Human exposure assessment of fluoride from tea (Camellia sinensis L.): A UK based issue?

Fluoride concentrations in UK tea, including the leading supermarket economy labelled products, were determined. Fluoride ranged from 93 to 820 mg/kg in the products and 0.43 to 8.85 mg/L in the infusions. The UK supermarket economy teas contained elevated fluoride, ranging from 3.60 to 7.96 mg/L in a 2 minute brewing infusion, comparable to Chinese brick tea, indicating the use of mature leaves in their manufacture. Considering the dietary reference intake (DRI) of 4 mg/day of fluoride for an adult consuming 1 L of tea, prepared from an economy tea, containing 6.0 mg/L fluoride, 75–120% of the DRI fluoride is available for absorption by the human system in the presence of food, increasing to 150% when fasting. Excess fluoride in the diet can lead to detrimental health effects such as fluorosis of the teeth and skeletal fluorosis and consuming economy branded tea will lead to exposure.     

Tea fluoride concentration and the pediatric patient

The purpose of this study was to measure the fluoride concentrations of various commercially available tea infusions, with a specific focus on risk of fluorosis. 100 ml infusions of 43 different tea brands were kept at a constant temperature of 85 °C and measured for fluoride concentration at 5, 15, 30, 60, and 120 min using a fluoride ion-specific electrode and millivolt meter. After 5 min at 85 °C mean fluoride concentration, in μg/ml with standard deviation, was 2.08 ± 1.24 for caffeinated tea infusions, 4.38 ± 0.97 for decaffeinated tea infusions, and 0.05 ± 0.02 for herbal teas. Caffeinated teas derived from the traditional source, Camellia sinensis, demonstrated significantly higher concentrations of fluoride than herbal teas (p < 0.01). Furthermore, decaffeinated teas demonstrated significantly higher concentrations of fluoride than caffeinated teas (p < 0.01). Some tea infusions may place a pediatric patient at higher risk for fluorosis if consumed as the primary source of hydration.     

Investigation of the interaction between soluble antioxidants in green tea and insoluble dietary fiber bound antioxidants

This work investigates the possibility of interaction between insoluble dietary fiber bound antioxidants, specifically of wheat bran, and soluble antioxidants like those provide by aqueous infusions of green tea. Solutions of pure catechins were also assayed for comparison with those naturally found in tea. To accomplish this, the aqueous and alcohol soluble fractions as well as the lipid components of wheat bran were firstly removed and the freeze-dried insoluble residue was then treated with different concentrations of green tea infusions or aqueous solutions of epicatechin (EC) and epigallocatechin-3-gallate (EGCG) for certain time. Treatment with EC (0–200 μM) had no significant effect on the antioxidant capacity of insoluble bran fraction. However, treatment with EGCG significantly (p < 0.05) increased linearly the antioxidant capacity as a function of concentration (0–100 μM). Treatment with great tea infusions (1–3 g/100 ml) also increased the resulting antioxidant capacity of insoluble bran fraction, but the effect was lesser at higher infusion concentrations. Liquid chromatography couple to mass spectrometry (LC–MS) analyses of aqueous phases after treatment indicated comparable levels of decrease in the concentrations of catechins confirming their reaction with the radical forms of antioxidants bound to insoluble bran matrix.     

Caffeic acid derivatives in dried Lamiaceae and Echinacea purpurea products

The concentrations of caffeic acid derivatives within Lamiaceae and Echinacea (herb, spice, tea, and dietary supplement forms) readily available in the US marketplace (n = 72) were determined. After the first identification of chicoric acid in Ocimum basilicum (basil), the extent to which chicoric acid could be found within the family Lamiaceae was investigated. The dominant phenolic acid in all Lamiaceae samples was rosmarinic acid, which ranged from 2.04 mg/100 g (one of 12 oregano samples) to 622.28 mg/100 g (lemon balm). Of the herbs tested in this study (marjoram, oregano, peppermint, rosemary, sage, spearmint, and thyme from the family Lamiaceae), only basil and lemon balm (Melissa officinalis) contained chicoric acid. Basil samples (starting material and resulting end product) obtained from an industry cooperator, showed substantial phenolic deficiency as a result of processing (approximately 78% loss).     

Cadmium Levels of Edible Offal from Saanen Goat Male Kids

Concentration of cadmium was investigated in the heart, tongue, lungs, spleen, liver, kidney, testis, brain and thymus of 15 Saanen goat male kids. This element was determined by inductively coupled plasma optical emission spectrometry (ICP-OES), after microwave digestion. The cadmium concentration was significantly influenced by the type of edible offal. Mean cadmium concentrations ranged from 0.018 mg/kg (heart) to 0.114 mg/kg (kidney). The maximum cadmium concentrations found in the kidney (0.133 mg/kg) and liver (0.075 mg/kg) were below maximum levels (1.0 and 0.5 mg/kg, respectively) set by legislation for these tissues.     

Tea and herbal infusions: Their antioxidant activity and phenolic profile

Tea and herbal infusions have been studied for their polyphenolic content, antioxidant activity and phenolic profile. The total phenolics recovered by ethyl acetate from the water extract, were determined by the Folin–Ciocalteu procedure and ranged from 88.1 ± 0.42 (Greek mountain tea) to 1216 ± 32.0 mg (Chinese green tea) GAE (Gallic acid equivalents)/cup. The antioxidant activity was evaluated by two methods, DPPH and chemiluminescence assays, using Trolox and quercetin as standards. The EC₅₀ of herbal extracts ranged from 0.151 ± 0.002 mg extract/mg DPPH (0.38 quercetin equivalents and 0.57 Trolox equivalents), for Chinese green tea, to 0.77 ± 0.012 mg extract/mg DPPH (0.08 quercetin equivalents and 0.13 Trolox equivalents), for Greek mountain tea. Chemiluminescence assay results showed that the IC₅₀ ranged from 0.17 ± 3.4 × 10⁻³ μg extract/ml of the final solution in the measuring cell (1.89 quercetin and 5.89 Trolox equivalents) for Chinese green tea, to 1.10 ± 1.86 × 10⁻² g extract/ml of the final solution in the measuring cell (0.29 quercetin and 0.90 Trolox equivalents) for Greek mountain tea. The phenolic profile in the herbal infusions was investigated by LC-DAD-MS in the positive electrospray ionization (ESI⁺) mode. About 60 different flavonoids, phenolic acids and their derivatives have been identified.     

Depuration of cadmium from blue mussel (Mytilus edulis) by hydrolysis peptides and chelating metal elements

The present experiment was conducted to investigate the effects of prepared hairtail (Lepidopusc audatus) hydrolysis peptide–metal element (Fe^2 +, Zn^2 +, Ca^2 +, or Mg^2 +) complexes (PH–Fe^2 +, PH–Zn^2 +, PH–Ca^2 +, or PH–Mg^2 +) on the depuration of cadmium (Cd) from blue mussel (Mytilus edulis) tissues. Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass of mussels were 11.391, 15.323, 63.672, 19.509, and 109.621 μg/g, respectively, after 5 days of exposure to 0.32 mg/L Cd. Five groups of these exposed mussels were then exposed to seawater laced with four different concentrations of the peptide complexes listed above (5, 10, 15, and 20 mg/L) for 8 days. After 8 days of depuration, 5 mg/L of PH–Fe^2 +, PH–Zn^2 +, and PH–Ca^2 + showed no significant (P > 0.05) effects on Cd concentrations in mussel tissues. However, significant differences (P < 0.05) were observed in groups exposed to 20 mg/L of PH–Fe^2 +, PH–Zn^2 +, and PH–Ca^2 +. The Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass were significantly (P < 0.05) decreased by 29.56–35.83%, 27.51–33.62%, 31.59–40.34%, 25.83–31.28%, and 33.62–33.97%, respectively. Nevertheless, the variables of Cd concentrations in tissues treated with 5–20 mg/L PH–Mg^2 + showed no significant (P > 0.05) differences from controls at any point during the experimental period. For these reasons, PH–Fe^2 +, PH–Zn^2 +, and PH–Ca^2 + can be recommended as depuration agents in mussel feed to decrease the Cd concentrations in tissues.     

The phenolic compounds and the antioxidant potential of infusion of herbs from the Brazilian Amazonian region

The consumption of tea increased significantly in the past few years as a result of its health benefits as potent antioxidants in the diet. However, studies on the antioxidant compounds from Brazilian tea are scarce. Thus, the aim of this work was to evaluate the total phenolic compounds (TPC) and total flavonoids (TF) contents and the antioxidant capacity (DPPH and β-carotene/linoleic acid system) of nine herb infusions from the Amazonian region, namely agirú (Chrysobalanus icaco), açoita-cavalo (Luehea speciosa), capim-santo (Cymbopogon citratus), erva-cidreira (Lippia alba), graviola (Annona muricata L.), jucá (Libidibia ferrea), pata-de-vaca (Bauhinia ungulata), parirí (Fridericia chica) and sacaca comum (Croton spp.). These herbs were chosen based on popular knowledge and consumption. C. ferrea (68.13 mg GAE/g), L. speciosa (47.54 mg GAE/g) and C. icaco (51.30 mg GAE/g) presented the highest TPC contents, while L. speciosa (12.85 mg CE/g) and L. alba (15.42 mg CE/g) showed the highest TF contents. The highest antioxidant capacity, using both assays, was shown by L. ferrea. The three herbs with the highest TPC contents were selected to be analyzed by high performance liquid chromatography (HPLC) coupled to a diode array detector (DAD). A commercial green tea (Camellia sinensis) was also analyzed as a reference. The main compounds tentatively identified were gallic acid (0.45 mg/g), myricetin (0.78 mg/g) and quercetin (0.14 mg/g) in C. icaco; (+)-catechin (1.20 mg/g) and quercetin (0.14 mg/g) in L. speciosa; gallic acid (0.59 mg/g) and quercetin (0.13 mg/g) in C. ferrea; and gallic acid (0.24 mg/g), (−)-epicatechin (2.44 mg/g), (+)-catechin (0.68 mg/g) and quercetin (0.66 mg/g) in green tea. Among the nine studied herbs, the importance of L. ferrea should be pointed out since it presented the highest TPC content and antioxidant capacity and its gallic acid content was much higher than that of green tea.     

Digestive stability and absorption of green tea polyphenols: Influence of acid and xylitol addition

The objective of this study was to determine the effect of sugar substitute and acid on digestive stability and intestinal uptake of catechins in Ready-To-Drink (RTD) green tea. Green tea extracts formulated with prescribed amounts of sucrose (200, 500, and 1000 mg), glucose (280, 700, and 1400 mg), and xylitol (200, 500, and 1000 mg) in combination with citric acid (10 mg) or vitamin C (10 mg) were subjected to an in vitro digestion model coupled with Caco-2 cells. Green tea extracts only showed a poor digestive recovery (5.3%) of total catechins and EGC and EGCG significantly decreased with the digestive recovery of 4.6% and 6.1%, respectively. However, measured amount of EGC, EGCG, or ECG in digestive fluids and caco-2 human intestinal cell significantly increased by adding citric acid or vitamin C. There was remarkable increase of digestive recovery of total catechins in green tea with xylitol/citric acid and xylitol/vitamin C by 1.7–2.5 times and 3 times, respectively, with different amounts of xylitol. It was also determined that intestinal uptake of total catechins significantly increased 6 and 11 times in green tea with xylitol/citric acid and xylitol/vitamin C, respectively, compared to green tea only.     

Characterization of the antioxidant functions of flavonoids and proanthocyanidins in Mauritian black teas

Tea drinking is associated with an improved antioxidant status in vivo which may contribute to the lowering of the risk of certain types of cancer, coronary heart disease and stroke. The polyphenolic bioactive composition and the antioxidant properties of Mauritian commercial black and fresh tea leaves were evaluated. Hot water infusates contained high levels of total phenols, total proanthocyanidins and total flavonoids. The concentrations of individual compounds, (+)-catechin, (−)-epicatechin, (−)-epicatechin 3-gallate, epigallocatechin, (−)-epigallocatechin 3-gallate, gallic acid, and procyanidin dimers B1 and B2 were high. The ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays were used to assess the antioxidant potential of tea infusates with the following order of potency: Ouvagalia tea > Buccaneer’s choice > Black Label > Red Label > Extra > Corson > Chartreuse > La Flora > 3-Pavillons. Linear regression analyses indicated high correlation coefficient with total proanthocyanidin (TEAC r = 0.96 and FRAP r = 0.95) and total phenol contents (TEAC r = 0.90 and FRAP r = 0.92) in infusates. Catechins and gallic acid significantly contributed to the overall antioxidant capacity of black tea extracts. In general, the fresh tea leaves had high levels of total phenols, total flavonoids, total proanthocyanidin and exhibited greater antioxidant potentials when compared with black teas. Thus Mauritian black teas and fresh tea leaves can be rich sources of polyphenolic compounds and antioxidants, which may be highly relevant to the maintenance of normal health and disease management, an observation that has led to the commencement of a clinical trial study to assess cardiovascular health in Mauritius.     

Yerba mate tea (Ilex paraguariensis): Phenolics,antioxidant capacity and in vitro inhibition of colon cancer cell proliferation

Mate tea (MT) is a rich source of phenolic compounds that vary depending on geographical origin and mode of preparation. Total phenolic concentration and antioxidant capacity of Mate tea (Ilex paraguariensis) products were determined in this work. In addition, a representative MT was tested for in vitro inhibition of human colon carcinoma cell proliferation. Total polyphenol concentration, was measured using Folin–Ciocalteau method, ranged from 90 to 176 mg gallic acid eq (GAE)/g dry leaves (DL) in traditional MT and from 40 to 113 mg GAE/g DL in MT added with other flavouring ingredients. It was estimated that a cup of tea (250 ml) containing one teaspoon (5 g) of instant MT could provide an average intake of 1.5 g GAE. Fresh tea (FT) from Mate leaves displayed high antioxidant capacity (85 ± 1%) and preferentially inhibited 50% of net growth of human colorectal adenocarcinoma cells CaCo-2 (GI₅₀ = 1.0 ± 0.03 μg/ml) and HT-29 (GI₅₀ = 105.2 ± 15.2 μg/ml) when compared with the CCD-33Co normal colon fibroblast cell line (GI₅₀ > 300 μg/ml). MT inhibited in vitro colon cancer cell proliferation possibly mediated via pro-oxidant activities, therefore represents a potential source of chemopreventive agents that deserve further investigation.     

Aluminium contents in baked meats wrapped in aluminium foil

In this investigation, the effect of cooking treatments (60 min at 150 °C, 40 min at 200 °C, and 20 min at 250 °C) on aluminium contents of meats (beef, water buffalo, mutton, chicken and turkey) baked in aluminium foil were evaluated. Cooking increased the aluminium concentration of both the white and red meats. The increase was 89–378% in red meats and 76–215% in poultry. The least increase (76–115%) was observed in the samples baked for 60 min at 150 °C, while the highest increase (153–378%) was in samples baked for 20 min at 250 °C. It was determined that the fat content of meat in addition to the cooking process affected the migration of aluminium (r² = 0.83; P < 0.01). It was also found that raw chicken and turkey breast meat contained higher amounts of aluminium than the raw chicken and turkey leg meat, respectively. Regarding the suggested provisional tolerable daily intake of 1 mg Al/kg body weight per day of the FAO/WHO Expert Committee on Food Additives, there are no evident risks to the health of the consumer from using aluminium foil to cook meats. However, eating meals prepared in aluminium foil may carry a risk to the health by adding to other aluminium sources.     

Daily green tea extract supplementation reduces prothrombotic and inflammatory states in dialysis patients

Cardiovascular disease (CVD) remains the most common cause for excess morbidity and mortality in patients with chronic kidney disease (CKD) and end stage renal disease (ESRD) under chronic dialysis. ESRD patients have increased oxidative stress and endothelial dysfunction alongside increased levels of inflammation related proteins, which has prompted the exploration of anti-inflammatory and antioxidant treatments to improve outcomes. As green tea is increasingly well recognized for its antioxidant properties, we probed the effect of consumption of 1 capsule daily of green tea as a commercially available, decaffeinated green tea capsule (1 g, catechin content 68 mg) for 6 months on fibrinogen and inflammation in dialysis patients. Chronic hemodialysis patients (N = 25) were recruited and fibrinogen, FDP-D-dimer, high sensitivity (hs) CRP and the mononuclear cell protein expression of p22^phox, were assessed before, i.e. baseline and after 6 months of ingestion of 1 green tea capsule per day. After 6 months of daily green tea capsule ingestion, dialysis patients showed reduced protein expression of p22^phox (p < 0.0001), reduced hsCPR (p = 0.032) and fibrinogen (p = 0.022) levels and increased FDP-D-dimer (p = 0.0019) compared to their values at baseline. These results document lower oxidative stress and inflammation with green tea capsule ingestion and suggest a likely positive impact of green tea treatment on the atherosclerotic process of ESRD patients under dialysis.     

Storage of extra virgin olive oil and its effect on the biological activity and concentration of oleocanthal

The olive oil phenolic, oleocanthal has recently received attention regarding its anti-inflammatory capacity and the thought that it is partially responsible for the beneficial health effects of the Mediterranean diet. Extra virgin olive oil (EVOO) containing oleocanthal is often consumed after storage for a substantial amount of time and for oleocanthal to indeed provide health benefits, it has to be present in a substantial quantity throughout the shelf-life of EVOO. Therefore, the aim of the current study was to investigate if natural light and/or oxygen (O₂) exposure (via atmospheric air) combined with extended storage, as would occur on a common domestic basis, affected the concentration of oleocanthal in EVOO. One EVOO containing 90 mg/kg oleocanthal was stored for 10 months with and without exposure to light and or O₂. Oleocanthal concentrations were quantified using high performance liquid chromatography–mass spectrometry (HPLC–MS) and its biological activity determined with a taste bioassay measuring the intensity of oropharyngeal irritation. A significant difference in oleocanthal concentration was observed amongst the different storage treatments (p = 0.05). Oleocanthal concentration degraded to a maximum of 37% (90 ± 13 mg/kg to 56 ± 9 mg/kg) after 10 months exposure to both light and O₂. Limiting light and O₂ over 10 months resulted in a 15% decrease in oleocanthal (90 ± 13 mg/kg to 76 ± 9 mg/kg). Oleocanthal biological activity mirrored the results of oleocanthal concentration (r = 0.8, p < 0.05). Overall, the findings support the role of oleocanthal as a potential health promoting compound in EVOO as significant concentrations remain in EVOO after exposure to light, oxygen and over time.     

A randomized,double-blind trial on the bioavailability of two CoQ10 formulations

The bioavailability of a single, 100 mg, dose of reduced Coenzyme Q10 (CoQH-CF) and Coenzyme Q10 formulation was compared in individuals of >60 years. Significantly higher (P < 0.001) plasma concentrations were demonstrated for the CoQH-CF formulation at 5, 6, 8, 12, 24, 48 and 72 h post-dose compared to the CoQ10 formulation. The area under the curve (AUC) of reduced and total Coenzyme Q10 was significantly higher (P < 0.001) in subjects administered CoQH-CF resulting in 4.3-fold higher plasma AUC_{0–72 h} (430% increase) in subjects receiving CoQH-CF compared to subjects receiving Coenzyme Q10. Oxidized Coenzyme Q10 in plasma was higher (P < 0.001) in subjects receiving CoQH-CF compared to subjects receiving Coenzyme Q10 resulting in a 3.3-fold higher plasma AUC_{0–72 h} (329% increase). Total CoQ10 reached maximum plasma concentrations 15.5 ± 19.6 h after supplementation with CoQH-CF and 26.5 ± 25.8 h after supplementation with Coenzyme Q10, respectively. Thus, reduced Coenzyme Q10 liquid soft gel formulation was found to be superior to the commercial formulation of Coenzyme Q10 for bioavailability.     

Effect of ozone on microbial,chemical and sensory attributes of shucked mussels

The effect of ozonation in aqueous solution (O₃ concentration=1 mg/l, time of ozonation: 60 and 90 min) on the shelf-life of shucked, vacuum-packaged mussels, stored under refrigeration was studied by monitoring the microbiological, chemical and sensory changes occurring in mussel samples, for a period of 12 days. Non-ozonated vacuum-packaged mussels served as the control sample. Ozonation affected populations of bacteria namely, aerobic plate count (APC) (0.7–2.1 log cycle reduction), Pseudomonas spp. (0.5–1.1 log cycle reduction) and H₂S-producing bacteria (1.1–2.5 log cycle reduction), Brochothrix thermosphacta (0.3–1.4 log cycle reduction), lactic acid bacteria (0.3–0.8 log cycle reduction) and Enterobacteriaceae (0.5–1.5 log cycle reduction). The effect of ozonation was more pronounced at the longer time of ozonation. Of the chemical indicators of spoilage monitored, trimethylamine values of all mussel samples remained relatively low throughout the entire storage period, attaining values of 7.5, 6.0 and 6.4 mg N/100 g for the control and ozonated for 60 and 90 min samples, respectively, on day 12 of storage. Total volatile basic nitrogen (TVB-N) values similarly remained relatively low (⩽20 mg N/100 g) until day 6 of storage, and increased to 31.9, 24.2 and 26.9 mg N/100 g mussel meat for the control and ozonated for 60 and 90 min samples, respectively, on day 12 of storage. Initial TBA values were surprisingly high (30–35 mg MA/kg) and decreased to 23.0, 21.7 and 13.3 mg MA/kg mussel meat on day 12 of storage for the control and the ozonated for 60 and 90 min samples, respectively. Sensory evaluation (odor, taste and texture) of cooked mussels showed a good correlation with bacterial populations. On the basis of sensory analyses, a shelf-life of 12 days was obtained for vacuum-packaged mussels ozonated for 90 min as compared to a shelf-life of 9 days for the control sample.     

Bean cultivars (Phaseolus vulgaris L.) have similar high antioxidant capacity,in vitro inhibition of α-amylase and α-glucosidase while diverse phenolic composition and concentration

Common beans are a good source of essential nutrients such as protein, fiber, vitamins, and minerals; they also contain phenolic compounds and other phytochemicals. Phenolic compounds exhibit high antioxidant capacity that promotes health benefits by reducing oxidative stress. The objective was to compare the composition and quantity of anthocyanins and other non-colored phenolic compounds in fifteen improved bean cultivars from Mexico and Brazil and their relation to antioxidant capacity and enzymes related to type-2 diabetes. Samples were analyzed for total phenolic compounds (TP), flavonoids, antioxidant capacity (AC), tannins and total anthocyanins. Type and quantity were evaluated by HPLC-ESI-MS. Delphinidin glucoside (0.9–129.0 mg/100 g dry coat), petunidin glucoside (0.7–115.0 mg/100 g dry coat) and malvidin glucoside (0.14–52.0 mg/100 g dry coat). Anthocyanidins were positively correlated when quantified by HPLC and colorimetric analysis (R = 0.99). Cultivar Negro-Otomi presented the highest concentration of anthocyanins (250 mg/100 g dry coat). Seventeen non-colored phenolic compounds were identified among cultivars; catechin, myricetin 3-O-arabinoside, epicatechin, vanillic acid, syringic acid and o-coumaric acid, presented the highest concentrations among identified phenolic compounds. The AC of all fifteen bean cultivars did not show significant differences (p > 0.05) ranging from 185.2 (FM-67) to 233.9 (FM-199) mmol TE/g coat. Compounds in the coat extracts of pinto and black cultivars were the most efficient to inhibit α-amylase and α-glucosidase. Studied cultivars differed in composition and concentration of phenolics including anthocyanins; however, there was no effect on AC as measured by oxygen radical absorbance capacity. Black beans contained delphinidin and ferulic acid, compounds commonly used as ingredients in functional foods due to their associated health benefits.     

The effect of the duration of infusion,temperature, and water volume on the rutin content in the preparation of mate tea beverages: An optimization study

The consumption of tea beverages has increased 30% over the last decade, mainly due to the presence of bioactive compounds. Mate tea, produced by infusing the leaves and stems of Ilex paraguariensis, is the most widely consumed beverage in Brazil. The present study employed a central composite experimental design to optimize the transfer of rutin from the leaves and stems to the beverage during the infusion process. The optimum condition was applied to three batches of mate tea beverages from five commercial samples. Analysis of the rutin content was performed by high performance liquid chromatography coupled to a photo diodo array detector. The maximum rutin content in the beverage was obtained when the infusion was performed using 2 g of mate tea added to 100 mL of water at 72 °C and infused for 9 min. The commercial tea beverages prepared under these conditions contained from 0.16 to 1.1 mg of rutin in the ready-to-drink product.     

Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT + S), with ascorbic acid (GT + AA) and with sucrose and ascorbic acid (GT + S + AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P < 0.05) enhanced in GT + S + AA formulations (AUC_0–6 h = 3237.0 and 181.8 pmol h/L plasma respectively) relative to GT control (AUC_0–6 h = 1304.1 and 61.0 pmol h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (～51–53%) relative to EGCG and epicatechin gallate (ECG) (<20%) and was modestly enhanced in GT + S and GT + S + AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P < 0.05) higher from GT + S + AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea.