Antioxidant and Phenolics: Cranberries

The antioxidant response mechanism by which phenolic phytochemicals show their positive benefits in plants and animals is not very well understood. The ability of cranberry juice powder (CP), ellagic acid (EA), rosmarinic acid (RA) and their synergies to elicit a phenolic response in germinating fava bean was investigated. Results indicated that elicitation with CP, EA, RA and their synergies resulted in increased endogenous phenolic synthesis linked to the stimulation of pentose phosphate pathway (PPP). Further, the stimulation of PPP was linked to the accumulation of free proline, suggesting a possible coupling of proline biosynthesis with PPP. Elicitation also resulted in the stimulation of guaiaicol peroxidase, suggesting a possible involvement in modulating structural development of the germinating sprout. Exogenous phenolic elicitation also resulted in the formation of malondialdehyde, which was gradually reduced because of the activation of antioxidant enzyme systems superoxide dismutase and catalase. The results indicate that the possible mode of action of exogenous phenolic phytochemicals in dark germinating fava bean could be by stimulating the PPP linked to proline biosynthesis and by the activation of the antioxidant enzyme system. The results also suggest that pure exogenous phenolics, EA and RA appeared to be effective when they were present in a cranberry phenolic background, suggesting a possible synergistic mode of action between EA, RA and cranberry phenolics in generating an endogenous fava bean antioxidant enzyme response.

Cranberry pomace modified by solid-state bioprocessing with the food-grade fungi Rhizopus oligosporus and Lentinus edodes was investigated for antimicrobial effects against Helicobacter pylori. The results indicated that solid-state bioprocessing enriched the cranberry pomace with phenolic antioxidants and important phenolic phytochemicals such as ellagic acid. The antimicrobial activity of the extracts against H. pyloriwas also enriched by solid-state bioprocessing. Further, the results also indicated that the antimicrobial activity correlated strongly with total soluble phenolic content and ellagic acid, suggesting different modes of antimicrobial function. A dose-dependent analysis of antimicrobial activity suggested that there could be a possible synergistic mode of interaction between the phenolic phytochemicals. Solid-state bioprocessing of cranberry pomace using the food-grade fungi R. oligosporus and L. edodes could therefore be an innovative approach to develop antimicrobial ingredients for dietary management of H. pylori infections.

The effects of cranberry phenols and their possible synergistic reactions with the functional biphenyls ellagic acid (EA) and rosmarinic acid (RA) in modulating cellular antioxidant response were examined using H2O2-treated minced pork steak as an animal model for oxidatively-stressed muscle tissue. Changes in the cellular antioxidant enzyme response pathway were used as markers of the redox status of tissues, and changes in the pentose phosphate pathway (PPP) and a possible link to proline biosynthesis were also assessed. Treatments with cranberry juice powder (CP), EA and RA and their combinations reduced or helped counter oxidative stress as indicated by reductions in the formation of malondialdehyde, whilst levels of cellular antioxidant enzyme systems involving superoxide dismutase (SOD), catalase (CAT) and peroxidase were stimulated. CP, EA, RA and their combinations also stimulated PPP activity and accumulation of free proline, suggesting a possible coupling of proline biosynthesis with PPP. It is further suggested that this coupled proline-PPP response may be involved in the stimulation of cellular antioxidant enzyme response by replenishing cellular NADPH2. It is concluded that these exogenously-applied phenols can reduce the oxidative stress in minced pork steak tissues, and that the pure exogenous phenols, EA and RA, appeared to be effective when they were present in a cranberry phenol background, suggesting a possible synergistic mode of action between EA, RA and cranberry phenols in mediating a cellular antioxidant enzyme response.

Cranberry pomace is a waste product from the cranberry juice processing industry. It contains a range of phenol antioxidants which may be of use for the control of food-borne pathogens. Previous research has shown that solid-state fermentation of cranberry pomace by Rhizopus oligosporus improves its phenol and antioxidant profiles, and, in this study, the release of phenol aglycones during this fermentation was assessed in relation to changes in antioxidant functionality, diphenyl mobilization and antimicrobial activity against Listeria monocytogenes, Vibrio parahaemolyticus and Escherichia coli O157:H7. After a 20-day fermentation, pomaces were tested for changes in phenol levels and profiles, antioxidant potential and antimicrobial activities. Pomace fermentation increased levels of soluble phenols generally and ellagic acid in particular, whilst antioxidative activity was also increased. Antimicrobial activity towards E. coli was correlated with ellagic acid levels and antioxidative activity as measured by DPPH, whilst antimicrobial activity towards the other 2 pathogens was correlated with soluble phenols and antioxidative activity as measured by beta-carotene oxidation. It is suggested that these differences may reflect membrane hyperacidification-based and membrane transport disruption-based modes of inhibition, respectively. Possible use of this fermented cranberry waste as an antimicrobial ingredient in foods and feeds is discussed.

Effects of solid state fermentation with Lentinus edodes on antimicrobial activity of cranberry pomace were investigated against Listeria monocytogenes, Vibrio parahaemolyticus and Escherichia coli O157:H7. Cranberry pomace inoculated with L. edodes spores was incubated at 28°C for 20 days. Antioxidant potential, changes in phenols profiles and antimicrobial activity during this time were assessed. Solid state fermentation increased the antimicrobial activity of cranberry pomace extracts in terms of increased levels of total soluble phenols, enrichment of ellagic acid and increased antioxidative activity. Inhibition of L. monocytogenes was well correlated with all 3 of these factors, while inhibition of E. coli and V. parahaemolyticus was correlated with the highest levels of ellagic acid and/or antioxidant potential, as measured by beta-carotene oxidation. It is suggested that the antimicrobial sensitivity of the 3 pathogens tested may be attributed to disruption of membrane integrity, blockage of membrane ion channels or inhibition of ATP synthesis as a result of electron transport chain disruption. Furthermore it is suggested that bioprocessing using L. edodes, has the potential to extend the application of cranberry pomace as an antimicrobial extract in foods and feeds.

Cranberry pomace is a byproduct of the cranberry processing industry that can be targeted for production of value-added phenolic ingredients. Bio-processing of pomace by a solid state process using food grade fungi provides a unique strategy to improve nutraceutical properties and to produce functional phenolic ingredients. The investigation was carried out to understand the changes and mobilizations of simple phenolics and diphenyls and their antioxidant properties in cranberry pomace processed by solid-state growth using food grade fungus Lentinus edodes. The role of -glucosidase in the mobilization of phenolic antioxidants by hydrolysis of the glycosides was also investigated. During the course of solid-state growth there was an increase in the extractable phenolic content. Antioxidant activity measured by both 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) inhibition system and -carotene oxidation model system increased over the course of growth. Both phenolics and antioxidant capacity correlated with the increase in the -glucosidase activity and peaked in a similar manner, showing that the enzyme may play an important role in the release of phenolic aglycones from cranberry pomace and, therefore, increase the antioxidant capacity. In addition, HPLC analysis indicated that the cranberry pomace was enriched with ellagic acid to a level of 350 g/g dw of pomace.

The effects of controlled-atmosphere (CA) storage on the firmness, respiration rate, quality, weight loss, total phenolics and flavonoids contents, and total antioxidant activities of the Pilgrim and Stevens cultivars of cranberries (Vaccinium macrocarpon Aiton) have been studied during storage in atmospheres of 2, 21, and 70% O2 with 0, 15, and 30% CO2 (balance N2); and 100% N2 at 3 C. Elevated CO2 concentrations decreased bruising, physiological breakdown, and decay of berries, thereby reducing fruit losses. Respiration and weight loss of fruits decreased, but fruit softening increased, at higher CO2 concentrations. Accumulations of acetaldehyde, ethanol, and ethyl acetate varied by cultivar and storage atmosphere but were generally highest in the 2 and 70% O2 and 100% N2 atmospheres and increased in response to elevated CO2 concentrations. Overall, the 30% CO2 plus 21% O2 atmosphere appeared optimal for the storage of cranberries. Sensory analysis is required, however, to confirm that accumulations of fermentation products at this atmosphere are acceptable for consumers. Stevens fruits had a higher phenolics content and total antioxidant activity than Pilgrim fruits. The storage atmosphere did not affect the content of total phenolics or flavonoids. However, the total antioxidant activity of the fruits increased overall by about 45% in fruits stored in air. This increase was prevented by storage in 30% CO2 plus 21% O2.

Cranberry pomace is a byproduct of the cranberry processing industry that can be targeted for production of value-added phenolic ingredients. Bio-processing of pomace by solid state fermentation (SSF) using food grade fungi provides unique strategies to improve nutraceutical properties and to produce functional phenolic ingredients. Several functional phenolic phytochemicals exist as glycosides or as other conjugated forms with reduced biological activity. We hypothesize that during SSF the fungal glycosidases mobilize some phenolic antioxidants in cranberry pomace and their activity by hydrolysis via β-glucosidase and releasing the aglycone. To develop this strategy we used food grade fungus Rhizopus oligosporus. Our goal was to target the release of simple phenolic aglycones and mobilized diphenyls. SSF of cranberry pomace was done for 16 days with nitrogen sources, ammonium nitrate (NH 4NO 3) and fish protein hydrolysate (FPH). The two nitrogen treatments increased water extractable phenolics by 15–26% by day 10 in the pomace. Antioxidant protection factor was highest on day 10 for both nitrogen treatments and was 20–25% higher than control for water extracts and 16.5–19.5% for ethanol extracts. The DPPH radical inhibition (DRI) capacity increased by 5% only for the NH 4NO 3 treatment and gradually decreased for FPH treatment in water extracts. There was no significant change in DRI of the ethanol extracts. The β-glucosidase activity increased by 60-fold for NH 4NO3 treatment and by over 100-fold for FPH treatment and correlated well with the increase in the extractable phenolics and antioxidant activity. Changes in diphenyl profiles during the solid-state process analyzed using HPLC indicated that ellagic acid increased by 4–5 fold in water extracts for both the nitrogen treatments. This increase was between 15–27% in the ethanol extracts. We conclude that SSF of cranberry pomace increased the antioxidant activity concurrent with increased β-glucosidase activity. The HPLC profile showed ellagic acid, a compound with anti-carcinogenic properties was enriched. The antioxidant function has implications for prevention of major oxidation-linked diseases such as cancer and CVD. This value-added SSF strategy is an innovative approach to enhance nutraceutically-relevant functional phytochemicals for food and feed applications.

A GC-MS method is reported for separation and characterization of widely different amounts of benzoic and phenolic acids as their trimethylsilyl derivatives simultaneously in cranberry. Fifteen benzoic and phenolic acids (benzoic, o-hydroxybenzoic, cinnamic, m-hydroxybenzoic, p-hydroxybenzoic, p-hydroxyphenyl acetic, phthalic, 2,3-dihydroxybenzoic, vanillic, o-hydroxycinnamic, 2,4-dihydroxybenzoic, p-coumaric, ferulic, caffeic, and sinapic acid) were identified in cranberry fruit in their free and bound forms on the basis of GC retention times and simultaneously recorded mass spectra. Except for benzoic, p-coumaric, caffeic, ferulic, and sinapic acids, 10 other phenolic acids identified have not been reported in cranberry before. The quantitation of the identified components was based on total ion current (TIC). The experimental results indicated cranberry fruit contains a high content of benzoic and phenolic acids (5.7 g/kg fresh weight) with benzoic acid being the most abundant (4.7 g/kg fresh weight). The next most abundant are p-coumaric (0.25 g/kg fresh weight) and sinapic (0.21 g/kg fresh weight) acid. Benzoic and phenolic acids occur mainly in bound forms and only about 10% occurs as free acid.

Polyphenolic compounds in cranberries have been investigated to determine their role in protection against cardiovascular disease and some cancers. Extracts of whole fruit were assayed for radical-scavenging activity and tumor growth inhibition using seven tumor cell lines. Selective inhibition of K562 and HT-29 cells was observed from a methanolic extract in the range of 16-125 microg/mL. Radical-scavenging activity was greatest in an extract composed primarily of flavonol glycosides. Seven flavonol glycosides were isolated and purified from whole fruit for further evaluation; the anthocyanin cyanidin 3-galactoside was also purified for comparison with the flavonoids. Three flavonol monoglycosides were newly identified by (13)C NMR as myricetin 3-alpha-arabinofuranoside, quercetin 3-xyloside, and 3-methoxyquercetin 3-beta-galactoside (isorhamnetin); the other four isolated were the previously identified myricetin 3-beta-galactoside, quercetin 3-beta-galactoside, quercetin 3-alpha-arabinofuranoside, and quercetin 3-alpha-rhamnopyranoside. These compounds were evaluated for 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity and ability to inhibit low-density lipoprotein oxidation in vitro. Most of the flavonol glycosides showed antioxidant activity comparable or superior to that of vitamin E; cyanidin 3-galactoside showed activity superior to that of the flavonoids as well as vitamin E or Trolox in both antioxidant assays.

Ten cranberry (Vaccinium macrocarpon Aiton) cultivars were evaluated for oxygen radical absorbance capacity (ORAC), anthocyanins, and total phenolics contents after three months of storage at 0, 5, 10, 15, and 20 C. The antioxidant capacity of cranberry was affected by cultivars and storage temperatures. Among the 10 cranberry cultivars used in this study, Early Black, Crowley, and Franklin had higher antioxidant capacities than the other cultivars. ORAC values, anthocyanins, and total phenolics contents increased during storage. The highest increases in antioxidant activity, anthocyanin, and phenolics contents occurred at 15 C storage. Fruit stored at 20 C had lower ORAC values than those stored at 15 C. A positive relationship existed between ORAC values and anthocyanin or phenolic content in all 10 cranberry cultivars at different storage temperatures.

Objective: To assess whether consumption of 500 ml of blueberry juice or cranberry juice by healthy female subjects increased plasma phenolic content and antioxidant capacity.

Design: Latin square arrangement to eliminate ordering effects. After an overnight fast, nine volunteers consumed 500 ml of blueberry juice, cranberry juice or a sucrose solution (control); each volunteer participated on three occasions one week apart, consuming one of the beverages each time. Blood samples were obtained by venipuncture at intervals up to four hours after consumption of the juices. Urine samples were also obtained four hours after consuming the juice.

Results: Consumption of cranberry juice resulted in a significant increase in the ability of plasma to reduce potassium nitrosodisulphonate and Fe(III)-2,4,6-Tri(2-pyridyl)-s-triazine, these measures of antioxidant capacity attaining a maximum after 60-120 min. This corresponded to a 30% increase in vitamin C and a small but significant increase in total phenols in plasma. Consumption of blueberry juice had no such effects.

Conclusion: The increase in plasma antioxidant capacity following consumption of cranberry juice could mainly be accounted for by an increase in vitamin C rather than phenolics. This also accounted for the lack of an effect of the phenolic-rich but vitamin C-low blueberry juice.