect selection such as estimated glycemic index (EGI) and amylose content (-0.803). Multivariate analyses, including principal component analysis (PCA) and hierarchical clustering analysis (HCA), revealed the similarities/differences in the nutritional attributes. Four principal components (PC) i.e., PC1, PC2, PC3, and PC4 were identified through principal component analysis (PCA) which, contributed 81.6% of the variance, where maximum loadings were from protein, oil, starch, and phytic acid. Sixteen clusters were identified through hierarchical clustering analysis (HCA) from which the trait-specific and biochemically most distant accessions could be identified for use in cultivar development in breeding programs.

Complexation of starch and phenolic compounds during food processing and impacts on the release of phenolic compounds

Phenolic compounds can form complexes with starch during food processing, which can modulate the release of phenolic compounds in the gastrointestinal tract and regulate the bioaccessibility of phenolic compounds. The starch-phenolic complexation is determined by the structure of starch, phenolic compounds, and the food processing conditions. In this review, the complexation between starch and phenolic compounds during (hydro)thermal and nonthermal processing is reviewed. A hypothesis on the complexation kinetics is developed to elucidate the mechanism of complexation between starch and phenolic compounds considering the reaction time and the processing conditions. The subsequent effects of complexation on the physicochemical properties of starch, including gelatinization, retrogradation, and digestion, are critically articulated. Further, the release of phenolic substances and the bioaccessibility of different types of starch-phenolics complexes are discussed. The review emphasizes that the processing-induced structural changes of starch are the major determinant modulating the extent and manner of complexation with phenolic compounds. The controlled release of complexes formed between phenolic compounds and starch in the digestive tracts can modify the functionality of starch-based foods and, thus, can be used for both the modulation of glycemic response and the targeted delivery of phenolic compounds.

Sorghum Flour Features Related to Dry Heat Treatment and Milling

Heat treatment of sorghum kernels has the potential to improve their nutritional properties. The goal of this study was to assess the impact of dry heat treatment at two temperatures (121 and 140 °C) and grain fractionation, on the chemical and functional properties of red sorghum flour with three different particle sizes (small, medium, and large), for process optimization. The results showed that the treatment temperature had a positive effect on the water absorption capacity, as well as the fat, ash, moisture and carbohydrate content, whereas the opposite tendency was obtained for oil absorption capacity, swelling power, emulsion activity and protein and fiber content. Sorghum flour particle size had a positive impact on water absorption capacity, emulsion activity and protein, carbohydrate and fiber content, while oil absorption capacity, swelling power and fat, ash and moisture content were adversely affected. The optimization process showed that at the treatment temperature at 133 °C, an increase in fat, ash, fiber and carbohydrate content was experienced in the optimal fraction dimension of red sorghum grains. Moreover, the antioxidant performance showed that this fraction produced the best reducing capability when water was used as an extraction solvent. Starch digestibility revealed a 22.81% rise in resistant starch, while the thermal properties showed that gelatinization enthalpy was 1.90 times higher compared to the control sample. These findings may be helpful for researchers and the food industry in developing various functional foods or gluten-free bakery products.

The Role of Ancient Grains in Alleviating Hunger and Malnutrition

Meeting the United Nation's sustainable development goals for zero hunger becomes increasingly challenging with respect to climate change and political and economic challenges. An effective strategy to alleviate hunger and its severe implications is to produce affordable, nutrient-dense, and sustainable food products. Ancient grains were long-forgotten due to the dominance of modern grains, but recently, they have been rediscovered as highly nutritious, healthy and resilient grains for solving the nutrition demand and food supply chain problems. This review article aims to critically examine the progress in this emerging field and discusses the potential roles of ancient grains in the fight against hunger. We provide a comparative analysis of different ancient grains with their modern varieties in terms of their physicochemical properties, nutritional profiles, health benefits and sustainability. A future perspective is then introduced to highlight the existing challenges of using ancient grains to help eradicate world hunger. This review is expected to guide decision-makers across different disciplines, such as food, nutrition and agronomy, and policymakers in taking sustainable actions against malnutrition and hunger.

Dietary Polyphenols and Obesity: A Review of Polyphenol Effects on Lipid and Glucose Metabolism, Mitochondrial Homeostasis, and Starch Digestibility and Absorption

Obesity is a major global public health concern, limiting socio-economic development and human productivity. As studies focus on finding sustainable solutions to this challenge, polyphenols have shown promising results and have become a research focus. This is mainly because of associated lower risks of side effects with their use, compared to synthetic pharmaceuticals. In this study, the anti-obesity potentials of dietary polyphenols have been reviewed. Using a narrative approach, the biological activities of polyphenols and their influence on energy metabolism and mechanisms are discussed. Specifically, their roles in insulin-dependent glucose uptake, insulin sensitivity, lipid metabolism and storage in adipocytes, starch digestibility, and regulation of mitophagy and mitogenesis in muscle cells and adipocytes, were considered. After considering the major findings of many related studies, it was confirmed that polyphenols can prevent and ameliorate obesity by fighting insulin resistance (IR) induced by pro-inflammatory cytokines, scavenging reactive oxygen species (ROS) and limiting their effects, and by regulating the expression and/or activity of key enzymes along relevant pathways. More human studies are needed to reveal more about the anti-obesity effects of dietary polyphenols and their effective doses in humans.

Effects of pretreatment with a combination of ultrasound and γ-aminobutyric acid on polyphenol metabolites and metabolic pathways in mung bean sprouts

Background

Polyphenols play an important role in human nutrition, therefore, how to improve its content with innovative approach is important, and understanding the metabolic pathys is necessary. Mung beans are rich in polyphenols, which made them have physiological functions such as hypoglycemia, antioxidant, and hypotension. However, the content of polyphenols in natural mung bean is relatively low, and it needs to be increased. The methods of increasing polyphenol content in grains and beans by enrichment include physical stress, such as ultrasonic stress, hypoxia stress and ultraviolet radiation, and single exogenous substance stress, such as exogenous amino acids, exogenous sugars. But, the enrichment of polyphenols using exogenous substances in combination with physical stress is less applied. Therefore, this study innovated the use of exogenous γ-aminobutyric acid (GABA) combined with ultrasonic stress to enrich mung bean sprouts polyphenols and enhance their content. The metabolic pathways of the enrichment process were also analyzed to provide a reference for studies related to the enrichment of polyphenols.

Methods

Mung bean seeds were pretreated with a combination of ultrasound and GABA under different conditions. Single-factor test and response surface methodology were used for optimizing pretreatment conditions of mung bean. Effects of combined pretreatments on the polyphenols content and antioxidant activity of sprouted mung beans were investigated. Additionally, metabolites were identified, and metabolic pathways were analyzed using non-targeted metabolomics techniques.

Results

Optimal conditions of mung bean pretreatment were found to be 370 W for ultrasound power, 40 min for ultrasonication time, 10 mmol/L for GABA concentration, and 8 h for the soaking duration. Under these conditions, the predicted polyphenol content was found to be 4.52 mg GAE/g DW. The pretreatment of mung beans with a combination of ultrasound and exogenous GABA resulted in mung bean sprouts with enhanced polyphenol content and antioxidant activity compared to mung beans germinated without pretreatment. A significant increase in the content of six polyphenols [Genistein, (-)-Epigallocatechin, Epicatechin, Nobiletin, Naringenin, Biochanin A] in the pretreated and germinated mung beans was found, and six metabolic pathways (flavonoid biosynthesis, isoflavones biosynthesis, biosynthesis of phenylpropanoids, anthocyanin biosynthesis, biosynthesis of secondary metabolites, and metabolic pathways) were significantly activated.

Conclusion

The obtained results suggest that a combination of ultrasound and exogenous GABA treatment can be used to produce mung bean sprouts with enriched polyphenols content and enhanced antioxidant activity.

Gluten-Free Sorghum Pasta: Composition and Sensory Evaluation with Different Sorghum Hybrids

Although whole grain (WG) sorghum is affordable and a healthier alternative to gluten-free pastas (GFPa), sorghum diversity requires evaluation for application in pasta. We aimed to develop GFPa using six sorghum hybrids. White commercial flour (WCF) and sorghums with brown (BRS 305 and 1167048), red (BRS 330 and BRS 332), and white (CMSXS 180) pericarp colors. Total phenolic content (TPC), total condensed tannins (TAN), total antioxidant activity (TAA—FRAP and DPPH), resistant starch (RS), cooking properties, texture, and sensory evaluation were carried out in sorghum pasta. The statistical analyses were ANOVA, Tukey and Friedman test, and multiple factorial analyses. Brown sorghum GFPa showed the best results for bioactive compounds (RS (1.8 and 2.9 g/100 g), TPC (69.9 and 42.8 mg/100 g), TAN (16.9 and 9.4 mg proanthocyanidin/100 g), TAA for FRAP (305 and 195 mM Teq/g), and DPPH (8.7 and 9.0 mg/mL)), but also the highest soluble solids loss (8.0 g/100 g) and lower flavor acceptance for BRS 305. BRS 332 was highlighted for its higher flavor acceptance and intermediary phenolics content. The most accepted pasta was obtained with WCF, and the least accepted with the brown BRS 305. Sweetness (SWE), soluble starch (SS), and DPPH were associated with liking. The main negative variables were WG_flavor, brown color, FRAP, sandy surface (SAN), WG_odor, and TAN. Sorghum hybrids of different pericarp colors are feasible for GFPa production, leading to differences in pasta quality. SAN and GRA, associated with disliking in antioxidant-rich GFPa, could be improved by milling process adjustments. Increasing the SS proportion and SWE with flavors can contribute to the balance between liking and nutritional advantages.

Solid-State Fermentation of Sorghum by Aspergillus oryzae and Aspergillus niger: Effects on Tannin Content, Phenolic Profile, and Antioxidant Activity

Sorghum contains antioxidants such as tannins. However, these are considered antinutritional factors since they are responsible for the low digestibility of proteins and carbohydrates. Nevertheless, these can be extracted by solid-state fermentation (SSF). Therefore, this study aimed to evaluate the effects of SSF from Aspergillus oryzae and Aspergillus niger Aa210 on the tannin contents, phenolic profiles determined by HPLC-MS, and antioxidant activities (ABTS, DPPH, and FRAP) of two genotypes of sorghum. The results showed that with SSF by A. niger Aa210, a higher tannin content was obtained, with yields of 70-84% in hydrolyzable tannins (HT) and 33-49% in condensed tannins (CT), while with SSF by A. oryzae the content of HT decreased by 2-3% and that of CT decreased by 6-23%. The extracts fermented by A. niger at 72 and 84 h exhibited a higher antioxidant activity. In the extracts, 21 polyphenols were identified, such as procyanidins, (+)-catechin, (-)-epicatechin, scutellarein, arbutin, and eriodictyol, among others. Therefore, SSF by A. niger was an efficient process for the release of phenolic compounds that can be used as antioxidants in different food products. It is also possible to improve the bioavailability of nutrients in sorghum through SSF. However, more studies are required.

Phenolic Release during In Vitro Digestion of Cold and Hot Extruded Noodles Supplemented with Starch and Phenolic Extracts

Dietary phenolic compounds must be released from the food matrix in the gastrointestinal tract to play a bioactive role, the release of which is interfered with by food structure. The release of phenolics (unbound and bound) of cold and hot extruded noodles enriched with phenolics (2.0%) during simulated in vitro gastrointestinal digestion was investigated. Bound phenolic content and X-ray diffraction (XRD) analysis were utilized to characterize the intensity and manner of starch-phenolic complexation during the preparation of extruded noodles. Hot extrusion induced the formation of more complexes, especially the V-type inclusion complexes, with a higher proportion of bound phenolics than cold extrusion, contributing to a more controlled release of phenolics along with slower starch digestion. For instance, during simulated small intestinal digestion, less unbound phenolics (59.4%) were released from hot extruded phenolic-enhanced noodles than from the corresponding cold extruded noodles (68.2%). This is similar to the release behavior of bound phenolics, that cold extruded noodles released more bound phenolics (56.5%) than hot extruded noodles (41.9%). For noodles extruded with rutin, the release of unbound rutin from hot extruded noodles and cold extruded noodles was 63.6% and 79.0%, respectively, in the small intestine phase, and bound rutin was released at a much lower amount from the hot extruded noodles (55.8%) than from the cold extruded noodles (89.7%). Hot extrusion may allow more potential bioaccessible phenolics (such as rutin), further improving the development of starchy foods enriched with controlled phenolics.

Effects of protein digestion on in vitro digestibility of starch in sorghum differing in endosperm hardness and flour particle size

In vitro digestibility of starch in sorghum grains differing in endosperm hardness and flour particle size was investigated. The starch digestibility increased as the particle size of flour decreased, but no clear trend was observed in digestibility of starch in sorghum flours milled from grains with different hardness. The protein matrix affected the digestion of starch. The pH value (2.0 vs. 1.3) was a critical factor affecting protein digestion. Optimum pH (pH 2.0 for pepsin) digested more protein, resulting in a greater digestion of starch. Resistant starch (RS) content was 8.5-26.3% in isolated sorghum starch but higher (10.6-29.5%) in sorghum flours. Protein digestibility decreased after cooking while starch digestibility increased compared to native sorghum flours; disulfide bonds formed between protein molecules. RS content of cooked sorghum flour was much higher without pepsin treatment (16.93-23.99%) than that of cooked sorghum flour with pepsin treatment (4.86-12.53%).

Metabolomics based inferences to unravel phenolic compound diversity in cereals and its implications for human gut health

Background

Scope and approach

Key findings and conclusion

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Phenolic compounds are critical in avoiding metabolic disorders associated with oxidative stress.

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Breeding cereal crops to enrich phenolic compounds in grains contributes to personalized nutrition.

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A diet rich in cereal phenolics likely to increase human gut health, thereby lowering the risk of non-communicable illness.

Technological, sensory, nutritional and bioactive potential of pan breads produced with refined and whole grain buckwheat flours

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Breads made with 30% refined buckwheat flour or 30% whole grain buckwheat flour had minor interference in technological quality.

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Breads made with 30% or 45% whole grain buckwheat flour presented higher mineral contents.

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Breads made with refined buckwheat flour presented higher mineral bioaccessibility.

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After baking, rutin and quercetin levels increased, mainly in breads with 45% whole grain buckwheat flour.

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Breads made with 30% refined buckwheat flour or 30% whole grain buckwheat flour were well accepted by consumers.

The nutritional quality and bioactive potential of breads made with partial replacement of refined wheat flour (RWF) with 30% or 45% refined buckwheat flour (RBF) or whole buckwheat flour (WGBF) was assessed through mineral bioaccessibility, starch digestibility, dietary fiber content and bioactive potential by determining rutin and quercetin levels during processing. Moreover, technological quality and sensory acceptance were also evaluated. Breads made with 30% or 45% WGBF showed higher mineral and fiber contents compared to the control, while the formulations with RBF showed higher bioaccessibility. No changes were observed in the rutin levels of the dough before and after fermentation, but after baking, rutin and quercetin levels increased. The highest starch hydrolysis was found in the formulation containing 45% RBF. The formulations made with 30% RBF or 30% WGBF were well accepted by consumers. Our study shows interesting results, as few studies report the effect of processing on bioactive compounds.

A review on the application of bioinformatics tools in food microbiome studies

There is currently a transformed interest toward understanding the impact of fermentation on functional food development due to growing consumer interest on modified health benefits of sustainable foods. In this review, we attempt to summarize recent findings regarding the impact of Next-generation sequencing and other bioinformatics methods in the food microbiome and use prediction software to understand the critical role of microbes in producing fermented foods. Traditionally, fermentation methods and starter culture development were considered conventional methods needing optimization to eliminate errors in technique and were influenced by technical knowledge of fermentation. Recent advances in high-output omics innovations permit the implementation of additional logical tactics for developing fermentation methods. Further, the review describes the multiple functions of the predictions based on docking studies and the correlation of genomic and metabolomic analysis to develop trends to understand the potential food microbiome interactions and associated products to become a part of a healthy diet.

Effects of potato and sweet potato flour addition on properties of wheat flour and dough, and bread quality

The effects of 10%-30% of wheat flour substitution with potato flour (PF) and sweet potato flour (SPF) on the flour and dough properties, the total polyphenol (TPC), and carotenoid contents (TCC) of bread, as well as their correlation with bread texture and starch digestibility, were investigated. With PF and SPF addition, the peak, breakdown, and setback viscosity of the flour decreased. The addition of PF and SPF reduced the dough formation and stabilization duration, as well as the hardness of the bread. The specific volume of the bread depended on the addition amount of PF and SPF. When the addition of PF and SPF was 15%, the bread had the lowest hardness and highest specific volume. The TPC and TCC in the bread depended on the added flour variety, and negatively influenced specific volume and positively influenced the content of resistant starch (RS).

Functional implications of bound phenolic compounds and phenolics-food interaction: A review

Sizeable scientific evidence indicates the health benefits related to phenolic compounds and dietary fiber. Various phenolic compounds-rich foods or ingredients are also rich in dietary fiber, and these two health components may interrelate via noncovalent (reversible) and covalent (mostly irreversible) interactions. Notwithstanding, these interactions are responsible for the carrier effect ascribed to fiber toward the digestive system and can modulate the bioaccessibility of phenolics, thus shaping health-promoting effects in vivo. On this basis, the present review focuses on the nature, occurrence, and implications of the interactions between phenolics and food components. Covalent and noncovalent interactions are presented, their occurrence discussed, and the effect of food processing introduced. Once reaching the large intestine, fiber-bound phenolics undergo an intense transformation by the microbial community therein, encompassing reactions such as deglycosylation, dehydroxylation, α- and β-oxidation, dehydrogenation, demethylation, decarboxylation, C-ring fission, and cleavage to lower molecular weight phenolics. Comparatively less information is still available on the consequences on gut microbiota. So far, the very most of the information on the ability of bound phenolics to modulate gut microbiota relates to in vitro models and single strains in culture medium. Despite offering promising information, such models provide limited information about the effect on gut microbes, and future research is deemed in this field.

Anti-obesity natural products and gut microbiota

The link between gut microbiota and obesity or other metabolic syndromes is growing increasingly clear. Natural products are appreciated for their beneficial health effects in humans. Increasing investigations demonstrated that the anti-obesity bioactivities of many natural products are gut microbiota dependent. In this review, we summarized the current knowledge on anti-obesity natural products acting through gut microbiota according to their chemical structures and signaling metabolites. Manipulation of the gut microbiota by natural products may serve as a potential therapeutic strategy to prevent obesity.

Advance on the Capitalization of Grape Peels By-Product in Common Wheat Pasta

Capitalization of winery by-products has received high interest among scientists, producers and consumers concerned with healthy diet and environment protection. Grape peels are rich in fiber and polyphenols and can be used as ingredients in pasta matrix in order to increase the nutritional and functional value of such a staple food. The aim of this paper was to investigate the effects of grape peel flour added in various amounts (1–6%) to common wheat pasta dough viscoelasticity and texture and on pasta chemical composition, color, cooking behavior and texture, revealing at the same time the relations between characteristics. Grape peel flour induced the increase of the elastic (G′) and viscous (G″) moduli, dough hardness, springiness, cohesiveness, pasta crude ash, crude fat, crude fiber, total polyphenols and resistant starch contents, pasta water absorption, cooking loss and breaking force as the addition level was higher and compared to the control. On the other hand, dough resilience, pasta luminosity, chewiness and firmness decreased as the amount of grape peel flour raised. Significant correlations (p < 0.05) were obtained between the chemical composition and color parameters, while crude fiber, protein and fat were correlated with dough and pasta texture, total polyphenols with resistant starch content, cooking loss with crude fiber and dough textural parameters. The obtained results underlined the opportunity to use a valuable byproduct such as grape peels in novel pasta formulations, being helpful for processors to extend the product variety and to optimize the processes in order to better satisfy consumer’s demand for functional foods.

Plant cell cultures of Nordic berry species: Phenolic and carotenoid profiling and biological assessments

Plant cell cultures from cloudberry (CL), lingonberry (LI), stone berry (ST), arctic bramble (AB), and strawberry (SB) were studied in terms of their polyphenol and carotenoid composition, antioxidant activity, antihemolytic activity and cytotoxicity effects on cancerous cells. High-resolution mass spectrometry data showed that LI, presented the highest antioxidant activity, contained the highest contents of flavones, phenolic acids, lignans, and total carotenoids, while CL, ST and SB presented the opposite behavior. AB and SB presented the lowest FRAP and CUPRAC values, while AB and CL presented the lowest reducing power. SB presented the lowest antioxidant activity measured by single electron transfer assays and the lowest content of lignans, phenolic acids, and flavones. CL and LI decreased the viability of in vitro mammary gland adenocarcinoma while only LI decreased the viability of in vitro lung carcinoma and showed protective effects of human erythrocytes against mechanical hemolysis.

Synergistic Effects of Heat-Moisture Treatment Regime and Grape Peels Addition on Wheat Dough and Pasta Features

Heat moisture treatment (HMT) can be a useful method of wheat flour functionality modification, improving the nutritional value of pasta along with grape peels (GPF) addition. The aim of this study was to investigate the combined effects of HMT temperature, time, and moisture and GPF level on dough and pasta properties. Dough rheology and texture, pasta color, texture, total polyphenols (TPC), dietary fiber (DF), and resistant starch (RS) contents were evaluated. Furthermore, an optimization was performed based on Response Surface Methodology (RSM) and desirability function. The results showed that HMT regime and GPF determined proportional dough viscoelastic moduli and firmness increase. On the other hand, cooked pasta firmness and gumminess decreased with HMT conditions and GPF level rise. Higher pasta RS and DF content was promoted by HMT and GPF components. The reduction effect of HMT on TPC was countered by the incorporation of GPF, a rich source of polyphenols. The optimization revealed that the recommended wheat flour treatment regime would be 87.56 °C, 3 h, and 26.01% moisture, while the quantity of GPF that could be added was 4.81%. For these values, the maximum functional and nutritional values would be achieved with minimum negative impact on pasta quality.

Use of Grape Peels By-Product for Wheat Pasta Manufacturing

Grape peels (GP) use in pasta formulation represents an economic and eco-friendly way to create value-added products with multiple nutritional benefits. This study aimed to evaluate the effect of the GP by-product on common wheat flour (Triticum aestivum), dough and pasta properties in order to achieve the optimal level that can be incorporated. Response surface methodology (RSM) was performed taking into account the influence of GP level on flour viscosity, dough cohesiveness and complex modulus, pasta color, fracturability, chewiness, cooking loss, total polyphenols, dietary fibers and resistant starch amounts. The result show that 4.62% GP can be added to wheat flour to obtain higher total polyphenols, resistant starch and dietary fiber contents with minimum negative effects on pasta quality. Flour viscosity, dough cohesiveness, complex modulus and pasta fracturability of the optimal sample were higher compared to the control, while chewiness was lower. Proteins' secondary structures were influenced by GP addition, while starch was not affected. Smooth starch grains embedded in a compact protein structure containing GP fiber was observed. These results show that GP can be successfully incorporated in wheat pasta, offering nutritional benefits by their antioxidants and fiber contents, without many negative effects on the final product's properties.

Structural changes of rice starch and activity inhibition of starch digestive enzymes by anthocyanins retarded starch digestibility

The effects of anthocyanins on in vitro and in vivo digestibility of rice starch were evaluated in this study. Then, the effects of anthocyanins on physicochemical properties of rice starch and on starch digestive enzymes (α-amylase and α-glucosidase) were investigated to understand the mechanism of the effects of anthocyanins on starch digestibility. Characterization of physicochemical properties of rice starch indicates a structural change due to the presence of anthocyanins, hindering its access to starch digestive enzymes. Besides, anthocyanins inhibited the activities of starch digestive enzymes by binding to their active sites, competing with the substrates and changing the secondary structure of the enzymes. The above stated changes of rice starch and starch digestive enzymes due to the presence of anthocyanins both contributed to retarding the digestibility of rice starch. This study could offer some theoretical guidance to the development of new type rice-based food with low glycemic index.

The combined effect of fermentation of lactic acid bacteria and in vitro digestion on metabolomic and oligosaccharide profile of oat beverage

Oat (Avena sativa L.) is widely appreciated for its beneficial properties for human health, which have led to the introduction of more food products on the market, including oat beverages. The fibre components found in the oat are recognized for their beneficial effects, despite other bioactive compounds with healthy properties being present. This work aimed to evaluate the metabolites profile of a commercial oat beverage, either fermented with lactic bacteria or not, following in vitro gastro-intestinal digestion. UHPLC-QTOF untargeted metabolomics allowed investigation of the bioaccessibility of health-related metabolites from the oat beverage at the intestinal level. The results identified flavonoids, phenolic acids (avenanthramides), amino acids and steroids as the major classes of compounds. In particular, after in vitro digestion, amino acids, peptides, and phenolic acids showed the highest increases. The co-fermentation of oat milk by Lactobacillus spp. and Bifidobacterium spp. strains decreased the levels of both lignans and phytic acid, while increased the levels of some polyphenols like avenanthramides. Furthermore, fermentation by microorganisms increased the bioaccessibility of specific amino acids, vitamins, and polyphenols (flavonoids and phenolic acids). Interestingly, despite lacking a significant part of beta-glucans, the HPAEC-PAD profiling of our oat beverage evidenced that the fermentation process did not alter the oligosaccharides profile, thus preserving its prebiotic potential. The phytochemical profile of oat milk was shown to have a functional potential. Nonetheless, the fermentation by bacterial strains changed the profile of metabolites during in vitro digestion, thus offering an interesting option in the future development of cereal-based beverages.

The Effect of Balsamic Vinegar Dressing on Protein and Carbohydrate Digestibility is Dependent on the Food Matrix

The balsamic vinegar of Modena (BVM), a food specialty under the European Protected Geographical Indication system, is made from grape must blended with wine vinegar exclusively in the Italian province of Modena or Reggio Emilia. Vinegar is associated to an improved digestive function and glycemic response to carbohydrate-rich meals, appetite stimulation, and reduction of hyperlipidemia and obesity. Although many of these effects are attributed to the high concentration of bioactive molecules, the modulation of digestive enzymes activity could have a role. The aim of this study was to investigate the effect of BVM on the digestibility and component release of three foods that are often seasoned with this dressing but have different composition: Parmigiano Reggiano cheese, Bresaola (cured meat), and boiled potatoes. BVM modulated the protein digestion of protein-rich foods (cheese and cured meat) in a matrix-dependent manner, and the BVM effect was mainly related to the inhibition of pepsin in the gastric phase. In the starch-rich food (boiled potatoes), the most impressive effect of BVM was the lower release of anomeric and total carbohydrates, which was consistent with the observed reduction of pancreatic amylase activity. The present investigation shed a new light on the impact of BVM on the digestion process.

Physicochemical properties and structure of modified potato starch granules and their complex with tea polyphenols

The physicochemical, rheological properties and structure of potato starch and starch-tea polyphenols (TPs) complex modified by enzyme and alcohol was investigated in this study. Cavities on the modified starch granules and morphology change could be investigated by SEM, while significant birefringence observed in complete granules by polarizing light microscope, but disappeared in crashed starch. TPs inhibited the aggregation of amylose and retrogradation of starch-TPs complex, resulting in the decrease of gel strength, and the increase of viscosity and gelatinization stability of starch granules. Fourier transform infrared (FT-IR) spectra showed that intramolecular hydrogen bond could be formed between TPs with modified starch, and the hydrogen bond force formed by starch and TPs was stronger than that between starch molecules. X-ray diffraction (XRD) analysis revealed that three modification methods did not change the crystalline structure of starch, but new diffraction peaks appeared in the four starch-TPs complex, suggesting that the hydrogen bond was incurred by interaction between TPs and amylose to form V-type crystalline. These results demonstrated that the complex formed by TPs and native/modified potato starch could be used in food industrial applications due to the inhibition of starch retrogradation.

Comparative phytochemical profile of the elephant garlic (Allium ampeloprasum var. holmense) and the common garlic (Allium sativum) from the Val di Chiana area (Tuscany, Italy) before and after in vitro gastrointestinal digestion

This study is aimed to comparatively investigate the phytochemical profiles, focusing on the nutritional and phytochemical properties of common garlic (Allium sativum L.; CG) and elephant garlic (EG) (Allium ampeloprasum var. holmense) collected from the Val di Chiana area (Tuscany, Italy). The results showed a lower amount of fibers, demonstrating a higher digestibility of the bulb, and sulfur-containing compounds in EG rather than in CG. Untargeted metabolomic profiling followed by supervised and unsupervised statistics allowed understanding the differences in phytochemical composition among the two bulbs, both as raw bulbs, processed following the in vitro gastrointestinal digestion process. Typical sulfur-containing compounds, such as alliin and N-gamma-glutamyl-S-allyl cysteine, could notably be detected in lower amounts in EG. EG maintains a distinct phytochemical signature during in vitro gastrointestinal digestion. Our findings support the distinct sensorial attributes of the bulbs.

Bridging Targeted and Untargeted Mass Spectrometry-Based Metabolomics via Hybrid Approaches

This mini-review aims to discuss the development and applications of mass spectrometry (MS)-based hybrid approaches in metabolomics. Several recently developed hybrid approaches are introduced. Then, the overall workflow, frequently used instruments, data handling strategies, and applications are compared and their pros and cons are summarized. Overall, the improved repeatability and quantitative capability in large-scale MS-based metabolomics studies are demonstrated, in comparison to either targeted or untargeted metabolomics approaches alone. In summary, we expect this review to serve as a first attempt to highlight the development and applications of emerging hybrid approaches in metabolomics, and we believe that hybrid metabolomics approaches could have great potential in many future studies.

UHPLC-ESI-QTOF-MS/MS characterization, antioxidant and antidiabetic properties of sorghum grains

The phenolic compounds composition, antioxidant and antidiabetic properties of eight brown sorghum genotypes were investigated. DPPH radical scavenging activity was highest in SOR 03, followed by SOR 11, SOR 08 and SOR 33. SOR 33, SOR 03, SOR 08, SOR 11 showed the highest ABTS radical scavenging activity. Furthermore, SOR 11, SOR 17 and SOR 33 exhibited significantly higher percentage inhibitory activity of α-glucosidase and α-amylase (IC₅₀ = 14.71, 32.98, 24.93 µg/ml and 27.6, 23.84, 45.01 µg/ml, respectively) compared to acarbose (IC₅₀ = 59.34 and 27.73 µg/ml, respectively). Similarly, SOR 17, SOR 11 and SOR 33 showed significantly potent inhibition of AGEs formation with IC₅₀ values of 14.19, 18.23 and 26.31 µg/ml, respectively, compared to aminoguanidine (AG) (52.30 µg/ml). Flavones, isoflavones and dihydroflavonols were the predominant flavonoids identified in SOR 11, SOR 17 and SOR 33 genotypes. Therefore, these sorghum grains are potential candidates for the development of functional foods.

Flavonoids in Decorticated Sorghum Grains Exert Antioxidant, Antidiabetic and Antiobesity Activities

Eight new genotypes of brown sorghum grain were decorticated and assessed for their antioxidant, antidiabetic and antiobesity activities in vitro. The DPPH and ABTS radical scavenging assays of the soluble fractions were evaluated, followed by digestive enzymes and advanced glycation end-products (AGEs) formation inhibition assays. DSOR 33 and DSOR 11 exhibited the highest DPPH (IC50 = 236.0 ± 1.98 µg/mL and 292.05 ± 2.19 µg/mL, respectively) and ABTS radical scavenging activity (IC50 = 302.50 ± 1.84 µg/mL and 317.05 ± 1.06 µg/mL, respectively). DSOR 17, DSOR 11 and DSOR 33 showed significantly higher inhibitory activity of both α-glucosidase and α-amylase (IC50 = 31.86, 35.10 and 49.40 µg/mL; and 15.87, 22.79 and 37.66 µg/mL, respectively) compared to acarbose (IC50 = 59.34 and 27.73 µg/mL, respectively). Similarly, DSOR 33, DSOR 11 and DSOR 17 showed potent inhibition of both AGEs and lipase with IC50 values of 18.25, 19.03 and 38.70 µg/mL; and 5.01, 5.09 and 4.94 µg/mL, respectively, compared to aminoguanidine (52.30 µg/mL) and orlistat (5.82 µg/mL). Flavonoids were the predominant compounds identified, with flavones being the major subclass in these three extracts. Our findings suggest that decorticated sorghum grains contain substantial amounts of flavonoids and could be promising candidates for the prevention and treatment of diabetes and obesity.

Determination of Polyphenols Using Liquid Chromatography-Tandem Mass Spectrometry Technique (LC-MS/MS): A Review

In recent years, the consumption of polyphenols has been increasing, largely due to its beneficial effects on health. They are present in a wide variety of foods, but their extraction and characterization are complicated since they are mostly in complex matrices. For this reason, the use of selective, sensitive, and versatile analytical techniques such as liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) is necessary. In this review, the most relevant studies of the last years regarding the analysis of polyphenols in different matrices by comprehensive LC–MS/MS are discussed. Relevant steps such as extraction, sample purification, and chromatographic analysis methods are emphasized. In particular, the following methodological aspects are discussed: (a) the proper selection of the extraction technique, (b) the extraction and elution solvents, (c) the purification step, (d) the selection of both stationary and mobile phases for the chromatographic separation of compounds, and (e) the different conditions for mass spectrometry. Overall, this review presents the data from the most recent studies, in a comprehensive way, thus providing and simplifying the information of the great variety of works that exist in the literature on this wide topic.

Chemical Characterization and Bioactive Properties of Different Extracts from Fibigia clypeata, an Unexplored Plant Food

Fibigia clypeata (L.) Medik. is a poorly studied plant species belonging to the Brassicaceae family, and usually used as cress in the salads. The current investigation aimed at assessing the antioxidant potential and inhibitory activity of ethyl acetate, methanol, and aqueous extracts of F. clypeata against key enzymes targeted in the management of type II diabetes (α-amylase and α-glucosidase), Alzheimer’s disease (acetylcholinesterase and butyrylcholinesterase), and skin hyperpigmentation (tyrosinase). Cytotoxicity of the extracts was also determined using normal VERO and cancer FaDu and SCC-25 cell lines. Besides, LC-MS was employed to investigate the detailed phytochemical profiles of the extracts. The methanol extract showed potent enzyme inhibitory activity (4.87 mg galantamine equivalent/g, 3.52 mg galantamine equivalent/g, 126.80 mg kojic acid equivalent/g, and 24.68 mg acarbose equivalent/g, for acetylcholinesterase, butyrylcholinesterase, tyrosinase, and α-glucosidase, respectively) and antioxidant potential (96.52, 109.10, 154.02, and 104.85 mg trolox equivalent/g, for DPPH, ABTS, CUPRAC, and FRAP assays, respectively). Interestingly, caffeic acid-O-hexoside derivative, caffeyl alcohol O-glucopyranoside, and ferulic acid derivative were identified in all extracts. F. clypeata extracts showed no cytotoxicity towards VERO cell line and a weak cytotoxic potential against FaDu and SCC-25 cell lines. Interesting scientific evidence gathered from the present study support further investigation on F. clypeata in the view of designing and developing a novel therapeutic agent for the management of Alzheimer’s disease, type II diabetes, skin hyperpigmentation problems, as well as cancer.

Phytochemical Profile and Biological Properties of Colchicum triphyllum (Meadow Saffron)

In this work, the phytochemical profile and the biological properties of Colchicum triphyllum (an unexplored Turkish cultivar belonging to Colchicaceae) have been comprehensively investigated for the first time. Herein, we focused on the evaluation of the in vitro antioxidant and enzyme inhibitory effects of flower, tuber, and leaf extracts, obtained using different extraction methods, namely maceration (both aqueous and methanolic), infusion, and Soxhlet. Besides, the complete phenolic and alkaloid untargeted metabolomic profiling of the different extracts was investigated. In this regard, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) allowed us to putatively annotate 285 compounds when considering the different matrix extracts, including mainly alkaloids, flavonoids, lignans, phenolic acids, and tyrosol equivalents. The most abundant polyphenols were flavonoids (119 compounds), while colchicine, demecolcine, and lumicolchicine isomers were some of the most widespread alkaloids in each extract analyzed. In addition, our findings showed that C. triphyllum tuber extracts were a superior source of both total alkaloids and total polyphenols, being on average 2.89 and 10.41 mg/g, respectively. Multivariate statistics following metabolomics allowed for the detection of those compounds most affected by the different extraction methods. Overall, C. triphyllum leaf extracts showed a strong in vitro antioxidant capacity, in terms of cupric reducing antioxidant power (CUPRAC; on average 96.45 mg Trolox Equivalents (TE)/g) and ferric reducing antioxidant power (FRAP) reducing power (on average 66.86 mg TE/g). Interestingly, each C. triphyllum methanolic extract analyzed (i.e., from tuber, leaf, and flower) was active against the tyrosinase in terms of inhibition, recording the higher values for methanolic macerated leaves (i.e., 125.78 mg kojic acid equivalent (KAE)/g). On the other hand, moderate inhibitory activities were observed against AChE and α-amylase. Strong correlations (p < 0.01) were also observed between the phytochemical profiles and the biological activities determined. Therefore, our findings highlighted, for the first time, the potential of C. triphhyllum extracts in food and pharmaceutical applications.