A combined procedure to evaluate the global antioxidant response of bread

Chemical Characterization and In Vitro Gas Production Kinetics of Alternative Feed Resources for Small Ruminants in the Maltese Islands

The ever-increasing human population, the problem associated with climate change and recent crises-COVID-19 disease and trade conflicts-all impacted on the availability and cost of animal feed raw materials. This is clearly visible in realities which heavily rely on importation such as islands and small states, where producers involved in the agricultural sector were strongly affected by the sharp increase in prices. To deal with these global issues, alternative resources are perceived to replace conventional ingredients. This work aimed at assessing the nutritive value of different resources (sheep feed, mature carob, Maltese bread, wild asparagus, prickly lettuce, and loquat) for small ruminants present in the Maltese Islands, analyzing their chemical composition, gas production kinetics and antioxidant properties. In general, the variation in chemical composition resulted in different rumen fermentation kinetics (p < 0.007). The ratio between GP-24 h and GP-48 h was higher in Maltese bread than other substrates; loquat, prickly lettuce and wild asparagus showed lower fermentation kinetics in accordance with their high NDF and ADF contents. The antioxidant activity may be partially related to the polyphenolic content that was higher in wild asparagus, prickly lettuce and loquat. All feed characteristic confirmed their potential to be included as ingredients in ruminant diets and as a source of fiber.

The cultivation of rye in marginal Alpine environments: a comparison of the agronomic, technological, health and sanitary traits of local landraces and commercial cultivars

Rye is a secondary crop that is characterized by a higher tolerance to climatically less favorable conditions than other cereal species. For this reason, rye was historically used as a fundamental raw material for bread production and as a supply of straw in northern parts of Europe as well as in mountain environments, such as Alpine valleys, where locally adapted landraces have continued to be cultivated over the years. In this study, rye landraces collected in different valleys in the Northwest Italian Alps have been selected as the most genetically isolated within their geographical contexts and cultivated in two different marginal Alpine environments. The traits concerning their agronomy, mycotoxin contamination, bioactive content, as well as their technological and baking quality were assessed to characterize and compare rye landraces with commercial wheat and rye cultivars. Rye cultivars showed the same grain yield level as wheat in both environments. Only the genotype selected from the Maira Valley was characterized by tall and thin culms and a proneness to lodging, thereby resulting in a lower yield capacity. Among the rye cultivars, the hybrid one presented the highest yield potential, but also the highest susceptibility to the occurrence of ergot sclerotia. However, the rye cultivars, especially the landraces, were characterized by higher concentrations of minerals, soluble fibers, and soluble phenolic acids, and thus both their flours and breads had superior antioxidant properties. A 40% substitution of refined wheat flour with whole-grain rye flour led to a higher dough water absorption and a lower stability, thereby resulting in lower loaf volumes and darker products. Agronomically and qualitatively speaking, the rye landraces diverged significantly from the conventional rye cultivars, thus reflecting their genetic distinctiveness. The landrace from the Maira Valley shared a high content in phenolic acids and good antioxidant properties with the one from the Susa Valley and, when combined with wheat flour, turned out to be the most suitable for bread making. Overall, the results have highlighted the suitability of reintroducing historic rye supply chains, based on the cultivation of local landraces in marginal environments and the production of value-added bakery goods.

Characteristics and Relationships between Total Polyphenol and Flavonoid Contents, Antioxidant Capacities, and the Content of Caffeine, Gallic Acid, and Major Catechins in Wild/Ancient and Cultivated Teas in Vietnam

Vietnam has diverse and long-established tea plantations but scientific data on the characteristics of Vietnamese teas are still limited. Chemical and biological properties including total polyphenol and flavonoid contents (TPCs and TFCs), antioxidant activities (DPPH, ABTS, FRAP, and CUPRAC), as well as the contents of caffeine, gallic acid, and major catechins, were evaluated for 28 Vietnamese teas from North and South Vietnam. Higher values of TPCs and TFCs were found for green (non-oxidised) and raw Pu'erh (low-oxidised) teas from wild/ancient tea trees in North Vietnam and green teas from cultivated trees in South Vietnam, as compared to oolong teas (partly oxidised) from South Vietnam and black teas (fully oxidised) from North Vietnam. The caffeine, gallic acid, and major catechin contents depended on the processing, geographical origin, and the tea variety. Several good Pearson's correlations were found (r² > 0.9) between TPCs, TFCs, the four antioxidant capacities, and the content of major catechins such as (-)-epicatechin-3-gallate and (-)-epigallocatechin-3-gallate. Results from principal component analysis showed good discriminations with cumulative variances of the first two principal components varying from 85.3% to 93.7% among non-/low-oxidised and partly/fully oxidised teas, and with respect to the tea origin.

Health-Promoting Nutrients and Potential Bioaccessibility of Breads Enriched with Fresh Kale and Spinach

Bread is a staple food and can be a potential product to be enriched with various deficient nutrients. The objective of the study was to characterize the nutritional properties of toasted bread enriched with 10% and 20% of kale and wholemeal bread with 20% and 40% of spinach. The supplementation increased the phenolic content up to 2−3 times in the bread with the addition of 20% spinach and 40% kale. The highest antioxidant properties were noticed in extracts of bread with 20% kale. The in vitro digestion released the hydrophilic and lipophilic antioxidative compounds, leading to higher bioaccessibility of the breads enriched with these selected green vegetables. Even more than a 2-fold increase in folate content was observed in breads with the greatest addition of kale (20%) and spinach (40%), from 18.1 to 45.3 µg/100 g and from 37.2 to 83.2 µg/100 g, respectively, compared to the non-enriched breads. Breads with spinach showed significantly (P < 0.05) higher contents of all of the tested minerals, Cu, Mn, Fe, Zn, Mg, Ca, Na, K, and P, whereas kale enriched breads showed most of them. The results suggest that the addition of fresh green vegetables can enhance the daily supply of micronutrients and significantly increase the bioavailability of bioactive compounds with high antioxidant status.

Bioaccessibility of Phenolic Acids and Flavonoids from Buckwheat Biscuits Prepared from Flours Fermented by Lactic Acid Bacteria

The literature reports that the consumption of common buckwheat (Fagopyrum esculentum Moench), exactly the polyphenols it contains, is associated with a wide spectrum of health benefits. Therefore, the determination of the bioaccessibility of phenolic acids and flavonoids from buckwheat biscuits formulated from liquid-state fermented flours (BB_F) by selected lactic acid bacteria (LAB) after gastrointestinal digestion was addressed in this study. Bioaccessibility could be defined as the fraction of a compound that is released from the food matrix in the gastrointestinal lumen and used for intestinal absorption. The bioaccessibility of eight phenolic acids (protocatechuic, vanillic, syringic ferulic, caffeic, sinapic, p-coumaric, and t-cinnamic) and six flavonoids (epicatechin, vitexin, orientin, apigenin, kaempferol, and luteolin) were provided for BB_F and BB_C (buckwheat biscuits prepared from fermented and unfermented flours, respectively). The bioaccessibility indexes (BI) indicated the high bioaccessibility of phenolic acids and improved bioaccessibility of flavonoids from BB_F. Moreover, the data provide evidence for the suitability of selected LAB strains to be used as natural sour agents for further bakery product development rich in phenolic acids and flavonoids with LAB-dependent bioaccessibility.

Buckwheat hull, a valuable bakery product ingredient: assessment of bioaccessible phenolics and antioxidant capacity

In this study, the bioaccessible total phenolic compounds (TPC) and antioxidant capacity (AC) of commonly consumed bakery products enriched with raw (BH) or roasted (RBH) buckwheat hull were evaluated. The soluble and insoluble fractions obtained after in vitro enzymatic digestion of mixed rye/wheat bread with 4% of RBH (BRBH), wheat bread with 3% of BH (BBH), and their control counterparts were separated (C-BRBH and C-BBH, respectively). The addition of buckwheat hull, raw and roasted, significantly increased the values of analyzed parameters compared to control samples. Before the digestion, the highest values of TPC and AC were found for bread with 4% of RBH. After in vitro digestion of the bakery products, the content of TPC and AC in the soluble fraction was 75–90% higher compared to the values found in the undigested fraction. Generally, a decrease in the bioaccessibility index of enriched bakery products compared to control samples was observed. The obtained results indicate that buckwheat by-products may be used as a valuable ingredient for commonly used bakery products. Also, it was shown that the in vitro digestion model may be of relevance in assessing the bioaccessibility of bioactive compounds in commonly used bakery products.

Interactions between Phenolic Acids, Proteins, and Carbohydrates-Influence on Dough and Bread Properties

The understanding of interactions between proteins, carbohydrates, and phenolic compounds is becoming increasingly important in food science, as these interactions might significantly affect the functionality of foods. So far, research has focused predominantly on protein-phenolic or carbohydrate-phenolic interactions, separately, but these components might also form other combinations. In plant-based foods, all three components are highly abundant; phenolic acids are the most important phenolic compound subclass. However, their interactions and influences are not yet fully understood. Especially in cereal products, such as bread, being a nutritional basic in human nutrition, interactions of the mentioned compounds are possible and their characterization seems to be a worthwhile target, as the functionality of each of the components might be affected. This review presents the basics of such interactions, with special emphasis on ferulic acid, as the most abundant phenolic acid in nature, and tries to illustrate the possibility of ternary interactions with regard to dough and bread properties. One of the phenomena assigned to such interactions is so-called dry-baking, which is very often observed in rye bread.

In Vitro Expanded Bioaccessibility of Quercetin-3-Rutinoside and Quercetin Aglycone from Buckwheat Biscuits Formulated from Flours Fermented by Lactic Acid Bacteria

The expanded bioaccessibility of rutin (Ru) and quercetin (Q) from buckwheat biscuits (BBs) formulated from liquid-state fermented flours by selected lactic acid bacteria (LAB) were determined after gastrointestinal digestion. Fermentation of buckwheat flours caused a LAB-dependent variation in Ru and Q content. BBs baked at 220 °C for 30 min showed lower content of Ru and Q, and no correlation was found between the content of these compounds in fermented flours and BBs. The expanded bioaccessibility of Ru from BBs was low when its content in the soluble and insoluble fractions remaining after digestion in vitro was taken into account. Contrary results were found for Q bioaccessibility which had an index greater than 1, indicating the high Q bioaccessibility from BBs. Since very low Q content was noted in the insoluble fraction remaining after BBs digestion, the high Q bioaccessibility was determined to be due to its concentration in the soluble fraction.

Biscuits from Fermented Roasted Buckwheat Flour - Phenolics Profile and Bioaccessible Angiotensin Converting Enzyme Inhibitory Activity

The bioaccessible angiotensin converting enzyme (ACE) inhibitory activity of biscuits formulated from roasted common buckwheat flour after fermentation by select bacteria was studied. The same content of total phenolic compounds was found in fermented flour and in biscuits obtained from them. Generally, fermentation of flour did not changes the ACE inhibitory activity, whereas baking process significantly increased the ACE inhibitory activity of examined products. The potential bioaccessible ACE inhibitory activity from biscuits was very high. Phenolic acids such as protocatechuic, vanillic and syringic acids as well as flavonoids: kaempferol and epicatechin in the digested buckwheat biscuits have the highest impact on ACE inhibitory activity. A high significant correlations were found between IC50 and total phenolic compounds of fermented flours, biscuits before and after digestion. The data obtained in this study closely associates phenolic compounds with ACE inhibitory activity.

Extractable and Non-Extractable Antioxidants Composition in the eBASIS Database: A Key Tool for Dietary Assessment in Human Health and Disease Research

The antioxidant properties of foods are crucial in nutrition, food chemistry, and medicine studies but are often underestimated, with significant amounts of bioactive compounds containing physiological and biochemical properties remaining in the residue from extraction as non-extractable antioxidants. Over the last decade, extractable and non-extractable compounds have become key in the evaluation/determination of the antioxidant properties of food matrices because of their relevance in human health. This has led to the need to include extractable and non-extractable antioxidants in comprehensive and harmonized food composition databases for a wide range of applications within research, food, pharmaceutical, nutraceutical, and cosmeceutical areas. Additionally, the databases are invaluable as part of the health claims application process. eBASIS, (Bioactive Substances in Food Information System) a comprehensive database containing quality-evaluated scientific data, covering the composition of bioactive compounds present in foods, has flexible structures, allowing it to be extended to include newly emerging data on extractable and non-extractable compounds. Search criteria were developed and defined for compiling suitable peer-reviewed literature. Data quality assessment methods were established for the addition of composition data and antioxidant activity, with a focus on various parameters including: the extraction procedure, the antioxidant measurements, the expression of results. A total of 437 quality-evaluated datapoints on the composition of extractable and/or non-extractable compounds were entered into the database. This database update represents one of the first examples of building a database dedicated to antioxidant properties. This expansion of eBASIS provides a novel and unique tool for nutritionists, dietitians, researchers to use for a wide range of applications, such as dietary assessment, exposure studies and epidemiological studies, and may contribute to an increase in high-bioactive food consumption by consumers.

Chemical and microbial evaluation of biscuits made from wheat flour substituted with wheat sprouts

The aim of this work was to produce biscuits from wheat flour substituted with different amounts of wheat sprout powder (2.5-7.5%). The biscuits were subjected to chemical, phytochemical, and microbial evaluations. The crude protein, fat, and ash contents and the energy value of the biscuits increased with increasing percentage of wheat sprout powder. Adding sprouts resulted in higher values of phenolics, alpha-tocopherol, and antioxidant activity. There was no statistically significant difference in the contents of total phenolics and alpha-tocopherol between biscuits supplemented with 5% sprouts and biscuits substituted with 7.5% sprouts. The phenolic content in biscuits containing 7.5% sprouts was 245 mg gallic acid equivalents (GAE)/100 g dm compared with 110 mg GAE/100 g dm in control biscuits. Antioxidant activity was the highest in biscuits substituted with 7.5% sprouts. All levels of substitution of wheat flour with wheat sprouts had an effect on the nutritional properties of biscuits, but the substitution level of 2.5-5% is recommended for the improvement of their sensorial properties. The biscuits produced had a low microbial load and were microbiologically safe. Escherichia coli, Salmonella spp., and sulfite-reduction clostridia were not detected in any sample during the period of investigation from 2 to 60 days of storage.

ACE Inhibitory Properties and Phenolics Profile of Fermented Flours and of Baked and Digested Biscuits from Buckwheat

The angiotensin converting enzyme (ACE) inhibitory activity and phenolics profile of fermented flours and of baked and digested buckwheat biscuits was studied. The fermentation of buckwheat flour by select lactic acid bacteria (LAB) caused a decrease in ACE inhibitory activity as compared to the non-fermented flour. The baking process significantly reduced the ACE inhibitory activity of biscuits obtained from fermented flours, whereas digestion significantly increased these properties. In non-fermented and fermented flours and buckwheat biscuits before and after in vitro digestion samples, ten phenolic acids and eight flavonoids were found. Highly significant correlations were found between sample concentration of 50% inhibition of ACE (IC50) and total phenolic compounds of fermented flour and biscuits before and after digestion for each applied LAB, thus indicating a link between phenolic compound content and ACE inhibitory activity. In the digested biscuits, the input to ACE inhibitory activity was provided by p-coumaric, sinapic, syringic, vanillic, and protocatechuic acids as well as by kaempherol, quercetin, apigenin, and orientin. Therefore, it can be concluded that cumulative action of those phenolic acids and flavonoids released after digestion is responsible, in part, for the bioaccessible ACE inhibitory activity of buckwheat biscuits.

Assessment of the glycaemic index, content of bioactive compounds, and their in vitro bioaccessibility in oat-buckwheat breads

This study addressed determinations of the glycaemic index (GI), antioxidant capacity (AC), and phenolics content (TPC) of oat, buckwheat, and mixed oat/buckwheat breads. The bioaccessibility of TPC and the AC of breads were studied after in vitro digestion. The lowest values of the GI were determined for oat bread, whereas breads with the highest content of buckwheat flour had the highest AC. The digestion of breads showed that most of the TPC were found in the soluble fraction, but the phenolic compounds were still present also in the insoluble fraction after digestion. It was concluded that the mixed oat-buckwheat breads may serve as products with a medium GI, as a source of TPC, and as products with a high AC. It should be noted that enzymatic digestion or fermentation by microbiota could potentially enhanced breads antioxidant activity during digestion in the gastrointestinal tract.

Buckwheat and buckwheat enriched products exert an anti-inflammatory effect on the myofibroblasts of colon CCD-18Co

Buckwheat (BW) constitutes a good source of bioactive components that show anti-inflammatory effects in vitro and in vivo. The use of functional foods in the prevention and treatment of inflammatory bowel diseases (IBDs) has aroused increasing interest. This study investigates the effect of in vitro digested BW and BW-enriched products (BW-enriched wheat breads, roasted BW groats -fermented and non-fermented-, and BW sprouts) on colon myofibroblasts, the cells involved in the regulation of inflammatory response in the intestine. The cells were treated with different digested-BW products, alone or together with TNF-α (20 ng mL-1), and the effects on the cell migration, mitochondrial membrane potential and cell cycle, processes altered during intestinal inflammation, were investigated. A significant reduction in TNF-α-induced migration (25.5%, p < 0.05) and attenuation of the TNF-α-altered cell cycle (p < 0.05) was observed in myofibroblasts treated with BW-enriched white wheat bread. These results contribute to extend the beneficial effects derived from BW bioactive compounds, and suggest that BW consumption can exert beneficial effects on IBDs.

Effects of in vitro Human Digestion on the Antioxidant Activity and Stability of Lycopene and Phenolic Compounds in Pork Patties Containing Dried Tomato Prepared at Different Temperatures

The antioxidant activity can be changed during digestion. The effects of in vitro human digestion on the antioxidant activity and stability of tomato powders (TPs), dried at three different temperatures (60, 80, and 100 °C) and added to pork patties (1% TP by weight), were investigated. The pork patties with three TPs underwent in vitro human digestion with enterobacteria. Lycopene and individual phenolic compounds were analyzed by using HPLC. The highest total phenolic compounds (6.96 g/100 g) and lycopene concentrations (2.68 mg/100 g) were observed in pork patties with TP dried at 100 °C. In addition, antioxidant activity of pork patties containing TPs were measured during in vitro human digestion. Gallic acid (23.8 to 41.6 g/100 g), chlorogenic acid (11.2 to 25.7 g/100 g), and caffeic acid (11.1 to 21.7 g/100 g) were detected as the main phenolic compounds in the TPs. Lycopene, and total and individual phenolic compound contents increased with increasing drying temperatures. Moreover, in vitro human digestion increased the antioxidant activity of TP-containing pork patties. The lycopene and total phenolics contents were increased during in vitro human digestion with enterobacteria by 146% to 220% and 1549% to 2095%, respectively as compared to the samples of before digestion. Hence, we hypothesized that the antioxidant activity of each TP increased during in vitro human digestion and depended on the amount of lycopene and phenolic compounds released. The TP dried at the highest temperature (100 °C) had the highest antioxidant activity in pork patties during in vitro human digestion.

PRACTICAL APPLICATION

In this study, we revealed that in vitro human digestion increases the antioxidant activities of tomato powder. In addition, tomato powder dried at the highest temperature (100 °C) showed the highest antioxidant activity. Therefore, tomato powder at 100 °C could be used as strong antioxidants in meat products.

Mineral Elements Bio-Accessibility and Antioxidant Indices of Blanched Basella rubra at Different Phases of in vitro Gastrointestinal Digestion

The present investigation was designed to evaluate the mineral element bio-accessibility and antioxidant indices of blanched Basella rubra at different phases of simulated in vitro digestion (oral, gastric, and intestinal). The phenolic composition of processed vegetable was determined using high-performance liquid chromatography (HPLC)-diode-array detection method. Mineral composition, total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and total antioxidant activity (TAA) of the in vitro digested blanched and raw vegetable were also determined. HPLC analysis revealed the presence of some phenolic compounds, with higher levels (mg/g) of polyphenols in raw B. rubra (catechin, 1.12; p-coumaric acid, 6.17; caffeic acid, 2.05) compared with the blanched counterpart, with exeption of chlorogenic acid (2.84), that was higher in blanched vegetable. The mineral content (mg/100 g) showed a higher value in enzyme treated raw vegetable compared to their blanched counterparts, with few exceptions. The results revealed a higher level of some of the evaluated minerals at the intestinal phase of digestion (Zn, 6.36/5.31; Mg, 5.29/8.97; Ca, 2,307.69/1,565.38; Na, 5,128/4,128.21) for raw and blanched respectively, with the exception of Fe, K, and P. The results of the antioxidant indices of in vitro digested B. rubra revealed a higher value at the intestinal phase of in vitro digestion, with raw vegetal matter ranking higher (TPC, 553.56 mg/g; TFC, 518.88 mg/g; FRAP, 8.15 mg/g; TAA, 5,043.16 μM Trolox equivalent/g) than the blanched counterpart. The studied vegetable contains important minerals and antioxidant molecules that would be readily available after passing through the gastrointestinal tract and could be harnessed as functional foods.

Fecal excretion of Maillard reaction products and the gut microbiota composition of rats fed with bread crust or bread crumb

A comparison between the impacts of advanced (N^ε-carboxymethyllysine - CML) and terminal (melanoidins) Maillard reaction products from bread on gut microbiota was carried out in this study. Gut microbiota composition as well as fecal excretion of CML from both bread crust and bread crumb, and of melanoidins from bread crust were assessed on a rodent model. Rats were fed with pellets supplemented or not with 13% of bread crust, bread crumb, a fiber-free bread crust model (glucose, starch and gluten heated together) or a fiber-free-melanoidin-free bread model (glucose-starch and gluten heated separately) for four weeks. These model systems were developed to limit the presence of wheat-native dietary fibers such as cellulose, hemicelluloses and lignin. CML and melanoidins in pellets and feces were evaluated by LC/MS-MS and HPLC/fluorescence respectively, and gut microbiota composition was determined by cultivation and molecular approaches. Diets supplemented with crumb or the fiber-free-melanoidin-free model contained respectively 17% and 64% less melanoidins than their respective controls. A higher excretion of melanoidins was observed for rats fed with crust or bread crust model compared to their controls, confirming that melanoidins are in contact with gut microbiota. No impact of diets was observed on Firmicutes, Bacteroidetes and lactic flora. A decrease of enterobacteria was only observed for rats fed with the diet supplemented with the fiber-free bread crust model. Moreover, a significant increase of bifidobacteria numbers in the presence of crust, crumb and both bread models was observed, showing that this bifidogenic effect of bread is not due to the presence of melanoidins or wheat-native dietary fibers.

Global antioxidant response of meat

BACKGROUND

The global antioxidant response (GAR) method uses an enzymatic digestion to release antioxidants from foods. Owing to the importance of digestion for protein breakdown and subsequent release of bioactive compounds, the aim of the present study was to compare the GAR method for meat with the existing methodologies: the extraction-based method and QUENCHER. Seven fresh meats were analyzed using ABTS and FRAP assays.

RESULTS

Our results indicated that the GAR of meat was higher than the total antioxidant capacity (TAC) assessed with the traditional extraction-based method. When evaluated with GAR, the thermal treatment led to an increase in the TAC of the soluble fraction, contrasting with a decreased TAC after cooking measured using the extraction-based method. The effect of thermal treatment on the TAC assessed by the QUENCHER method seemed to be dependent on the assay applied, since results from ABTS differed from FRAP.

CONCLUSION

Our results allow us to hypothesize that the activation of latent bioactive peptides along the gastrointestinal tract should be taken into consideration when evaluating the TAC of meat. Therefore, we conclude that the GAR method may be more appropriate for assessing the TAC of meat than the existing, most commonly used methods. © 2016 Society of Chemical Industry.

Study Approach of Antioxidant Properties in Foods: Update and Considerations

The assessment of interactions between natural antioxidants and other food matrix components represents the main step in the investigation of total antioxidant properties, in terms of potential health benefits. The diversity of chemical structures of natural compounds, besides their possible interactions, as well as the biological role and different modes of action makes it difficult to assess a single and reliable procedure for the evaluation of antioxidant activity. Today, much attention is given to the distinction between extractable and non-extractable antioxidants as a key tool in the description of the nutritional and healthy properties of food matrices. The starting point for the investigation of antioxidant effects of food extracts is the analysis of antioxidant properties of pure compounds and their interactions. Another complementary approach could be represented by the study of how different biologically active compound-rich extracts contribute to the total antioxidant capacity.

Evaluation of the Availability and Antioxidant Capacity of Maillard Compounds Present in Bread Crust: Studies in Caco-2 Cells

Bread crust is one of the major contributors to the intake of Maillard reaction products (MRP). MRP improve the organoleptic properties of foods and can provide biological actions such as antioxidant properties. The transport and availability of Amadori compounds (measured as furosine) and hydroxymethylfurfural (HMF)-early and intermediary MRP-from enzymatically digested bread crust (BC) and from its soluble low-molecular weight (LMW) and high-molecular weight (HMW) fractions were investigated in the Caco-2 cell line. The absorption of the early and final MRP pool was tested by measuring the absorbance recovery (280 and 420 nm). The ability of soluble BC or its fractions to lessen the production of reactive oxygen species (ROS) was examined. Amadori compounds (furosine) were transported across Caco-2 cell monolayers from the soluble BC in percentages ranging between 40% and 56%; the lower amount of the compound supplied, the higher transport rate. However, HMF transport rate (35%) was unaffected by the initial amount of the compound. Amadori compounds and HMF contained in the LMW fraction were more efficiently transported than those present in the HMW fraction, suggesting improved absorption when supplied as free forms or linked to LMW compounds. Absorbance recovery at 280 nm was higher from the LMW fraction, whereas higher recovery was detected for the HMW fraction at 420 nm. The digested BC-but not its isolated fractions-was able to significantly reduce ROS production at basal conditions and after subjecting cells to an oxidant. A clear positive action of BC on the antioxidant defence is manifested, seemingly attributable to the combined presence of soluble LMW and HMW products.

Antioxidant potential of phenolic-rich two varieties of Nigerian local rice and their anti-cholinesterase activities after in vitro digestion

Purpose

– The purpose of this paper is to focus on the antioxidant properties of two phenolic-rich varieties of Nigerian local rice and their anti-cholinesterase potential after in vitro-simulated gastrointestinal digestion, with the aim of establishing their actual antioxidant and nutraceutical potential after their passage through the gastrointestinal tract upon consumption.

Design/methodology/approach

– Two local rice varieties, commonly referred to as “Gboko” and “Ofada” rice commonly grown in Benue State, a middle belt region of Nigeria and south western regions of Nigeria, respectively, were locally processed. Each of the processed grains were divided into two portions; one portion was left uncooked, while the second portion was boiled conventionally as eaten, dried and subsequently milled into powder. The milled samples of the raw and boiled rice were treated with acidified methanol to obtain the methanol extracts; another portion of each samples was subjected to in vitro enzyme digestion using standard methods to mimic human digestion; and the third portion was treated using the same scheme of in vitro digestion without the sets of enzyme which was used to serve as a control for enzyme treatment. The quali-quantitative phenolic profiles of the two local varieties were carried out with the aid of high-performance liquid chromatography with diode-array detection (HPLC-DAD) method. The antioxidant potential and anti-cholinesterase action of the methanolic extracts, the simulated in vitro digested model and the enzyme-treated controls of the rice samples were determined using standard methods and data obtained were subjected to ANOVA; the differences of means were separated using Duncan’s multiple range test (DMRT).

Findings

– The quali-quantitative assessment of phenolic compounds in the two studied local varieties revealed the presence of some phenolic acids and flavonoids, with a decreased level of most of the identified phenolic compounds after boiling. In vitro enzyme-digested rice for both raw and boiled rice samples showed significantly higher total phenolic content, total flavonoid content, ferric-reducing antioxidant power, 2, 2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS+) scavenging and NO− inhibitory activities than the aqueous-methanolic extracts and the enzyme-treated controls. The aqueous-methanolic extracts displayed a higher 1, 1 diphenyl-2-picrylhdrazyl radical scavenging activity and inhibited Fe2+-induced lipid oxidation in rat’s brain and liver homogenate than that displayed by the in vitro enzyme-digested samples. In vitro enzyme-digested and boiled “Gboko” and “Ofada” rice and raw “Ofada” rice have the potential of inhibiting acetylcholine esterase (AChE) activity. While methanolic extracts of raw and boiled “Ofada” and “Gboko” rice exhibited the potential to inhibit butrylcholinesterase activity. The result of this paper indicates that the selected rice varieties possess antioxidant capacities which are better released after the simulated in vitro enzyme digestion; the result also showed the anti-cholinesterase potential of the studied rice grains and, therefore, they can be considered as nutraceutical health supplements.

Originality/value

– The paper has demonstrated the antioxidant potentials of the phenolic-containing two Nigerian local rice varieties and established their anti-cholinesterase potential after simulated in vitro enzyme digestion.

Delivery of Flavonoids and Saponins from Black Bean (Phaseolus vulgaris) Seed Coats Incorporated into Whole Wheat Bread

Cereal-based products can be used as vehicles for the delivery of relevant bioactive compounds since they are staple foods for most cultures throughout the world. The health promoting benefits of flavonoids and saponins contained in black bean seed coats have been previously described. In the present work, the effect of adding flavonoids and saponins from black bean seed coat to the typical yeast-leavened whole wheat bread formulation in terms of bread features, organoleptic properties and phytochemical profile was studied. The retention of bioactive compounds was determined and the inhibitory effects of in vitro enzyme digested samples on two colon cancer cell lines (Caco-2 and HT29) was evaluated. The addition of bioactive compounds did not significantly affect baking properties or texture parameters. Among organoleptic properties of enriched breads, only crumb color was affected by the addition of bioactive compounds. However, the use of whole wheat flour partially masked the effect on color. More than 90% of added flavonoids and saponins and 80% of anthocyanins were retained in bread after baking. However, saponins were reduced more than 50% after the in vitro enzyme digestion. The black bean seed coat phytochemicals recovered after in vitro enzyme digestion of enriched breads significantly reduced by 20% the viability of colon cancer cells without affecting standard fibroblast cells (p < 0.05).

Antioxidant capacity and bioaccessibility of buckwheat-enhanced wheat bread phenolics

The impact of an in vitro procedure that mimics the physiochemical changes occurring in gastric and small intestinal digestion on the antioxidant capacity and bioaccessibility of phenolic compounds from 16 types of buckwheat-enhanced wheat breads was assessed. The methodology was based on the Global Antioxidant Response (GAR) which combined bioaccessible antioxidant capacity of the soluble fraction from digestible portion measured by the standard Trolox Equivalent Antioxidant Capacity (TEAC) assay and antioxidant capacity of the insoluble fraction from the undigested portion by the QUENCHER method. The bioaccessibility of the phenolics was measured in the soluble fraction with Folin-Cicalteu reagent and in the insoluble fraction by modified QUENCHER method. The studies showed almost 20-fold higher GAR values as compared to the antioxidant capacity of the respective undigested reference breads. The bioaccessible antioxidant capacity of soluble fraction from digestible portion increased significantly whereas the undigested residue displayed antioxidant capacity that accounted for up to 15 % of the GAR. The bioaccessible phenolics accounted for up to 90 % of the total phenolics after digestion and were highly correlated with GAR results of buckwheat-enriched wheat breads. Our results indicate that in vitro digestion is the crucial step that releases of high amount of phenolic antioxidants. The combination of QUENCHER assay with Total Antioxidant Capacity (TAC) and Total Phenolic Content (TPC) assay estimated on Folin-Ciocalteu reagent has been useful for the determination of the bioaccessible antioxidant activity and phenolics of the soluble and insoluble fraction of buckwheat-enhanced wheat breads.

Evaluation of Antioxidant Properties in Cereals: Study of Some Traditional Italian Wheats

Whole grain cereals contain a wide range of phytochemicals and it is often difficult to ascribe protective effects on metabolic health to any one particular constituent. The interactions among bioactive components, which contribute highly to the total antioxidant capacity of cereals, represent the first step in the evaluation of food potential health benefits. This research focused on the determination of antioxidant properties in grains and whole flours of some traditional Italian wheats. Results showed that hydrolysable polyphenols in grains are 85% of total polyphenols and contribute 95% of the total antioxidant properties, which indicates that hydrolysable polyphenols represent an important fraction of polyphenols in cereals. The distinction between extractable and non-extractable antioxidants was shown to be of paramount importance for an adequate determination of antioxidant capacity in cereals and represents a key element in the definition of potential nutritional value of the food matrix under consideration.

Adaptation and Validation of QUick, Easy, New, CHEap, and Reproducible (QUENCHER) Antioxidant Capacity Assays in Model Products Obtained from Residual Wine Pomace

Evaluation of the total antioxidant capacity of solid matrices without extraction steps is a very interesting alternative for food researchers and also for food industries. These methodologies have been denominated QUENCHER from QUick, Easy, New, CHEap, and Reproducible assays. To demonstrate and highlight the validity of QUENCHER (Q) methods, values of Q-method validation were showed for the first time, and they were tested with products of well-known different chemical properties. Furthermore, new QUENCHER assays to measure scavenging capacity against superoxide, hydroxyl, and lipid peroxyl radicals were developed. Calibration models showed good linearity (R(2) > 0.995), proportionality and precision (CV < 6.5%), and acceptable detection limits (<20.4 nmol Trolox equiv). The presence of ethanol in the reaction medium gave antioxidant capacity values significantly different from those obtained with water. The dilution of samples with powdered cellulose was discouraged because possible interferences with some of the matrices analyzed may take place.

Antioxidant properties of chemical extracts and bioaccessible fractions obtained from six Spanish monovarietal extra virgin olive oils: Assays in Caco-2 cells

The antioxidant activity and the total phenolic content of six Spanish commercial monovarietal extra virgin olive oils were evaluated in chemical extracts and in bioaccessible fractions obtained after in vitro digestion.