Synergistic effects of superfine grinding and high hydrostatic pressure on the contents, distribution, digestive behaviors and antioxidant activities of polyphenols in barley leaves

Barley leaves (BLs) naturally contained abundant phenolics, most of which are hardly completely released from food matrix during gastrointestinal digestion. Superfine grinding (SFG) and high hydrostatic pressure (HHP) are generally used to treat the functional plants due to their effectiveness to cell wall-breaking and improvement of nutraceutical bioavailability. Thus, this study investigated the synergistic effects of SFG and HHP (100, 300, 500 MPa/20 min) on the bioaccessbility of typical phenolics in BLs during the simulated in-vitro digestion. The results demonstrated that the highest bioaccessbility (40.98%) was found in the ultrafine sample with HHP at 500 MPa. CLSM and SEM confirmed SFG led to microstructurally rapture of BLs. Moreover, the recovery index of ABTS radical scavenging activity and FRAP of HHP-treated ultrafine and fine BLs samples maximumly increased by 53.62% and 9.61%, respectively. This study is expecting to provide the theoretical basis to improve the consumer acceptance of BLs.

Understanding the physical breakdown and catechin bioaccessibility of third generation extruded snacks enriched with catechin using the human gastric simulator

The nutritional quality of third-generation snacks prepared from rice flour by extrusion can be improved by the addition of polyphenols such as catechins, which are known to be more stable at high temperatures. However, the extrusion parameters can impact the breakdown and release of bioactive compounds and decrease the catechin bioaccessibility. Accordingly, this study investigated the impact of different extrusion parameters, including different extrusion temperatures (110, 135, and 150 °C) and moisture content prior to extrusion (27 and 31%), on the breakdown and bioaccessibility of catechin-enriched snacks during in vitro dynamic digestion using the Human Gastric Simulator (HGS). The extrusion parameters did not significantly impact most measured variables by themselves, indicating that within the tested ranges, any of the processing conditions could be used to produce a product with similar digestive behavior. However, the interaction of extrusion parameters (temperature and moisture content) played a significant role in the snack behavior during digestion. For example, the combination of 27% moisture content and 150 °C extrusion temperature had higher catechin bioaccessibility and higher starch hydrolysis than the other treatments. Overall, these findings suggest that the processing conditions of third generation snacks enriched with catechin can be optimized within certain ranges with limited modifications in the digestive properties.

Stability of vitamin C, carotenoids, phenols, and antioxidant capacity of pasteurised orange juice with resistant maltodextrin storage

Resistant maltodextrin (RMD) was added at increasing concentrations (0%, 2.5%, 5% and 7.5%) before pasteurisation to orange juice to analyse its potential protective effect on the health-related bioactive compounds of pasteurised orange juice throughout its storage time. Samples were characterised in terms of basic physico-chemical properties and bioactive compounds at the beginning of the storage. Higher concentrations of RMD proved to better preserve the bioactive compounds of orange juice, thus obtaining a higher antioxidant capacity (AC). Stability of all samples was determined by measuring the same parameters at days 0, 15, 45, 75, 105, 136 and 170 of storage. °Brix and pH were very stable in all samples along storage, while all bioactive compouds had negative variations. However, RMD addition slightly improved ascorbic acid, vitamin C, total phenols, and total carotenoids retention, improving then its AC. This effect was greater in the 5% RMD-added samples. All bioactive compounds showed a positive Pearson's correlation coefficient with AC. Colour variations were also measured at days 105 and 170. All samples had a positive variation of all colour parameters, being this clearer at day 170. This work enlights the potential functionality of RMD to better preserve the health-related compounds of pasteurised orange juice.

Polyphenols—Ensured Accessibility from Food to the Human Metabolism by Chemical and Biotechnological Treatments

Polyphenols are plant-based compounds famous for their positive impact on both human health and the quality of food products. The benefits of polyphenols are related to reducing cardiovascular diseases, cholesterol management, cancers, and neurological disorders in humans and increasing the shelf life, management of oxidation, and anti-microbial activity in food products. The bioavailability and bio-accessibility of polyphenols are of the highest importance to secure their impact on human and food health. This paper summarizes the current state-of-the-art approaches on how polyphenols can be made more accessible in food products to contribute to human health. For example, by using food processing methods including various technologies, such as chemical and biotechnological treatments. Food matrix design and simulation procedures, in combination with encapsulation of fractionated polyphenols utilizing enzymatic and fermentation methodology, may be the future technologies to tailor specific food products with the ability to ensure polyphenol release and availability in the most suitable parts of the human body (bowl, intestine, etc.). The development of such new procedures for utilizing polyphenols, combining novel methodologies with traditional food processing technologies, has the potential to contribute enormous benefits to the food industry and health sector, not only reducing food waste and food-borne illnesses but also to sustain human health.

A review of in vitro methods to evaluate the bioaccessibility of phenolic compounds in tropical fruits

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.

Fate of Phytometabolites of Antibiotics during In Vitro Digestion and Implications for Human Health

Antibiotics are released into the environment as their global consumption increases. Uptake, accumulation, and metabolism of antibiotics by food crops is an emerging health concern as the associated risks of consuming food crops containing antibiotics are still largely unknown. This study investigated the fate of sulfamethazine, sulfamethoxazole, and their phytometabolites during in vitro digestion of the model plantArabidopsis thaliana. The amounts of parent antibiotics released during in vitro digestion were 4-5 times higher than those quantified in plant tissues prior to digestion, which was attributed to back transformation of the phytometabolites into the parent aglycones. These findings demonstrated that overlooking the proportions of phytometabolites in recent health risk assessment studies would considerably underestimate the realistic human exposure through consumption of contaminated food crops. New risk assessment frameworks are necessary to include these critical factors for comprehensively addressing human exposure to emerging contaminants through food chains.

Effect of Adding Resistant Maltodextrin to Pasteurized Orange Juice on Bioactive Compounds and Their Bioaccessibility

Resistant maltodextrin (RMD) is a water-soluble and fermentable functional fiber. RMD is a satiating prebiotic, reducer of glucose and triglycerides in the blood, and promoter of good gut health, and its addition to food is increasingly frequent. Therefore, it is necessary to study its potential effects on intrinsic bioactive compounds of food and their bioaccessibility. The aim of this study was to evaluate the effect of adding RMD on the bioactive compounds of pasteurized orange juice with and without pulp, and the bioaccessibility of such compounds. RMD was added at different concentrations: 0 (control sample), 2.5%, 5%, and 7.5%. Ascorbic acid (AA) and vitamin C were analyzed using HPLC, whereas total phenols, total carotenoids (TC), and antioxidant capacity were measured using spectrophotometry. After that, sample in vitro digestibility was assessed using the standardized static in vitro digestion method. The control orange juice with pulp presented significantly higher values of bioactive compounds and antioxidant capacity than the control orange juice without pulp (p < 0.05). RMD addition before the juice pasteurization process significantly protected all bioactive compounds, namely total phenols, TC, AA, and vitamin C, as well as the antioxidant capacity (AC) (p < 0.05). Moreover, this bioactive compound protective effect was higher when higher RMD concentrations were added. However, RMD addition improved phenols and vitamin C bioaccessibility but decreased TC and AA bioaccessibility. Therefore, the AC value of samples after gastrointestinal digestion was slightly decreased by RMD addition. Moreover, orange pulp presence decreased total phenols and TC bioaccessibility but increased AA and vitamin C bioaccessibility.

Interactions between whey proteins and cranberry juice after thermal or non-thermal processing during in vitro gastrointestinal digestion

This study entails the possible interactions between whey protein and cranberry juice after processing, impacting either the protein digestibility or the bioaccessibility of cranberry antioxidants using an in vitro gastrointestinal digestion model.

Assessing the Fate and Bioavailability of Glucosinolates in Kale (Brassica oleracea) Using Simulated Human Digestion and Caco-2 Cell Uptake Models

Glucosinolates and their hydrolysis products were characterized in fresh and in in vitro gastric and intestinal digesta of Dinosaur kale (Brassica oleracea L var. palmifolia DC). In fresh kale, glucoraphanin, sinigrin, gluconapin, gluconasturtiin, glucoerucin, glucobrasscin, and 4-methoxylglucobrassicin were identified. After 120 min of gastric digestion, the levels of glucoraphanin, sinigrin, and gluconapin decreased, and no glucoerucin or glucobrasscin was detected. However, a concomitant increase in the glucosinolate hydrolysis products allyl nitrile, 3-butenyl isothiocyanate, phenylacetonitrile, and sulforaphane was observed. This trend continued through intestinal digestion. After 120 min, the levels of allyl nitrile, 3-butenyl isothiocyanate, phenylacetonitrile, and sulforaphane were 88.19 ± 5.85, 222.15 ± 30.26, 129.17 ± 17.57, and 13.71 ± 0.62 pmol/g fresh weight, respectively. Intestinal digesta were then applied to Caco-2 cell monolayers to assess the bioavailability. After 6 h of incubation, no glucosinolates were detected and the percentage of total cellular uptake of the glucosinolate hydrolysis products ranged from 29.35% (sulforaphane) to 46.60% (allyl nitrile).

Fruit-based juices: Focus on antioxidant properties-Study approach and update

This paper proposes a perspective literature review of the antioxidant properties in fruit-based juices. The total antioxidant properties due to compounds such as carotenoids, polyphenolic compounds, flavonoids, and tannins as well as the assessment of interactions between natural active compounds and other food matrix components can be seen as the first step in the study of potential health benefits of fruit-based juices. A brief summary is given on the significance of antioxidant properties of fruit juices, the conventional methods for antioxidant activity evaluation, and on the newly emerged sample analysis and data interpretation strategies, that is, chemometric analysis based on spectroscopic data. The effect of fruit processing techniques and the addition of ingredients on the antioxidant properties of fruit-based juices are also discussed.