The content of potentially antioxidant, anticarcinogenic and antiallergic flavonoid aglycons, quercetin, kaempferol, myricetin, apigenin and luteolin of 45 fruits were determined by RP-HPLC with UV detection. Fresh and dried fruits were purchased in the local markets in Budapest at a period of their most frequent consumption. Total flavonoid content of fruits varied between 0–1000 mg kg –1, the average concentration was about 30 mg kg –1 fresh weight. Quercetin could be detected in most fruits, namely in apples, pear, plums, sweet and sour cherry and berries between 10–53 mg kg –1. Luteolin at a concentration of 20 mg kg –1 was found in melons, apples, kiwi and lemon. Myricetin was in detectable amount in redcurrant, and at very high concentration in some berry fruits (mulberry 453 mg kg –1, raspberry 540 mg kg –1, blackberry 636 mg kg –1, strawberry 994 mg kg –1), and in walnut (4565 mg kg –1). Kaempferol and apigenin were not found in the fruits investigated. None of the five flavonoids was found in some variety of grapes, in peach, pear, banana, orange, grapefruit and tangerine, in nuts such as almond, pistachio, nuts, and in dried fruits such as raisin, date, fig and prunes. These data provide a basis for the evaluation of the average daily intake of Hungarian population and for an epidemiological evaluation of health-promoting effects of flavonoids. __
Authors:K.C. Hor, L.C Lew, S.B. Choi, and M.T. Liong
The oral administration of hyaluronic acid has been shown to improve skin health. This study aimed at utilizing ultrasound treatment to enhance the production of hyaluronic acid by lactobacilli. Among the 16 strains of lactobacilli screened, a higher production of hyaluronic acid (P<0.05) was observed from seven strains namely, Lactobacillus casei BT 2113, Lactobacillus casei BT 1268, Lactobacillus casei BT 8633, Lactobacillus casei FTDC 8033, Lactobacillus acidophilus FTDC 1231, Lactobacillus gasseri FTDC 8131 and Lactobacillus rhamnosus FTDC 8313. Upon ultrasonic treatment, hyaluronic acid concentration increased significantly (P<0.05) in all the seven strains studied. The use of ultrasonication at 100% amplitude increased the hyaluronic acid content (P<0.05) up to 51.6 % with concentrations ranging from 0.262 mg ml−1 to 0.385 mg ml−1, while an amplitude of 20% yielded a lower increase ranging from 0.227 mg ml−1 to 0.310 mg ml−1. Increasing duration of ultrasonic treatment (from 1 min to 3 min) also significantly (P<0.05) improved the concentration of hyaluronic acid in some strains. Our data demonstrated that a sub-lethal physical treatment, such as ultrasonication, can be applied to increase the membrane permeability of lactobacilli cells and subsequently increase the release of bioactive metabolites.
Authors:M. Croitoru, I. Fülöp, M. Ajtay, G. Dudutz, O. Crăciun, and M. Dogaru
To date, monosodium glutamate is the most used flavour enhancing food additive. Because high levels of glutamate are toxic to brain concerns appeared regarding the safe use of glutamate and there is a 10 g kg
concentration limit in foodstuff. A simple HPLC-UV method, based on a derivatization procedure with
-phthaldialdehyde, was developed for determination of glutamate in meat products, soup bases and vegetable concentrates. Even if our method is less sensitive than the HPLC-fluorescence ones widely available, it is able to measure amounts at least 200 times smaller than the maximum allowed one, has good reproducibility (CV under 2% for intraday and under 3% for interday determinations), linearity and accuracy. Less expensive HPLC systems are required and the formed derivative is very stable (at least 1 week), good separation is obtained with the less expensive 5 μm particle C
columns and methanol as organic phase. Concentration of free glutamate ranged between 0.14 g kg
in sausage without added glutamate to as high as 2.16 g kg
in a pork sausage. Concentration in vegetable mixes and soup bases were between 80–120 g kg
Authors:M. Lešnik, A. Cencič, S. Vajs, and A. Simončič
The influence of three milling techniques (MT1: industrial roller-grinder, MT2: grain hammer crasher, and MT3: traditional millstone) and two baking methods (BM1: industrial oven, BM2: traditional ceramic stove heated by wood (log fire oven)) on mycotoxin deoxynivalenol (DON) and nivalenol (NIV) levels in bread were investigated. The DON and NIV concentrations in wheat grain, flour, and bread were analysed using high performance liquid chromatography with UV-detection methods. The 2 500 kg lot of wheat grain containing 1 400–1 900 μg kg
deoxynivalenol and 130–200 μg kg
nivalenol was divided into sub-lots which were processed to get three types of flour (F1: industrial bread flour, F2: industrial wholegrain flour and F3: traditional wholegrain flour). The concentrations of DON and NIV measured after milling the grain according to MT1 (yielding F1) amounted to 310–370 \g kg
and <50–70 μg kg
, respectively. After applying MT2 to the grain (yielding F2), the DON and NIV levels were measured to be 1 060–1 400 μg kg
and 60–87 μg kg
, respectively. Applying MT3 (yielding F3) produced a DON level of 1 100–1 770 μg kg
1 and a NIV level of 80–95 μg kg
. Six types of bread were baked from the three types of flour according to BM1 or BM2, and the mycotoxin levels were analysed. The average reduction in DON concentration after baking (70 min at 195–235 °C) was 47.2% for bread baked in the industrial oven and 48.7% for bread baked in the log fire oven. Concentrations of DON in bread prepared by the industrial MT1 were under the permitted limit of 500 μg kg
stated in EC (2006) regulation, despite the fact that the bread was baked from grains highly contaminated with mycotoxins. In the bread baked from traditional wholegrain flour, mycotoxin concentrations were higher (850–950 μg kg
characteristics, dissolved oxygen concentration, biomass amount). It has a long tradition to use Activated Sludge Models (ASM) model family [ 10 ], therefore a lot of experience is gained in model calibration and validation procedure. These models focus on
Authors:Mester Tamás, Cavalli Daniele, Balla Dániel, and Szabó György
Growing NH4+ content of groundwater results in increasing exchangeable and fixed ammonium ion content of the soil. NH4+ bond in the soil may go again into solution parallel with the dilution of the soil solution but at a slower rate than fixing. This process influences significantly the NH4+ content of the soil. In settlements with no sewerage system the high NH4+ content of sewage flowing out of uninsulated septic tanks may increase the fixed NH4-N content of the soil that could have a significant effect on the quality of groundwater even after the potential disappearance of pollution sources.
In this study the effects of the fixed NH4-N content of the soil around an uninsulated residential septic tank on the purification processes of the groundwater were investigated. The septic tank in the study area was dismantled in 2014 after 27 years of operation as a sewerage system was constructed. When the tank was still in operation in 2012 and 2013, very high, 55–75 mg l-1 NH4+ content was measured in the water of the monitoring well 1 metre from the tank in the course of seasonal sampling. When sewage outflow was terminated in 2014 concentrations decreased right away but even 5 years after pollutant supply was stopped, concentrations (35–57 mg l-1) highly exceeding the pollution limit (0.5 mg l-1) were measured. Considering this very high concentration, it can be assumed that great amount of NH4+ is still released into the groundwater.
In order to prove this, the exchangeable and fixed NH4-N and NO3-N contents of the soil were determined by 20 cm down to a depth of 4 metres (2019). The measurements indicated the significant accumulation of exchangeable and fixed NH4-N in the zone between 220 and 400 cm. Highest fixed NH4-N concentrations of 457 mg l-1 were found between 220 and 240 cm suggesting that sewage outflow was most intense at this depth. Slow decrease in concentrations can be observed in deeper zones but concentrations higher than 350 mg l-1 were measured between 220 and 380 cm. Based on correlation analyses, the quantity of fixed NH4-N shows no correlation with the soil texture thus it can be stated that the vertical pattern of NH4-N content is determined dominantly by sewage outflow and its depth. In the unsaturated zone of the borehole a significant accumulation of NO3-N was also identified. The maximum of NO3-N was found in the zone between 100 and 140 cm. The peak nitrate calculated for NO3- ion with a value >1300 mg kg-1 is 2.5 times the limit set for the nitrate content of the geological medium.
Based on the results, exchangeable and fixed NH4-N contents in the soil are still very high, 5 years after sewage outflow was stopped. The continuous solution of this component still contributes to the high NH4+ content of the groundwater. As a result, the contaminated soil in the immediate environment of the septic tank is still a pollution source.
Competition between a bacteriocinogenic and a non-bacteriocinogenic Lactococcus lactis strain, respectively, and a Listeria monocytogenes strain was studied in two semi-synthetic liquid media at various temperatures. The media used for the study were ST I and modified ST I broth (ST I broth + 1 g l-1 Tween 80). In both media, at 30 °C, a significant cell count reduction (5 log) of L. monocytogenes occurred only when the cell concentration of the bacteriocinogenic competitor reached the level of at least 107 CFU ml-1 required for the production of sufficient concentration of nisin-like bacteriocin. The same phenomenon was also observed when the initial level of the lactic acid bacteria (LAB) was one log higher or lower than that of the Listeria, however, the reduction of Listeria cell count occurred earlier with the higher initial concentration of the LAB. Incubation of the mixed cultures at 20 °C gave similar results but the bacteriocinogenic activity resulted in only a three log decline of the cell count of L. monocytogenes. At 10 °C Lactococcus lactis produced much less bacteriocin than at 30 °C, therefore, a drastic decrease of the Listeria cell count was not observed. Suppression of the Listeria growth was expressed in its decreased maximum population level (i.e. in an earlier appearance of the stationary phase). When the non-bacteriocinogenic Lac. lactis and Listeria were present at the same initial level (approx. 105 CFU ml-1), the Lactococcus did not affect the growth of L. monocytogenes at 30 °C in modified ST I broth.
Even if plants can contain high levels of nitrate and nitrite, milk and dairy products are not described as sources of these anions. The purpose of this paper was to measure the concentrations of nitrate and nitrite in forage, cow blood, and milk.The results show that the nitrate ratio of milk to plasma is very low, suggesting that milk contamination with nitrate is unlikely to occur. This finding also proves the lack of an active transport mechanism to transfer nitrate from blood to milk. The nitrite anion almost disappears from milk through an enzymatic conversion; usually levels of μg l−1 were measured.
Lactic acid bacteria were isolated from tungrymbai, a traditional fermented soybean product of Meghalaya, India and assessed for their probiotic properties. Survival under simulated gastric conditions was tested and five acid tolerant strains were selected. By using 16S rDNA sequencing, these isolates were confirmed to be Enterococcus species. The strains exhibited good survivability in high concentrations of bile salts. The strains were susceptible to antibiotics and they were also found to inhibit growth of Staphylococcus aureus and Escherichia coli. The strains were gelatinase negative and non-haemolytic. The strains also assimilated cholesterol up to a certain level. The study confirmed that all identified five strains have in vitro probiotic properties.
Authors:L. Hernández Rodríguez, D. Afonso Morales, E.M. Rodríguez-Rodríguez, and C. Díaz Romero
Proximate composition was determined in 19 wheat cultivars from the Canary Islands in order to establish differences between them and contribute to their characterization. All parameters analysed showed significant differences between cultivars; and also many parameters were affected by the species and subspecies of wheat. Triticum aestivum had higher mean moisture, protein, and fibre and lower mean starch, sucrose, and amylose concentrations than Triticum turgidum. Low starch content and high fibre content could be due to the transformation of starch into resistant starch during desiccation process. An important contribution of complex carbohydrates, including fibre as well as protein and phenolic compounds, was observed for the consumption of wheat.