Sacha inchi (Plukenetia volubilis L.): Nutritional composition, biological activity, and uses.

Sacha inchi (Plukenetia volubilis L.) is native to the Peruvian Amazon and is recognised in other parts of the world as a sustainable crop with viable commercial applications. In recent years, there has been growing interest in developing the sacha inchi plant as a novel source of oil rich in unsaturated fatty acids. This review presents information on the major and minor chemical components, health effects and utilization of different parts (seeds, seed shells and leaves) of this plant. In particular, the physicochemical properties and oxidative stability of sacha inchi seed oil are described. The whole sacha inchi plant has been utilized to generate nutritional, cosmetic and pharmaceutical products with the goal to maximize its economic value. The sacha inchi plant may become a valuable resource for high value-added compounds used in many diverse food and non-food products.

Characterization of lycopene hydrocolloidal structure induced by tomato processing.

Tomato juice and paste are special type of dispersions, composed of suspended particles (pulp) dispersed in a colloidal liquid medium (serum). The bright red appearance of soluble solid separated by high speed centrifugation denoted the presence of lycopene in this fraction. Since lycopene is a hydrophobic compound it is not expected to appear in the water soluble fraction. HPLC analysis indicated presence of substantial amount of lycopene in soluble fraction which was confirmed by the appearance of lycopene crystals when observed under Transmission Electron Microscope (TEM). Considerable amount of pectin in the soluble fraction led to hypothesis that pectin facilitated the formation of hydrocolloidal system of suspended lycopene during processing. Enzyme treatment confirmed this hypothesis when pectinase effectively disrupted colloidal system and precipitated lycopene. Necessity of the divalent ions to retain the suspension signified the electrostatic interactions in the matrix surrounding lycopene crystals.

Recombinant production of omega-3 fatty acids by probiotic Escherichia coli Nissle 1917.

Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have beneficial effects on human health. The probiotic bacterium Escherichia coli Nissle is unable to produce either EPA or DHA. Escherichia coli Nissle was transformed with the pfBS-PS plasmid carrying the EPA/DHA gene cluster, previously isolated from a marine bacterium. The transgenic E. coli Nissle produced EPA when grown at 10ºC (16.52 ± 1.4 mg g(-1) cell dry weight), 15ºC (31.36 ± 0.25 mg g(-1) cell dry weight), 20ºC (13.71 ± 2.8 mg g(-1) cell dry weight), 25ºC (11.33 ± 0.44 mg g(-1) cell dry weight) or 30ºC (0.668 ± 0.073 mg g(-1) cell dry weight). Although DHA was also produced at all these temperatures, it comprised less than 0.2% of total extracted fatty acids. Transcriptomic analysis using Reverse Transcription qPCR showed upregulation of the entire gene cluster in E. coli Nissle. Among EPA/DHA genes, pfaB, pfaC and pfaD were overexpressed (expression ratio of 181.9, 39.86 and 131.61, respectively) as compared to pfaA (expression ratio of 3.40) and pfaE (expression ratio of 4.05). The EPA/DHA-producing probiotic E. coli Nissle may be used as a safe, alternative and economic source for the industrial and pharmaceutical production of EPA and DHA.

Encapsulation of folic acid and its stability in sodium alginate-pectin-poly(ethylene oxide) electrospun fibres.

In this study, we investigated the effect of alginate-pectin-poly(ethylene oxide) (PEO) electrospun fibres on the stability of folic acid. Fibre-forming solutions containing folic acid were prepared by blending low- or medium-viscosity alginate with pectin. PEO was added to make the electrospinning process possible. Folic acid encapsulated in electrospun fibres achieved close to 100% retention when stored in the dark at pH 3 after 41 days of storage. By contrast, recovery of unencapsulated folic acid was 0% and 8% within the first day when stored at pH 3 in the presence and the absence of light, respectively. Electrospun fibres produced from the combination of alginate-pectin resulted in higher retention of folic acid compared to that of alginate alone. Nucleic magnetic resonance and FTIR results show that folic acid has been encapsulated in electrospun fibres through physical entrapment.

In vitro antioxidant synergism and antagonism between food extracts can lead to similar activities in H2O2-induced cell death, caspase-3 and MMP-2 activities in H9c2 cells.

BACKGROUND: The cardio-health-promoting activity of some foods may be due to their specific antioxidant content. The antioxidant activity of a mixture of plant extracts has been shown to differ from the activity of the individual extracts. As a result, the activity of the mixture can be described as synergistic, antagonistic or additive. This in vitro study evaluated the relationship between the in vitro antioxidant capacity of mixtures and their bioactivity when cardiomyocytes (H9c2) were challenged with H(2)O(2). RESULTS: A mixture of raspberry and adzuki bean extracts produced a synergistic response and a mixture of broccoli and soybean extracts produced an antagonistic response in chemical-based antioxidant assays. When these extracts were tested in cell cultures, individually and in mixtures, the mixture of raspberry and adzuki bean protected the cardiomyocytes from H(2)O(2)-induced cell damage significantly better than the individual extracts. Conversely, the mixture of broccoli and soybean extracts was less effective in protecting H9c2 cells. The synergistic and antagonistic effects of the mixtures in protecting cell damage were brought about by enhanced or reduced ability in attenuating caspase-3 and matrix metalloproteinase-2 activities elevated by H(2)O(2). CONCLUSION: Food mixtures with synergistic antioxidant activity and protective property against reactive oxygen species-induced cell death can potentially be incorporated into novel functional foods or beverages with optimum health benefit. The antagonistic effect of food mixtures can be a health concern and thus should be avoided.

Comparison of two methods for determination of tomato paste solids: vacuum oven versus microwave oven.

Two analytical procedures used to determine total, soluble, and insoluble solids in tomato paste were evaluated. The microwave oven (MO) method was compared to the vacuum oven (VO) method. The VO method is tedious and measured the three solids fractions in the paste directly, while the MO method measured the total solids directly but used an equation to calculate the water-soluble and -insoluble solids. The MO method was faster and less labor-intensive, and yielded small but statistically significant higher values for total and insoluble solids and lower statistically significant values for soluble solids.

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.

Electrospinning of sodium alginate-pectin ultrafine fibers.

In this study, we investigated the electrospinning process of sodium alginate-pectin fibers intended to be used as a carrier for stabilizing folic acid. Fiber-forming solutions containing 0.01% (w/w) folic acid were prepared by blending low- or medium-viscosity sodium alginate with pectin in a 70 : 30 ratio to form LSAP and MSAP solutions, respectively. Similar to other polysaccharide polymers reported previously, these solutions could not be electrospun. However, the incorporation of poly(ethylene oxide) (PEO) effectively enabled the electrospinning process. Electrospun fibers of different morphologies, ranging from fiber to fiber-bead, were obtained, depending on the blend ratio, concentration, and viscosity of the polymer-PEO solution used. Fibers electrospun from 3% MSAP/PEO (80%/20% w/w) had the smallest diameter (about 40 nm), whereas fibers containing higher PEO contents were larger in diameter. Bead-free fibers were formed when 4% LSAP/PEO (50/50) and 5% LSAP/PEO (80/20 to 50/50) were electrospun. The electrical conductivity and surface tension lowering effects of PEO on the polymer solution were likely the contributing factors for the observed electrospinning behaviors. By adjusting the formulation of the polymer solution, fibers of various morphologies may be obtained to suit different end-use applications. A study is currently ongoing to investigate the effectiveness of these fibers for stabilizing folic acid.

Stability of all-trans-beta-carotene under ultrasound treatment in a model system: effects of different factors, kinetics and newly formed compounds.

The effects of factors and kinetics of all-trans-beta-carotene degradation under ultrasound treatment in a model system were investigated. The compounds of degradation were also tentatively identified by HPLC-DAD, Raman and FT-IR spectroscopy. The type of solvents and temperature were important factors in determining the degradation reaction. Liquid height, ultrasonic intensity and duty cycle of ultrasound exposure only affected the rate of degradation but did not change the nature of degradation. Degradation rate of beta-carotene in dichloromethane was the highest. Degradation rate of beta-carotene decreased with increasing of temperature. Degradation kinetics of all-trans-beta-carotene under ultrasound fitted first-order reaction at -5 to 15 degrees C, and fitted second-order reaction at 25 degrees C. Degradation products included isomers: 15-cis-beta-carotene, di-cis-beta-carotene and other compounds with function group of C-O.

Purification and identification of antioxidant peptides from grass carp muscle hydrolysates by consecutive chromatography and electrospray ionization-mass spectrometry.

Grass carp muscles were hydrolyzed with various proteases (papain, bovine pancreatin 6.0, bromelain, neutrase 1.5MG and alcalase 2.4L) to extract antioxidant peptides. The hydrolysates were assessed using methods of hydroxyl radical scavenging ability and lipid peroxidation inhibition activity. Hydrolysate prepared with alcalase 2.4L was found to have the highest antioxidant activity. It was purified using ultrafiltration and consecutive chromatographic methods including ion-exchange chromatography, multilayer coil high-speed counter-current chromatography, and gel filtration chromatography. The purified peptide, as a potent antioxidant, was identified as Pro-Ser-Lys-Tyr-Glu-Pro-Phe-Val (966.3Da) using RP-HPLC connected on-line to an electrospray ionization mass spectrometry. As well, it was found that basic peptides had greater capacity to scavenge hydroxyl radical than acidic or neutral peptides and that hydrophobic peptides contributed more to the antioxidant activities of hydrolysates than the hydrophilic peptides. In addition, the amino acid sequence of the peptide might play an important role on its antioxidant activity.

Enhancement of polyunsaturated fatty acid production by Tn5 transposon in Shewanella baltica.

Transposon Tn5 mutagenesis was used to generate random mutations in Shewanella baltica MAC1, a polyunsaturated fatty acid (PUFA)-producing bacterium. Three mutants produced 3-5 times more eicosapentaenoic acid (EPA 20:5 n-3) compared to the wild type at 10 degrees C. One of the mutants produced 0.3 mg EPA g(-1) when grown at high temperature (30 degrees C). Moreover, 2 mg docosahexaenoic acid (DHA 22:6 n-3) g(-1) was produced by S. baltica mutants at 4 degrees C. Sequencing of insertion mutation(s) showed 96% homology to trimethylamine N-oxide (TMAO) reductase gene and 85% homology to rRNA operons of E. coli. Tn5 transposon mutagenesis therefore is a suitable technique to increase PUFA formation in bacteria.

Seasonal variations of phenolic compounds in Australia-grown tea (Camellia sinensis).

Seasonal variations of phenolic compounds in fresh tea shoots grown in Australia were studied using an HPLC method. Three principal tea flavanols [epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and epigallocatechin (EGC)] and four grouped phenolics [total catechins (Cs), total catechin gallates (CGs), total flavanols (Fla), and total polyphenols (PPs)] in fresh tea shoots were analyzed and compared during the commercial harvest seasons from April 2000 to May 2001. The levels of EGCG, ECG, and CGs in the fresh tea shoots were higher in the warm months of April 2000 (120.52, 34.50, and 163.75 mg/g, respectively) and May 2000 (128.63, 44.26, and 183.83 mg/g, respectively) and lower during the cool months of July 2000 (91.39, 35.16, and 132.30 mg/g, respectively), August 2000 (91.31, 31.56, and 128.64 mg/g, respectively), and September 2000 (96.12, 33.51, and 136.90 mg/g, respectively). Thereafter, the levels increased throughout the warmer months from October to December 2000 and remained high until May 2001. In the warmer months, the levels of EGCG, ECG, and CGs were in most cases significantly higher (P < 0.05) than those in the samples harvested in the cooler months. In contrast, the levels of EGC and Cs were high and consistent in the cooler months and low in the warmer months. The seasonal variations of the individual and grouped catechins were significant (P < 0.05) between the cooler and warmer months. This study revealed that EGCG and ECG could be used as quality descriptors for monitoring the seasonal variations of phenolics in Australia-grown tea leaves, and the ratio (EGCG + ECG)/EGC has been suggested as a quality index for measuring the differences in flavanol levels in fresh tea shoots across the growing seasons. Mechanisms that induce seasonal variations in tea shoots may include one or all three of the following environmental conditions: day length, sunlight, and/or temperature, which vary markedly across seasons. Therefore, further studies under controlled conditions such as in a greenhouse may be required to direct correlate flavonoid profiles of green tea leaves with their yields and also to with conditions such as rainfall and humidity.

Saponins from edible legumes: chemistry, processing, and health benefits.

Demand for bean products is growing because of the presence of several health-promoting components in edible bean products such as saponins. Saponins are naturally occurring compounds that are widely distributed in all cells of legume plants. Saponins, which derive their name from their ability to form stable, soaplike foams in aqueous solutions, constitute a complex and chemically diverse group of compounds. In chemical terms, saponins contain a carbohydrate moiety attached to a triterpenoid or steroids. Saponins are attracting considerable interest as a result of their diverse properties, both deleterious and beneficial. Clinical studies have suggested that these health-promoting components, saponins, affect the immune system in ways that help to protect the human body against cancers, and also lower cholesterol levels. Saponins decrease blood lipids, lower cancer risks, and lower blood glucose response. A high saponin diet can be used in the inhibition of dental caries and platelet aggregation, in the treatment of hypercalciuria in humans, and as an antidote against acute lead poisoning. In epidemiological studies, saponins have been shown to have an inverse relationship with the incidence of renal stones. Thermal processing such as canning is the typical method to process beans. This study reviews the effect of thermal processing on the characteristics and stability of saponins in canned bean products. Saponins are thermal sensitive. During soaking and blanching, portions of saponins are dissolved in water and lost in the soaking, washing, and blanching liquors. An optimum thermal process can increase the stability and maintain the saponins in canned bean products, which is useful for assisting the food industry to improve thermal processing technology and enhance bean product quality.

Antioxidative properties of lycopene and other carotenoids from tomatoes: synergistic effects.

Lycopene is the major carotenoid in tomatoes. Tomatoes contain a matrix of many bioactive components, including vitamin C, vitamin E, other carotenoids (a-, beta-, gamma- carotene, lutein), and flavonoids. Their synergistic interactions, when used in combination, may be responsible for the observed beneficial effects of tomato-based products. This study investigated the synergistic antioxidant activity of lycopene in combination with beta-carotene, vitamin E, and lutein. A liposome system was used to test the synergistic antioxidant activity. The carotenoid mixtures were more efficient in protecting liposome from oxidation than the individual carotenoid. Mixtures of lycopene and vitamin E appear to have the greatest synergistic antioxidant activity.

Amaranth as a rich dietary source of beta-sitosterol and other phytosterols.

The analysis of 4 commonly available amaranth varieties (Amaranthus K343, RRC1011, K433, K432) revealed the presence of all three major phytosterols (beta-sitosterol, campesterol, stigmas-terol) with a total sterol content being several fold higher than those found in other studied plants. Substantial differences in total phytosterol content and beta-sitosterol content were found between the amaranth varieties. The most commonly cultivated amaranth variety in the United States, i.e., Amaranthus K343 was found to possess the highest levels of phytosterols of the varieties tested. The possibility of screening for superior amaranth varieties with various health properties is outlined.

Polyphenolics in grape seeds-biochemistry and functionality.

Grape seeds are waste products of the winery and grape juice industry. These seeds contain lipid, protein, carbohydrates, and 5-8% polyphenols depending on the variety. Polyphenols in grape seeds are mainly flavonoids, including gallic acid, the monomeric flavan-3-ols catechin, epicatechin, gallocatechin, epigallocatechin, and epicatechin 3-O-gallate, and procyanidin dimers, trimers, and more highly polymerized procyanidins. Grape seed extract is known as a powerful antioxidant that protects the body from premature aging, disease, and decay. Grape seeds contains mainly phenols such as proanthocyanidins (oligomeric proanthocyanidins). Scientific studies have shown that the antioxidant power of proanthocyanidins is 20 times greater than vitamin E and 50 times greater than vitamin C. Extensive research suggests that grape seed extract is beneficial in many areas of health because of its antioxidant effect to bond with collagen, promoting youthful skin, cell health, elasticity, and flexibility. Other studies have shown that proanthocyanidins help to protect the body from sun damage, to improve vision, to improve flexibility in joints, arteries, and body tissues such as the heart, and to improve blood circulation by strengthening capillaries, arteries, and veins. The most abundant phenolic compounds isolated from grape seed are catechins, epicatechin, procyanidin, and some dimers and trimers.

Characterization of the proteins of pili nut (Canarium ovatum, Engl.).

The storage proteins of the pili nut (Canarium ovatum, Engl.), quantitatively extracted using the modified Osborne protein fractionation scheme, revealed that the aqueous soluble globulin was the main storage protein within the kernel (i.e., >> 60.3%). Further physicochemical characterization of this aqueous soluble globulin revealed that it existed in an 11S like form and was composed of two main subunits of 22,600 and 31,600 Da. These subunits were found to be disulfide-linked (in a 1:1 ratio) forming intermediary subunits (i.e., dimers) with a molecular weight of approximately 52,600 Da. The overall molecular weight of the 11S globulin was determined to be approximately 300,000 Da suggesting that the globulin possessed a dodecameric-like structure of 6 dimers for a total of 12 subunits. Using differential scanning microcalorimetry, the denaturation temperature of the globulin was shown to occur at 89.3 degrees C. Overall, the pili nut 11S globulin was found to possess many similar physicochemical properties to those of other 11S oilseed globulins.