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Alternative milk products such as A2 milk are gaining popular stand within consumer market, for their healthy profile and expected greater digestibility characteristics. However, total mineral content and its bioaccessible profile have lacked in studies through the years, even more because of their relevance in public health. The present study aimed to evaluate the mineral profile of commercial A2 bovine milk (AT) and estimate the bioaccessibility of calcium, phosphorus and magnesium using the INFOGEST protocol. Non-A2 samples (NAT) were evaluated for comparison purpose. The determination of Ca, Mg, Na and K was performed by FAAS and total P was quantified by colorimetric method. Total protein content was determined by Kjeldahl method. Free amino acids were quantified by OPA method along the in vitro digestion stages. Total content of Ca, Na and P exhibited equivalent results between samples, although A2 milk showed elevated levels of total Mg and K in the analyzed batches. AT showed protein content equivalent to NAT. In addition, levels of free NH2 were observed 2 times higher in AT, during the first hour of pancreatic phase in the intestinal digestion. Bioaccessibility of Ca showed equivalent percentages for AT (12-42 %) and NAT (10-39 %). The observed low values were possibly derived from interferences with saturated fatty acids and standardized electrolytes during digestion. Similar amounts of bioaccessible Mg were found for all milk samples (35-97 %), while A2 samples evidenced percentages of bioaccessible P exceeding 60 % across the three batches. Despite the health benefits associated to A2 milk, the study did not evidence clear distinction from non-A2 milk in terms of enhanced essential mineral solubility in digestive tract simulation, considering the association of greater digestibility expected for A2 milk.

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This work aimed to study and characterize a product based on vegetable extract of quinoa (WVEQ) fermented with water kefir grains. The effect of sucrose concentration (SC), inulin concentration (IC), and xanthan gum (XG) concentration were evaluated using a central composite design (CCD) 23. They were subsequently characterized regarding cellular growth of the grains, beverage yield, pH, soluble solids, carbon dioxide (CO2) production, lactic acid, and ethanol production. Therefore, for the final stage, two formulations (F1 and F8) of the CCD were chosen to be characterized in terms of proximate composition, microbiological composition of the kefir culture, analysis of organic compounds, sensory analysis, and enzymatic and microbiological characterization before and after simulation of in vitro gastrointestinal digestion. In the two chosen products, one can see that fermentation optimized the bioavailability of proteins due to the high proteolytic activity of the microorganisms in kefir and the increase in lipid content. In identifying microorganisms, there was a prevalence of Saccharomyces sp. yeasts. In the sensory analysis, the F8 formulation showed better results than the F1 formulation. In vitro, gastrointestinal digestion showed reduced lactic acid bacteria and yeast and increased acetic acid bacteria in the liquid phase for both formulations. In the enzymatic profile, there was a reduction in all enzymes analyzed for both formulations, except for amylase in F1, which went from 14.05 U/mL to 39.41 U/mL. Therefore, it is concluded that using WVEQ as a substrate for the product appears to be a viable alternative with nutritional and technological advantages for serving a specific market niche.

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BACKGROUND: The large quantities of by-products generated in the coffee industry are a problem. Studies related to the biological potential of organic coffee husks are still limited. The aim of this work was to investigate the occurrence of phenolic compounds in organic coffee husks and to evaluate their potential as a source of bioactive dietary components. RESULTS: To achieve this objective, three extracts were prepared, namely extractable polyphenols (EPs), hydrolyzable non-extractable polyphenols (H-NEPs), and non-extractable polyphenols (NEPs). These extracts were characterized and evaluated for their bioactive properties after simulated gastrointestinal digestion. The results show that the extraction process affected the occurrence of phenols from coffee peels, especially for caffeic acid, gallic acid, and chlorogenic acid. The free and bound polyphenols found in the extracts and digests not only showed antioxidant properties against 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals but were also strongly bioavailable and had good anticoagulant potential. CONCLUSION: These results highlight the potential health benefits of phytochemicals from coffee husks and open new perspectives for the use of such compounds in dietary supplements. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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Breast milk is known to contain bioactive peptides that are released during digestion, being a major source of bioactive peptides to the new-born, some of which act against invading pathogens. However, the formation of bioactive peptides during digestion of human colostrum remains largely uninvestigated. This study aimed to investigate the formation of peptides during simulated digestion of human colostrum from adult women and to prospect antimicrobial peptides. For this purpose, we used high-resolution MS to monitor the release of peptides during in vitro digestion. Bioinformatics was used for the prospection of antimicrobial activity of peptides. During simulated digestion (oral, gastric and duodenal phases), 2318 peptide sequences derived from 112 precursor proteins were identified. At the end of simulated digestion, casein-derived peptide sequences were the most frequently observed. Among precursors, some proteins were seen for the first time in this study. The resulting peptides were rich in proline, glutamine, valine and leucine residues, providing characteristic traits of antimicrobial peptides. From bioinformatics analysis, seven peptides showed potentially high antimicrobial activity towards bacteria, viruses and fungi, from which the latter was the most prominent predicted activity. Antimicrobial peptides released during digestion may provide a defence platform with controlled release for the new-born.

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Grain germination increases the contents of benzoxazinoids and the antioxidant capacity of wheat and differentially affects the phytochemical composition of hard and soft wheat cultivars. It was investigated whether wheat cultivars (sprouted or not) with distinct grain texture characteristics (BRS Guaraim, soft vs. BRS Marcante, hard texture) would have different behavior in relation to changes in phytochemical compounds, bioaccessibility and antioxidant capacity during simulated gastrointestinal digestion of a tabbouleh preparation. Sprouting increased the nominal amount of phytochemicals in tabbouleh resulting in increased release of phenolic acids (up to 7.5-fold) and benzoxazinoids (up to 12.5-fold) during all digestion phases besides higher bioaccessibility (up to 2.8-fold). Sprouting caused greater increase in the bioaccessibility of phenolic acids for the soft wheat cultivar (4.5-fold) than for the hard cultivar (1.9-fold) and it increased the colon available index of phenolic acids only for the soft cultivar (1.8-fold). Flavonoids, mainly represented by apigenin glycosides, were marginally increased after sprouting but underwent relative increase along digestion being the major phytochemicals found in the bioaccessible fraction obtained after intestinal digestion (73-94% of total phytochemicals). The increase in apigenin glycosides was associated to the increase of in vitro and intracellular antioxidant capacity of tabbouleh along digestion. Sprouting increased the peroxyl radical removal capacity of tabbouleh in the gastric phase and in the non-bioaccessible fraction regardless of the cultivar. The highest hydroxyl radical removal capacities were found in non-sprouted cultivars, especially in the soft texture cultivar in the undigested and bioaccessible fractions. The bioaccessible fraction obtained after wheat digestion was more efficient to scavenge intracellular ROS than undigested samples, the highest scavenging potency being observed for the hard texture cultivar with no effect of sprouting. These findings confirm the hypothesis that the phytochemicals of hard and soft wheat cultivars (sprouted or not) have different behavior during digestion in terms of biotransformation, bioaccessibility and ability to remove reactive species and indicate that tabbouleh produced from sprouted wheat results in increased release of bioactive phytochemicals during digestion.

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Bauhinia forficata Link is a plant rich in polyphenols that has been used mainly for its hypoglycemic activity, which is related to its antioxidant and anti-inflammatory potential. However, the beneficial effect of these bioactive compounds is directly dependent on their bioaccessibility and bioavailability, requiring processing techniques that can improve and preserve their biological activities. This work aimed to obtain nanocapsulated extracts from the infusion (ESIN) and decoction (ESDC) of B. forficata Link leaves, by spray drying. The encapsulating agents used were maltodextrin and colloidal silicon dioxide. The nanocapsules were characterized by HPLC-PDA-ESI-IT-MS n , evaluated the bioaccessibility of polyphenols after simulated digestion and their antioxidant activity. Additionally, an extensive physicochemical characterization of the nanocapsulated extracts was carried out and their stability and technological parameters were evaluated. The ESIN and ESDC extracts had yields of 57.3 % and 62.7 %, with average nanocapsules sizes of 0.202 µm and 0.179 µm, low humidity and water activity (<0.5), powder density and proper flow properties (Hausner ratio ≤ 1.25; Carr index 18-19 %). Scanning electron microscopy showed a spherical and amorphous morphology and low viscosity, which may have favored the solubility profile. The phenolic compounds of the nanocapsules degraded after 400 °C, showing high thermal stability. The infrared spectra identified the presence of maltodextrin and phenolic compounds and that there were no reactions between them. Chromatography confirmed the presence of phenolic compounds, mainly flavonols and their O-glycosylated derivatives, as well as carbohydrates, probably maltodextrin. Simulated in vitro digestion showed that polyphenols and flavonoids from ESIN and ESDC nanocapsules were bioaccessible after the gastric phase (49.38 % and 64.17 % of polyphenols and 64.08 % and 36.61 % of flavonoids) and duodenal (52.68 % and 79.06 % of polyphenols and 13.24 % and 139.03 % of flavoids), with a variation from 52.27 % to 70.55 % of the antioxidant activity maintained, by the ORAC method, after gastric digestion and still 25 %, after duodenal. Therefore, the nanoencapsulation of extracts of B. forficata is a viable option for the preservation of their bioactive compounds, making them bioaccessible and with antioxidant activity, which make them suitable for incorporation into various nutraceutical formulations, such as capsules, tablets and sachets.

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International guidelines strongly advise about the frequent and varied intake of plant in diet. In this scenario, the consumption of fruits is closely related to health benefits due to the abundant presence of bioactive substances. Accordingly, the production of tropical fruits has stood out worldwide, reaching records since the past decade. However, to ensure that phenolic substances are indeed used by the body, they need to be accessible for absorption. For this purpose, several methods are used to assess the phenomenon of bioaccessibility. We provide information on i) in vitro methods for the evaluation of the bioaccessibility of phenolic compounds in tropical fruits, including their derivatives and by-products; ii) a study performed using a semi-dynamic in vitro digestion model; iii) simulated digestion with a dialysis membrane step, polyphenol transport/uptake using cell culture, and in vitro colonic fermentation process. Although standardized static and semi-dynamic in vitro digestion methods already exist, few studies use these protocols to assess the bioaccessibility of polyphenols in tropical fruits. To guarantee that in vitro digestion assays reproduce consistent results compared to in vivo reference methods, it is essential to universalize standardized methods that allow the comparison between results, enabling the validation of in vitro digestion methods.

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Sapota-do-solimões (Quararibea cordata) juice was fermented by Lacticaseibacillus casei B-442 to produce a probiotic and a synbiotic juice. The synbiotic juice was obtained by adding fructooligosaccharides (FOS, 7%, w/v). After the fermentation (37 °C by 15 h) the L. casei viability was above 11 log CFU/mL in both juices. The microbial survival rate after 30 days of cold storage (4 °C) was higher in probiotic juice (97%) than in prebiotic juice (82%). The effect of fermentation and the food matrix on L. casei viability was assessed by the simulated digestion at the beginning and the end of cold storage (4 °C for 30 days). After the simulated digestion, the probiotic counts were above 8 log CFU/mL in synbiotic juice and above 4 log CFU/mL in probiotic juice. The main L. casei metabolites produced in the sapota-dos-solimões juice were lactic acid and acetic acid. Isobutyric, and propionic acids presented higher production in synbiotic juice compared to the probiotic juice. No FOS hydrolysis was observed during the storage or the simulated digestion. L. casei did not consume FOS as carbon source. Thus, sapota-do-solimões juice is an exotic suitable non-dairy-based matrix for functional beverages.

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The aim of this study is to investigate the bioaccessibility and gut metabolism of free and melanoidin-bound phenolic compounds from coffee and bread. Phenolics from coffee were predominantly found in free forms (68%, mainly chlorogenic acids), whereas those from bread were mostly bound to melanoidins (61%, mainly ferulic acid). Bioacessibility of coffee total free phenolics slightly decreased during simulated digestion (87, 86, and 82% after the oral, gastric, and intestinal steps, respectively), with caffeoylquinic acids being isomerized and chlorogenic acids being partially hydrolyzed to the corresponding hydroxycinnamic acids. Bioacessibility of bread total free phenolics decreased during simulated digestion (91, 85, and 67% after the oral, gastric, and intestinal steps, respectively), probably related to complexation with the proteins in simulated gastric and intestinal fluids. Upon gut fermentation, the bioaccessibility of total free phenolics from both coffee and bread decreased, mainly after the first 4 h (56 and 50%, respectively). Caffeic and ferulic acids were the predominant metabolites found during coffee and bread gut fermentation, respectively. Melanoidin-bound phenolics from coffee and bread were progressively released after the gastric and intestinal steps, probably due to hydrolysis caused by the acidic conditions of the stomach and the action of pancreatin from the intestinal fluid. The bioaccessibilities of all phenolics from coffee and bread melanoidins after the gastric and intestinal steps were, on average, 11 and 26%, respectively. During gut fermentation, phenolics bound to both coffee and bread melanoidins were further released by the gut microbiota, whereas those from coffee were also metabolized. This difference could be related to the action of proteases on melanoproteins during gastrointestinal digestion, probably anticipating phenolics release. Nevertheless, bioaccessibilities of melanoidin-bound phenolics reached maximum values after gut fermentation for 24 h (50% for coffee and 51% for bread). In conclusion, the bioaccessibilities of coffee and bread free phenolics during simulated digestion and gut fermentation were remarkably similar, and so were the bioaccessibilities of coffee and bread melanoidin-bound phenolics.

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ABSTRACT The objective of this study was to analyze the chemical composition and bioaccessibility of phenolic compounds as well as their antioxidant capabilities of organic peppermint leaves after each phase of simulated digestion. Moisture was determined until a constant weight was obtained in an oven at 105 °C; ash was determined after sample calcination in a muffle furnace at 550 °C. The protein concentration was determined by the Macro-Kjeldahl method and lipid content by hot-extraction in a Soxhlet apparatus. Carbohydrates were calculated from differences and energy values based on the Atwater conversion factors. Total phenolic, flavonoid content, and antioxidant activity were determined by spectrophotometry. A four-step procedure was used for in vitro digestion. Organic peppermint was found to contain the following: 78% moisture, 1.7% ash, 1.5% lipids, 0.3% proteins, 17.7% carbohydrates, and a total of 85.5 kcal/100 g. Values of 705 mg GAE/100 g of phenolic, 918 mg QE/100 g of flavonoids, and 58.8 mg/g of vitamin C were also measured. It was discovered that total phenolics had the highest bioaccessible fraction relative to flavonoids; the salivary phase was identified as that with the highest release of these compounds and thus the phase in which peppermint showed significant antioxidant activity (1509 μmol TEAC/100g). This study demonstrated that organic peppermint has a high content of phenolic compounds that can be extracted from the alimentary matrix in the salivary and intestinal phases of the digestive system. Because of the antioxidant activity of these compounds, the use of this aromatic plant as seasonings and spices is relevant.

RESUMEN El objetivo de este estudio fue analizar la composición química de hojas de menta orgánica y la bioaccesibilidad de los compuestos fenólicos así como su capacidad antioxidante. Se determinó la humedad hasta obtener un peso constante en el horno a 105 °C, la ceniza se determinó en un horno de mufla a 550 °C. La concentración de proteína se determinó mediante el método Macro-Kjeldahl y los lípidos mediante extracción en un aparato Soxhlet. Los carbohidratos se calcularon por diferencia y energía basadas en los factores de conversión de Atwater. El contenido fenólico y la actividad antioxidante se determinaron por espectrofotometría. Se usó un procedimiento de cuatro pasos para la digestión in vitro. La menta orgánica contiene 78% de humedad, 1,7% de cenizas, 1,5% de lípidos, 0,3% de proteínas, 17,7% de carbohidratos y 85,5 kcal/100 g. También se midieron valores de 705 mg GAE/100g de fenólico, 918 mg QE/100 g de flavonoides y 58,8 mg/g de vitamina C. Se descubrió que los fenólicos tenían la fracción bioaccesible más alta en relación con los flavonoides; la fase salival se identificó como aquella con la mayor liberación de estos compuestos y, por lo tanto, la menta mostró una actividad antioxidante significativa (1509 μmol de TEAC/100 g). La menta orgánica tiene un alto contenido de fenólicos que se pueden extraer en las fases salival e intestinal. Debido a la actividad antioxidante de estos compuestos, el uso de esta planta como condimentos y especias es relevante.

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Whey protein isolate (WPI) interactions with (-)-epigallocatechin gallate (EGCG) and caffeic acid (CA) at pH 3.5 and 7.0 were investigated concerning complex formation and antioxidant capacity, before and after simulated digestion. Complex formation was evidenced by protein structural changes when WPI was associated with CA or EGCG. Reducing capacity and FRAP values increased as the phenolic compound concentration increased while ORAC values remained unchanged. In general, compared to the isolated compounds, complexation suppressed the antioxidant capacity possibly due to hydrophobic interaction and H-bonding between these compounds. Protein:phenolic complexation in 1:0.5 M ratio did not affect the digestibility compared to WPI (83%), except for WPI:CA at pH 7.0 (73%). The hydrophilicity profile of the digested samples suggested that pH of complexation and type of phenolic affected the protein cleavage pattern. Furthermore, the phenolic compounds were more stable when associated with the protein since they were protected from the simulated gastrointestinal environment.

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The native Chilean red strawberry (Fragaria chiloensis spp. chiloensis f. patagonica) is a wild strawberry with high polyphenol content and antioxidant activity originating in central-southern Chile. The aim of the present work was to compare the composition and bioactivity of polyphenol-concentrated extracts (PCE) of the fruit, before and after simulated gastrointestinal digestion (GID). Twenty nine compounds were tentatively identified in the non-digested PCE. After GID, 26 and 23 compounds were detected, in the gastric and intestinal steps, respectively. The compounds that were more affected by the simulated GID were cyanidin hexoside, bis hexahydroxydiphenic acid (HHDP) hexosides, bis HHDP galloyl hexosides, apigenin hexoside, and quercetin dihexoside. Results show a decrease in the total phenolic content by 3.4% and 43% at the end of the gastric and intestinal steps, respectively. In the same way, the total flavonoid content decreased by 60.4% and 90.9% at the end of the gastric and intestinal step, respectively. Overall, the antioxidant activity decreased during the gastrointestinal process; as well as the inhibitory activity against α-glucosidase and lipase was reduced by the simulated digestion. These results are a first approach to understand the effects induced by the gastrointestinal digestion on the bioactivity and polyphenolic profile of this native fruit.

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This study evaluated the antimicrobial effect of essential oils (EO) and organic acids (OA) against Salmonella Enteritidis in chicken feed and during an in vitro model that mimics the chicken digestive process. The minimal inhibitory concentration (MIC) of allyl isothiocyanate (AITC), carvacrol (CV), propionic acid (PROP) and caproic acid (CAP) were individually determined. Then, based on the MICs of each compound, combinations of EOs and/or OAs were tested to evaluate their synergic antimicrobial effect. The synergic effect of AITC and CAP was the most efficient against the bacterial strain tested. Commercial feed was inoculated with a 5-strain cocktail of S. Enteritidis and treated with different doses of AITC + CAP to evaluate their effect on the growth/survival of the pathogen. In addition, the simulated digestion model was used to access the antimicrobial effect of AITC + CAP added to the feed towards S. Enteritidis and Lactobacillus plantarum. Synergistic effect was found between AITC (0.065 mM) and CAP (17.5 mM) against S. Enteritidis in chicken feed, where S. Enteritidis was reduced to undetectable levels (<1.00 log CFU/g). AITC (1.95 mM) + CAP (45 mM) also decreased (p < 0.05) the population of S. Enteritidis in the simulated digestion, while the growth of L. plantarum was not affected. Therefore, the addition of AITC + CAP in feed might be a potential natural antimicrobial able to prevent economic losses caused for Salmonella in chicken.

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The microstructure of cooked gluten-free pasta depends on the ingredients used, and this microstructure affects the starch hydrolysis (SH), the release of phenolic compounds (PC) and their antioxidant capacity (AC). The aim of this study was to evaluate the SD and bioaccessibility of PC during in vitro gastrointestinal digestion of gluten-free pasta and its relationship with the microstructure. The highest SH was during the intestinal phase (≈60%), but pasta with the highest content of unripe plantain and chickpea presented the lowest release of PC (≈60%). The insoluble dietary fibre could be responsible (≈12.5%) for these effects. The cooked pasta showed high AC in the intestinal phase. Regions with gelatinized starch granules in a less dense protein network and other regions with intact or swollen granules surrounded by a protein network were observed. The starch digestion and bioaccessibility of PC were related to the structure of the matrix.

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The evaluation of selenium-enriched vegetables as potential dietary sources of selenium, an essential element for humans, requires an assessment of the plant's accumulation ability as well as of the bioaccessibility and speciation of the accumulated selenium, which influence its biological effects in humans. Lettuce hydroponically grown at three selenite (SeVI)/selenate (SeIV) amendment levels was characterized accordingly. Selenium accumulation in lettuce leaves was greatest with Se(VI) amendment, whereas bioaccessibility was 70% on average in both cases. Selenium speciation in gastrointestinal hydrolysates, characterized by anion and cation exchange HPLC-ICP-MS, showed that Se(IV) was largely biotransformed into organoselenium metabolites, with selenomethionine accounting for 1/3 of the total detected species, whereas Se(VI) was incorporated as such in the edible portion of the plant, with only a small fraction (∼20%) converted into organic species. Taking into account both nutritional quality and safety, the Se(IV)-enriched lettuce appeared more favorable as a potential selenium source for human consumption.