"Exotic" seeds from Southern Africa as potential Novel Foods? - Chemical composition of manketti nuts (Schinziophyton rautanenii) and ushivi beans (Guibourtia coleosperma).

Various species of Southern African plants and their edible seeds have gained huge importance due to positive health aspects, and there is increasing interest to introduce such seeds as Novel Food on the international market. Especially the seeds of Schinziophyton rautanenii (manketti) and Guibourtia coleosperma (ushivi) could have great potential as a food and food ingredient. Hence, extensive analyses on the chemical composition of manketti nuts and ushivi beans including the analysis of total solids, protein and fat content, soluble carbohydrates, ash, total and free amino acids, biogenic amines and polyamines, fatty acid profile as well as the content of certain B-vitamins and tocopherols were performed. Results obtained showed a valuable nutritional composition, e.g., a true protein content of 22.6% with a ratio of essential amino acids to total amino acid composition of 48% in manketti nuts, while ushivi beans had a true protein content of 8.2% with a similar ratio of essential to total amino acids (45%). Lipid content was 54.1% in manketti nuts, ushivi beans had a value of 7.7%. In both, linoleic acid was the most abundant. Furthermore, ushivi beans had high amounts of vitamin B1 and B2.

Acute and chronic effects of temperature on membrane adjustments in the gills of a neotropical catfish.

Structural modifications in the gill membranes maintain homeostasis under the influence of temperature changes. We hypothesized that thermal acclimation would result in significant modification of phospholipid fatty acids, with modulation of sodium pump activity during acute (24 and 48 h) and chronic (15 days) thermal shifts in the neotropical reophilic catfish Steindachneridion parahybae. Indeed, the time-course experiment showed acute and chronic changes in gill membrane at the lowest temperatures, notably linked to maintenance of membrane fluidity: significant preferential changes in phosphatidylethanolamine, with decrease of saturated fatty acids and increase of C18:1 in all groups kept below 30 °C in chronic trial, increase in polyunsaturated fatty acids n6 and C18:1 at 17 and 12 °C compared to 24 °C, as soon as the temperature was changed (initial time). Additionally, the activity of the sodium pump increased at 12 °C, but without apparent connection with the altered lipid environment. The animals maintained at the lowest temperature showed a higher mortality, possibly because of the approach to the minimum critical temperature for this species, and unexpected results of changes in the fatty acid profile, such as decreased docosahexaenoic acid in phosphatidylethanolamine and increased saturated fatty acids in phosphatidylcholine. This set of mechanisms highlights rheostatic adjustments in this species in the face of temperature changes.

Characterization of phenolic compounds and antioxidative potential of pot-pollen produced by stingless bees (Tetragonula biroi Friese) from the Philippines.

Eight pot-pollen samples produced by Philippine stingless bees (Tetragonula biroi Friese) were analyzed for the antioxidant composition and capacity. The methanolic extracts showed values of 7.95-24.75 mg GAE/g, 16.13-35.04 mg QE/g, and 0.19-0.74 mg CGE/g for total phenolics, flavonoids, and anthocyanins, respectively. All pot-pollens contained substantial amounts of rutin (0.471-1.547 mg/g), quercetin glucoside (1.427-3.390 mg/g), other flavonol glycosides, and hydroxycinnamic acids. Additionally, pollen samples contained 24-methylenecholesterol and Δ5-avenasterol as dominant phytosterols. Antioxidant activities based on ferric ion reducing antioxidant power (FRAP), DPPH• , and ABTS•+ scavenging activities, and lipid peroxidation (LPO) inhibition showed a high correlation with phenolic and flavonoid contents, except for LPO inhibition. Results suggested that there might be synergistic effects among antioxidants. Summing up, this study revealed that T. biroi Friese pot-pollen can be used as a food supplement with high nutraceutical potential. PRACTICAL APPLICATIONS: The recognition of Tetragonula biroi Friese pot-pollen as a nutraceutical product is strongly limited because its bioactive properties are not well-studied compared to other bee pollens. The results showed a rich occurrence of compounds with antioxidative effects like flavonoids and sterols. Antioxidant activities except lipid peroxidation inhibition revealed a high correlation with analyzed ingredients and shown interactions indicated that there might be synergistic effects among antioxidants.

Stabilities of tocopherols and phenolic compounds in virgin olive oil during thermal oxidation.

The effects of thermal oxidation at 60 °C on tocopherols (α, ß, γ) and phenolic compounds (hydroxytyrosol and tyrosol) of olive oil were studied. Tocopherols were determined by HPLC and phenolic compounds by HPLC and GC-MS. Peroxide value of olive oil increased with treatment time until it reached to 56.6 meq/kg. α-Tocopherol, ß-tocopherol and γ-tocopherol contents of olive oil decreased with treatment time. α-Tocopherol in olive oil was decomposed after 63 days of treatment. ß-Tocopherol in olive oil was depleted after 33 days of treatment. The reduction in γ-tocopherol of olive oil was 75% after 63 days of treatment. The degradation of hydroxytyrosol in olive oil was 91% after 63 days of treatment. Tyrosol was more stable than hydroxytyrosol in olive oil. Inverse correlations of peroxide value with hydroxytyrosol, α-Tocopherol, ß-tocopherol and γ-tocopherol were observed.

Carotenoid-cleavage activities of crude enzymes from Pandanous amryllifolius.

Carotenoid degradation products, known as norisoprenoids, are aroma-impact compounds in several plants. Pandan wangi is a common name of the shrub Pandanus amaryllifolius. The genus name 'Pandanus' is derived from the Indonesian name of the tree, pandan. In Indonesia, the leaves from the plant are used for several purposes, e.g., as natural colorants and flavor, and as traditional treatments. The aim of this study was to determine the cleavage of ß-carotene and ß-apo-8'-carotenal by carotenoid-cleavage enzymes isolated from pandan leaves, to investigate dependencies of the enzymatic activities on temperature and pH, to determine the enzymatic reaction products by using Headspace Solid Phase Microextraction Gas Chromatography/Mass Spectrophotometry (HS-SPME GC/MS), and to investigate the influence of heat treatment and addition of crude enzyme on formation of norisoprenoids. Crude enzymes from pandan leaves showed higher activity against ß-carotene than ß-apo-8'-carotenal. The optimum temperature of crude enzymes was 70°, while the optimum pH value was 6. We identified ß-ionone as the major volatile reaction product from the incubations of two different carotenoid substrates, ß-carotene and ß-apo-8'-carotenal. Several treatments, e.g., heat treatment and addition of crude enzymes in pandan leaves contributed to the norisoprenoid content. Our findings revealed that the crude enzymes from pandan leaves with carotenoid-cleavage activity might provide a potential application, especially for biocatalysis, in natural-flavor industry.

Purification of infective baculoviruses by monoliths.

A chromatographic process based on monoliths for purification of infective baculovirus without prior concentration step has been established. Baculovirus produced in Spodoptera frugiperda cells (Sf-9) were harvested by centrifugation, filtered through 0.8 µm filters and directly loaded onto radial 1 mL anion exchange monoliths with a channel size of 1.5-2.0 µm operated at a volumetric flow rate of one bed volume per minute. Optional an epoxy monolith was used as pre-column to reduce interfering compounds and substances influencing the capacity of anion exchange monoliths for baculovirus infectious virus could be eluted with a step gradient at salt concentrations of 440 mM NaCl. Recovery of infectious virus was highly influenced by composition and age of supernatant and ranged from 20 to >99% active baculovirus. Total protein content could be reduced to 1-8% and DNA content to 38-48% in main virus fraction. Infective virus could be 52-fold concentrated within 20.5h and simultaneously an 82-fold volume reduction was possible when loading 1150 mL (2.1×10(8) pfu/mL) onto 1 mL scale support.

Colostrum and milk selenium, antioxidative capacity and immune status of dairy cows fed sodium selenite or selenium yeast.

Dietary selenium (Se) can be supplemented from organic or inorganic sources and this may affect Se metabolism and functional outcome such as antioxidative status and immune functions in dairy cows. A feeding trial was performed with 16 Holstein-Friesian dairy cows fed with a total mixed ration (0.18 mg Se/kg dry matter (DM)) either without Se supplement (Control, n = 5), or with Se from sodium selenite (Group SeS, n = 5) or Se yeast (Group SeY, n = 6). In Groups SeS and SeY, the Se supplementation amounted to an additional intake of 4 mg Se and 6 mg Se/d during gestation and lactation, respectively. The effect of both Se sources was characterised by milk Se and antioxidant levels, and the phenotyping and functional assessment of phagocytic activity of milk immune cells. Se yeast has been found to increase (p ≤ 0.001) the milk Se and antioxidant levels markedly compared to the control group. The experimental treatment did not affect the immune parameters of the cows. Lymphocyte subpopulations and phagocytosis activity of neutrophilic granulocytes were affected neither by the Se intake nor by the two different dietary supplements. It can be concluded that sodium selenite and Se yeast differ considerably in their effects on antioxidant status in dairy cows. However, the basal dietary Se concentration of 0.18 mg/kg DM seemed to be high enough for the measured immune variables.

Development and validation of a combined method for the biomonitoring of omega-3/-6 fatty acids and conjugated linoleic acids in different matrices from human and nutritional sources.

BACKGROUND: During the last decade, the contribution of omega-3 and -6 long chain-polyunsaturated fatty acids (LC-PUFA) and conjugated linoleic acids (CLA) to the prevention and development of many inflammatory and cardiovascular diseases has been of growing interest. In order to investigate the etiology of these diseases, rapid, combined and comparable methods are invaluable for monitoring both the intake and the incorporation of these fatty acids (FA). METHODS: The fatty acid methyl esters (FAME) were analyzed using a gas chromatography/flame ionization detector (GC-FID) system and quantified with an internal standard (C18:0 iso). RESULTS: An effective and rapid protocol for sample preparation and the analysis of FAME was developed and validated. The comparison of different extraction methods showed that the Hara and Radin method gave the best results for serum and erythrocyte membranes. Excellent mean within-day and day-to-day precisions for serum, erythrocytes and cow's milk LC-PUFAs demonstrated the high reproducibility of the method. Recovery rates for FAMEs in serum and milk were close to 100%. In addition, high mean method linearity (R(2)) (>0.99) was shown for serum, erythrocytes and cow's milk. The sensitivity for FA achieved by GC analysis was acceptable. CONCLUSION: With the newly adapted protocols, combined and rapid analyses of up to 46 FAMEs, including CLAs and omega-3/-6 LC-PUFAs, can be conducted with high reliability and reproducibility using serum, erythrocyte membranes or cow's milk. This provides a novel tool that can be easily implemented in epidemiological studies or clinical diagnostics.

Methane production through anaerobic digestion of various energy crops grown in sustainable crop rotations.

Biogas production is of major importance for the sustainable use of agrarian biomass as renewable energy source. Economic biogas production depends on high biogas yields. The project aimed at optimising anaerobic digestion of energy crops. The following aspects were investigated: suitability of different crop species and varieties, optimum time of harvesting, specific methane yield and methane yield per hectare. The experiments covered 7 maize, 2 winter wheat, 2 triticale varieties, 1 winter rye, and 2 sunflower varieties and 6 variants with permanent grassland. In the course of the vegetation period, biomass yield and biomass composition were measured. Anaerobic digestion was carried out in eudiometer batch digesters. The highest methane yields of 7500-10200 m(N)(3)ha(-1) were achieved from maize varieties with FAO numbers (value for the maturity of the maize) of 300 to 600 harvested at "wax ripeness". Methane yields of cereals ranged from 3200 to 4500 m(N)(3)ha(-1). Cereals should be harvested at "grain in the milk stage" to "grain in the dough stage". With sunflowers, methane yields between 2600 and 4550 m(N)(3)ha(-1) were achieved. There were distinct differences between the investigated sunflower varieties. Alpine grassland can yield 2700-3500 m(N)(3)CH(4)ha(-1). The methane energy value model (MEVM) was developed for the different energy crops. It estimates the specific methane yield from the nutrient composition of the energy crops. Energy crops for biogas production need to be grown in sustainable crop rotations. The paper outlines possibilities for optimising methane yield from versatile crop rotations that integrate the production of food, feed, raw materials and energy. These integrated crop rotations are highly efficient and can provide up to 320 million t COE which is 96% of the total energy demand of the road traffic of the EU-25 (the 25 Member States of the European Union).

Quantification of long chain polyunsaturated fatty acids by gas chromatography. Evaluation of factors affecting accuracy.

The accurate and reproducible analysis of long-chain polyunsaturated fatty acids (PUFA) is of growing importance. Especially for labeling purposes, clear guidelines are needed in order to achieve optimum accuracy. Since calibration standards cannot be used for method validation due to the instability of PUFAs, there is no direct way to check for the absence of systematic errors. In this study the sources of error that weaken the accuracy were evaluated using theoretical considerations and calibration standards with corrected composition. It was demonstrated that the key role for optimum accuracy lies in the optimization of the split injection system. Even when following the instructions outlined in the official methods of the American Oil Chemist's Society (AOCS), systematic errors of more than 7% can arise. Clear guidelines regarding system calibration and selection of appropriate internal standards (IS) can improve precision and accuracy significantly.

Determination of the carbon deficiency in the flame ionization detector response of long-chain fatty acid methyl esters and dicarboxylic acid dimethyl esters.

Carbon deficiencies (CDs) of long-chain fatty acid methyl esters (FAMEs) and dicarboxylic acid dimethyl esters (DDMEs), which lead to decreased response in a flame ionization detection (FID) system, were determined by using full responding hydrocarbons (heptadecane, eicosane and alpha-cholestane) as references. For saturated FAMEs ranging from C12 to C22 and for DDMEs ranging from C4 to C10, CDs between 1.3+/-0.12 and 1.7+/-0.36 per ester group were recorded. All values were significantly (P < 0.05) greater than 1. Generally, response factors for gas-chromatographic analysis using FID have been calculated on the theory that the CD of FAMEs is 1 per ester group. However, this theory could not be confirmed experimentally for short-chain FAMEs of less than 8 carbons as CDs of around 1.5 were reported for C4 and C6 FAMEs. The study presented here contributes an approach to this problem by confirming the validity of response factors calculated from a CD of 1.5 per ester group as well as for long-chain FAMEs and DDMEs.

Determination of water-soluble vitamins in soft drinks and vitamin supplements using capillary electrophoresis.

A method for the determination of six water-soluble vitamins based on capillary electrophoresis (CE) operated in micellar mode was developed. Thiamine hydrochloride (vitamin B1), riboflavin (vitamin B2), pyridoxine hydrochloride (vitamin B6), pantothenic acid (vitamin B5), nicotinamide (vitamin B3), and cobalamin (Vitamin B12) could be separated in a single run. All CE parameters such as buffer composition and operation temperature were optimized in order to achieve better separation. Relative standard deviations (RSDs) of the described method ranged from 1.08 to 3.68% (intra-day precision) and 1.26 to 3.35% (inter-day precision). The method was then used for measuring various soft drinks and vitamin supplements directly without any step of sample cleanup. The determination of niacin was successful for all samples tested, reaching recoveries near 100%. Riboflavin and pyridoxine were quantified successfully in some but not all samples. Therefore, an evaluation on a case-by-case basis is mandatory. When applicable, this method provides a fast, accurate, simple, and inexpensive way to quantify selected vitamins, and is therefore well suited for routine analysis in soft drink industry.