Massimo F. Marcone

Synergistic, additive, and antagonistic effects of food mixtures on total antioxidant capacities.

Different foods possess different bioactive compounds with varied antioxidant capacities. When foods are consumed together, the total antioxidant capacity of food mixtures may be modified via synergistic, additive, or antagonistic interactions among these components, which may in turn alter their physiological impacts. The main objective of this study was to investigate these interactions and identify any synergistic combinations. Eleven foods from three categories, including fruits (raspberry, blackberry, and apple), vegetables (broccoli, tomato, mushroom, and purple cauliflower), and legumes (soybean, adzuki bean, red kidney bean, and black bean) were combined in pairs. Four assays (total phenolic content, ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl, radical scavenging capacity, and oxygen radical absorbance capacity) were used to evaluate the antioxidant capacities of individual foods and their combinations. The results indicated that within the same food category, 13, 68, and 21% of the combinations produced synergistic, additive, and antagonistic interactions, respectively, while the combinations produced 21, 54, and 25% synergistic, additive, and antagonistic effects, respectively, across food categories. Combining specific foods across categories (e.g., fruit and legume) was more likely to result in synergistic antioxidant capacity than combinations within a food group. Combining raspberry and adzuki bean extracts demonstrated synergistic interactions in all four chemical-based assays. Compositional changes did not seem to have occurred in the mixture. Results in this study suggest the importance of strategically selecting foods or diets to maximum synergisms as well as to minimum antagonisms in antioxidant activity.

Salt-soluble seed globulins of various dicotyledonous and monocotyledonous plants—I. Isolation/purification and characterization

Abstract Detailed characterization of 21 purified seed globulins derived from both monocotyledonous and dicotyledonous plants indicated that globulins from both class types (as well as within the same class type) lay within a narrow molecular weight range between 300000 and 370000 Da and were composed of multiple subunits. In all cases, purified globulins could be classified as hetero-oligomers being composed of a non-equimolar ratio of various subunits. The vast majority of subunits forming these globulins were shown to be held together by non-covalent bond forces. A small percentage of linkages between subunits were also shown to be disulfide linked, in the case of dicotyledonous seed globulins. It was also found that the majority of subunits composing the dicotyledonous and monocotyledonous seed globulins examined fell within two very narrow molecular weight ranges, i.e. 20000–27000 and 30000–39000 Da and were believed to correspond to basic and acidic subunits, respectively. Unlike monocotyledonous seed globulins, globulins derived from dicotyledonous plants were found to undergo alkaline-induced dissociation due to electrostatic repulsion between subunits. The amino acid composition of both dicotyledonous and monocotyledonous seed globulins suggests that they have a storage role and may be similar proteins based on a high content of amides (glutamic acids-glutamine and aspartic acid-asparagine and arginine). From the results of the structural and chemical data obtained in this study, it is concluded that the 11S storage globulin, having several similar properties, exists in many leguminous and non-leguminous dicotyledonous plants as well as monocotyledonous plants. This similarity among 11S storage globulins could be due either to convergent evolution in response to a common functional need, or to common ancestry.

Salt-soluble seed globulins of dicotyledonous and monocotyledonous plants II. Structural characterization

Abstract Structural characterization of 21 seed globulins from monocotyledonous and dicotyledonous plants revealed that they generally possessed low levels of α-helix and high levels of β-sheet secondary structure fractions. This finding suggested that the interior conformation of these globulins was very similar. In contrast to internal conformations, tertiary conformations indicated that very distinct surface properties existed between these two globulin classes. It now appears that surface properties are the most variable physico-chemical properties measured between globulins. Calorimetric analysis revealed that both classes of globulins possessed temperatures of denaturation (Td) which were in the temperature range of 83.8 to 107.8 °C. Although dicotyledonous seed globulins had more pronounced thermal transitions than their monocotyledonous counterparts, most endothermic transitions occurred as co-operative events indicating that the various domains present in these globulins were held together by interdependent structural domains. These interdependent domains rendered the globulins stable to high temperatures and in connection with previous data (Marcone and Yada, 1998), it was believed that both monocotyledonous and dicotyledonous seed globulins share similar structural domains.

Biochemical and biophysical properties of plant storage proteins : a current understanding with emphasis on 11S seed globulins

Abstract The increased use of non-cereal grains as supplements for nutritional and functional foods purposes will require a more in-depth understanding of the 11S globulin (their main storage protein). Studies indicate that 11S globulins from both mono- and dicotyledonous plant seeds are highly conserved with regards to their overall molecular weights, classification of subunits and internal conformation. In contrast, surface physicochemical properties appear to be highly variable between globulins. Evidence clearly indicates that great potential exists in the screening of seeds of various plant species for both “highly preferred subunit profiles” for enhanced food functional properties as well as for high concentrations of physiologically active peptides.

Properties of Cordyceps Sinensis: A review

Abstract A great mystique and aura surrounds Cordyceps sinensis (syn.: Cephalosporium sinensis), an endoparasitic fungus which has claims of anti-cancer and anti-aging properties. Much research has been conducted over the years on crude extracts and its bioactivity. More research is now focused on culturing C. sinensis and on isolating and identifying pure compounds novel to C. sinensis in an attempt to alleviate strain on demand for the natural fungi. Several polysaccharides, nucleosides and sterols all have had reports of promoting health both in vitro and in vivo. Specific and novel compounds which are characteristic to C. sinensis are emerging with reports of two new epipolythiodioxopiperazines, gliocladicillins A and B capable of inhibiting growth of HeLa, HepG2 and MCF-7 tumor cells. Exclusive to natural C. sinensis, five constituents of cordysinin (A–E) has also been reported for the first time and has been linked to anti-inflammatory properties. Although it may still be premature to believe these results should translate into pharmaceutical use, there is sufficient evidence to warrant further research.

Soluble protein fractions from pH and heat treated sodium caseinate: physicochemical and functional properties

Abstract The physicochemical (solubility and hydrophobicity), and functional (emulsifying activity index and emulsifying capacity) properties of soluble sodium caseinate fractions were studied as a function of pH (3–8) and temperature (50–100°C). Solubility was determined by measuring protein with the Bradford and 280 nm absorbency methods. Hydrophobicity was determined fluorometrically with 1-anilino-8-naphtalenesulfonate (ANS), and cis -parinaric acid (CPA). Sodium caseinate solubility was minimal at pH 3.75–4 but the ANS and CPA-hydrophobicities and the functional properties of the soluble proteins increased in this pH range. Circular dichroic and 280 nm absorptivity measurements detected conformational changes. SDS-PAGE and reversed phase HPLC revealed substantial losses of αs 1 and β caseins following pH and heat treatment (pH 3.75 and 92.5°C) and the concomitant appearance of modified compounds. Under these same conditions, the o-phtaldialdehyde values increased suggesting partial hydrolysis of sodium caseinate. The soluble protein fractions from sodium caseinate heat treated near the pI of the caseins were shown to have enhanced emulsifying activity and capacity.

Characterisation of fatty acid, carotenoid, tocopherol/tocotrienol compositions and antioxidant activities in seeds of three Chenopodium quinoa Willd. genotypes

Composition of fatty acids, tocopherols, tocotrienols, and carotenoids, and their contribution to antioxidant activities were investigated in seeds of three coloured quinoa cultivars (white, red and black). The major components and individual compounds were significantly different, and their concentrations were higher in darker seeds (p < 0.05). The oil yield was 6.58-7.17% which contained predominantly unsaturated fatty acids (89.42%). The ratio of omega-6/omega-3 fatty acid was ca. 6/1. The total tocopherol content ranged from 37.49 to 59.82 μg/g and mainly consisted of γ-tocopherol. Trace amount of α- and β-tocotrienols was also found. Black quinoa had the highest vitamin E followed by red and white quinoas. Carotenoids, mainly trans-lutein (84.7-85.6%) and zeaxanthin were confirmed for the first time in quinoa seeds, and the concentration was also the highest in black seeds. The antioxidant activities of lipophilic extracts were positively correlated with polyunsaturated fatty acids, total carotenoids and total tocopherols.

Characterization of free, conjugated and bound phenolics and lipophilic antioxidants in regular- and non-darkening cranberry beans (Phaseolus vulgaris L.)

Cranberry beans (Phaseolus vulgaris L.) from 7 different cultivars were characterized for phytochemicals and assessed for antioxidant activities. In vitro colorimetric methods were used to measure total phenolic (TPC) and total proanthocyanidin (PAC) contents. Free, conjugated and bound phenolic acids and flavonoids were also identified and quantified using HPLC-DAD/ESI-MS(n). Regular-darkening (RD) seeds contained higher TPC, PAC and flavonoids which were absent in the non-darkening (ND) seeds. Bound and conjugated phenolics in RD and ND mainly included cinnamic and benzoic acids. DPPH, FRAP and ORAC showed strong positive correlation with TPC, PAC, and with specific phenolics such as free catechin and bound p-hydroxybenzoic acid. Lipophilic extracts were rich in polyunsaturated fatty acids (69.20-76.89%). Carotenoid and tocopherol were limited to γ-tocopherol and β-carotene. Results from this study can contribute to the development of cranberry bean cultivars with increased health benefits and addresses specific phenolic contributors to antioxidant activity.

Evidence confirming the existence of a 7S globulin-like storage protein in Amaranthus hypochondriacus seed

Abstract The 7S amaranth globulin (‘conamaranthin’) was successfully identified, isolated and purified from the seed of Amaranthus hypochondriacus K343 and physico-chemical properties determined. The 7S globulin was found to exist as a hetero-oligomer with a molecular weight of 186.0 KDa and to be composed of a variety of eight non-convalently linked subunits namely: 90.1, 70.9, 40.0, 37.4, 35.2, 31.2, 23.6, and 15.6 KDa. Structural analysis of this protein using far-UV circular dichroism (CD) revealed that it possessed low levels of α-helical and very high β-sheet secondary fractions whereas near-UV CD measurements revealed that its aromatic amino acids were highly motile within its tertiary structure. The globulin was found to undergo a larger surface charge density change with decrease in pH below its isoelectric point of 5.2–5.8 than with increase in pH above this point. An acid-induced dissociation of its subunits was also noted below its determined isoelectric point. Immunochemical investigation of the 7S globulin with the anti-11S amaranth globulin antibody revealed an approximate 30% homology with its 11S amaranth globulin ‘Amaranthin’ counterpart and to be due to structural not sequential epitope recognition. In summary, this study was instrumental in demonstrating that there are substantial differences between the physico-chemical properties of the amaranth’s 7S and 11S globulins. ©

5-hydroxymethyl-2-furfural and derivatives formed during acid hydrolysis of conjugated and bound phenolics in plant foods and the effects on phenolic content and antioxidant capacity.

A common protocol for the extraction of phenolic aglycons or bound phenolics in plants generally involves hydrothermal hydrolysis in an aqueous methanol or ethanol solution containing 2-4 N HCl. However, as shown in the present study, this process also forms 5-(hydroxymethyl)furan-2-carbaldehyde (HMF) and its derivative products 5-(methoxymethyl)furan-2-carbaldehyde (MMF) and 5-(ethoxymethyl)furan-2-carbaldehyde (EMF), as identified by HPLC-DAD-ESI-MS/MS and NMR. These compounds are commonly misidentified as phenolics due to similar UV absorption at 280 nm. In this study, production of HMF, MMF, and EMF was shown to be dependent on the solvent condition and duration and temperature of hydrolysis. Fruits and vegetables produced HMF more readily than grains. HMF and its derivatives were subjected to various spectrophotometric antioxidant assays [2-diphenyl-1-picryhydrazyl radical scavenging activity (DPPH), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC)] and displayed antioxidant activity mainly in the ORAC assay. Results of this study help avoid overestimation of phenolic content and antioxidant activities of plant foods.