Total antioxidant capacity, total phenolic content and iron and zinc dialyzability in selected Greek varieties of table olives, tomatoes and legumes from conventional and organic farming.

The objective was to compare 10 types of table olives, 11 types of tomatoes and tomato products and 18 types of legumes from conventional or organic farming for selected nutritional properties. All products were tested for their total antioxidant capacity (TAC) (Ferric Reducing Antioxidant Power (FRAP) assay) and total phenolic content (Folin-Ciocalteau method). Tomatoes and legumes were further tested for iron and zinc dialyzability after in vitro digestion. Ascorbic acid content of tomatoes was also measured. The study resulted that the nutritional properties of olives, tomatoes and legumes tested were different among the various cultivars but, in most cases, not between products from organic or conventional farming. Natural black olives, cherry and santorini tomatoes and lentils exhibited superior nutritional properties.

Effect of green tea on postprandial antioxidant capacity, serum lipids, C-reactive protein and glucose levels in patients with coronary artery disease.

PURPOSE: Cardiovascular risk factors have been identified in the postprandial state, particularly in patients with coronary artery disease (CAD). Tea consumption has been linked to cardiovascular risk reduction, but the beneficial effect of tea has not been investigated under postprandial conditions. The objective was to examine the effect of green tea on postprandial levels of plasma total antioxidant capacity (TAC), serum lipids, C-reactive protein (CRP) and glucose in patients with CAD. METHODS: In a randomized controlled, parallel design with 2 arms, 43 patients with CAD were assigned to consume breakfast consisting of bread, butter and 330 ml water or tea (4.5 g green tea/330 ml, providing approximately 400 mg catechins). Blood samples were drawn immediately before and 1.5, 3 and 5 h after breakfast. TAC was measured in plasma with the ferric reducing antioxidant power of plasma and oxygen radical absorbance capacity assays. Total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides, glucose, CRP, uric acid and pancreatic lipase levels were measured in serum. RESULTS: Tested biomarkers did not differ between tea and water group at baseline, 1.5, 3 and 5 h (P > 0.05) postprandially. However, TAC increased 1.5 and 3 h after consumption of breakfast with tea (P < 0.005), but no change was observed after consumption of breakfast with water. Serum triglycerides levels significantly increased 3 h after breakfast with water (P = 0.031), but not after breakfast with tea. Serum uric acid decreased 1.5 h after breakfast with tea (P = 0.038). Pancreatic lipase, CRP, total cholesterol, HDL-C, LDL-C and glucose levels remained unchanged after breakfast with tea at any time point (P > 0.05). CONCLUSIONS: Tea consumption did not affect selected biomarkers at any postprandial time point in patients with CAD.

Patterns of major metabolites biosynthesis by different mushroom fungi grown on glucose-based submerged cultures.

The biosynthetic potential of four basidiomycetes (Agrocybe aegerita, Flammulina velutipes, Ganoderma applanatum and Pleurotus pulmonarius) and one ascomycete (Morchella esculenta) was examined in regard to biomass, intracellular (endopolysaccharides and lipids) and extracellular (exopolysaccharides) compounds' production in liquid media with glucose as substrate, in static and agitated cultures. Exopolysaccharides' production presented significant negative correlation with biomass, endopolysaccharides and lipids, while biomass was positively related to the production of endopolysaccharides and lipids. Maximum values of biomass, endo- and exo-polysaccharides obtained were quite impressive: P. pulmonarius produced 22.5 g/L of biomass, A. aegerita 60.4 % (w/w) of endopolysaccharides and F. velutipes 1.2 g/L of exopolysaccharides. Polysaccharides and lipids synthesized at the early growth stages were subjected to degradation as the fermentation proceeded. Mycelial lipids of all strains were highly unsaturated, dominated by linoleic acid, whereas glucose was the main building block of endopolysaccharides. The ability of the examined mushroom fungi to synthesize in high quantities biomass and polysaccharides, products with biotechnological and medicinal interest, renders these fungi as potential candidates in sugar-based bio-refineries.

Adaptation dynamics of Clostridium butyricum in high 1,3-propanediol content media.

Aim of the present study was to evaluate the effect of exogenous additions of 1,3-propanediol (1,3-PDO) on microbial growth and metabolites production of Clostridium butyricum VPI 1718 strain, during crude glycerol fermentation. Preliminary batch cultures in anaerobic Duran bottles revealed that early addition of 1,3-PDO caused growth cessation in rather low quantities (15 g/L), while 1,3-PDO additions during the middle exponential growth phase up to 70 g/L resulted in an almost linear decrease of the specific growth rate (µ), accompanied by reduced glycerol assimilation, with substrate consumption being used mainly for energy of maintenance requirements. During batch trials in a 3-L bioreactor, the strain proved able to withstand more than 70 g/L of both biologically produced and externally added 1,3-PDO, whereas glycerol assimilation and metabolite production were carried on at a lower rate. Adaptation of the strain in high 1,3-PDO concentration environments was validated during its continuous cultivation with pulses of 1,3-PDO in concentrations of 31 and 46 g/L, where no washout phenomena were noticed. As far as C. butyricum cellular lipids were concerned, during batch bioreactor cultivations, 1,3-PDO addition was found to favor the biosynthesis of unsaturated fatty acids. Also, fatty acid composition was studied during continuous cultures, in which additions of 1,3-PDO were performed at steady states. Lipids were globally more saturated compared to batch cultures, while by monitoring of the transitory phases, it was noticed that the gradual diol washout had an evident impact in the alteration of the fatty acid composition, by rendering them more unsaturated.

Effect of biodiesel-derived waste glycerol impurities on biomass and 1,3-propanediol production of Clostridium butyricum VPI 1718.

Aim of the present study was to assess and evaluate the impact of various kinds of impurities of biodiesel-derived raw glycerol feedstock, upon microbial growth and 1,3-propanediol (1,3-PDO) production by Clostridium butyricum. Preliminary trials in 200-mL anaerobic bottles revealed that the presence of NaCl at a concentration of 4.5% (w/w of glycerol) in growth medium imposed an evident inhibitory effect, in contrast with phosphoric salts. However, the application of NaCl at elevated quantities during batch bioreactor experiments [up to 30% (w/w of glycerol)], did neither affect the microbial growth, nor the 1,3-PDO production. Moreover, when oleic acid was added into the growth medium at 2% (w/w of glycerol), a total preclusion of the strain was observed. In order to further investigate whether the nature of oleic acid itself or the presence of the double bond induced the inhibitory phenomenon, stearic acid was added into the medium at the same concentration (2%, w/w, of glycerol). Indeed, no inhibitory effect was observed in the fermentor, suggesting that the presence of the double bond may play a key role in the growth behavior of the microorganism. Finally, methanol effect was tested in batch and continuous bioreactor operations. Interestingly enough, the alcohol addition did not affect the microbial bioconversion of glycerol into 1,3-PDO, even when imposed at relatively high concentrations (10%, w/w, of glycerol) in batch-bioreactor operations. In continuous experiments, methanol was added when steady state had been achieved, and although in one case high concentration was added into the chemostat (5 g/L), the system re-obtained a steady state without indications of negative effect upon biomass production due to the alcohol.

Green tea, white tea, and Pelargonium purpureum increase the antioxidant capacity of plasma and some organs in mice.

OBJECTIVE: We tested in mice the hypothesis that ingestion of infusions of green tea, white tea, or the aromatic plant Pelargonium purpureum increases total antioxidant capacity (TAC) of plasma and organs. METHODS: Twenty-five mice were randomly assigned to five groups, each of which received by gavage 0.1 mL of infusion from green tea, white tea, or P. purpureum (8 g/100 mL of water) or catechin (0.01 g/100 mL) or water for 5 consecutive days. On the fifth day the animals were euthanized. Blood was taken by heart puncture and the heart, lungs, liver, spleen, kidney, and brain were removed. TAC was measured in plasma and in all organ homogenates with the ferric reducing antioxidant power assay and in selected organ homogenates by the total radical-trapping antioxidant parameter assay. RESULTS: Green tea and P. purpureum increased TAC in the plasma and lungs, whereas green tea, white tea, and catechin increased TAC in heart homogenates. No effect was observed on the liver, brain, spleen, and kidney homogenates in comparison with the water control with the ferric reducing antioxidant power assay or the total radical-trapping antioxidant parameter assay. CONCLUSION: These results suggest that green tea, white tea, and P. purpureum exhibit antioxidant effects in vivo that may be observed not only in plasma but also in some organs.

Citric acid production by Yarrowia lipolytica cultivated on olive-mill wastewater-based media.

Yarrowia lipolytica ACA-DC 50109 cultivated on olive-mill wastewater (O.M.W.)-based media, enriched with commercial-industrial glucose, presented an efficient cell growth. Parameters of growth were unaffected by the presence of O.M.Ws in the growth medium. In diluted O.M.Ws enriched with high glucose amounts (initial sugar concentration, 65 g l(-1)), a notable quantity of total citric acid was produced (28.9 g l(-1)). O.M.W.-based media had a noteworthy stimulating effect on the production of citric acid, since both final citric acid concentration and conversion yield of citric acid produced per unit of sugar consumed were higher when compared with the respective parameters obtained from trials without added O.M.W. Adaptation of the strain in O.M.W.-based media favoured the biosynthesis of cellular unsaturated fatty acids (principally of oleic and palmitoleic acids). Additionally, a non-negligible decrease of the phenolic compounds in the growth medium [up to 15% (wt/wt)], a slight decrease of the phyto-toxicity, and a remarkable decolourisation of the O.M.W. were observed. All these results suggest the potentiality of O.M.Ws utilisation in the fermentation process of citric acid production.

Gamma-linolenic acid production by Cunninghamella echinulata growing on complex organic nitrogen sources.

Growth of two strains of Cunninghamella echinulata on various nitrogen containing raw materials (corn gluten, corn steep, whey concentrate,yeast extract and tomato waste hydrolysate) yielded important amounts of biomass containing various quantities of gamma-linolenic acid (GLA) rich cellular lipids. Especially, growth on tomato waste hydrolysate (TWH) yielded 17.6 g/l of biomass containing 39.6% oil and significant quantities of GLA corresponding to 800 mg/l GLA. Mycelium-bounded proteolytic activity was detected during early growth stages on TWH and declined thereafter, increasing the concentration of assimilable nitrogen in the medium. However, addition of glucose in the medium during the stationary phase triggered the biosynthesis of reserve lipid, since an increase of the proportion of neutral lipids from 45% to 79% in total lipids was observed, while polar lipids decreased from 35% to 12% and from 20% to 9% for glycolipids plus sphingolipids and phospholipids, respectively.

Evaluation of an integrated biorefinery based on fractionation of spent sulphite liquor for the production of an antioxidant-rich extract, lignosulphonates and succinic acid.

Spent sulphite liquor (SSL) has been used for the production of lignosulphonates (LS), antioxidants and bio-based succinic acid. Solvent extraction of SSL with isopropanol led to the separation of approximately 80% of the total LS content, whereas the fermentations carried out using the pretreated SSL with isopropanol led to the production of around 19g/L of succinic acid by both Actinobacillus succinogenes and Basfia succiniciproducens. Fractionation of SSL via nanofiltration to separate the LS and solvent extraction using ethyl acetate to separate the phenolic compounds produced a detoxified sugar-rich stream that led to the production of 39g/L of succinic acid by B. succiniciproducens. This fractionation scheme resulted also in the production of 32.4g LS and 1.15g phenolic-rich extract per 100g of SSL. Both pretreatment schemes removed significant quantities of metals and heavy metals. This novel biorefinery concept could be integrated in acidic sulphite pulping mills.

Investigation of volatiles evolution during the alcoholic fermentation of grape must using free and immobilized cells with the help of solid phase microextraction (SPME) headspace sampling.

A biocatalyst was prepared by immobilization of Saccharomyces cerevisiae strain AXAZ-1 on delignified cellulosic material (DCM). Repeated batch fermentations were conducted using these biocatalysts and free cells, separately, at temperatures of 20, 15, and 10 degrees C. Solid phase microextraction (SPME) was used in monitoring the formation of volatile alcohols, acetate esters, and ethyl esters of fatty acids. The kinetics of volatile production were similar for free and immobilized cells. In all cases immobilized cells showed a better rate of volatile production, which was directly connected to sugar consumption. The main difference observed was in propanol production, which increased with temperature decrease for the immobilized cells, whereas it remained constant for the free ones. In the case of immobilized cells significant amounts of esters were also produced. It is well-known that esters contribute to the fruity aroma of wine. It was also established that SPME is a very sensitive, accurate, and reliable technique and can be used without any reservation in the characterization of volatile constituents of wine.

Evolution of volatile byproducts during wine fermentations using immobilized cells on grape skins.

A biocatalyst was prepared by immobilization of Saccharomyces cerevisiae cells on grape skins. Repeated batch fermentations were conducted using this biocatalyst as well as free cells, at 25, 20, 15, and 10 degrees C. Solid phase microextraction (SPME) was used in monitoring the evolution of volatile byproducts. The effect of immobilization and temperature on evolution patterns of volatiles was obvious. The major part of esters was formed after consumption of 40-50% of the sugars. Similar processes were observed for amyl alcohols and 2-phenylethanol, whereas 1-propanol and 2-methyl-1-propanol were formed during the whole alcoholic fermentation period at an almost constant formation rate. Acetaldehyde and acetoin were synthesized in the early stages of fermentation. Afterward, their amount decreased. In most cases, immobilized cells exhibited higher formation rates of volatiles than free cells. The final concentration of esters was higher in wines produced by immobilized biocatalyst. Their amount increased with temperature decrease. The opposite was observed for higher alcohols.

Volatile compounds of wines produced by cells immobilized on grape skins.

A biocatalyst was prepared by immobilization of Saccharomyces cerevisiae cells on grape skins. Repeated batch fermentations were conducted using the immobilized biocatalyst as well as the free yeast cells at 25, 20, 15, and 10 degrees C. The major volatile byproducts were determined by GC, whereas the minor volatile constituents were extracted in dichloromethane and analyzed by HRGC-MS. The qualitative profiles of the wines produced were similar in every case. Immobilized cells gave wines with higher contents of ethyl and acetate esters that increased with temperature decreases from 25 to 15 degrees C. The amount of volatile alcohols was more pronounced in wines produced by free cells and decreased dramatically at low fermentation temperatures (10 degrees C).

A new technological approach proposed for distillate production using immobilized cells.

A new technological approach to distillate production using immobilized cells was investigated. The effect of temperature on the main volatile by-products in distillates was determined. Wines produced by delignified cellulose-, gluten- and kissiris-supported biocatalysis were used as starting materials. The produced distillates were analyzed for ethanol, methanol, acetaldehyde, ethyl acetate, propanol-1, isobutanol and amyl alcohol content. The results showed that distillates from delignified cellulosic material (DCM) at 16 degrees C contained smaller amounts of amyl alcohols, 57% of that produced by gluten and 32% of that produced by kissiris. The ethyl acetate content of distillates from DCM improved the aroma of distillates. These results agree with those of sensory evaluation. Subsequently, the scale-up for low-temperature distillate production at 16 degrees C using DCM was further investigated. A new version of an industrial multi-stage fixed bed tower (MFBT) bioreactor with a capacity of 11,000 l proved to be suitable for continuous fermentation by DCM-supported biocatalysis. Economic analysis showed a reduction in the cost of almost 30% for distillate production and 78% for wine production.

Single cell oil (SCO) production by Mortierella isabellina grown on high-sugar content media.

Mortierella isabellina cultivated in nitrogen-limited media presented remarkable cell growth (up to 35.9 g/l) and high glucose uptake even with high initial sugar concentrations (e.g. 100 g/l) in media. After nitrogen depletion, significant fat quantities were accumulated inside the fungal mycelia (50-55%, wt/wt oil in dry biomass), resulting in a notable single cell oil production of 18.1 g/l of culture medium. Total dry biomass and lipid yields presented greatly increased values (0.34 and 0.17 g respectively per gram of glucose consumed). The microbial lipid produced contained gamma-linolenic acid (GLA) at a concentration of 3.5+/-1.0%, wt/wt, which corresponded to 16-19 mg GLA per gram of dry microbial mass and a maximum concentration of 0.801 g GLA per liter of culture medium.

The effect of iron and fat in a diet containing green tea extract (Camellia sinensis) on the antioxidant capacity of some organs and the mRNA expression of specific genes in mice.

The hypothesis that iron and fat in the diet may affect green tea extract (GTE) bioactivity, in particular antioxidant capacity and gene expression, was proposed and tested in mice. Thirty mice were randomly assigned to have for 37 days free access to standard or high-fat diets with or without GTE and ferrous lactate. Mice were euthanized and specific organs were removed. Total antioxidant capacity (TAC) was measured using the ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity assays. Polymerase chain reaction was performed on liver and heart mRNA extracts. The FRAP assay showed that GTE from the standard diet did not affect plasma TAC but increased TAC of heart, aorta, and duodenum. GTE from diets enriched with iron resulted to lower TAC of liver and heart than diets with GTE alone. GTE from the fatty diet did not have any effect on TAC compared with fatty control diet, but increased TAC in heart and aorta compared with standard control diet. An effect on expression of the mapk-1 and NF-kB genes in heart was observed in the presence of GTE. These results suggest that GTE may exhibit bioactivity in some organs affected by dietary fat and iron. The findings of this study contribute to the elucidation of the role of dietary components on tea bioactivity.

Analysis of Naturally Occurring Phenolic Compounds in Aromatic Plants by RP-HPLC Coupled to Diode Array Detector (DAD) and GC-MS after Silylation.

The following aromatic plants of Greek origin, Origanum dictamnus (dictamus), Eucalyptus globulus (eucalyptus), Origanum vulgare L. (oregano), Mellisa officinalis L. (balm mint) and Sideritis cretica (mountain tea), were examined for the content of phenolic substances. Reversed phase HPLC coupled to diode array detector (DAD) was used for the analysis of the plant extracts. The gas chromatography-mass spectrometry method (GC-MS) was also used for identification of phenolic compounds after silylation. The most abundant phenolic acids were: gallic acid (1.5-2.6 mg/100 g dry sample), ferulic acid (0.34-6.9 mg/100 g dry sample) and caffeic acid (1.0-13.8 mg/100 g dry sample). (+)-Catechin and (-)-epicatechin were the main flavonoids identified in oregano and mountain tea. Quercetin was detected only in eucalyptus and mountain tea.

Mushroom polysaccharides and lipids synthesized in liquid agitated and static cultures. Part I: screening various mushroom species.

The effect of four synthetic media containing glucose (initial concentration 30 g l(-1)) on mycelial growth, exopolysaccharides (EPS) and cellular lipids production was examined in 11 mushroom species after 12 and 16 days of culture in static- and shake-flasks. Fatty acid analysis of cellular lipids produced was also performed. Agitation had a positive effect on biomass production, glucose consumption and lipid biosynthesis. Media that favoured the production of biomass were not suitable for EPS biosynthesis and vice versa. Biomass values varied from ~1.0 g l(-1) (Lentinula edodes) to ~19 g l(-1) (Pleurotus ostreatus), while the highest EPS quantity achieved ranged between 1.6 and 1.8 g l(-1) (for Ganoderma lucidum and L. edodes, respectively). Quantities of total cellular lipids varied between 2.5 and 18.5 % w/w, in dry mycelial mass for the fungi tested. Lipid in dry weight values were influenced by the medium composition. Cellular lipids presented noticeable quantities of poly-unsaturated fatty acids like linoleic acid. Compared to most of the mushrooms tested, lipids of Volvariella volvacea were more saturated. The ability of several mushroom species of our study to produce in notable quantities the above-mentioned added-value compounds renders these fungi worthy for further investigations.

Mushroom polysaccharides and lipids synthesized in liquid agitated and static cultures. Part II: study of Volvariella volvacea.

Volvariella volvacea strains were studied in relation with their ability to produce biomass, lipids and polysaccharides. Firstly, screening of four strains (AMLR 188, 190, 191 and 192) was performed in agar cultures, where the mycelial growth rate of the strains was measured, and in static liquid cultures, where the production of biomass, the biosynthesis of total cellular lipids and the consumption of glucose were monitored. For all strains, biomass production was significant (13-15 g l(-1)) and total lipid in dry weight (%, w/w) ranged from 3 to 12 %. Afterwards, a detailed kinetic analysis of mycelial biomass, extra- and intra- cellular polysaccharides (EPS, IPS, respectively) as well as lipid production by a V. volvacea selected strain was conducted in submerged static and agitated cultures. Maximum values of 15 g l(-1) biomass, ~1.0 g l(-1) EPS and 5.5 g l(-1) IPS were recorded. Agitation did not have severe impact on biomass, EPS and IPS production, but it increased total lipid in dry weight quantities. EPS, IPS and lipid in dry weight values decreased with time. Glucose was the major cellular carbohydrate detected. Total fatty acid analysis of cellular lipids was performed for all V. volvacea strains and linoleic acid (Δ9,12)C18:2 was predominant. Neutral lipids constituted the major fraction of cellular lipids, but their quantity decreased as fermentation proceeded. Phospholipids were the most saturated lipid fraction.

Impact of anaerobiosis strategy and bioreactor geometry on the biochemical response of Clostridium butyricum VPI 1718 during 1,3-propanediol fermentation.

The impact of anaerobiosis strategy on 1,3-propanediol production during cultivation of Clostridium butyricum VPI 1718 in different size bioreactors was studied. In batch trials with N2 gas infusion, the fermentation was successfully accomplished, regardless of initial glycerol concentration imposed and bioreactor geometry. However, in the absence of N2 continual sparging, significant variations concerning the biochemical response of the strain were observed. Specifically, at 1-L bioreactor, the absence of N2 infusion at high initial glycerol concentration induced lactate dehydrogenase activity and thus lactic acid synthesis, probably due to partial blockage of phosphoroclastic reaction caused by insufficient self-generated anaerobiosis environment. During fed-batch cultivation with continual N2 sparging, the strain produced ∼71 g L(-1) of 1,3-propanediol, whereas under self-generated anaerobiosis, 1,3-propanediol pathway was evidently restricted, as only 30.5 g L(-1) of 1,3-propanediol were finally produced. Apparently, N2 infusion strategy paired with bioreactor geometry can alter the biochemical behavior of the particular strain.

Milk peptides increase iron dialyzability in water but do not affect DMT-1 expression in Caco-2 cells.

In vitro digestion of milk produces peptide fractions that enhance iron uptake by Caco-2 cells. The objectives of this study were to investigate whether these fractions (a) exert their effect by increasing relative gene expression of DMT-1 in Caco-2 cells and (b) enhance iron dialyzability when added in meals. Two milk peptide fractions that solubilize iron were isolated by Sephadex G-25 gel filtration of a milk digest. These peptide fractions did not affect relative gene expression of DMT-1 when incubated with Caco-2 cells for 2 or 48 h. Dialyzability was measured after in vitro simulated gastric and pancreatic digestion. Both peptide fractions enhanced the dialyzability of iron from ferric chloride added to PIPES buffer, but had no effect on dialyzability from milk or a vegetable or fruit meal after in vitro simulated gastric and pancreatic digestion. However, dialyzability from milk was enhanced by the addition of a more concentrated lyophilized peptide fraction.