Folate content in Swedish eggs: influence of breed,feed and processing

Folate content in eggs from three different breeds of hens fed with three different feeds, one organic and two conventional, was compared using a simplified microbiological assay. Retention of folate when boiling the eggs was also studied. Folate content in eggs did not differ significantly due to the breed of hen or the feed used. The loss of folate when boiling the eggs was 9%. The results from the microbiological assay were confirmed by LC/MS. According to this study, 1 egg (60 g) provides 40–50 μg of folate. This corresponds to 13–17% of the recommended daily intake, 300 μg for adults in the Nordic Nutrition Recommendations. The folate forms found in egg yolk with LC/MS were 5-methyl-tetrahydrofolate and 10-formyl-folic acid, whereas no folates were found in egg white. In this study, no polyglutamate folate forms could be detected in eggs.     

Isolation and molecular identification of yeasts in Greek kefir

The aim of this study was to enumerate and identify yeasts present in Greek kefir. Total yeast counts in kefir grains were 7.7 ± 0.5 log cfu/g, whereas in kefir drinks counts ranged from <0.4 to 6.7 log cfu/mL. Molecular identification tests revealed 14 different yeast species belonging to 10 genera (Candida spp., Debaryomyces spp., Galactomyces spp., Issatchenkia spp., Kazachstania spp., Kluyveromyces spp., Pichia spp., Saccharomyces spp., Wickerhamomyces spp., Yarrowia spp.). This study is the first to identify yeast species present in Greek kefirs and to isolate Pichia membranifaciens and Candida zeylanoides as part of the kefir microbiota.     

Ethanol from lactose in salted cheese whey by recombinant Saccharomyces cerevisiae

 Seven yeast recombinants were selected from 57 fusant colonies on the basis of higher DNA content, nuclear diameter and ethanol yield compared to parental Saccharomyces cerevisiae ATCC 4126 and Kluyveromyces lactis CBS 683. Six recombinants out of the above colonies revealed growth on lactose and sucrose, indicating that they are S. cerevisiae with transformed β-galactosidase systems. The fusant colonies were investigated with respect to their capacity to convert lactose in salted cheese whey into ethanol. Among these recombinants that showed high tolerance towards sodium chloride and higher ethanol yield than lactose fermenting parental K. lactis CBS 683, SK-1 exhibited high tolerance up to 4 g dl^–1 sodium chlonride with an ethanol yield of 4.66 ml dl^–1 (v/v) , SK-23 tolerated 6 g dl^–1 sodium chloride with an ethanol yield of 4.14 ml dl^–1 (v/v) and SK-26 showed resistance towards 8 g dl^–1 sodium chloride and give an ethanol yield of 3 ml dl^–1 (v/v).     

Die Bestimmung der Folsäure-Gehalte von Lebensmitteln tierischer Herkunft mit Hilfe der Hochleistungsflüssigchromatographie (HPLC)

The folic acid content of food of animal origin was determined by means of high-performance liquid chromatography (HPLC). Free folate (monoglutamate forms) and total folate (monoglutamate + polyglutamate forms) were differentiated. Liver (bovine 963, hog 136 μg/100 g) and kidney (bovine 410, hog 93 μg/100 g) contained the highest content of total folate, followed by egg (67μg/100g), soft cheese (44-62μg/100 g), milk and other dairy products (3-28 μg/100 g). Chicken, fish, beef and pork contained only a low content of total folate (1-12 μg/100 g). The free folate portion ranged from 14.7 to 100% (mean 69.2%). The main folate derivatives tetrahydrofolic acid (THF), 5-methyl-THF and 5-formyl-THF showed the following distribution. In milk and milk products the mean was 70% for 5-formyl-THF, 20% for 5-methyl-THF and 10% for THF; in the other products the three derivatives were distributed about equally but the range of variation was high.     

Technological performances of commercial yeast strains (Saccharomyces cerevisiae) in different complex dough formulations

Four commercial baker's yeasts strains in compressed form (S. cerevisiae), having different suggested use, were tested in the present research: LM (croissanterie products), LP (bread), OS (frozen doughs) and BL (festivity Italian cakes). The final goal was to highlight any possible difference in their technological performances when employed in the complex dough formulations bread, croissant and panettone. Microbiological analysis (total count, viability, glutathione and trehalose content) as well as technological tests (rheofermentographic analysis and evaluation of the dough-volume increase through image analysis) were carried out. All yeast samples resulted consistent with the commercial standards, although showing a certain viability variation (48/100%). Trehalose content resulted higher (max. 14% dw) in the osmotolerant–cryotolerant OS and BL yeast samples. As regards technological performances, LM and LP strains, proposed for croissant and bread production respectively, confirmed their good technological performances in these preparations. OS strain proved to be the only one able to produce a certain volume increase in the complex formulation panettone. Evaluation of this parameter through image analysis evidenced interesting correlations with data obtained by rheofermentometer (R ²: 0.9098–0.9980).     

Phenolic composition and antioxidant activity of Thai and Eri silk sericins

The present study investigates the phenolic contents and antioxidant activities of silk sericin extracted (SSE) from Thai mulberry silkworms (Bombyx mori) and non-mulberry silkworm (Samia ricini). The SSE from all strains revealed the mainly presence of flavonoid compounds including (+)-catechin (20.63–145.64 mg/100 g), quercetin (7.89–35.95 mg/100 g), and (−)-epicatechin (3.36–44.19 mg/100 g). The antioxidant activity of the SSE with water from Chokumnoui 1 was found to have low EC50 values (0.96 mg/mL), the concentrations of the SSE that exhibit 50% reduction in DPPH, and highest scavenging of ABTS^{· +} radicals (1.73 mg TEAC/g) and highest reduce TPRZ-Fe (III) complex to TPTZ-Fe (II) (8.03 mg Fe(II)/g), thus indicating high antioxidant activities. Total phenolic content and total flavonoid content of the SSE showed positive correlated to the scavenging activity of DPPH and ABTS^{· +} radicals and the ferric reducing ability (FRAP assay).     

Turkish kefir and kefir grains: microbial enumeration and electron microscobic observation†

Microbial populations in kefir and kefir grains were enumerated by plating. Total lactic acid bacteria, lactoccocci, lactobacilli and yeast populations increased during fermentation and increased slightly during cold storage. Kefir grains had a lactic acid bacteria : yeast ratio of 10 ⁹  : 10 ⁶ . In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods, which indicated yeast colonization on the surface and middle part of the kefir grain. Three types of lactobacilli (short, long and curved) were noted throughout the grain. Lactococci were not observed under SEM; preparation of kefir grains for SEM may have caused removal of lactococci from the grains.     

Functionality Enhancement of Composite Cassava Flour in the Production of Maize Tuwo (A Non-fermented Maize-Based Food Dumpling)

The study was focused on the evaluation of textural and sensory quality enhancing functionality of cassava flour in the production of maize tuwo (a non-fermented maize-based food dumpling). The cassava flour was added to maize flour at the level of 5%, 10%, 15%, 20%, 25% and 30% (w/w), respectively. The bulk density and water holding capacity of maize/cassava flour mixes ranged from 0.77–0.83 g/cm³ and 1.91–2.05 g/g, respectively, while those of 100% maize flour were 0.84 g/cm³ and 2.09 g/g, respectively. There were variations in the pasting properties of maize/cassava flour mixes including the pasting temperature (75.4–78.8°C), peak viscosity (112.1–170.0 RVU), breakdown viscosity (38.4–53.7 RVU) and final viscosity (132.1–142.2 RVU), while those of 100% maize flour were 74.6°C, 108.1 RVU, 38.1 RVU and 148.3 RVU, respectively. The colour characteristics of tuwo prepared from maize/cassava flour mixes showed an increase in the colour lightness, L*-value (68.6–71.8) and chroma, C-value (9.4–11.4) while tuwo from 100% maize flour gave 67.7 and 9.1, respectively. The cohesiveness indexes (15.4–24.2%) of tuwo from maize/cassava flour mixes increased with an increase in the quantity of cassava flour in the mix while that from 100% maize flour was 15.2%. The softness indexes (17.5–18.4°mm) of tuwo from the mixes were also higher than that from 100% maize flour (17.4°mm). The sensory quality rating of tuwo from maize/cassava flour mixes showed that tuwo from 25% cassava flour inclusion was the highest in terms of texture (hand-mouldability), taste and overall acceptability while that from 30% cassava flour inclusion was the highest in terms of colour.     

Comparative study of trans fatty acid content in 2005 and 2008 processed foods from Korean market

Trans fatty acids (t-FA) contents were analyzed in 26 food items that were collected from Korean grocery stores in 2005 and 2008. Lipid was extracted through Soxhlet and Mojonnier methods. Fatty acid profile, including t-FA and positional fatty acid composition was analyzed by gas chromatography. The comparative study of fatty acids composition including t-FA was employed in 2005 and 2008. Among the analyzed food items, most of the food items showed higher lipid content in 2005 than in 2008. Some food items such as biscuits (0.4–7.2 g/100 g of food), fried snacks (0.1–3.6 g/100 g of food), and cookies (0.4–2.4 g/100 g of food) contained relatively higher level of t-FA than other food groups (cracker, processed chocolate, and ice cream) in 2005. Comparing t-FA content in 2005, it was considerably decreased up to 91.5% in 2008 whereas saturated fatty acids (SFA) were increased up to 43.3% in the analyzed food items.     

Chitosan, chitin-glucan and chitin effects on minerals (iron, lead, cadmium) and organic (ochratoxin A) contaminants in wines

Chitosan (F7), chitin (F2), chitin-glucan (F1) and chitin glucan hydrolysate (F5) of fungal origin were tested for removal of mineral (Fe or Pb and Cd) and organic (ochratoxin A: OTA) contaminants in wines. Red, white and sweet wines are spiked with either Fe (20 mg L⁻¹), or Pb (500 μg L⁻¹) and Cd (20 μg L⁻¹) or OTA (5 μg L⁻¹). The wines were then treated with F1, F2, F5 or F7 at doses of 0.1 g, 0.5 and 2 g L⁻¹. After 2 days, the levels of iron, copper, lead and cadmium were measured using a flame and graphite furnace atomic absorption spectrophotometer. Depending on the treatment red wines showed reductions of iron by 73–90%, cadmium by 29–57% and lead by 33–74%. The same treatments with white wine gave reductions for iron of 32–91%, cadmium fell by 11–23%, lead by 50–65%. In the case of sweet wines iron was reduced by 51–90%, cadmium by 17–25%, and lead by 38–84%. For wine enriched in OTA, treatments with F1, F2, F5, F7 were carried out at doses of 2 and 5 g L⁻¹. After 2 days, the levels of OTA in wines were analyzed by HPLC with fluorimetric detection. OTA was reduced by 56.7–83.4% in red wine, by 53.4–64.5% in white wine and 26.1–43.5% in sweet wine. These findings indicate that chitosan, chitin, chitin-glucan, or chitin glucan hydrolysate from fungal origin may be useful ancillaries for wine limpidity prevention by reducing levels of Fe, heavy metals (Pb, Cd) and mycotoxins (OTA) and thereby improving wine safety.     

Bioactive lipids and fatty acids profile of Cistanche phelypaea

Oil extracted from the wild plant of Cistanche phelypaea was analyzed for its fatty acid, sterol, hydrocarbon and tocopherol contents. Total lipids (TL) content was 10 g/kg (on dry weight basis). The majority of fatty acids were of the unsaturated type (50.4 % of total fatty acids), while the saturated (mainly palmitic acid) were about 43.2 % of the total fatty acids. Oleic acid was the dominating fatty acid followed by palmitic and linoleic acids. High amounts of sterols were found in the oil with the main component β-sitosterol. Other phytosterols (e.g. stigmasterol, ∆⁷-avenasterol and ∆⁵-avenasterol) were present at approximately equal amounts (6–9 % of total sterols). The main identified hydrocarbon compounds were C₂₁, C₂₆ and C₃₂ constituting about 61.2 % of total hydrocarbons. Small amounts of C₁₂, C₁₈ and C₂₂, however, were also detected. Tocopherol levels were high in the oil (3.36 g/kg oil), wherein β-tocopherol was the main component followed by α-isomer. Both tocopherol components comprised more than 87 % of total vitamin E content in the oil. Furthermore, γ- and δ-tocopherols were detected in small amounts in the oil accounting for 14–16 % of the total vitamin E content. Information provided by the present work will be of importance for food applications and chemotaxonomy of Cistanche phelypaea.     

Rheological behaviour and physicochemical properties of kefir with honey

The effect of the flower and pine honey on the rheological behavior of kefir was investigated. Major aim was to produce a new functional fermented milk beverages with honey. Soluble solid was changed from 6.37 to 25.28; refractive index values were between 1.342 and 1.374; pH was changed from 4.04 to 4.65 and color values, L of samples were determined as 63.10–73.18. The rheological properties of the samples were determined using a controlled stress rheometer. It was observed that an empirical power-law model was suitable to describe the rheological behavior of kefir with honey with correlation coefficients (R ²) between 0.991 and 0.96. The apparent viscosity of the kefir with honey decreased with increasing shear rate. Flow behavior index (n) and consistency index (K) values for the kefir with honey ranged from 0.3711 to 0.4691, 130 to 204 mPa s, respectively. The model kefir with honey was found to exhibit non-Newtonian behavior.     

Short communication: Physicochemical features and microbial community of milk kefir using a potential probiotic Saccharomyces cerevisiae KU200284

The aim of this study was to analyze the β-glucan contents, physicochemical features, and microbial communities in milk kefir prepared using Saccharomyces cerevisiae KU200284 isolated from cucumber jangajji, a fermented vegetable commonly eaten in Korean. Three types of milk kefir were manufactured, with (1) activated kefir grain, (2) activated kefir grain with commercial S. cerevisiae BOF, and (3) activated kefir grain with S. cerevisiae KU200284. β-Glucan contents of milk kefir using kefir grain and kefir grain with S. cerevisiae strains BOF and KU200284 were 8.29, 8.59, and 8.57%, respectively. The pH, titratable acidity, viscosity, Brix level, and alcohol contents of milk kefir using kefir grain with S. cerevisiae strains were acceptable compared with milk kefir using only kefir grain. In milk kefir produced using kefir grains and S. cerevisiae strains, 16S rRNA reads showed representative strains of Lactobacillus kefiranofaciens (>72% relative abundance) and Acetobacter fabarum (>16% relative abundance). In particular, milk kefir using kefir grain with S. cerevisiae KU200284 had the highest relative abundance of L. kefiranofaciens. In addition, the internal transcribed sequence (ITS) rRNA reads in tested milk kefir showed representative strains of Kluyveromyces marxianus (>52% relative abundance) and Saccharomyces cerevisiae (>16% relative abundance). In contrast, milk kefir using S. cerevisiae strains had higher relative abundance of S. cerevisiae (>37%). The β-glucan production, physicochemical properties, and microbial community profiling indicate that S. cerevisiae KU200284 could be used in functional dairy products as a starter culture.     

Dietary fibre and physicochemical properties of edible Spanish seaweeds

 Total dietary fibre content of five edible marine Spanish seaweeds: Fucus vesiculosus, Laminaria digitata (Kombu), Undaria pinnatifida (Wakame), Chondrus crispus (Irish moss), and Porphyra tenera (Nori) ranged from 33.6 to 50% of which 19.6 to 64.9% was soluble. For brown algae, the soluble fibre obtained by the AOAC method followed by dialysis, contained uronic acids from alginates and neutral sugars from sulphated fucoidan and laminarin. For red seaweeds, the main neutral sugars corresponded to sulphated galactans: carrageenan (Chondrus) or agar (Nori), respectively. Insoluble fibres (12–40%) were essentially made of cellulose, plus residual fucose-containing polysaccharides, except for the red seaweed Nori, which contained an insoluble mannan and xylan. Protein content in powdered algae was higher in red (20.9–29.8%) than in brown seaweeds (6.9–16%), although protein digestibility was apparently low as inferred from preliminary in vitro results with Fucus and Laminaria. Ashes (21–39.8%) and sulphate content (2.8–10.5%) were high in all seaweeds. Minor components were lipids (0.2–2.5%) and extractable polyphenols (0.4%). Regarding the physicochemical properties, oil retention was low, while swelling, water retention, and cation exchange capacity were higher in brown algae, related to their higher uronic acid plus sulphate content. Received: 2 May 2000 / Revised version: 13 June 2000     

Low folate content in gluten-free cereal products and their main ingredients

Folate content in some gluten-free cereal products and their main ingredients was determined using a validated method based on reversed-phase high performance liquid chromatography (HPLC) with fluorescence and diode array detection. The main folate forms found in gluten-free products were 5-methyl-tetrahydrofolate and tetrahydrofolate. Starches and low protein flours commonly used as main components in gluten-free products appeared to be poor folate sources with folate content ?6 μg/100 g fresh weight. Folate content in gluten-free breads was higher (15.1–35.9 μg folate/100 g fresh weight) due to use of bakery yeast which is a rich folate source. Overall, folate content in gluten-free products was lower than in their gluten-containing counterparts. Therefore, fortification of gluten-free products with folic acid or enrichment of these products with nutrient-dense fractions of cereals naturally free from gluten (such as buckwheat, quinoa, amaranth or millet) can be of interest.     

Folate content in frozen vegetarian ready meals and folate retention after different reheating methods

Folate content and retention were evaluated in 10 different precooked vegetarian ready meals before and after reheating. Folate was quantified using a validated high-performance liquid chromatography method. The only form of folate found was 5-methyltetrahydrofolate. Folate content in thawed ready meals varied from 23 to 81 μg/portion (400 g) on fresh weight basis. Products served with couscous and potatoes contained more folate than products served with rice. Folate retention during reheating was investigated in the microwave oven (900 W/5.5 min), in a saucepan on stove until the food reached 85 °C, and in oven (225 °C/40 min). The true vitamin retention varied for the three investigated portions as follows: on stove (63-93%), microwaving (55-89%) and in oven (50-92%). Our results indicate that folate content in the ready meals prior to reheating, contributed to 6-27% of the recommended intake (300 or 400 μg folate per day). After reheating folate content was significantly (P<0.05) reduced in some meals but were kept constant in others and folate content was reduced to 3-25% of the recommended value. No clear pattern in folate retention between different heating methods was seen. However, the meals with ingredients suggesting high concentrations of antioxidants were less prone to loose folate when heated since the antioxidants probably protected the folates.     

Applicability of NIR spectroscopy to determine oil and other physicochemical parameters in Rosa mosqueta and Chilean hazelnut

Due to the increasing interest in certain components, specially the oil, from non-conventional seeds as Rosa mosqueta (Rosa rubiginosa) and Chilean hazelnut (Gevuina avellana), quick determinations of oil and other parameters were carried out by using near-infrared (NIR) spectroscopy. Moisture, oil, fiber (as acid detergent fiber) and protein from solid samples of the seeds as mentioned, along with those of soybean (Glycine max), already analyzed by NIR and for serving as control for the variability of the method, were studied. Sample interactions to NIR radiations were processed using the multivariate regression algorithm Partial Least Squared (PLS) to build a calibration model. Standard error of cross-validation (SECV) was used to estimate the prediction error. Moisture of Rosa mosqueta, Chilean hazelnut presscake and soybean meal (in the ranges 10–15, 10–15, 8–10%, respectively), acid detergent fiber (60–68, 12–16, 10–15%, respectively), oil (1–4, 14–20, 5–13%, respectively) and protein (1–5, 8–15, 27–45%, respectively) were previously determined by wet analysis using standard methods, so creating a library. The possibility to analyze parameters from very different oilseeds with an acceptable uncertainty was also established. Standard errors of cross-validation were between 1.25 and 2.99%, being the oil content the best predicted parameter.     

Antioxidant properties of some commonly consumed and underutilized tropical legumes

The antioxidant properties of some commonly consumed [cowpea (Vigna unguiculata)] and underutilized [pigeon pea (Cajanus cajan) and African yam bean (Sphenostylis sternocarpa)] legumes were assessed with regard to their Vitamin C, total phenol, and phytate content, as well as antioxidant activity as typified by their reducing power and free radical scavenging ability. The Vitamin C content of the cowpeas ranged from 0.5 to 0.9 mg/100 g, while that of underutilized legumes were 0.9 mg/100 g for pigeon pea and 0.8 mg/100 g for African yam beans. The phenol content of the cowpeas were 0.3–1.0 mg/g, African yam bean had 0.7 mg/g total phenols, while pigeon pea contained 0.4 (white) and 1.2 mg/g (brown) total phenol content, respectively. The phytate content of all the legumes [cowpea (2.0–2.9%), pigeon pea (2.0–2.4%), African yam beans (2.4%)] analyzed were generally high, while the reducing power and free radical scavenging ability for all the legumes were very low except in African yam beans (23.6%), cowpea brown (29.9%), and pigeon pea brown (54.5%) that had a relatively high free radical scavenging ability. Therefore, one of the commonly consumed cowpea V. unguiculata (brown) and underutilized legumes C. cajan (brown) and S. sternocarpa could be considered as a functional food due to their relatively higher antioxidant activity (free radical scavenging ability and redox potential) which could be as a result of their relative higher total phenol content.     

Rapid characterization and identification of fatty acids in margarines using horizontal attenuate total reflectance Fourier transform infrared spectroscopy (HATR-FTIR)

Fourier transform infrared spectroscopy (FTIR) with horizontal attenuated total reflectance (HATR) coupled to multivariate analysis was used to predict chemical composition, fatty acid profile, nutritional relationships between fatty acids, and to identify trans fatty acids (TFA) of margarines. For model building and validation, a set of 42 margarines samples were analyzed in terms of fatty acid profile, total fat, moisture, and salt content. The quantitative models were based on incorporating the above chemical parameters of the different margarines and HATR-FTIR spectral information into the calibration model using chemometric analysis. Chemical parameters for total fat, moisture, and salt content ranged 39–84.5%, 14.5–59%, and 0.3–2.6%, respectively. Regarding fatty acids, the concentration of TFA, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) ranged 0–34.06%, 17.17–54.20%, 15.26–34.49%, and 4.02–53.89% (g/100 g margarine), respectively. Principal components regression (PCR) and partial least square analysis (PLS) were used to inspect the variation within the sample set. The best model to predict the chemical composition was obtained using the algorithm partial least squares (PLS) with a R ² greater than 0.933 and SEC and SEP less than 1.294 and 1.406, respectively. The optimized SIMCA model used to identify high or low TFA content showed 100% correct classification rate of both margarines with less than 2.0 g TFA/100 g fat as more than 2.0 g TFA/100 g fat. Compared with traditional chemical analysis, the FTIR-HATR models analyzed margarines in minutes and directly in their neat form.     

Characteristics of Monascus sp. isolated from Monascus fermentation products

To screen for the strains suitable for industrial applications, 15 Monacus sp. were isolated from various Monascus fermentation products. The isolated strains were belonging to Monascus pilosus, Monascus purpureus, Monascus albidulus, and Monascus femeus based on the ITS sequence and morphological characteristics. They produced globular and hyaline conidia, and red, orange, or hyaline ascomata except for M. fumeus, in which ascomata was not observed in malt extract media. Each strain produced monacolin K and citrinin at different levels on different media: 15.79–20.05 mg/L of monacolin K and 0–255 μg/L of citrinin in submerged culture of monacolin K producing media, 1.27–2.69 mg/L and about 507.4 μg/L in YES medium, 0–0.78 g/kg and 0–9.7 mg/kg in Monascus red rice products, suggesting that it is necessary to adopt the similar conditions to a specific application for screening as well. These various isolated strains would be great resources for industrial application to develop Monascus fermented functional products.