Impact of cooking and fermentation by lactic acid bacteria on phenolic profile of quinoa and buckwheat seeds

Metabolomics applications for plant-based foods origin tracing, cultivars identification and processing: Feasibility and future aspects

Metabolomics, the systematic study of metabolites, is dedicated to a comprehensive analysis of all aspects of plant-based food research and plays a pivotal role in the nutritional composition and quality control of plant-based foods. The diverse chemical compositions of plant-based foods lead to variations in sensory characteristics and nutritional value. This review explores the application of the metabolomics method to plant-based food origin tracing, cultivar identification, and processing methods. It also addresses the challenges encountered and outlines future directions. Typically, when combined with other omics or techniques, synergistic and complementary information is uncovered, enhancing the classification and prediction capabilities of models. Future research should aim to evaluate all factors affecting food quality comprehensively, and this necessitates advanced research into influence mechanisms, metabolic pathways, and gene expression.

Elucidating the Differentiation Synthesis Mechanisms of Differently Colored Resistance Quinoa Seedings Using Metabolite Profiling and Transcriptome Analysis

Quinoa (Chenopodium quinoa wild.), a dicotyledonous plant native to the Andes, is an increasingly popular pseudograin owing to its high nutritional value, stress resistance capabilities, and gluten-free properties. In this study, we aimed to explore the dynamic changes in different varieties of quinoa at the seedling stage and their regulatory networks. Here, we found that the leaves of quinoa showed obvious coloration after 45 days, and four quinoa seedling types (red, white, yellow, and black) were subjected to ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and transcriptome sequencing to identify their differentially expressed genes and metabolites. A total of 29 differential metabolites and 19 genes (14 structural and 5 regulatory genes) were identified, and consistent differences were observed in the flavonoid, phenolic acid, and alkaloid metabolites in the different quinoa types. These differential metabolites were significantly enriched in flavonoid and flavonol biosynthesis, flavonoid biosynthesis, and phenylpropanoid biosynthesis pathways. In addition, real-time fluorescence quantitative PCR (RT-qPCR) technology was used to detect the expression of four structural genes involved in the flavonoid biosynthesis pathway and four regulatory genes (interaction network). The results revealed that the structural and regulatory gene transcript levels in the flavonoid pathway were higher in the red quinoa cultivars than in the white, yellow, and black. Additionally, the differences in the leaves of these four quinoa cultivars were mainly due to differences in flavonoid, phenolic acid, and alkaloid accumulation. Our findings provide a basis for understanding the accumulation and coloration mechanisms of flavonoids, phenolic acids, and alkaloids in quinoa seedlings of different colors and also provide a theoretical basis for future investigations.

Propionibacteria as promising tools for the production of pro-bioactive scotta: a proof-of-concept study

Dairy propionibacteria are Gram positive Actinomycetota, routinely utilized as starters in Swiss type cheese making and highly appreciated for their probiotic properties and health promoting effects. In this work, within the frame of a circular economy approach, 47 Propionibacterium and Acidipropionibacterium spp. were isolated from goat cheese and milk, and ewe rumen liquor, and characterized in view of their possible utilization for the production of novel pro-bioactive food and feed on scotta, a lactose rich substrate and one of the main by-products of the dairy industry. The evaluation of the Minimum Inhibitory Concentration (MIC) of 13 among the most common antibiotics in clinical practice revealed a general susceptibility to ampicillin, gentamycin, streptomycin, vancomycin, chloramphenicol, and clindamycin while confirming a lower susceptibility to aminoglycosides and ciprofloxacin. Twenty-five isolates, that proved capable of lactose utilization as the sole carbon source, were then characterized for functional and biotechnological properties. Four of them, ascribed to Propionibacterium freudenreichii species, and harboring resistance to bile salts (growth at 0.7-1.56 mM of unconjugated bile salts), acid stress (>80% survival after 1 h at pH 2), osmostress (growth at up to 6.5% NaCl) and lyophilization (survival rate > 80%), were selected and inoculated in scotta. On this substrate the four isolates reached cell densities ranging from 8.11 ± 0.14 to 9.45 ± 0.06 Log CFU mL-1 and proved capable of producing different vitamin B9 vitamers after 72 h incubation at 30°C. In addition, the semi-quantitative analysis following the metabolomics profiling revealed a total production of cobalamin derivatives (vitamin B12) in the range 0.49-1.31 mg L-1, thus suggesting a full activity of the corresponding biosynthetic pathways, likely involving a complex interplay between folate cycle and methylation cycle required in vitamin B12 biosynthesis. These isolates appear interesting candidates for further ad-hoc investigation regarding the production of pro-bioactive scotta.

Amaranth and quinoa as potential nutraceuticals: A review of anti-nutritional factors, health benefits and their applications in food, medicinal and cosmetic sectors

Amaranth and quinoa are small-seeded grains with high nutritional and phytochemical profiles that promote numerous health benefits and offer protection against various chronic ailments including hypertension, diabetes, cancer, and cardiovascular disorders. They are classified as pseudocereals and possess significant nutritional benefits due to their abundance of proteins, lipids, fiber, vitamins, and minerals. Moreover, they exhibit an exceptional balance of essential amino acids. Despite having several health benefits, these grains have lost their popularity due to their coarse nature and are neglected in developed countries. Research and development activities are growing to explore these underutilized crops, characterizing and valorizing them for food applications. In this context, this review highlights the latest advancements in use of amaranth and quinoa as nutraceutical and functional foods, covering their bioactive substances, anti-nutritional factors, processing techniques, health benefits, and applications. This information will be valuable for planning novel research for efficient use of these neglected grains.

Metabolomics analysis reveals the accumulation patterns of flavonoids and phenolic acids in quinoa (Chenopodium quinoa Willd.) grains of different colors

Quinoa grains are gaining increasing popularity owing to their high nutritional merits. However, only limited information is available on the metabolic profiles of quinoa grains. In this study, we determined the metabolic profiles of black, red, and white quinoa grains via an ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS)-based metabolomics. A total of 689 metabolites were identified, among which 251, 182, and 317 metabolites displayed different accumulation patterns in the three comparison groups (Black vs Red, Black vs White, and Red vs White), respectively. In particular, flavonoid and phenolic acid contents displayed considerable differences, with 22 flavonoids, 5 phenolic acids, and 1 betacyanin being differentially accumulated among the three quinoa cultivars. Additionally, correlation analysis showed that flavonoids and phenolic acids could act as betanin co-pigments in quinoa grains. In conclusion, this study provides comprehensive insights into the adequate utilization and development of novel quinoa-based functional foods.

Antioxidant capacity, flavor and physicochemical properties of FH06 functional beverage fermented by lactic acid bacteria: a promising method to improve antioxidant activity and flavor of plant functional beverage

The ability of natural plants to treat chronic diseases is closely related to their antioxidant function. Lactic acid bacteria (LAB) fermentation is an effective way to improve the nutritional value, biological activity and flavor of food. This study investigated the pH, titratable acidity, total polysaccharide, total flavone, total saponin, total polyphenol, and antioxidant activity of the FH06 beverage before and after probiotic fermentation. Results: After fermentation, FH06 had lower contents of total polysaccharides, total flavonoids, total saponins and total polyphenols but higher titratable acidity. The antioxidant activity was tested by total antioxidant capacity (FRAP method) and DPPH· scavenging ability. The FRAP value significantly increased after fermentation (P < 0.05), and the maximum increase was observed for Lactobacillus fermentum grx08 at 25.87%. For DPPH· scavenging ability, the value of all fermentations decreased, and L. fermentum grx08 had the smallest reduction at 2.21% (P < 0.05). The results of GC-MS and sensory analysis showed that fermentation eliminated bad flavors, such as grass, cassia and bitterness, and highlighted the fruit aroma and soft sour taste. Conclusion: The FRAP value and sensory flavor of FH06 fermentation by L. fermentum grx08 were significantly improved, indicating its great potential as a functional food with both strong antioxidant activity and good flavor.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s13765-022-00762-2.

Isolation of a Novel Anti-Diabetic α-Glucosidase Oligo-Peptide Inhibitor from Fermented Rice Bran

At present, the incidence rate of diabetes is increasing gradually, and inhibiting α-glucosidase is one of the effective methods used to control blood sugar. This study identified new peptides from rice bran fermentation broth and evaluated their inhibitory activity and mechanism against α-glucosidase. Rice bran was fermented with Bacillus subtilis MK15 and the polypeptides of <3 kDa were isolated by ultrafiltration and chromatographic column, and were then subjected to LC-MS/MS mass spectrometry analysis. The results revealed that the oligopeptide GLLGY showed the greatest inhibitory activity in vitro. Docking studies with GLLGY on human α-glucosidase (PDB ID 5NN8) suggested a binding energy of −7.1 kcal/mol. GLLGY acts as a non-competitive inhibitor and forms five hydrogen bonds with Asp282, Ser523, Asp616, and His674 of α-glucosidase. Moreover, it retained its inhibitory activity even in a simulated digestion environment in vitro. The oligopeptide GLLGY could be developed into a potential anti-diabetic agent.

An overview of the nutritional profile, processing technologies, and health benefits of quinoa with an emphasis on impacts of processing

Consumers are becoming increasingly conscious of adopting a healthy lifestyle and demanding food with high nutritional values. Quinoa (Chenopodium quinoa Willd.) has attracted considerable attention and is consumed worldwide in the form of a variety of whole and processed products owing to its excellent nutritional features, including richness in micronutrients and bioactive phytochemicals, well-balanced amino acids composition, and gluten-free properties. Recent studies have indicated that the diverse utilization and final product quality of this pseudo-grain are closely related to the processing technologies used, which can result in variations in nutritional profiles and health benefits. This review comprehensively summarizes the nutritional properties, processing technologies, and potential health benefits of quinoa, suggesting that quinoa plays a promising role in enhancing the nutrition of processed food. In particular, the effects of different processing technologies on the nutritional profile and health benefits of quinoa are highlighted, which can provide a foundation for the updating and upgrading of the quinoa processing industry. It further discusses the present quinoa-based food products containing quinoa as partial or whole substitute for traditional grains.

Fermented Plant Beverages Stabilized with Microemulsion: Confirmation of Probiotic Properties and Antioxidant Activity

The purpose of this study was to experimentally confirm the probiotic properties and antioxidant activity of plant fermented beverages stabilized with microemulsion. The object of the study were beverages obtained from hemp seeds and fermented with Bifidobacterium longum. To stabilize the plant base, the microemulsion with a bioactive substance (curcumin) was introduced with simultaneous ultrasound treatment. A significant increase in the viscosity of beverages with microcellulose-stabilized microemulsion was noted. Non-fermented plant beverages are characterized by their smaller diameter and distribution of particles in the micro-range, from 0.81 to 6.5 µm. When Twin-stabilized microemulsion was added to beverages, a monodisperse distribution of particles sufficiently small in diameter was observed. A significant increase of 29.4–33.6% in the antioxidant activity of plant beverages stabilized by ME with curcumin was established. A maximum concentration of flavonoids was noted in non-fermented plant beverages containing microemulsion. The results of this study proved the possibility of obtaining fermented plant beverages with identified probiotic and antioxidant properties. A positive effect of stabilizing with a microemulsion loaded with biologically active components on the development of probiotic microorganism cultures in the system of fermented plant products and the formation of their antioxidant activity was established.

Fermented Minor Grain Foods: Classification, Functional Components, and Probiotic Potential

Fermented minor grain (MG) foods often have unique nutritional value and functional characteristics, which are important for developing dietary culture worldwide. As a kind of special raw material in fermented food, minor grains have special functional components, such as trace elements, dietary fiber, and polyphenols. Fermented MG foods have excellent nutrients, phytochemicals, and bioactive compounds and are consumed as a rich source of probiotic microbes. Thus, the purpose of this review is to introduce the latest progress in research related to the fermentation products of MGs. Specific discussion is focused on the classification of fermented MG foods and their nutritional and health implications, including studies of microbial diversity, functional components, and probiotic potential. Furthermore, this review discusses how mixed fermentation of grain mixtures is a better method for developing new functional foods to increase the nutritional value of meals based on cereals and legumes in terms of dietary protein and micronutrients.

Novel cookie formulation with defatted sesame flour: Evaluation of its technological and sensory properties. Changes in phenolic profile, antioxidant activity, and gut microbiota after simulated gastrointestinal digestion

Defatted sesame flour (DSF), a coproduct of the sesame oil extraction process, is often discarded despite having high polyphenol content. The aim of this study was to improve the antioxidant properties of cookies with increasing amounts of DSF (5, 10, and 20%) and study its impact on processing and gastrointestinal digestion. Besides, we evaluated the effect of this incorporation on the technological and sensory properties of cookies. The formulation with 10% (SFC10) showed technological quality similar to control, and was the most accepted by consumers. After baking, 13 out of 25 polyphenols from DSF were observed, and only 19% of the initial SFC10 polyphenols would be potentially absorbed after digestion. Besides, the addition of DSF benefits the microbiota composition after colonic fermentation. In conclusion, supplementation with 10% of DSF in cookies improves sensorial acceptance and antioxidant properties, without affecting the technological ones.

Effect of Fermentation on the Biochemical Parameters Antioxidant Capacity and Dispersed Composition of Plant Beverages Based on Barley and Hemp Seeds

Enzymatic processes play a key role in the production of grain-containing food due to their effect on the nutritional properties, rheological characteristics, and contribution to improving the functional and antioxidant proprieties. Eight samples of beverages based on barley grain and hemp seeds were produced (control beverages and beverages fermented by bifidobacteria and propionic acid bacteria). It was found that lactic acid accumulated during fermentation alongside a gradual shift in the pH level in the acidic direction. A comparative analysis of the DPPH activity revealed the highest values for barley-based beverages, ranging from 71.0 to 100.7%, while for the hemp seed-based beverages, the DPPH activity was 64.1–97.9%. The maximum values of DPPH activity were observed during fermentation with a combination of bifidobacteria and propionic acid bacteria concentrates. The highest concentration of polyphenolic compounds and flavonoids was found in barley-based beverages fermented with Propionibacterium freudenreichii (1.26 mg GAE/g and 0.11 mg EQ/g) and a combination of Propionibacterium freudenreichii and Bifidobacterium longum (1.24 mg GAE/g and 0.14 mg EQ/g). Studies have shown an increase in the nutrient content for fermented beverages compared to the control samples. The barley-based beverages exhibited the largest average dynamic particle diameter, and all beverage samples showed a more uniform particle size distribution after microbial fermentation.

Nutritional and antioxidant changes in lentils and quinoa through fungal solid-state fermentation with Pleurotus ostreatus

Solid-state fermentation (SSF) may be a suitable bioprocess to produce protein-vegetal ingredients with increased nutritional and functional value. This study assessed changes in phenol content, antinutrient content, biomass production and protein production resulting from the metabolic activity of Pleurotus ostreatus, an edible fungus, in lentils and quinoa over 14 days of SSF. The impact of particle size on these parameters was also assessed because the process was conducted in both seeds and flours. Fungus biomass increased during fermentation, reaching 30.0 ± 1.4 mg/g dry basis and 32 ± 3 mg/g dry basis in lentil grain and flour and 52.01 ± 1.08 mg/g dry basis and 45 ± 2 mg/g dry basis in quinoa seeds and flour after 14 days of SSF. Total protein content also increased by 20% to 25% during fermentation, in all cases except lentil flour. However, the soluble protein fraction remained constant. Regarding phytic acid, SSF had a positive impact, with a progressive decrease being higher in flours than in seeds. Regarding antioxidant properties, autoclaving of the substrates promoted the release of polyphenols, together with antioxidant activity (ABTS, DPPH and FRAP), in all substrates. However, these parameters drastically decreased as fermentation progressed. These results provide scientific knowledge for producing lentil- or quinoa-based ingredients with low antinutrient content enriched with protein fungal biomass.

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.

Recent developments and knowledge in pseudocereals including technological aspects

Amaranth, buckwheat, quinoa, and less known, canihua are the most important pseudocereals. Their high nutritional value is well recognized and they are increasingly used for the development of a wide range of starch-based foods, which has been fostered by intensified research data performed in recent years. In addition to health driven motivations, also environmental aspects like the ongoing climate change are an important stimulus to increase agricultural biodiversity again. As pseudocereals are botanically classified as dicotyledonous plants their chemical, physical and processing properties differ significantly from the monocotyledonous cereals. Most important factors that need to be addressed for processing is their smaller seed kernel size, their specific starch structure and granule architecture, their gluten-free protein, but also their dietary fibre and secondary plant metabolites composition. This review gives a condensed overview of the recent developments and gained knowledge with special attention to the technological and food processing aspects of these pseudocereals.

Quinoa sourdough-based biscuits with high antioxidant activity fermented with autochthonous lactic acid bacteria

AIMS

To evaluate the capacity of autochthonous lactic acid bacteria (LAB) (43) from Andean grains to increase the antioxidant activity (AOA) and total phenolic compounds (TPCs) in quinoa sourdough to select best performing strains to be used as starter cultures in the elaboration of biscuits.

METHODS AND RESULTS

Microbial growth (CFU per g) and pH were evaluated during quinoa dough fermentation. Counts were increased in a range of 0.61-2.97 log CFU per g and pH values between 3.95 and 4.54 were determined after 24 h at 30°C of fermentation. Methanolic (ME) and aqueous (AE) extracts were obtained at the end of fermentation, and free radical scavenging capacity was performed by the DPPH and ABTS methods. ME was selected for further analysis using other methods and TPC quantification. Principal component analysis showed the highest scores of growth, acidification capacity, AOA and TPC for the strains Lc. mesenteroides subsp. mesenteroides CRL 2131 and L. plantarum CRL 1964 and CRL 1973. AOA and TPC in biscuits made with sourdough from these LAB were higher than the acidified and uninoculated controls.

CONCLUSIONS

Autochthonous LAB strains (3) increased the AOA of quinoa-based biscuits.

SIGNIFICANCE AND IMPACT OF THE STUDY

Quinoa sourdough obtained with selected LAB is suitable as an ingredient for bakery foods with improved antioxidant status.

New Insight into Bacterial Interaction with the Matrix of Plant-Based Fermented Foods

Microorganisms have been harnessed to process raw plants into fermented foods. The adaptation to a variety of plant environments has resulted in a nearly inseparable association between the bacterial species and the plant with a characteristic chemical profile. Lactic acid bacteria, which are known for their ability to adapt to nutrient-rich niches, have altered their genomes to dominate specific habitats through gene loss or gain. Molecular biology approaches provide a deep insight into the evolutionary process in many bacteria and their adaptation to colonize the plant matrix. Knowledge of the adaptive characteristics of microorganisms facilitates an efficient use thereof in fermentation to achieve desired final product properties. With their ability to acidify the environment and degrade plant compounds enzymatically, bacteria can modify the textural and organoleptic properties of the product and increase the bioavailability of plant matrix components. This article describes selected microorganisms and their competitive survival and adaptation in fermented fruit and vegetable environments. Beneficial changes in the plant matrix caused by microbial activity and their beneficial potential for human health are discussed as well.

Viscozyme L hydrolysis and Lactobacillus fermentation increase the phenolic compound content and antioxidant properties of aqueous solutions of quinoa pretreated by steaming with α-amylase

In this work, red quinoa was successively subjected to α-amylase steaming, complex enzyme Viscozyme (R) L hydrolysis, and lactic acid bacteria (LAB) fermentation. The total phenolic compound content (TPC), flavonoid content (TFC), and antioxidant capacities of the solvent-extractable (free) and bound fractions and the individual phenolic compounds released were determined. Compared to steaming with α-amylase, enzymatic hydrolysis and fermentation of quinoa resulted in approximately 82.6, 26.9, 36.3, and 45.2% increases in the TPC (the sum of free and bound fractions), TFC, DPPH, and ORAC values, respectively. HPLC-QqQ-MS/MS analysis showed that enzymolysis and fermentation increased the content of protocatechuic acid, catechin, procyanidin B₂ , and quercetin by 126.3, 101.9, 524, and 296.3%, respectively. Moreover, a major proportion of individual phenolic compounds existed as bound form. The results indicated that complex enzymatic hydrolysis and LAB fermentation were practical and useful to release promising polyphenols. This research provides a basis for the processing of quinoa beverages rich in phenolic compounds. PRACTICAL APPLICATION: In this work, liquefying with α-amylase, hydrolyzing with cellulolytic enzyme mixture, and fermenting with Lactic acid bacteria (LAB), successively, were exploited to process quinoa. This is an innovative method of quinoa processing to produce beverage products. Complex enzymatic hydrolysis and fermentation with LAB can significantly enhance phenolic compound, especially protocatechuic acid, catechin, procyanidin B₂ , and quercetin. In additional, LAB fermentation is very beneficial to improve the antioxidant activity of quinoa. We also found that a major proportion of phenolic compounds existed as bound forms in quinoa.

Specialty seeds: Nutrients, bioactives, bioavailability, and health benefits: A comprehensive review

Seeds play important roles in human nutrition and health since ancient time. The term "specialty" has recently been applied to seeds to describe high-value and/or uncommon food products. Since then, numerous studies have been conducted to identify various classes of bioactive compounds, including polyphenols in specialty seeds. This review discusses nutrients, fat-soluble bioactives, polyphenols/bioactives, antioxidant activity, bioavailability, health benefits, and safety/toxicology of commonly consumed eight specialty seeds, namely, black cumin, chia, hemp, flax, perilla, pumpkin, quinoa, and sesame. Scientific results from the existing literature published over the last decade have been compiled and discussed. These specialty seeds, having numerous fat-soluble bioactives and polyphenols, together with their corresponding antioxidant activities, have increasingly been consumed. Hence, these specialty seeds can be considered as a valuable source of dietary supplements and functional foods due to their health-promoting bioactive components, polyphenols, and corresponding antioxidant activities. The phytochemicals from these specialty seeds demonstrate bioavailability in humans with promising health benefits. Additional long-term and well-design human intervention trials are required to ascertain the health-promoting properties of these specialty seeds.

Metabolite profiling, antioxidant and α-glucosidase inhibitory activities of buckwheat processed by solid-state fermentation with Eurotium cristatum YL-1

Buckwheat was processed by solid-state fermentation (SSF) with the probiotic fungal strain Eurotium cristatum YL-1. The effects of SSF on the phytochemical content, as well as the antioxidant and α-glucosidase inhibitory activities, on buckwheat were revealed. Metabolite differences between non-fermented buckwheat (BW) and E. cristatum fermented buckwheat (FBW) were investigated by LC-MS/MS-based untargeted metabolomics. Results showed that 103 and 68 metabolites remarkably differed between BW and FBW in positive and negative ionization modes, respectively. Most phenolic compounds and alkaloids were significantly up-regulated during SSF. Hydrolytic enzymes (i.e., β-glucosidase, α-amylase, protease, and cellulase) were produced by the filamentous fungus E. cristatum during SSF. In vitro spectrophotometric assays demonstrated that the total phenolics content, ferric reducing antioxidant power, reducing power, scavenging activities of DPPH radical and ABTS⁺, and α-glucosidase inhibitory activity of buckwheat were considerably enhanced after processing by SSF with E. cristatum. Additionally, solvents with different polarities significantly influenced the antioxidant and α-glucosidase inhibitory activities of buckwheat extracts. Our study indicated that processing by SSF with E. cristatum can greatly improve the phytochemical components of buckwheat and consequently contribute to its antioxidant and α-glucosidase inhibitory activities. SSF with E. cristatum is an innovative method for enhancing the health-promoting components and bioactivities of buckwheat.

Functional Components and Anti-Nutritional Factors in Gluten-Free Grains: A Focus on Quinoa Seeds

Quinoa (Chenopodium quinoa Willd.) has recently received increasing interest from both scientists and consumers due to its suitability in gluten-free diets, its sustainability, and its claimed superfood qualities. The aim of this paper is to systematically review up-to-date studies on quinoa functional components and anti-nutritional factors, in order to define a baseline for food scientists approaching the investigation of quinoa phytochemicals and providing evidence for the identification of healthier sustainable foods. State of the art evaluations of phytochemical contents in quinoa seeds were obtained. It emerged that phenolic compounds are the most investigated functional components, and spectrophotometric methods have been mostly applied, despite the fact that they do not provide information about single components. Saponins are the most studied among anti-nutritional factors. Betalains, tannins, and phytoecdysteroids have been poorly explored. Information on factors affecting the phytochemical content at harvesting, such as quinoa ecotypes, crop geographical location and growing conditions, are not always available. A comprehensive characterization, encompassing several classes of functional components and anti-nutritional factors, is mainly available for quinoa varieties from South America. However, defining a standard of quality for quinoa seeds is still challenging and requires a harmonization of the analytical approaches, among others.

Impact of Fermentation on Phenolic Compounds and Antioxidant Capacity of Quinoa

Quinoa (Chenopodium quinoa Willd.) is increasingly singled out as a healthy food with an excellent nutritional profile. Besides being suitable for gluten-free diets, it is rich in proteins of excellent quality and is a good source of minerals and vitamins, as well as of natural antioxidants, such as phenolic compounds. The aim of this work is to present how fermentation can affect phenolic compound content and antioxidant capacity of quinoa. It emerged that fermentation can be used to increase phenolic compound content and antioxidant capacity in both quinoa seeds and flours. The use of fermented quinoa flours allowed obtaining bread and pasta richer in phenolic compounds and with a greater antioxidant capacity. Fungi are the main starters used in quinoa seed fermentation, while Lactobacillus strains have been applied to produce sourdoughs. Quinoa has been also fermented to obtain yogurt-like beverages with a higher content in phenolic compounds and a greater antioxidant activity. Strains of Lactobacillus sp. and Bifidobacterium sp. have been used as starters.

Release of characteristic phenolics of quinoa based on extrusion technique

Quinoa is rich in phenolics which are benefit for human health for their outstanding antioxidant capacity, anti-inflammatory property and special biological functions. However, most of phenolics existed as bound form that with low bioavailability in quinoa. In this study, extrusion technique was applied for the release of bound phenolics in red quinoa (RQ), and effects of extruded temperature (120 °C, 140 °C, 160 °C and 180 °C) on the release of characteristic phenolics of RQ was investigated as well. Phenolics both presented as free and bound forms were identified in RQ and extruded quinoa samples, and result showed rutin, ferulic acid and vanillic acid were most common. The content of bound phenolics in RQ was 155.52 mg/kg, however, in extruded red quinoa (ERQ) was 77.25 mg/kg (ERQ-140 °C)-84.08 mg/kg (ERQ-120 °C). In corresponding, free phenolics in RQ was 22.15 mg/kg, while in ERQ was 41.04 mg/kg (ERQ-140 °C)-47.25 mg/kg (ERQ-160 °C). In conclusion, extrusion was excellent for the release of bound phenolics in quinoas and the best extruded temperature was 160 °C. Extrusion technique was potential in the processing of quinoa.

Lactic Acid Fermentation of Cereals and Pseudocereals: Ancient Nutritional Biotechnologies with Modern Applications

Grains are a substantial source of macronutrients and energy for humans. Lactic acid (LA) fermentation is the oldest and most popular way to improve the functionality, nutritional value, taste, appearance and safety of cereal foods and reduce the energy required for cooking. This literature review discusses lactic acid fermentation of the most commonly used cereals and pseudocereals by examination of the microbiological and biochemical fundamentals of the process. The study provides a critical overview of the indispensable participation of lactic acid bacteria (LAB) in the production of many traditional, ethnic, ancient and modern fermented cereals and beverages, as the analysed literature covers 40 years. The results reveal that the functional aspects of LAB fermented foods are due to significant molecular changes in macronutrients during LA fermentation. Through the action of a vast microbial enzymatic pool, LAB form a broad spectrum of volatile compounds, bioactive peptides and oligosaccharides with prebiotic potential. Modern applications of this ancient bioprocess include the industrial production of probiotic sourdough, fortified pasta, cereal beverages and "boutique" pseudocereal bread. These goods are very promising in broadening the daily menu of consumers with special nutritional needs.

Quinoa pasta fermented with lactic acid bacteria prevents nutritional deficiencies in mice

In recent years, quinoa (Chenopodium quinoa Willd), an ancestral crop of the Andean region of South America, has gained worldwide attention due to its high nutritional value. This grain is a good source of several vitamins and minerals; however, their bioavailability is decreased by the presence of antinutritional factors such as phytic acid. These compounds can be reduced using lactic acid bacteria (LAB), that have a GRAS (Generally Recognized as Safe) status and have traditionally been associated with food fermentation due to their biosynthetic capacity and metabolic versatility. The objective of this study was to evaluate the effectiveness of a pasta made with quinoa sourdough fermented by L. plantarum strains producing vitamins B₂ and B₉ and phytase to prevent vitamins and minerals deficiency using an in vivo mouse model. The results showed that the pasta fermented with the mixed culture containing L. plantarum CRL 2107 + L. plantarum CRL 1964 present increased B₂ and B₉ levels in mice blood. Likewise, higher concentrations of P, Ca⁺², Fe⁺², Mg⁺² (18.75, 10.70, 0.37, 4.85 mg/dL, respectively) were determined with respect to the deficient group (DG) (9.85, 9.90, 0.26, 3.34 mg/dL, respectively). Hematological studies showed an increase in hemoglobin (14.4 ± 0.6 g/dL), and hematocrit (Htc, 47.0 ± 0.6%) values, compared to the DG (Hb: 12.6 ± 0.5 g/dL, Hto: 39.9 ± 1.1%). Furthermore, histological evaluations of the intestines showed an increase of the small intestine villi length in this latter group. The results allow us to conclude that bio-enrichment of quinoa pasta using LAB could be a novel strategy to increase vitamin and minerals bioavailability in cereal/pseudocereal - derived foods.

Health-Promoting Components in Fermented Foods: An Up-to-Date Systematic Review

Fermented foods have long been produced according to knowledge passed down from generation to generation and with no understanding of the potential role of the microorganism(s) involved in the process. However, the scientific and technological revolution in Western countries made fermentation turn from a household to a controlled process suitable for industrial scale production systems intended for the mass marketplace. The aim of this paper is to provide an up-to-date review of the latest studies which investigated the health-promoting components forming upon fermentation of the main food matrices, in order to contribute to understanding their important role in healthy diets and relevance in national dietary recommendations worldwide. Formation of antioxidant, bioactive, anti-hypertensive, anti-diabetic, and FODMAP-reducing components in fermented foods are mainly presented and discussed. Fermentation was found to increase antioxidant activity of milks, cereals, fruit and vegetables, meat and fish. Anti-hypertensive peptides are detected in fermented milk and cereals. Changes in vitamin content are mainly observed in fermented milk and fruits. Fermented milk and fruit juice were found to have probiotic activity. Other effects such as anti-diabetic properties, FODMAP reduction, and changes in fatty acid profile are peculiar of specific food categories.