Antioxidant Bioaccessibility Research Articles

Effect of high-pressure carbon dioxide combined with modified atmosphere packaging on the quality of fresh-cut squash during storage.

The study evaluated the application of a novel high-pressure microbial inactivation method combining dense carbon dioxide with modified atmosphere packaging on organic fresh-cut squash (Cucurbita moschata). Approximately 4g or 32g of squash was packed in plastic pouches filled with CO2 to test two different gas-to-product ratios and treated with the high-pressure method at previously optimized process conditions (45°C, 6.0MPa and 40min). The products were then stored for 21days at 4°C and assessed for enzymatic activity, product quality, sugar content, bioaccessibility (polyphenols, DPPH antioxidant activity, and carotenoids), and sensory acceptance, with products packed in air and CO2 serving as controls. The high-pressure treatment effectively inactivated inoculated E. coli to undetectable levels (inactivation >3.63±0.53 Log CFU/g) and reduced the activity of the browning-responsible enzymes up to 50%. During the shelf life, treated samples exhibited significantly higher scavenging activity for DPPH, ABTS, OH, O2-, and NO compared to non-treated samples, with minor exceptions at a high gas-to-product ratio. Additionally, treated samples showed increased levels of glucose and fructose and a comparable or higher bioaccessibility of antioxidants with respect to the products packed in air or in CO2. Sensory evaluation indicated that the treatment enhanced color and smell appreciation among panelists, demonstrating the potential of this method to improve both safety and quality of fresh-cut squash.

Variation in Phenol and Antioxidant Bioaccessibility of Olive Oil According to Olive Maturity and Region

Variation in Phenol and Antioxidant Bioaccessibility of Olive Oil According to Olive Maturity and Region

Spent coffee grounds as an alternative fertilizer: impact on bioaccessibility of antioxidants and commercial quality of lettuce.

During the processing of spent coffee grounds (SCGs) several residues are obtained, which are mostly disposed of in landfills. There is an urgent need for a comprehensive waste management strategy for these residues. This study evaluates the potential of SCGs as a biofertilizer by assessing their effects on lettuce leaves and the release of antioxidants following in vitro digestion and fermentation. Lettuce plants were grown with different amounts of SCGs (0-150 g kg-1) in the substrate. High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color, less root development, and lower dry weight of leaves (P < 0.05). The SCG levels also affected the release of antioxidants by the final product. This effect was more pronounced in the digested fraction: applying the Ferric Reducing Antioxidant Power (FRAP) method, the addition of SCGs from 10 g kg-1 to 125 g kg-1 increased the amount of antioxidant from 43.88 ± 4.81 to 105.96 ± 29.09 μmol Trolox g-1 of dry weight (P < 0.05). The Indigo Carmine Reducing Capacity (ICRED) method also showed a similar trend, but in this case the highest value was obtained with 150 g kg-1 of SCGs (16.41 ± 3.93 mmol catechin g-1 of dry weight) (P < 0.05). Moreover, in the fermented fraction a significant increase in the antioxidant released was found with low levels of SCG(P<0.05), while lettuces fertilized with intermediate amounts of SCGs (25 and 50 g kg-1) presented the highest amount of insoluble antioxidant (P < 0.05). A compromise should be found in order to achieve a product with a high antioxidant capacity and an acceptable visual quality. © 2024 Society of Chemical Industry.

Physicochemical Characterization of Yogurt Fortified with Microencapsulated Cinnamon (Cinnamomum zeylanicum) and Its Effects on Metabolic Syndrome Induced in Rabbits (Oryctolagus cuniculus).

Chronic noncommunicable diseases are a global health problem causing increased rates of mortality and sick leaves, which can be reduced by controlling dyslipidemia and hyperglycemia. Experimental and clinical studies have demonstrated the antidiabetic, lipid-lowering, antiobesogenic, anti-inflammatory, and antihypertensive properties of cinnamon; therefore, its use in yogurt can help reverse the effects of these diseases. Our study aims to evaluate the effect of a microencapsulated aqueous extract of cinnamon (Cinnamomum zeylanicum) (MCE Cz) incorporated in a yogurt drink on metabolic syndrome (MS) in a rabbit (Oryctolagus cuniculus). Physicochemical, microbiological, and proximal chemical characterization; total phenol, flavonoid, and 2,2-diphenyl-1-picrylhydrazil activity quantification; intestinal bioaccessibility; sensory analysis; MS induction through diet; and treatment with 5, 10, and 20 mg/kg of flavonoids contained in the MCE Cz were performed to help evaluate morphological, biochemical, and lipid peroxidation measurements in the liver and heart. The results show that the addition of MCE Cz in the yogurt modified the yogurt texture, increased its adhesiveness and firmness, and imparted a characteristic cinnamon color and biological value by providing intestinally bioaccessible antioxidants with antioxidant potential by reducing lipoperoxidation in the liver and heart after treatment. MCE Cz reduced the weight of the animals by up to 38.5% and the abdominal circumference by 29%. Biochemically, it decreased glucose levels by 24.38%, total cholesterol levels by 69.2%, triglyceride levels by 72.69%, and low-density lipoprotein levels by 89.25%; it increased high-density lipoprotein levels by 67.08%. Therefore, adding MCE Cz in doses of 5 and 10 mg of flavonoids in drinkable yogurt can be an alternative to preparing functional foods with physicochemical attributes and biological properties that can be consumed at all stages of life without undesirable effects. Moreover, it can act as a potential adjuvant in the treatment of comorbidities related to MS.

Elderberry pomace for food/nutraceutical product development: impact of drying methods and simulated in vitro gastrointestinal digestion on phenolic profile and bioaccessibility

SummaryThe aim of this work was to develop ingredients from elderberry pomace (EP) analysing the effect of different drying methods (conventional air‐drying (C), freeze‐drying (F), and fluidised‐bed drying (FB)) on phenolic compounds retention and their bioaccessibility. The dry pomaces were chemically characterised before and after an in vitro gastrointestinal digestion (GID). Cianidin‐3‐glucoside and rutin were the main phenolic compounds determined by HPLC‐DAD. After GID, phenolic content and antioxidant capacity were drastically reduced regardless of the drying process. Freeze‐drying better preserved the total polyphenol and monomeric anthocyanin content, and the antioxidant capacity, however, EP‐C and EP‐FB presented more bioaccessible antioxidant compounds than EP‐F. Fluidised‐bed drying generated, in a shorter drying time, a more bioaccessible granular product (EP‐FB), that could be used directly in ready‐to‐eat foods. EP‐C and EP‐F products could be used as functional foods or nutraceutical ingredients. Also, the obtained elderberry products were not cytotoxic against the Caco‐2 cell line.

Blackcurrant (Fruits, Pomace, and Leaves) Phenolic Characterization before and after In Vitro Digestion, Free Radical Scavenger Capacity, and Antioxidant Effects on Iron-Mediated Lipid Peroxidation.

Blackcurrant (Ribes nigrum L.) is a berry bush widely cultivated in Europe for producing juices, jams, jellies, and syrups. In addition to berries, blackcurrant leaves and pomace, as byproducts, have also been shown to have health-promoting effects. Static digestion, simulating oral, gastric, and small intestinal digestion, was applied, and blackcurrant leaves, fruits, and pomace and the polyphenol bioaccessibility were evaluated in terms of recovery index. The results were related to sample type, and the recovery index presented higher values in the case of fruits, indicating this morphological part of blackcurrant as the most bioaccessible. The antioxidant potential of blackcurrant was evaluated using four different methods, with the leaves proving to be a significant and powerful antioxidant compared to fruits and pomace. The counteracting potential of inhibiting the oxidation process was evaluated using in vitro-induced lipid peroxidation and the inhibition potential of superoxide and hydroxyl anions. The antioxidant evaluation and the inhibition of biological and non-biological radicals indicate the leaf extract is the most powerful antioxidant studied. Also, the results proved that not only fruits but also the blackcurrant byproducts (pomace and leaves) are promising sources of bioaccessible antioxidants with potential benefits in animal nutrition.

Bioaccessibility and Antioxidant Capacity of Grape Seed and Grape Skin Phenolic Compounds After Simulated In Vitro Gastrointestinal Digestion

Grapes present recognized beneficial effects on human health due to their polyphenolic composition. The grape overproduction together with the wine sales down and the world socioeconomic situation makes the wine grape valorization a promising strategy to give an added-value to this natural product. The objective of the present work was to study the influence of in vitro gastrointestinal digestion on antioxidant capacity and polyphenolic profile of skin and seed extracts of different grape varieties (Tempranillo, Graciano, Maturana tinta and Hondarrabi zuri). After in vitro gastrointestinal digestion, total phenolic content (TPC) of seed polyphenolic extracts decreased significantly for all the varieties. The highest decrease was for Tempranillo going from 108 ± 9 to 50 ± 3 mg / g dry matter (dm). This variety also showed the highest decrease of 90% in antioxidant capacity. However, for all the skin polyphenolic extracts there was an increase in TPC. The highest variation was also for Tempranillo. It varied from 10.1 ± 0.8 to 55.1 ± 0.9 mg / g dm. Among red varieties Tempranillo skin polyphenolic extract showed the lowest undigested anthocyanin content but the highest bioaccessibility index (BI) of 77%. For flavanols, flavonols and procyanidins the seed polyphenolic extracts showed a BI at the intestinal phase between 11% for (+)-epicatechin gallate to 130% procyanidin A2. The results of this study suggest that grape skin extracts and grape seed extracts are a reliable source of bioaccessible antioxidant polyphenols, to be used for the development of antioxidant supplements with specific functionalities depending on the grape variety.

Quality of High-Fibre Pasta Supplemented with Watermelon Rind Powder with Different Particle Sizes.

Watermelon rind, a by-product of watermelon juice processing, contains large amounts of dietary fibre and phenols with antioxidant capacity. The use of agro-industrial by-products would both improve economic benefits and reduce environmental emissions. The aim of this research is to examine the effect of the particle size of watermelon rind powder on the quality of high-fibre pasta. The nutritional, physical and physicochemical quality of three samples of watermelon rind powder, sieved through three sieves with aperture size of 400, 210 and 149 μm, were analysed. Durum wheat semolina with watermelon rind powder mass fraction of 10 % were mixed and used to make pasta. Nutritional, textural and cooking quality, sensory acceptability, in vitro glycaemic index and antioxidant bioaccessibility of high-fibre pasta with added watermelon rind powder of different particle sizes were evaluated and compared. When the sieve aperture size was reduced from 400 to 149 µm, the soluble dietary fibre and total phenolic contents of watermelon rind powder were increased by 35 and 15 %, respectively, while its insoluble dietary fibre content was decreased by 21 %. Decrease in sieve aperture size from 410 to 149 µm reduced phenolic bioaccessibility of the fortified pasta from 63 to 57 %, but enhanced its predicted glycaemic index from 50 to 69. It also decreased the pasta hardness by 13 %, but improved its elongation rate and tensile strength by 13 and 40 %, respectively. The finer the particles of the watermelon rind powder, the longer the optimal cooking time, the higher the water absorption index, and the lower the cooking loss of the supplemented pasta. Consumers did not notice any significant differences in the overall acceptability among all pasta samples. The particle size of the watermelon rind powder had a major effect on nutritional value, texture and cooking quality of the fortified pasta. In particular, the predicted glycaemic index and antioxidant bioaccessibility of high-fibre pasta were significantly affected by the particle size of the dietary fibre material used in the recipe.

Bioactivity and influence on colonic microbiota of polyphenols from noni (Morinda citrifolia L.) fruit under simulated gastrointestinal digestion

Noni (Morinda citrifolia L.) is a tropical fruit rich in bioactive compounds. Little is known about its polyphenol composition at different ripeness levels and digestive characteristics. Here, we studied changes in polyphenols and antioxidant activity as noni ripened. Rutin and kaempferol-3-O-rutinoside were found in high amounts in noni, with antioxidant capacity increasing as it ripened. Under simulated digestion, polyphenols were gradually released from the oral to gastrointestinal phases, partially decomposing in the small intestine due to their instability. Conversely, fiber-bound phenols were released during colonic fermentation, leading to high bioaccessible antioxidant activity. Additionally, noni consumption affected the intestinal microbiome by reducing the Firmicutes/Bacteroidetes ratio and increasing bacteria with prebiotic properties like Prevotella and Ruminococcus. These findings demonstrate that polyphenols significantly contribute to the health benefits of noni fruit by providing absorbable antioxidants and improving the structure of the intestinal microbiome.

Optimization of Thermoultrasound Process of Soursop (Annona muricata) Nectar and Comparison of Its Physicochemical Properties and In Vitro Bioaccessibility of Antioxidants with Pasteurized Sample.

Soursop nectar contains antioxidants and is preserved by pasteurization. However, this technology impairs its physicochemical properties and bioactive compounds. An alternative is therefore thermoultrasound, which could counteract these effects. The thermosonicated nectar was compared with a pasteurized one and the in vitro bioaccessibility of antioxidants was estimated. The soursop nectar (25 %) was processed and the response surface methodology was used to determine the optimal conditions for thermoultrasound treatment (TUS). The TUS (75-90 % amplitude, 3.15-15 min) was applied, and 2 % stevia and 6 % agave inulin were added as sweeteners. The microbiological, physicochemical, enzymatic and antioxidant properties were analyzed. The properties of thermosonicated nectar obtained under optimal conditions were compared with pasteurized nectar. In addition to the above determinations, microstructure, total dietary fiber (TDF) and in vitro bioaccessibility of antioxidants were determined. The response variables that fit the mathematical model were L*, b*, chroma (C*), total phenolic content (TPC) and antioxidant activity determined by ABTS•+, DPPH˙ and Fe(III) reducing antioxidant power (FRAP). The L* and DPPH˙ were affected by quadratic time and TPC by time (p<0.0001). The optimum TUS condition was 82 % amplitude for 9.15 min and the responses variables were L*, b* and C* (45.48, 3.55 and 3.62, respectively), TPC expressed as gallic acid equivalents (38.40 mg/100 mL), ABTS•+ expressed as Trolox equivalents (TE) (31.28 μmol/100 mL), DPPH˙ expressed as TE (124.22 μmol/100 mL) and FRAP expressed as Fe(II) (3.06 μmol/100 mL). Compared to the pasteurized sample, thermosonicated sample had high values of L* (45.56), h° (-56.49), TPC (26.63 mg/100 mL), ABTS•+ and DPPH˙ (22.03 and 129.22 μmol/100 mL, respectively), FRAP (3.10 μmol/100 mL) and low pectin methylesterase (PME) activity (0.28 U/mL). For in vitro bioaccessibility, thermosonicated nectar showed high absorption of TPC (15.26/100 mL) and high antioxidant activity determined by ABTS (34.92 μmol/100 mL) and FRAP (7.88 μmol/100 mL). The thermoultrasound improves the physicochemical properties and in vitro bioaccessibility of antioxidants in soursop nectar. On the other hand, as an alternative, this beverage offers low-calorie alternative with prebiotic properties that benefits consumer health.

Effect of freezing, osmodehydro-freezing, freezedrying and osmodehydro-freezedrying on the physicochemical and nutritional properties of arazá (Eugenia stipitata McVaugh)

Effect of freezing, osmodehydro-freezing, freezedrying and osmodehydro-freezedrying on the physicochemical and nutritional properties of arazá (Eugenia stipitata McVaugh)

Use of excipient emulsions for improving the bioaccessibility of antioxidants in tomato sauce.

In this study, tomato sauces were prepared by adding different levels of emulsified oil (0, 5, 10, or 20wt%) to tomato pomace. The effects of adding these excipient emulsions on the concentration, bioaccessibility, and bioactivity of the carotenoids and phenolics in the tomato sauces were then determined. The carotenoid and phenolic profiles were analyzed by HPLC and LC-MS/MS, respectively. The bioaccessibility values of the lycopene, lutein, and β-carotene were around 36-82%, 73-112%, and 67-94% for tomato sauces with excipient emulsions, respectively. In contrast, they were considerably lower for tomato sauces without excipient emulsions, being around 24-31%, 69-71%, and 45-62%, respectively. The TPC and TAC values of the tomato sauces with the excipient emulsions were significantly higher than those without. Considerably higher concentrations of carotenoids and phenolic compounds were detected in the tomato sauce samples containing the excipient emulsions. These results suggest that the presence of the oil droplets increased the extractability, stability, and bioaccessibility of the nutraceuticals in the tomato sauce.

Assessment of in vitro digestion of reduced sugar biscuits with extruded brewers’ spent grain

This study aimed to evaluate the nutritional value and potential health claims for reduced sugar biscuits containing extruded brewers' spent grain (EBSG) and fructooligosaccharides (FOS). One traditional biscuit with added sugar and three reduced sugar biscuits containing 15.2% FOS and EBSG (0, 8 and 17%), with nutrition claims "high in fiber" and "source of protein" for those containing 17% of EBSG, were formulated. Biscuits were characterized by analysis of nutrients and bioactive compounds before and after digestion under in vitro enzymatic oral-gastro-intestinal and colonic fermenting conditions. The bioaccessibility of antioxidants, anti-inflammatory and antidiabetic compounds in biscuits' intestinal digests and short-chain fatty acids in colonic samples was analyzed. EBSG-added biscuits showed significantly lower (p<0.05) glucose intestinal bioaccessibility and significantly higher (p<0.05) phenolic compounds intestinal bioaccessibility compared to biscuits without EBSG. EBSG-added biscuits showed significantly (p<0.05) higher in vitro antidiabetic potential than the other did. Moreover, the intestinal digest of biscuits containing 17% EBSG exhibited significantly (p<0.05) better in vitro inhibition of intracellular ROS formation and in vitro anti-inflammatory properties. FOS addition (p<0.05) significantly improved the production of butyric acid while EBSG did for valeric acid which possess chemoprotective effect. In conclusion, the combined use of FOS (15.2%) and EBSG (17%) allowed obtaining a human healthier snack formulation for satisfying consumers' demands and achieving nutrition security.

Bioaccessibility of Antioxidant Capacity of Wedang Uwuh a Traditional Indonesian Beverage by Gastrointestinal Digestion

Wedang uwuh is a traditional Indonesian beverage that contains natural antioxidants. Hence, it is generally consumed by people to get health benefits. The antioxidant compounds can exert their activity only after passing through the digestive system. This study aims to determine the impact of boiling time on the antioxidant bioaccessibility of wedang uwuh beverages after passing through digestive process, which are gastric and intestinal stages. The antioxidant bioaccessibility was evaluated using the bioaccessibility index (BI) of antioxidant capacity (FRAP, DPPH, and ABTS assay) and the bioaccessibility of phenolic content was also measured using total phenolic content (folin–ciocalteu method). The research found that lengthening of boiling time could increase significantly (p&lt;0.05) number of phenolic content, as well as antioxidant capacity. The 15 minutes of boiling resulted in the highest phenolic content and antioxidant capacity before digestion. Otherwise, after wedang uwuh beverage passes through gastric and intestinal digestion, boiling for 5 minutes resulted in the highest phenolic content and capacity of antioxidants. This was due to heat processing influencing the stability of phenolic and antioxidant compounds before and after digestion. The bioaccessibility of antioxidant and phenolic compounds in wedang uwuh beverage was higher in the 5 minutes boiling process than in the 15 minutes. The boiling process for 5 minutes resulted in the bioaccessibility index of wedang uwuh beverage were 32.25% for total phenolic content, 37.25% for FRAP, 25.88% for scavenging of radical DPPH• and 83.45% for scavenging of radical ionic ABTS•+. Hence, it was recommended to use a boiling time of 5 minutes to prepare a wedang uwuh beverage. This study found that pH conditions and enzymatic activity in gastrointestinal digestion decreased phenolic and antioxidant contents.

Changes in the Bioaccessibility of Antioxidants after Simulated In Vitro Digestion of Bioprocessed Spelt-Enhanced Wheat Bread.

The aim of the study was to determine whether the partial replacement of wheat flour with bioprocessed spelt flour contributes to a higher bioaccessibility of the antioxidants in bread. The results showed that the type and amount of bioprocessed spelt flour in a bread recipe has a major impact on the extractable and bound TPC, the content of individual phenolics, their antioxidant activity, and their bioaccessibility as determined by in vitro digestion. Extractable p-coumaric and trans-ferulic acids in breads decreased after digestion, while extractable cis-ferulic and p-hydroxybenzoic acids increased. The bioaccessibility of TPC in the control bread (100% wheat flour), and in bread enriched with 5% "germinated + fermented" spelt flour (GFB5), did not differ. However, the digested GFB5 bread contained 5.2-times more extractable, and 1.3-times more bound, trans-ferulic acid than the digested control bread. trans-Ferulic acid showed the lowest bioaccessibility, up to 2.8%. In GFB2.5 and GFB5 breads, the bioaccessibility of p-coumaric, trans-ferulic, and cis-ferulic acids was higher than in other digested breads. PCA visualized the difference between the undigested and digested breads. The incorporation of germinated and fermented, or germinated and enzymatic, treated spelt flour in a white bread recipe could be an attractive way of providing consumers with nutritionally interesting foods.

Kidney bean (Phaseolus vulgaris L.) milk substitute as a novel plant-based drink: Fatty acid profile, antioxidant activity, in-vitro phenolic bio-accessibility and sensory characteristics

Kidney bean (Phaseolus vulgaris L.) milk substitute as a novel plant-based drink: Fatty acid profile, antioxidant activity, in-vitro phenolic bio-accessibility and sensory characteristics

Gluten-free wafer formulation: Development, characterisation and addition of flavourings with antioxidant capacity.

The incidence of celiac disease is increasing, therefore the demand for gluten-free products that also satisfy the nutritional requirements of celiac individuals is rising. Thus, the objective of the present work was to develop a gluten-free nutritionally balanced wafer formulation with a high content of antioxidants. First, the animal fat used in the traditional formulation was successfully replaced by high oleic sunflower. Second, the antioxidant content of several flavourings (cinnamon/honey/anise/vanilla) was measured and their addition to a gluten-free wafer formulation was evaluated. Third, multivariate statistical tools were used to select the formulation that properly mimicked the characteristics of a gluten-containing wafer. According to the results, anise and cinnamon were the most suitable flavourings to prepare gluten-free wafers, and the sensory analysis concluded that these formulations were highly acceptable (means>6.7 on the hedonic scale). Finally, the storage time analysis indicated that the texture of the gluten-free wafers was more susceptible to water absorption than gluten-containing wafers. Besides, cinnamon wafers presented a higher bioaccessible antioxidant capacity than anise wafers (43.5 ± 0.1 mg Trolox/g and 18.8 ± 0.9 mg Trolox/g respectively) (p < 0.05), which remained stable for four months. This indicates that during its shelf life, the product could be consumed with its beneficial effects intact.

Phytochemical screening and antioxidants in vitro bioaccessibility of Coccinia grandis: an underutilized wild edible plant in Sri Lanka

Coccinia grandis (L.) J. Voigt is an underutilized wild edible plant in Sri Lanka that consists of a number of medicinal and nutritional values. Underutilized wild edibles have multiple positive health effects for humans, attributed to their bioactive compounds including minerals, antioxidants and phytochemicals. Even though these plant extracts are enriched with a number of bioactive compounds, the bioaccessibility as well as, the bioavailability of those compounds significantly depend on the structure and the form in which they are introduced into the human body. Therefore, crude extract of C. grandis was subjected to evaluate their phytochemicals, antioxidant activity and antioxidant in vitro bioaccessibility fraction of digested samples were calculated. Organic solvents namely, ethanol, hexane and chloroform were used to extract the samples and qualitative in vitro phytochemical screening was conducted to screen for the presence or absence of the phytochemicals. Results indicate that alkaloids, saponins, flavonoids, tannins, phenols, quinone, terpenoids and steroids are the available phytochemicals in every organic extract of C. grandis. Evaluation of antioxidant activity was done by two different assays such as DPPH and ABTS. In the hexane extract it was detected relatively high antioxidant activity as 0.008 mg/mL (IC50) in DPPH assay and 561.94 mg TEAC/ g in ABTS assay. Antioxidant bioaccessibility was also tested through an in vitro digestion model and a 42% bioavailability rate was indicated against the corresponding antioxidant activity in un-digested ethanol extract of C. grandis. Based on the presence of various phytochemicals and is a natural source of antioxidants, this species can be used to improve the human diet, especially for low-income people.

The Protein-Rich Powdered Beverages Stabilized with Flax Seeds Gum—Antioxidant and Antiproliferative Properties of the Potentially Bioaccessible Fraction

The functional beverages market is one of the fastest-growing sectors of functional food production. An innovative recipe for powdered fruit and vegetable drinks fortified with lentil proteins (AGF) and stabilized with flax seed gums (FSG) was developed. The study focused on the analysis of potentially bioaccessible fractions from the produced beverages in terms of their antioxidant, antiproliferative activities and physicochemical properties. The contents of bioactive components were tailored by the incorporation of lyophilized fruits and vegetables, the FSG and the AGF. Digestion in vitro effectively released phenolics from all matrices. The highest contents of potentially bioavailable polyphenols were recorded for the AGF based beverages enriched with 5% of FSG and green-leafy vegetables (58 mg/100 mL) and those with lyophilized fruit (54 mg/100 mL). The reducing power of the beverages was mainly affected by the presence of the AGF, while the FSG and lyophilized fruit improved the chelating power. The digests applied in the concentrations mimicking physiological concentrations showed antiproliferative properties against gastric and colon adenocarcinoma—they seemed to be tailored by bioactive peptides and phenolics, respectively. The addition of the FSG improved the stability of the beverages increasing the time required for a reduction of 20% of the initial optical density by 16- and 28-times in the beverages without additives or enriched with vegetables. Both, the AGF and FSG stabilize the beverages after rehydration and are sources of bioaccessible antioxidant and anticancer components, which create their functionality.

Effect of dietary fiber addition on the content and in vitro bioaccessibility of antioxidants in red raspberry puree

The aim of the present study was to understand how the addition of pectin (2.5% and 5%) affected the content and bioaccessibility of phenolics in red raspberry puree. The results showed that the concentration of antioxidants in red raspberry puree was reduced with the addition of pectin. Similarly, addition of pectin to red raspberry puree significantly reduced the total phenolic content (15-20%), total antioxidant capacity (18-70%), and total monomeric anthocyanin (25-30%) after in vitro digestion. On the other hand, significant decreases in the bioaccessible amount of cyanidin (41%), cyanidin-3-glucoside (14%), cyanidin-3-rutinoside (17%), pelargonidin 3-glucoside (16%), and peonidin (28%) were observed after the addition of pectin (5% (w/w)) compared to the control (p<0.05) as analyzed with the HPLC method. According to the LC-MS/MS analysis of red raspberry samples, five flavonoids (rutin, quercetin, kaempferol, myricetin, and phlorizin) and six phenolic acids (gallic acid, caffeic acid, chlorogenic acid, sinapic acid, p-coumaric acid, and ferulic acid) were detected. The effect of in vitro gastrointestinal digestion varied depending on the type of the phenolic compounds. Sinapic acid and phlorizin were not detected at all in the intestinal phase, indicating that they were completely degraded during digestion. The percentage bioaccessibility of gallic acid (49-88%), rutin (6-16%), and quercetin (23-33%) was decreased proportionally with the increase in the pectin content in red raspberry purees (p<0.05). On the other hand, only 5% pectin addition to red raspberry puree resulted with a significant decrease in the amount of bioaccessible caffeic acid (8% to 5%), kaempferol (24% to 13%), ferulic acid (26% to 10%), and myricetin (91% to 57%) (p<0.05). Overall, the present study highlighted that incorporation of pectin to red raspberry puree reduced the amount of bioaccessible polyphenols.