The type and concentration of milk increase the in vitro bioaccessibility of coffee chlorogenic acids

Macronutrient digestion and polyphenol bioaccessibility in oat milk tea products: an in vitro gastrointestinal tract study

People are increasingly preparing milk tea using plant-based milks rather than cow's milk, e.g., vegans, those with lactose intolerance, and those with flavor preferences. However, adding plant-based milks to tea may impact the digestion, release, and bioaccessibility of nutrients and nutraceuticals in both the tea and milk. In this study, oat milk tea model systems (OMTMSs) containing different fat and tea polyphenol concentrations were used to explore the impact of tea on macronutrient digestion in oat milk, as well as the impact of oat milk matrix on the polyphenol bioaccessibility in the tea. An in vitro gastrointestinal model that mimics the mouth, stomach, and small intestine was used. Tea polyphenols (>0.25%) significantly reduced the glucose and free fatty acids released from oat milk after intestinal digestion. Tea polyphenols (>0.10%) also inhibited protein digestion in oat milk during gastric digestion but not during intestinal digestion. The bioaccessibility of the polyphenols in the tea depended on the fat content of oat milk, being higher for medium-fat (3.0%) and high-fat (5.8%) oat milk than low-fat (1.5%) oat milk. Liquid chromatography-tandem mass spectrometry (UPLC-ESI-MS/MS) analysis showed that lipids improved the tea polyphenol bioaccessibility by influencing the release of flavonoids and phenolic acids from the food matrices. These results provide important information about the impact of tea on the gastrointestinal fate of oat milk, and vice versa, which may be important for enhancing the healthiness of plant-based beverages.

Protein-Chlorogenic Acid Interactions: Mechanisms, Characteristics, and Potential Food Applications

The interactions between proteins and chlorogenic acid (CGA) have gained significant attention in recent years, not only as a promising approach to modify the structural and techno-functional properties of proteins but also to enhance their bioactive potential in food systems. These interactions can be divided into covalent (chemical or irreversible) and non-covalent (physical or reversible) linkages. Mechanistically, CGA forms covalent bonds with nucleophilic amino acid residues of proteins by alkaline, free radical, and enzymatic approaches, leading to changes in protein structure and functionality, such as solubility, emulsification properties, and antioxidant activity. In addition, the protein-CGA complexes can be obtained by hydrogen bonds, hydrophobic and electrostatic interactions, and van der Waals forces, each offering unique advantages and outcomes. This review highlights the mechanism of these interactions and their importance in modifying the structural, functional, nutritional, and physiological attributes of animal- and plant-based proteins. Moreover, the potential applications of these protein-CGA conjugates/complexes are explored in various food systems, such as beverages, films and coatings, emulsion-based delivery systems, and so on. Overall, this literature review provides an in-depth overview of protein-CGA interactions, offering valuable insights for future research to develop novel protein-based food and non-food products with improved nutritional and functional characteristics.

Can Daily Dietary Choices Have a Cardioprotective Effect? Food Compounds in the Prevention and Treatment of Cardiometabolic Diseases

Cardiovascular diseases accompanying metabolic syndrome comprise one of the leading causes of death worldwide. The medical community undertakes attempts to improve treatment options and minimize cardiovascular diseases' numerous consequences and exacerbations. In parallel with pharmacotherapies provided by physicians, nutritionists are developing strategies for diet therapy and prevention based on lifestyle changes, with high success rates. Consumption of specified food compounds included in various products with proven protective properties can be helpful in this regard. Due to the wide possibilities of diet in metabolic health promotion, it seems necessary to systematize information about the metabolically protective and cardioprotective properties of fiber, probiotic bacteria, plant sterols, folic acid, vitamins B12, C, and E, PUFAs, lycopene, polyphenols, arginine, CoQ10, and allicin. The aim of this review was to present the food compounds with potential use in cardiometabolic prevention and diet therapy based on the latest available literature.

Nutritional, biochemical, and clinical applications of carob: A review

Carob is botanically called as Ceratonia siliqua and belongs to the Legumes family. The fruit is derived from hermaphrodite trees and hard in shape. The carob contains high sugar contents in pulp, fat in seed and minerals like potassium, calcium, and phosphorus are present in pods. Polyphenols and antioxidants are abundant in leaves and pods. It can be used for enhancing human health due to its high nutritional profile. Carob gum is used in the pharmaceutical industry in the form of pomades, anti-celiac ingredients, pills, and dental paste. The clinical carob can aid as an anti-cancer, anti-reflux, anti-diabetic, anti-diarrheal, anti-hyperlipidemia, anti-bacterial, anti-microbial, and anti-fungal. Nowadays, carob seeds are being used as an alternative to cocoa powder in food items whereas the leaves, pods, and seeds of carob are also historically used as food for animal feed. However, these parts of carob are available in markets with reasonable prices. Carob production, though with a rising contribution, contributes to the local economy. In this sense, we can incorporate knowledge on the chemical properties and the biological effect of carob fruits on human health. In this study, the supportive and health-promoting impacts of carob are discussed along with the clinical testing obtained from natural constituents of carob. In addition, further studies can be performed to extract and separate polyphenols and antioxidant potential for the development of functional that play a valuable role in pharmaceutical and food sectors.

In Vitro Bioaccessibility and Antioxidant Activity of Phenolic Compounds in Coffee-Fortified Yogurt

Yogurt is considered one of the most popular and healthy dairy products, and has been exploited as a delivery matrix for phenolic compounds. In this study, coffee powder was added to yogurt as a functional ingredient to produce coffee-fortified yogurt. Total phenolic compounds, antioxidant activity and individual hydroxycinnamic acids have been identified and quantified through mass spectrometry. The results from coffee-fortified yogurt were compared with fermented coffee and plain yogurt. Coffee-fortified yogurt had higher total phenolic content and antioxidant activity compared to plain yogurt. However, the total phenolic compounds found in coffee-fortified yogurt represented only 38.9% of the original content in coffee. Caffeoylquinic acids were the most abundant phenolic compounds in coffee. Fermented coffee and coffee-fortified yogurt displayed lower amounts of individual phenolic compounds with respect to coffee (69.8% and 52.4% of recovery, respectively). A protective effect of the yogurt matrix on total and individual coffee phenolic compounds has been observed after in vitro digestion, resulting in a higher bioaccessibility in comparison with digested fermented coffee. Moreover, coffee-fortified yogurt showed the highest antioxidant values after digestion. These findings clearly demonstrate that coffee-fortified yogurt can be considered a significant source of bioaccessible hydroxycinnamic acids, besides its health benefits as a fermented dairy product.

The magical smell and taste: Can coffee be good to patients with cardiometabolic disease?

Coffee is a beverage consumed globally. Although few studies have indicated adverse effects, it is typically a beneficial health-promoting agent in a range of diseases, including depression, diabetes, cardiovascular disease, and obesity. Coffee is rich in caffeine, antioxidants, and phenolic compounds, which can modulate the composition of the gut microbiota and mitigate both inflammation and oxidative stress, common features of the burden of lifestyle diseases. This review will discuss the possible benefits of coffee on complications present in patients with diabetes, cardiovascular disease and chronic kidney disease, outwith the social and emotional benefits attributed to caffeine consumption.

Tamarillo Polyphenols Encapsulated-Cubosome: Formation, Characterization, Stability during Digestion and Application in Yoghurt

Tamarillo extract is a good source of phenolic and anthocyanin compounds which are well-known for beneficial antioxidant activity, but their bioactivity maybe lost during digestion. In this study, promising prospects of tamarillo polyphenols encapsulated in cubosome nanoparticles prepared via a top-down method were explored. The prepared nanocarriers were examined for their morphology, entrapment efficiency, particle size and stability during in vitro digestion as well as potential fortification of yoghurt. Tamarillo polyphenol-loaded cubosomes showed cubic shape with a mean particle size of 322.4 ± 7.27 nm and the entrapment efficiency for most polyphenols was over 50%. The encapsulated polyphenols showed high stability during the gastric phase of in vitro digestion and were almost completely, but slowly released in the intestinal phase. Addition of encapsulated tamarillo polyphenols to yoghurt (5, 10 and 15 wt% through pre- and post-fermentation) improved the physicochemical and potential nutritional properties (polyphenols concentration, TPC) as well as antioxidant activity. The encapsulation of tamarillo polyphenols protected against pH changes and enzymatic digestion and facilitated a targeted delivery and slow release of the encapsulated compounds to the intestine. Overall, the cubosomal delivery system demonstrated the potential for encapsulation of polyphenols from tamarillo for value-added food product development with yoghurt as the vehicle.

Effect of In Vitro Gastrointestinal Digestion on Amino Acids, Polyphenols and Antioxidant Capacity of Tamarillo Yoghurts

Laird’s Large tamarillo powder is high in protein (10%) essential amino acids (EAAs), gamma-aminobutyric acid (GABA) and polyphenols (0.6% phenolics plus anthocyanins) and fibre 25%. This study aimed to investigate, using a standardized static in vitro digestion model, the stability of amino acids and antioxidant capacity of polyphenols in yoghurt fortified with 5, 10 and 15% tamarillo powder either before (PRE) or after (POS) fermentation. Compared to plain yoghurt, the fruit polyphenols (rutinosides and glycosides) were retained and substantial increases in FEAAs (free essential amino acids), total phenolic content (TPC) and antioxidant activity were observed particularly at the end of intestinal phase of digestion. Together with SDS-PAGE results, peptides and proteins in tamarillo yoghurts were more easily digested and therefore may be better absorbed in the small intestine compared to the control. TPC and antioxidant activity of fortified yoghurts increased significantly after in vitro digestion. Relatively high bioaccessibilty of chlorogenic acid and kaempferol-3-rutinoside in digested PRE samples was observed. The results suggest that the yoghurt matrix might protect some compounds from degradation, increasing bioaccessibility and in the small intestine allow increased absorption and utilization possible. Fortification would deliver intact polyphenols and fibre to the large intestine and improve gut health. Further research of acceptability, shelf life, and then trials for health effects should be implemented.

Analysis of the Factors Affecting Static In Vitro Pepsinolysis of Food Proteins

In this meta-analysis, we collected 58 publications spanning the last seven decades that reported static in vitro protein gastric digestion results. A number of descriptors of the pepsinolysis process were extracted, including protein type; pepsin activity and concentration; protein concentration; pH; additives; protein form (e.g., ‘native’, ‘emulsion’, ‘gel’, etc.); molecular weight of the protein; treatment; temperature; and half-times (HT) of protein digestion. After careful analysis and the application of statistical techniques and regression models, several general conclusions could be extracted from the data. The protein form to digest the fastest was ‘emulsion’. The rate of pepsinolysis in the emulsion was largely independent of the protein type, whereas the gastric digestion of the native protein in the solution was strongly dependent on the protein type. The pepsinolysis was shown to be strongly dependent on the structural components of the proteins digested—specifically, β-sheet-inhibited and amino acid, leucine, methionine, and proline-promoted digestion. Interestingly, we found that additives included in the digestion mix to alter protein hydrolysis had, in general, a negligible effect in comparison to the clear importance of the protein form or additional treatment. Overall, the findings allowed for the targeted creation of foods for fast or slow protein digestion, depending on the nutritional needs.

The reciprocal interaction between polyphenols and other dietary compounds: Impact on bioavailability, antioxidant capacity and other physico-chemical and nutritional parameters

Polyphenols are plant secondary metabolites, whose biological activity has been widely demonstrated. However, the research in this field is a bit reductive, as very frequently the effect of individual compound is investigated in different experimental models, neglecting more complex, but common, relationships that are established in the diet. This review summarizes the data that highlighted the interaction between polyphenols and other food components, especially macro- (lipids, proteins, carbohydrates and fibers) and micronutrients (minerals, vitamins and organic pigments), paying particular attention on their bioavailability, antioxidant capacity and chemical, physical, organoleptic and nutritional characteristics. The topic of food interaction has yet to be extensively studied because a greater knowledge of the food chemistry behind these interactions and the variables that modify their effects, could offer innovations and improvements in various fields ranging from organoleptic, nutritional to health and economic field.

Bioaccessibility of terebinth (Pistacia terebinthus L.) coffee polyphenols: Influence of milk, sugar and sweetener addition

In this study, terebinth coffee formulations were prepared with whole or skimmed milk with or without sugar/sweetener in order to study the matrix effect on the bioaccessibility of terebinth polyphenols. Quercetin glycosides and catechin were the major flavonoids identified in the terebinth formulations, whereas gallic, protocatechuic, syringic and ellagic acids were determined as the non-flavonoid compounds. The in vitro gastrointestinal digestion model results revealed that addition of whole milk to terebinth coffee increased the total bioaccessible flavonoids significantly (45%) (p < 0.05), whereas skim milk addition did not result in any significant change. Furthermore, antioxidant capacity results measured with CUPRAC assay showed that addition of milk alone or together with sugar/sweetener increases the bioaccessibility of terebinth coffee antioxidants (36-70%) (p < 0.05). Overall, terebinth coffee + whole milk + sugar formulation was found to contain the highest amount of bioaccessible flavonoid and non-flavonoid compounds (42.71-47.07 mg/100 g).

In vitro phenolic bioaccessibility of coffee beverages with milk and soy subjected to thermal treatment and protein-phenolic interactions

The effect of skimmed bovine milk and soy protein on the in vitro bioaccessibility of polyphenols in coffee beverages under thermal treatment (25, 90, and 121 °C) and the protein-phenolic interaction was investigated. Thermal treatment at 90 °C and 121 °C reduced the in vitro bioaccessibility of total and individual phenolic. Skimmed milk and soy protein addition increased the total (by 37.01%-64.21% and 24.74%-47.32%, respectively) and individual phenolic in vitro bioaccessibility (by 4.40%-27.29% and 12.02%-28.61%, respectively) of coffee beverages subjected to thermal treatment at 25, 90 and 121 °C. Compared with soy protein, skimmed milk significantly enhanced the in vitro bioaccessibility of coffee polyphenols, possibly owing to the presence of different types and strengths of noncovalent protein-phenolic interactions. These findings can provide certain theoretical knowledge for optimizing the processing technology and formula of the food industry to help improve the health benefits of milk coffee beverages.

Bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey fermented with lactic acid bacteria

Microbial fermentation with lactic acid bacteria (LAB) is a natural food biopreservation method. Yellow mustard and milk whey are optimum substrates for LAB fermentation. The aim of the present study was to evaluate the bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey both with and without LAB fermentation. All extracts were subjected to a simulated digestion process. Total polyphenols, DL-3-phenyllactic acid (PLA), lactic acid, and the antioxidant activity were determined in the studied matrices before and after simulated digestion. Yellow mustard flour was significantly richer in total polyphenols, whereas significantly higher concentrations of PLA and lactic acid were observed in milk whey. Similar antioxidant activity was determined in both ingredients being in all cases strongly reduced after in vitro digestion. Higher bioaccessibility was found for polyphenols and PLA in milk whey. Transepithelial transport of total polyphenols was higher in yellow mustard flour compared to milk whey, reaching bioavailability values between 3-7% and 1-2%, respectively. PLA transepithelial transport was only significant in both fermented matrices with bioavailability around 4-6%. Transepithelial transport of lactic acid reached values of 31-34% (bioavailability ∼ 22%) and 15-78% (bioavailability ∼ 3%) in milk whey and yellow mustard flour, respectively. LAB fermentation showed beneficial effects on enriching extracts with PLA, lactic acid, and antioxidant activity, as well as increasing bioaccessibility of these acids in yellow mustard flour and total polyphenol bioavailability in milk whey. Results pointed to yellow mustard flour and milk whey as natural preservative ingredients used in the food industry, especially when fermented with LAB.

Beneficial Effects of Phenolic Compounds on Gut Microbiota and Metabolic Syndrome

The human intestine contains an intricate community of microorganisms, referred to as the gut microbiota (GM), which plays a pivotal role in host homeostasis. Multiple factors could interfere with this delicate balance, including genetics, age, medicines and environmental factors, particularly diet. Growing evidence supports the involvement of GM dysbiosis in gastrointestinal (GI) and extraintestinal metabolic diseases. The beneficial effects of dietary polyphenols in preventing metabolic diseases have been subjected to intense investigation over the last twenty years. As our understanding of the role of the gut microbiota advances and our knowledge of the antioxidant and anti-inflammatory functions of polyphenols accumulates, there emerges a need to examine the prebiotic role of dietary polyphenols. This review firstly overviews the importance of the GM in health and disease and then reviews the role of dietary polyphenols on the modulation of the gut microbiota, their metabolites and how they impact on host health benefits. Inter-dependence between the gut microbiota and polyphenol metabolites and the vital balance between the two in maintaining the host gut homeostasis are also discussed.

In vitro phenols bioaccessibility and antioxidant activity of goat milk yogurt fortified with Rhus coriaria leaf powder

Goat yogurt samples fortified with 20% (w/v) Rhus coriaria leaf powder were in vitro digested in order to evaluate the total phenolic content (TPC), antioxidant activity (AA), and bioaccessibility of phenolic compounds in the digestate. After digestion, TPC and AA values of the R. coriaria-fortified yogurts increased compared to the undigested yogurts (P < 0.001). In particular, TPC has increased about twice; whereas, AA values have increased about 10 and 6 times, for ABTS and FRAP assays, respectively. The bioaccessibility index was well above the 100% for all identified phenols; except for (-)-epicatechin (82.04%), rutin (51.51%), and gallic acid (5.42%). This different behavior highlighted that the bioaccessibility was modulated by both the yogurt-polyphenol complexes and phenol stability under digestion system. These findings can contribute to elucidate the influence of in vitro digestion on antioxidant capacity and polyphenols recovery infortified yogurts, and may help in the design of dairy products with better functional quality PRACTICAL APPLICATION: Rhus coriaria L. (Sumac) is a polyphenol-rich Mediterranean plant that may be used as functional ingredient to enrich fermented food such as yogurt. However, in fortified yogurts the evaluation of bioaccessibility, that is, the compounds released from the yogurt and stable in the digestive environment, thus able to exert their biological effects on the gastrointestinal system, is more important than the content of these compounds in the corresponding food. This study highlighted the phenolic content, antioxidant activity, and bioaccessibility of phenolic compounds in goat milk yogurt fortified with R. coriaria leaf powder after simulated gastro-pancreatic digestion.

Addition of milk to coffee beverages; the effect on functional, nutritional, and sensorial properties

To date, there exists a debate on the effect of milk added to coffee infusions/beverages concerning the nutritional quality of coffee and the functional properties of its phenolic compounds. Yet, the full nutritional quality and functional properties of a coffee beverage without a significant negative impact on its sensorial profile are highly desired by the consumers. Negative/masking, positive, and neutral effects of milk on the antioxidant activity and bioavailability of coffee phenolics (particularly, chlorogenic acids) have been reported. Some potential factors including the type and amount of milk added, type of coffee beverage, the composition of both milk (protein and fat) and coffee (phenolic compounds), preparation method, assays used to measure antioxidant properties, and sampling size may account for the various reported findings. Interactions between phenolic compounds in coffee and milk proteins could account as the main responsible aspect for the reported masking/negative impact of milk on the antioxidant activity and bioaccessibility/bioavailability of coffee bioactives. However, considering the interactions between milk components and coffee phenolics, which result in the loss of their functionality, the role of milk fat globules and the milk fat globule membrane can also be crucial, but this has not been addressed in the literature so far.HighlightsIn most cases, milk is added to the coffee beverages in several various ways.Effect of milk on the nutritional/functional properties of coffee is controversial.Enough evidence suggests negative effects of milk addition on properties of coffee.Interactions of coffee phenolics and milk proteins could account as the main aspect.The role of milk fat globules and milk fat globule membrane may also be crucial.

The Use of Winery by-Products to Enhance the Functional Aspects of the Fresh Ovine "Primosale" Cheese

Fresh ovine "primosale" cheese was processed with the addition of grape pomace powder (GPP). Cheese making was performed using pasteurized ewes' milk and four selected Lactococcus lactis strains (Mise36, Mise94, Mise169 and Mise190) inoculated individually. For each strain the control cheese (CCP) was not added with GPP, while the experimental cheese (ECP) was enriched with 1% (w/w) GPP. GPP did not influence the starter development that reached levels of 10⁹ CFU/g in all final cheeses. The comparison of the bacterial isolates by randomly amplified polymorphic DNA (RAPD)-PCR showed the dominance of the added strains over indigenous milk bacteria resistant to pasteurization. GPP addition reduced fat content and determined an increase of protein and of secondary lipid oxidation. Sensory tests indicated that cheeses CCP94 and ECP94, produced with the strain Mise94, reached the best appreciation scores. Following in vitro simulated human digestion, bioaccessible fraction of ECP94 showed antioxidant capacity, evaluated as radical scavenging activity and inhibition of membrane lipid oxidation, significantly higher than that from CCP94, with promising increase in functional properties. Thus, the main hypothesis was accepted since the functional aspects of the final cheeses improved, confirming that GPP is relevant for sustainable nutrition by using winemaking by-products.

Effect on the Antioxidant, Lipoperoxyl Radical Scavenger Capacity, Nutritional, Sensory and Microbiological Traits of an Ovine Stretched Cheese Produced with Grape Pomace Powder Addition

An innovative ovine cheese enriched with red grape pomace powder (GPP) was produced to improve the functional properties of Vastedda cheese typology. Vastedda cheese making was performed adding GPP and four selected Lactococcus lactis strains (Mise36, Mise94, Mise169 and Mise190). For each strain, 40 L of pasteurized ewe's milk was divided into two aliquots representing control and experimental trials. Control cheese (CC) production did not contain GPP, while the experimental cheese (EC) production was enriched with 1% (w/w) GPP. GPP did not slow down starter development and acid generation. Plate counts and randomly amplified polymorphic DNA (RAPD)-PCR analysis confirmed the dominance of the starters in all trials. The evolution of the physicochemical parameters showed that EC productions were characterized by lower fat content, higher protein content, and higher values of secondary lipid oxidation. Sensory evaluation indicated that the cheeses produced with the strain Mise94 were those more appreciated by the judges. Thus, the last cheeses were investigated for some functional aspects: GPP enrichment significantly increased antioxidant activity and lipoperoxyl radical scavenger capacity, confirming that grape polyphenol inclusion in cheese represents an optimal strategy for the valorization of ovine cheeses as well as winemaking industry by-products.

Colon Bioaccessibility under In Vitro Gastrointestinal Digestion of Different Coffee Brews Chemically Profiled through UHPLC-Q-Orbitrap HRMS

Coffee represents one of the most traditionally consumed beverages worldwide, containing a broad range of human health–related compounds. According to previous studies, regular coffee consumption may display protective effects against colorectal cancer and other chronic diseases. The main goal of this research was to evaluate the bioaccessibility of phenolic content and variation in antioxidant capacity of three different types of coffee brews after simulated gastrointestinal digestion. This would allow to elucidate how antioxidant compounds present in coffee may exert their effect on the human body, especially in the colonic stage. Moreover, the content of bioactive compounds namely chlorogenic acids (CGAs, n = 11) and caffeine was also assessed throughout ultra-high-performance liquid chromatography followed by high-resolution Orbitrap mass spectrometry (UHPLC-Q-Orbitrap HRMS). The three main isomers of caffeoylquinic acid constituted the highest fraction of CGAs present in the samples, accounting for 66.0% to 70.9% of total CGAs. The bioaccessibility of coffee polyphenols significantly increased in digested samples from 45.9% to 62.9% at the end of the colonic passage, compared to the non-digested samples. These results point to the colonic stage as the major biological site of action of the active antioxidant coffee compounds.

In vitro digestion nullified the differences triggered by roasting in phenolic composition and α-glucosidase inhibitory capacity of coffee

Coffee beans were roasted to medium, dark and very dark degrees, and respective brews were in vitro digested and tested for α-glucosidase inhibition, to explore their antidiabetic potential. Phenolic acids (PA) and Maillard reaction indices (MRI) were quantified before and after digestion. Molecular docking was carried out to investigate α-glucosidase inhibition mechanisms. In vitro digested coffee inhibited α-glucosidase more effectively, compared to undigested samples, but without differences between roasting degrees. The inhibitory effect may be attributed to chlorogenic acids (CGA), which were the most abundant PA in digested coffees. In fact, molecular docking predicted a high affinity of CGA for α-glucosidase. Even though digestion nullified roasting-induced differences in α-glucosidase inhibition, CGA showed a decreasing trend upon digestion. Similarly, MRI did not differ among coffees upon digestion but decreased compared to undigested samples. Overall, the results reported in this study suggest that the presence of different compounds in coffee matrix may contribute to an antidiabetic effect.

Application of an in vitro digestion model to study the metabolic profile changes of an herbal extract combination by UHPLC-HRMS

BACKGROUND

STW 5 is a fixed herbal combination containing extracts from nine medicinal plants: bitter candytuft, greater celandine, garden angelica roots, lemon balm leaves, peppermint leaves, caraway fruits, licorice roots, chamomile flowers, and milk thistle fruit. STW 5 is a clinically proven treatment for functional dyspepsia and irritable bowel syndrome.

PURPOSE

Using a static in vitro method, we simulated oral, gastric, and small intestinal digestion and analyzed the metabolic profile changes by UHPLC-HRMS to determine the impact of oro-gastro-intestinal digestion on STW 5 constituents.

STUDY DESIGN AND METHODS

STW 5 was incubated according to the InfoGest consensus method. Samples of each digestive phase were analyzed by UHPLC-HRMS in ESI positive and negative modes. After data processing, background subtraction, and normalization, the peak areas of detectable compounds were compared to untreated reference samples and recovery ratios were calculated to monitor the metabolic profile of STW 5 during simulated digestion.

RESULTS

Although the levels of some constituents were reduced, we did not observe complete degradation of any of the constituents of STW 5 upon in vitro digestion. We did not detect any new metabolites beyond increased levels of caffeic acid and liquiritigenin due to degradation of progenitor compounds. Changes observed in intestinal bioaccessibility ratios were mainly a result of isomerization, hydrolysis, protein binding, and low water solubility.

CONCLUSION

The majority of STW 5 constituents are stable towards simulated in vitro digestion and can reach the colon to interact with gut microbiota if they remain unabsorbed in the upper intestinal tract.

Consuming decaffeinated coffee with milk and sugar added before a high-glycaemic index meal improves postprandial glycaemic and insulinaemic responses in healthy adults

The present study aimed to compare the effects of drinking different types of coffee before a high-glycaemic index (GI) meal on postprandial glucose metabolism and to assess the effects of adding milk and sugar into coffee. In this randomised, crossover, acute feeding study, apparently healthy adults (n 21) consumed the test drink followed by a high-GI meal in each session. Different types of coffee (espresso, instant, boiled and decaffeinated, all with milk and sugar) and plain water were tested in separate sessions, while a subset of the participants (n 10) completed extra sessions using black coffees. Postprandial levels of glucose, insulin, active glucagon-like peptide 1 (GLP-1) and nitrotyrosine between different test drinks were compared using linear mixed models. Results showed that only preloading decaffeinated coffee with milk and sugar led to significantly lower glucose incremental AUC (iAUC; 14 % lower, P = 0·001) than water. Preloading black coffees led to greater postprandial glucose iAUC than preloading coffees with milk and sugar added (12-35 % smaller, P < 0·05 for all coffee types). Active GLP-1 and nitrotyrosine levels were not significantly different between test drinks. To conclude, preloading decaffeinated coffee with milk and sugar led to a blunted postprandial glycaemic response after a subsequent high-GI meal, while adding milk and sugar into coffee could mitigate the impairment effect of black coffee towards postprandial glucose responses. These findings may partly explain the positive effects of coffee consumption on glucose metabolism.

Phenolic content and potential bioactivity of apple juice as affected by thermal and ultrasound pasteurization

Thermal (T) and ultrasound (US) pasteurization processes were applied to apple juice and the phenolic compounds (TPC) were quantified before and after in vitro digestion by HPLC-DAD-ESI-MSⁿ, with their bioaccessibility ascertained. Digested samples were analysed for their inhibitory capacity against α-glucosidase. Since some of the compounds exhibit fluorescence, both steady state and time-resolved fluorescence methods were used to investigate the binding to a blood transport protein, human serum albumin (HSA). It was found that processing induced an increase in the TPC content, which was more pronounced when US was applied. In contrast, digestion reduced the TPC content, evening out the overall effect. Still T and US pasteurized juices exhibited a higher quantity of TPC upon digestion as compared to the raw sample. No correlation was found between the TPC content and α-glucosidase inhibition, as the T and US pasteurized juices showed the highest and lowest inhibitory capacities against the enzyme, respectively. This is indicative that other compounds, such as those formed upon thermal treatment, may be involved in the antidiabetic effect of apple juice. The fluorescence study showed that binding occurred to HSA, at slightly different rates for different species present in the US treated extract. Considering energy consumption, US pasteurization is the most power consuming treatment despite its shorter duration. Overall, no univocal indication on the best pasteurization process can be gathered. Thus, it is necessary to define the desired target in order to drive technological interventions by a customized approach.

Effect of milk addition and processing on the antioxidant capacity and phenolic bioaccessibility of coffee by using an in vitro gastrointestinal digestion model

An in vitro gastrointestinal digestion model was used to investigate the effects of milk matrix: skimmed milk (Sm), whole milk (Wm) and processing methods: pH adjustment, high pressure homogenization processing (HPHP), thermal treatment (TT) on the antioxidant capacity, phenolics bioaccessibility of coffee. Our findings showed that the antioxidant capacity of all the samples decreased or unchanged after in vitro digestion. The total phenolic bioaccessibility of coffee (C), coffee with whole milk (Cwm), and coffee with skimmed milk (Csm) decreased by 29.2%, 28.5%, 21.1% from the HPHP treatment and by 14.7%, 34.2%, and 33.8% from TT, respectively. pH adjustment had little effect on the total phenolic bioaccessibility of Cwm and Csm but significantly decreased that of C. Wm showed better protective effect on the phenolic bioaccessibility than Sm. These results may contribute to the optimization of formulations and processing methods in coffee beverage production, thereby increasing the health benefits of coffee.

Effects of Milk Proteins on the Bioaccessibility and Antioxidant Activity of Oat Phenolics During In Vitro Digestion

This study investigated the effects of milk solution or milk proteins (casein and whey protein) on the bioaccessibility and antioxidant activity of oat phenolics during in vitro gastric and pancreatic digestion. During digestion, most of oat phenolics were partially degraded by alkaline pH of pancreatic fluid (pH 7.5). For phenolic acids, both milk solution and milk protein only had a slight influence on their bioaccessibility, while exhibited a significant effect on antioxidant activity of oat phenolic extracts and bioaccessibility of avenanthramides (AVs), a kind of bioactive phenols exclusively found in oats. The antioxidant activity and bioaccessibility of AVs were decreased by adding milk and casein, while significantly improved when mixed with milk whey protein. Remarkably, the bioaccessibility of AV 2c, which had the highest antioxidant activity among all phenolic compounds detected in oats, increased above 360% after intestinal digestion by mixing with whey protein. This result suggested the possibility of protecting AVs against digestive alteration and oxidation by milk whey protein. PRACTICAL APPLICATION: In recent years, oats are often consumed with milk under different conditions of preparation, and there have been many oat milk products manufactured by food companies all over the world. The results of this paper showed that the adding of milk may reduce the absorption and antioxidant activity of phenolic compounds from oat. However, the antioxidant activity and bioaccessibility of oat phenolics were significantly increased when mixed with milk whey protein, suggesting that oats could be consumed with milk whey protein to improve their functional properties.

Consumption of Chlorogenic Acids through Coffee and Health Implications

Chlorogenic acids (CGA) are the main antioxidant compounds in the Western diet, due to their high concentrations in coffee associated with the high consumption of the beverage. Until about 10 years ago, like many other phenolic compounds, CGA were thought to be poorly absorbed in the human digestive system. Along the years, large amounts of information on the absorption and metabolism of these compounds have been unveiled, and today, it is known that, on average, about one third of the consumed CGA from coffee is absorbed in the human gastrointestinal tract, although large inter-individual variation exists. Considering results from in vitro animal and human studies, it is possible to conclude that the antioxidant and anti-inflammatory effects of coffee CGA are responsible for, at least to a certain extent, the association between coffee consumption and lower incidence of various degenerative and non-degenerative diseases, in addition to higher longevity.

Bioactivity and cell metabolism of in vitro digested sweet cherry (Prunus avium) phenolic compounds

In this study, the bioaccessibility of phenolic compounds after in vitro gastrointestinal digestion of two cherry cultivars was assessed. The phenolic profile was modified during in vitro digestion, with a considerable decrease of total and individual phenolic compounds. Hydroxycinnamic acids and especially coumaroylquinic acids showed the highest bioaccessibility. Isomerisation of caffeoylquinic and coumaroylquinic acids was observed after in vitro digestion. Modification of the phenolic profile after digestion resulted in an increased or decreased scavenging activity depending on the assay. In vitro digested phenolic-rich fractions also showed antiproliferative activity against SW480 but no effect against Caco-2 cell lines. Both Caco-2 and SW480 cell lines were able to metabolise cherry phenolic compounds with remarkable differences. An accumulation of glycosylated flavonols was observed in SW480 medium. In conclusion, phenolic compounds from cherries and especially hydroxycinnamic acids were efficiently released and remained bioaccessible after in vitro digestion, resulting in antioxidant and antiproliferative activities.

The effect of dietary factors on strawberry anthocyanins oral bioavailability

Strawberries are a dietary source of anthocyanins, particularly pelargonidin glycosides. Dietary anthocyanins have received increasing attention among researchers and consumers due to their health benefits. The oral bioavailability of anthocyanins is reported to be low and various dietary factors may influence their oral bioavailability further. Milk is suggested to reduce (poly)phenols' oral bioavailability. However, the effect of milk on anthocyanin oral bioavailability remains uncertain. Likewise, mixed nutrient meals may influence the oral bioavailability of anthocyanins. Therefore, the purpose of this study was to assess the effect of milk on the oral bioavailability and other pharmacokinetic (PK) variables of strawberry anthocyanins consumed with and without a meal. Nine healthy participants consumed a strawberry beverage prepared in milk or water with a standard meal on two occasions. On two additional occasions, the beverages were given to a subset (n = 4) of participants to determine the impact of the meal on anthocyanin PK variables, including oral bioavailability. Independent of the meal, beverages prepared in milk significantly reduced the peak plasma concentrations (C_max) of pelargonidin-3-O-glucoside (P-3-G), pelargonidin-glucuronide (PG) and pelargonidin-3-O-rutinoside (P-3-R), as well as the PG and P-3-R area under the curve (AUC) (p < 0.05) compared to beverages prepared in water. Milk did not influence the oral relative bioavailability of pelargonidin anthocyanins under meal conditions; however, the oral relative bioavailability of pelargonidin anthocyanins was reduced by ∼50% by milk under without meal conditions (p < 0.05). Consuming strawberry beverages made with milk and consuming those made with water with and without a meal influenced different aspects of strawberry anthocyanin PKs. The significance of this effect on clinical efficacy requires additional research.

Polyphenol content, in vitro bioaccessibility and antioxidant capacity of widely consumed beverages

BACKGROUND

Beverages prepared from antioxidant-rich plants are sources of polyphenols, the bioactivity of which depends on bioaccessibility in the gastrointestinal tract. This work evaluated the polyphenol content and antioxidant capacity of widely consumed beverages such as chamomile tea, yerba mate, a coffee blend (65% roasted: 35% green), and coffee-like substitutes such as chicory, malt and a soluble cereal mixture. Additionally, the bioaccessibility of the two beverages with the highest antioxidant capacity was evaluated using an in vitro digestion model.

RESULTS

Total phenolic content ranged from 11.15 mg 200 mL^-1 in chamomile tea, up to 154.53 mg 200 mL^-1 in mate or 215.05 mg 200 mL^-1 in the blend. These results correlated with the antioxidant capacity analysed by ferric reducing antioxidant power, oxygen radical scavenging capacity and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid methods. Yerba mate and the coffee blend showed an average polyphenol recovery after in vitro gastrointestinal digestion of 57% and 78%, respectively. Although both beverages showed similar phenolic composition, polyphenols in coffee were more stable than in yerba mate. Alkaline pH in the intestinal digestion stage was responsible for the observed reduction in polyphenol stability.

CONCLUSION

Regular consumption of the studied beverages provides considerable amounts of antioxidants which are relatively stable after simulated digestion, and thus have the potential to prevent oxidative stress-related disorders. © 2017 Society of Chemical Industry.

Food processing strategies to enhance phenolic compounds bioaccessibility and bioavailability in plant-based foods

Phenolic compounds are important constituents of plant-based foods, as their presence is related to protective effects on health. To exert their biological activity, phenolic compounds must be released from the matrix during digestion in an absorbable form (bioaccessible) and finally absorbed and transferred to the bloodstream (bioavailable). Chemical structure and matrix interactions are some food-related factors that hamper phenolic compounds bioaccessibility and bioavailability, and that can be counteracted by food processing. It has been shown that food processing can induce chemical or physical modifications in food that enhance phenolic compounds bioaccessibility and bioavailability. These changes include: (i) chemical modifications into more bioaccessible and bioavailable forms; (ii) cleavage of covalent or hydrogen bonds or hydrophobic forces that attach phenolic compounds to matrix macromolecules; (iii) damaging microstructural barriers such as cell walls that impede the release from the matrix; and (iv) create microstructures that protect phenolic compounds until they are absorbed. Indeed, food processing can produce degradation of phenolic compounds, however, it is possible to counteract it by modulating the operating conditions in favor of increased bioaccessibility and bioavailability. This review compiles the current knowledge on the effects of processing on phenolic compounds bioaccessibility or bioavailability, while suggesting new guidelines in the search of optimal processing conditions as a step forward towards the design of healthier foods.

Chemical constituents and pharmacological actions of carob pods and leaves (Ceratonia siliqua L.) on the gastrointestinal tract: A review

Carob tree, Ceratonia siliqua L., is a medicinal plant used in Tunisian traditional medicine for the treatment of the gastro-intestinal (GI) disorders. In this respect, a relatively large number of scientific publications on the carob tree have been published in recent years. Therefore, the present review was aimed to analyze the traditional uses, phytochemical constituents and pharmacological activities of Ceratonia siliqua on the GI tract. Indeed, previous investigations on the carob pods and leaves have revealed the presence of a number of compounds including high amounts of carbohydrates, dietary fibers, minerals, polyphenols, flavonoids and low amounts of protein and lipids. This plant possesses anti-inflammatory, antimicrobial, anti-diarrheique, antioxidant, anti-ulcer, anti-constipation and anti-absorptive of glucose activities in the gastrointestinal tract. Based on the chemical and pharmacological characteristics of C. siliqua, we concluded that this species has beneficial preventive and therapeutic properties, especially, in digestive tract.

Optimization of the Preparation Conditions of Yerba Mate tea Beverage to Maximize Chlorogenic Acids Extraction

The beverage obtained from the yerba mate tea, besides being the most consumed in Brazil, has high concentrations of chlorogenic acids. In this study, a central composite design was employed to establish the best infusion time, temperature and water volume to maximize the extraction of chlorogenic acids 5-caffeoylquinic (5CQ), 3.4-dicaffeoylquinic (3.4 DQ), 3.5-dicaffeoylquinic (3.5 DQ) and 4.5-dicaffeoylquinic (4.5 DQ), from the leaves and stems of yerba mate tea (beverage ready for consumption). Analyses were performed by high-performance liquid chromatography and the optimum conditions were obtained through the use of the desirability function of Derringer and Suich. The maximum chlorogenic acids content in the beverage was obtained when the infusion was prepared with 2 g of mate tea, in 300 mL of water at 95 °C, under infusion for 16 min. The optimal conditions were applied for the preparation of beverages from 15 commercial samples of yerba mate tea, and it was observed that the sum of the concentration of the four compounds showed variation of up to 79 times between the average of the samples, which can be attributed to climatic conditions of cultivation of the plant and/or of processing.

Chlorogenic acids and the acyl-quinic acids: discovery, biosynthesis, bioavailability and bioactivity

This review is focussed upon the acyl-quinic acids, the most studied group within theca.400 chlorogenic acids so far reported.

Antioxidant activity and nutrient release from polyphenol-enriched cheese in a simulated gastrointestinal environment

Polyphenol recovery during the in vitro intestinal digestion of cheese with tea extract.

Role of Chlorogenic Acids in Controlling Oxidative and Inflammatory Stress Conditions

Chlorogenic acids (CGAs) are esters formed between caffeic and quinic acids, and represent an abundant group of plant polyphenols present in the human diet. CGAs have different subgroups that include caffeoylquinic, p-coumaroylquinic, and feruloyquinic acids. Results of epidemiological studies suggest that the consumption of beverages such as coffee, tea, wine, different herbal infusions, and also some fruit juices are linked to reduced risks of developing different chronic diseases. These beverages contain CGAs present in different concentrations and isomeric mixtures. The underlying mechanism(s) for specific health benefits attributed to CGAs involves mitigating oxidative stress, and hence the related adverse effects associated with an unbalanced intracellular redox state. There is also evidence to show that CGAs exhibit anti-inflammatory activities by modulating a number of important metabolic pathways. This review will focus on three specific aspects of the relevance of CGAs in coffee beverages; namely: (1) the relative composition of different CGA isomers present in coffee beverages; (2) analysis of in vitro and in vivo evidence that CGAs and individual isomers can mitigate oxidative and inflammatory stresses; and (3) description of the molecular mechanisms that have a key role in the cell signaling activity that underlines important functions.