Boxin Ou

Impact of Alkalization on the Antioxidant and Flavanol Content of Commercial Cocoa Powders

Cocoa is a food ingredient that is important for the contribution of flavor to foods but is also associated with potential health benefits. The chemistry thought to be responsible for its cardiovascular health benefits is the flavanol (flavan-3-ol) antioxidants. Evidence from the literature indicates that natural cocoas are high in flavanols, but when the cocoa is processed with alkali, also known as Dutch processing or Dutching, the flavanols are substantially reduced. This paper provides a survey of the physical and chemical composition of representative natural cocoas and lightly, medium, and heavily alkalized cocoas. As part of the survey, both brown/black and red/brown alkali-processed cocoas were measured. Natural cocoa powders have an extractable pH of 5.3-5.8. Alkalized cocoa powders were grouped into lightly treated (pH 6.50-7.20), medium-treated (pH 7.21-7.60), and heavily treated (pH 7.61 and higher). The natural, nonalkalized powders had the highest ORAC and total polyphenols and flavanols (including procyanidins). These chemical measurements showed a linear decrease as the extractable pH of the cocoa powder increased. Likewise, the flavanol monomers, oligomers, and polymers all showed a linear decrease with increasing pH of the final cocoa powder. When brown/black cocoa powders were compared to red cocoa powders, similar decreases in flavanols were observed with increased alkalization. The average total flavanol contents were 34.6 +/- 6.8 mg/g for the natural cocoas, 13.8 +/- 7.3 mg/g for the lightly processed cocoas, 7.8 +/- 4.0 mg/g for the medium processed cocoas, and 3.9 +/- 1.8 mg/g for the heavily processed cocoa powders. The observed linear and predictable impact of alkalization on flavanol content is discussed with respect to other reports in the literature as well as what implications it may have on diet and food manufacturing.

When east meets west: the relationship between yin-yang and antioxidation-oxidation

Ancient traditional Chinese medicine (TCM) has effectively relied on the theory of yin‐yang balance in diagnoses and treatments of diseases and disorders for more than 2000 years. However, in eastern society, yin‐yang is regarded as an incomprehensible ideology without definite physical meaning. Consequently, the yin‐yang balance in medicine has not been studied by modern scientific means. In the western world, yin‐yang balance is often misunderstood as a religious belief or a principle of lifestyle. Herein, we attempted to define the physical meaning of yin‐yang in TCM by correlating it with biochemical processes. We propose that yin‐yang balance is antioxidation‐oxidation balance with yin representing antioxidation and yang as oxidation. Our proposal is partially supported by the fact that the yin‐tonic traditional Chinese herbs have, on average, about six times more antioxidant activity and polyphenolic contents than the yang‐tonic herbs. Our hypothesis opens an avenue to systematically study the yin‐yang balance and its health implications with the use of modern biochemical tools.—Ou, B., Huang, D., Hampsch‐Woodill, M., Flanagan J.A. When east meets west: the yelationship between yin‐yang and antioxidation‐oxidation. FASEB J. 17, 127–129 (2003)

Survey of Commercially Available Chocolate- and Cocoa-Containing Products in the United States. 2. Comparison of Flavan-3-ol Content with Nonfat Cocoa Solids, Total Polyphenols, and Percent Cacao

A survey of a broad range of chocolate- and cocoa-containing products marketed in the United States was conducted to provide a more detailed analysis of flavan-3-ol monomers, oligomers, and polymers, which can be grouped into a class of compounds called procyanidins. Samples consisted of the three or four top-selling products within the following six categories: natural cocoa powder, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized for percent fat (% fat), percent nonfat cocoa solids (% NFCS), antioxidant level by ORAC, total polyphenols, epicatechin, catechin, total monomers, and flavan-3-ol oligomers and polymers (procyanidins). On a gram weight basis epicatechin and catechin content of the products follow in decreasing order: cocoa powder > baking chocolate > dark chocolate = baking chips > milk chocolate > chocolate syrup. Analysis of the monomer and oligomer profiles within product categories shows there are two types of profiles: (1) products that have high monomers with decreasing levels of oligomers and (2) products in which the level of dimers is equal to or greater than the monomers. Results show a strong correlation (R(2) = 0.834) of epicatechin to the level of % NFCS and also very good correlations for N = 2-5 oligomers to % NFCS. A weaker correlation was observed for catechin to % NFCS (R(2) = 0.680). Other analyses show a similar high degree of correlation with epicatechin and N = 2-5 oligomers to total polyphenols, with catechin being less well correlated to total polyphenols. A lesser but still good correlation exists between the calculated percent cacao (calcd % cacao) content, a proxy for percent cacao, and these same flavanol measures, with catechin again showing a lesser degree of correlation to calcd % cacao. Principal component analysis (PCA) shows that the products group discretely into five classes: (1) cocoa powder, (2) baking chocolate, (3) dark chocolate and semisweet chips, (4) milk chocolates, and (5) syrup. PCA also shows that most factors group closely together including the antioxidant activity, total polyphenols, and the flavan-3-ol measures with the exception of catechin and % fat in the product, which group separately. Because catechin distribution appears to be different from the other flavan-3-ol measures, an analysis of the epicatechin to catechin ratio was done, indicating there is a >5-fold variation in this measure across the products studied. The cocoa-containing products tested range from cocoa powder with 227.34 +/- 17.23 mg of procyanidins per serving to 25.75 +/- 9.91 mg of procyanidins per serving for chocolate syrup. These results are discussed with respect to other studies on commercial products, the bioavailability of the flavanols, and the possible role of processing on the amount of catechin in products.

Preservation of Cocoa Antioxidant Activity, Total Polyphenols, Flavan-3-ols, and Procyanidin Content in Foods Prepared with Cocoa Powder

Little is known about the effects of common cooking processes on cocoa flavanols. Antioxidant activity, total polyphenols (TP), flavanol monomers, and procyanidin oligomers were determined in chocolate frosting, a hot cocoa drink, chocolate cookies, and chocolate cake made with natural cocoa powder. Recoveries of antioxidant activity, TP, flavanol monomers, and procyanidins ranged from 86% to over 100% in the chocolate frosting, hot cocoa drink, and chocolate cookies. Losses were greatest in the chocolate cake with recoveries ranging from 5% for epicatechin to 54% for antioxidant activity. The causes of losses in baked chocolate cakes were investigated by exchanging baking soda with baking powder or combinations of the 2 leavening agents. Use of baking soda as a leavening agent was associated with increased pH and darkening color of cakes. Losses of antioxidant activity, TP, flavanol monomers, and procyanidins were associated with an increased extractable pH of the baked cakes. Chocolate cakes made with baking powder for leavening resulted in an average extractable pH of 6.2 with essentially complete retention of antioxidant activity and flavanol content, but with reduced cake heights and lighter cake color. Commercially available chocolate cake mixes had final pHs above 8.3 and contained no detectable monomeric flavanols after baking. These results suggest that baking soda causes an increase in pH and subsequent destruction of flavanol compounds and antioxidant activity. Use of an appropriate leavening agent to moderate the final cake pH to approximately 7.25 or less results in both good leavening and preservation of cocoa flavanols and procyanidins.

Daily consumption of a mangosteen-based drink improves in vivo antioxidant and anti-inflammatory biomarkers in healthy adults: a randomized, double-blind, placebo-controlled clinical trial

Mangosteen (Garcinia mangostana) is a tropical fruit cultivated mainly in Southeast Asia. Recent studies have shown mangosteen has many health benefits. In this study, we aimed to determine the effects of a mangosteen-based beverage on antioxidant and anti-inflammatory and immunity biomarkers in plasma of healthy adults. A randomized, double-blind, placebo-controlled clinical trial was conducted using 60 participants, 30 men, and 30 women, ages 18–60. Participants were randomly divided into two groups, placebo and mangosteen groups, with the same number of male and female participants in each group. The trial duration was 30 days. ORAC as an antioxidant biomarker was measured in both groups. It was found that after the 30-day trial, the group given the mangosteen-based drink formula showed 15% more antioxidant capacity in the bloodstream than did the placebo group. As for the inflammatory biomarkers, in the mangosteen group, between the preintervention and postintervention, the C-reactive protein level significantly decreased by 46%, while no significant decreases for the same biomarker was observed in the placebo group. Immunity biomarkers IgA, IgG, IgM, C3 and C4 were not affected in either group. In addition, the effects on hepatic function (Aspartate Aminotransferase and Alanine Aminotransferase) and kidney function (creatinine) were investigated. Our results indicated that after the 30-day consumption of the beverage, there were no side effects on human hepatic and kidney functions. The outcome of this study showed that the mangosteen-based formula significantly increases antioxidant capacity and possesses anti-inflammatory benefits with no side effects on immune, hepatic, and renal functions for long-term consumption.

West African Sorghum bicolor Leaf Sheaths Have Anti-Inflammatory and Immune-Modulating Properties In Vitro

The impact of chronic inflammatory conditions on immune function is substantial, and the simultaneous application of anti-inflammatory and immune modulating modalities has potential for reducing inflammation-induced immune suppression. Sorghum-based foods, teas, beers, and extracts are used in traditional medicine, placing an importance on obtaining an increased understanding of the biological effects of sorghum. This study examined selected anti-inflammatory and immune-modulating properties in vitro of Jobelyn™, containing the polyphenol-rich leaf sheaths from a West African variant of Sorghum bicolor (SBLS). Freshly isolated primary human polymorphonuclear (PMN) and mononuclear cell subsets were used to test selected cellular functions in the absence versus presence of aqueous and ethanol extracts of SBLS. Both aqueous and nonaqueous compounds contributed to reduced reactive oxygen species formation by inflammatory PMN cells, and reduced the migration of these cells in response to the inflammatory chemoattractant leukotriene B4. Distinct effects were seen on lymphocyte and monocyte subsets in cultures of peripheral blood mononuclear cells. The aqueous extract of SBLS triggered robust upregulation of the CD69 activation marker on CD3- CD56+ natural killer (NK) cells, whereas the ethanol extract of SBLS triggered similar upregulation of CD69 on CD3+ CD56+ NKT cells, CD3+ T lymphocytes, and monocytes. This was accompanied by many-fold increases in the chemokines RANTES/CCL5, Mip-1α/CCL3, and MIP-1β/CCL4. Both aqueous and nonaqueous compounds contribute to anti-inflammatory effects, combined with multiple effects on immune cell activation status. These observations may help suggest mechanisms of action that contribute to the traditional use of sorghum-based products, beverages, and extracts for immune support.

Decrease of free radical concentrations in humans following consumption of a high antioxidant capacity natural product.

ORAC and other in vitro methods have to date proved useful in measuring antioxidant potential in foods. In order to better understand the potential relationship between diet and free radical production/mitigation, an in vivo analytic method can provide new insight into directly measuring reactive oxidant species (ROS). Dihydrorhodamine-6G (DHR6G) is indiscriminate to the various free radicals found in humans, and therefore can be useful in quantifying total ROS in vivo. Our aim was to investigate whether the total ROS in human subjects can be quantified using DHR6G after intake of a blend of antioxidants-rich fruit and vegetable-based materials. Twelve participants were given 100 mg of a proprietary blend of fruit, vegetable, and herb powders and concentrates commercially marketed under the trade name “Spectra™”. Blood samples were collected at 0, 60, 120 and 180 min and were subsequently tested for ROS in serum using DHR6G as a fluorescent probe. By quantifying this fluorescence, we were able to measure ROS concentrations in human blood. This method is both reliable and efficient for evaluating the efficacy of antioxidants against ROS in vivo. Our data indicate that eleven participants responded to the intake of Spectra™ by significant decreases of ROS concentrations.

Functional beverage of Garcinia mangostana (mangosteen) enhances plasma antioxidant capacity in healthy adults

This study was to investigate the absorption and antioxidant effect of a mangosteen-based functional beverage in humans. The beverage contained mangosteen, aloe vera, green tea, and multivitamins. A randomized, double-blind, placebo-controlled clinical trial was conducted with generally healthy male and female subjects between 18 and 60 years of age. Ten men and 10 women participated in this study. Participants were randomly divided into two groups, treatment and placebo group. Participants received either a daily single dose (245 mL) of the beverage or a placebo. Blood samples were collected from each participant at time points 0, 1, 2, 4, and 6 h. The plasma samples were analyzed by LC/MS for α-mangostin and vitamins B2 and B5. Results indicated that the three analytes were bioavailable, with observed Cmax at around 1 h. The antioxidant capacity measured with the oxygen radical absorbance capacity (ORAC) assay was increased with a maximum effect of 60% after 1 h, and the elevated antioxidant level lasted at least 6 h. This study demonstrated the bioavailability of α-mangostin and B vitamins from a xanthone-rich beverage and the mechanisms of the increase in plasma antioxidant may be direct effects from antioxidants, enhancement of endogenous antioxidant activity through activation of Nrf2 pathway, and synergism of the antioxidants.

Supercritical CO2 Decaffeination of Unroasted Coffee Beans Produces Melanoidins with Distinct NF‐κB Inhibitory Activity

UNLABELLED The supercritical CO(2)-decaffeination process causes unroasted coffee beans to turn brown. Therefore, we suspected that the decaffeinated beans contained melanoidins. Decaffeinated unroasted coffee extract absorbed light at 405 nm with a specific extinction coefficient, K(mix 405 nm), of 0.02. Membrane dialysis (molecular weight cut-off, 12 to 14 kDa) increased the K(mix 405 nm) value 15 fold. Gel filtration chromatography showed that the high-MW fraction (MW > 12 kDa) had an elution profile closer to that of melanoidins of medium-roast coffee than to the corresponding fraction of unroasted coffee, indicating the presence of melanoidins in decaffeinated unroasted beans. Using murine myoblast C2C12 cells with a stably transfected nuclear factor-κB (NF-κB) luciferase reporter gene, we found that the high-MW fraction of decaffeinated unroasted beans had an NF-κB inhibitory activity of IC(50) = 499 μg/mL, more potent than that of regular-roast coffee (IC(50) = 766 μg/mL). Our results indicate that melanoidins form during the supercritical CO(2)-decaffeination process and possess biological properties distinct from those formed during the regular roasting process. PRACTICAL APPLICATION We discovered the roasting effect of decaffeination process, reporting the discovery of melanoidins in green (unroasted) decaf coffee beans. Our results indicated that melanoidins form during the supercritical CO2-decaffeination process and possess biological properties distinct from those formed during the regular roasting process. Our results offer new insights into the formation of bioactive coffee components during coffee decaffeination process.

Rapid quantitation of avenanthramides in oat-containing products by high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-TQMS)

Avenanthramides (AVNs) are a family of nitrogen-containing phenolic compounds produced in oat; AVN 2c, 2p, and 2f are the three major members. An LC-MS/MS method was developed, with the limit of detection (LOD) and the limit of quantitation (LOQ) being, respectively, 0.29ng/mL and 1.96ng/mL for AVN 2c, 0.24ng/mL and 0.60ng/mL for AVE 2p, and 0.42ng/mL and 2.2ng/mL for AVN 2f. The method was validated in oat-containing hot cereal and snack bar samples. The recovery of AVN 2c, 2p, and 2f from these two oat products was 95-113%, and the relative standard deviations ranged from 5% to 9%. This method was used to evaluate oat products and raw oat samples. The effects of location and variety on AVN composition were investigated. The method presented here provides a novel and rapid tool to quantitate the abundance of AVN 2c, 2p, and 2f in oat-containing products.