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Abstract

This research aims to determine whether the treatment of food products in a microwave electromagnetic field is advantageous or disadvantageous compared to conventional technologies. In household practice, microwave energy transfer is used mostly for heating. One of the most important tangible benefits of microwave heat treatment is that it causes less damage to the nutritional value of the product due to its speed.

Despite the fact that microwave technology was introduced more than 70 years ago, it is still not clear whether its application results in equivalent products in terms of quality and food safety.

This study demonstrates how heat-treated wines with microwave energy transmission and with convective heating in a thermostatic water bath are affected. In the white, rose and red wine samples pasteurized at a temperature of 74 ± 0.5 °C, significant differences between the two heating methods regarding colour characteristics could be indicated.

Open access

Abstract

Industrial wastewater is a growing environmental challenge due to its high concentrations of organics and its limited biological degradability. Up to date, however, no published work discussed industrial wastewater characterization, which is the focus of this study. Moreover, the effect of hydrothermal treatment on the chemical oxygen demand (COD) removal and the soluble chemical oxygen demand (SCOD) release was investigated in this work. Wastewater samples were collected from different industrial sites and characterized in order to determine their initial properties. It was summarized that the salinity of wastewater estimated by EC was relatively low, and its pH values were in the acceptable range. On the other hand, however, high values of sodium absorption ratio (SAR) were obtained in all samples post to hydrothermal treatment. Nonetheless, our results revealed higher SCOD release post to hydrothermal treatment suggesting better efficiency of COD removal obtained by this treatment technique.

Open access

Abstract

In milling industry, the object of milling is to separate endosperm and bran parts of wheat, and to recover flour. The most important and the highest energy requirement operation is grinding. The quantity and quality of flour depends on: the variety of wheat that will be milled, the type of grinding equipment and the condition used before the grinding. During our experiments two different grain structured varieties of wheat were milled in laboratory conditions with disk, stone grinder and roller miller in air-dry, and conditioned states. The performance of the equipment and the particle size distribution (PSD) of the produced grist were measured, then the energy requirements of the grinders were calculated. In the milling experiments the ash contents of the different particle sized fractions were compared to map particular properties of wheat cultivars.

Open access
Progress in Agricultural Engineering Sciences
Authors: Tamás Zsom, Petra Polgári, Lien Phuong Le Nguyen, Géza Hitka and Viktória Zsom-Muha

Abstract

Broccoli's high perishability and its sensitivity to negative quality changes (i.e., mass loss, ethylene induced degreening, abscission of leaves, and florets) generates quality problems during postharvest. Freshly harvested samples were stored at 5 and 21 °C after separately treated for 24 h with 625 ppb 1-methyl-cyclopropene (1-MCP), 24 h with 2 ppm ethylene and 1-MCP followed by ethylene. Quality maintenance effectivity of 1-MCP was investigated during cold and room storage by non-destructive optical methods (chlorophyll fluorescence and DA-index®) and by the evaluation of the visual physiological symptoms. The highly positive effects of 1-MCP treatment combined with cold storage were obviously proven on quality maintenance providing better retention of initial quality related to the initial mature green stage as chlorophyll content related DA-index®; F m, F v, F v/F m, and F m/F 0 chlorophyll fluorescence values. From the practical point of view, the rapid, and easy-to-use Sintéleia FRM01-F Vis/NIR DA-meter® could be applied relatively easy for the quality measurement of broccoli. The reproducibility of quality determination could be increased by the enhanced number of measuring points or using computer aided imaging methods (i.e., chlorophyll fluorescence imaging, machine vision system) providing global and more reliable information about quality changes.

Open access

Abstract

Liensinine is a bisbenzyltetrahydroisoquinoline alkaloid extracted from lotus (Nelumbo nucifera GAERTNER., Nelumbonaceae), especially in its embryo loti “Lien Tze Hsin” (green embryo of mature seed). A rapid and simple UPLC-MS/MS method was developed to determine liensinine in mouse blood and its application to a pharmacokinetic study. The blood samples were preprocessed by protein precipitation using acetonitrile. Midazolam (internal standard, IS) and liensinine were gradient eluted by mobile phase of methanol and water (0.1% formic acid) in a Waters UPLC BEH C18 column. The multiple reaction monitoring of m/z 611.3 → 206.1 for liensinine and m/z 326.2 → 291.1 for IS with an electrospray ionization (ESI) source was used for quantitative detection. The calibration curve ranged from 0.5 to 400 ng/mL (r > 0.995). The accuracy ranged from 92.2 to 108.2%, the precision of intra-day and inter-day was less than 14%, and the matrix effect was between 100.0% and 109.6%, the recovery was better than 71.0%. The developed UPLC-MS/MS method was successfully used for a pharmacokinetic study of liensinine in mice after oral (5 mg/kg) and intravenous administration (1 mg/kg), and the absolute availability of liensinine was 1.8%.

Open access

Abstract

A highly sensitive high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of eight biogenic amines in aquatic products. The biogenic amines in the sample were extracted with 5% trichloroacetic acid, derived with dansyl chloride (Dns-Cl) and quantified by a UV detector. The results showed that tryptamine (TRY), 2-phenethylamine (PHE), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TPY), spermidine (SPD), and spermine (SPM) were effectively separated in 18 min in the range of 0.1–50 mg/kg with a good linear coefficient (r 2 > 0.999). The detection limits (LODs) of the eight biogenic amines were 0.007–0.021 mg/kg while the limits of quantification (LOQs) were 0.024–0.069 mg/kg with the recoveries basically between 68 and 123%. The determination of eight biogenic amines in five commercial fermented aquatic products indicating that the developed method could be applied for the simultaneous detection of biogenic amines in multiple aquatic products.

Open access
Progress in Agricultural Engineering Sciences
Authors: Judit Perjéssy, Ferenc Hegyi, Magdolna Nagy-Gasztonyi, Rita Tömösközi-Farkas and Zsolt Zalán

Abstract

Nowadays, demand for products which beyond the overall nutritional value have a feature that protects the consumer health, have increased. Several studies have proved that fruit juices can become a suitable carrier or medium for probiotic organisms. Therefore, the aim of our study was to investigate the possibility of the probiotication of sour cherry juice (SCJ) by fermentation with probiotic starter culture. During the fermentation 9 Lactobacillus strains were used and Újfehértói fürtös sour cherry species as raw material. To reach the recommended probiotic cell count we investigated the pH adjustment, supplementation of nutrients, the effect of dilution, and strain adaptation to SCJ. In our study the properties of the strains – such as reproduction and metabolism – and its effect on the raw material were investigated. A significant difference was observed between the number of viable cells of certain Lactobacillus strains, that is important in point of view of the development of probiotic-containing products. Furthermore, the lactic acid fermented SCJ can enhance the polyphenol content and antioxidant activity to promote the health of consumers.

Open access

Abstract

Similarly to other industries wineries also increasingly attempt to minimize and utilize waste to protect our environment. The aim of this study was to determine the optimal parameters (temperature, solvent concentration, and time) of extracting total polyphenol content (TPC) from Tokaji Aszú marc using two different extraction solvents: ethanol–water and isopropanol–water (1:4 solid/liquid ratio). The extractions were achieved based on Central Composite Design with Response Surface Method (CCRD–RSM). The optimal extraction parameters in the case of ethanol–water solvent: 60 °C temperature, 59.5% ethanol concentration in solvent, 5 h. At these parameters the probable TPC concentration is 23966.2 uM GAE/L. The optimal extraction parameters in the case of isopropanol–water solvent: 60 °C temperature, 52% ethanol concentration in solvent, 5 h. At these parameters the probable TPC concentration is 7188.44 uM GAE/L. In both cases the binary solvent was better than the mono-solvent. Ethanol–water solvent was more efficient than the isopropanol–water solvent.

Open access

Abstract

An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS) method was developed to determine the fenofibric acid (FA) in human plasma and applied to a pharmacokinetic study of fenofibrate tablet (Lipanthyl® supra, 160 mg) on Chinese subjects which had not been reported. Bezafibrate was used as an internal standard (IS), and the plasma samples were precipitated by methanol. Multiple reaction monitoring (MRM) mode was used to quantitatively analyzed FA m/z 317.2 → 230.7 and the IS m/z 360.0 → 274.0 in the electrospray ionization (ESI) negative interface. The calibration curves were linear over the range of 50–30,000  ng/mL (r 2  ≥  0.996). The intra-day and inter-day precision (coefficient of variation, CV%) was less than 2.7 and 2.5%, respectively. The accuracy (relative error, RE%) ranged from −4.5 to 6.9%. The average recovery was higher than 86.2%, and the matrix effect was between 95.32 and 110.55%. The simple, rapid, and selectivity method was successfully applied to the pharmacokinetic study of fenofibrate tablets on Chinese subjects.

Open access

Summary

In this study, single-walled carbon nanotubes (SWNTs) were used to determine organochlorine pesticides (chlorothalonil and pentachloronitrobenzene) in water using dispersive solid-phase extraction (DSPE), followed by gas chromatography (GC). The optimal adsorption conditions were determined by analyzing the effect of adsorbent dosage, adsorption time, eluent type and volume, and elution time. Under the optimal conditions, a good linearity was obtained at concentrations from 10 to 400 μg L−1 with correlation coefficients ranging from 0.9991 to 0.9986. The limits of detection (LOD) for the two organochlorine pesticides were 0.025 and 0.049 μg L−1, and the limits of quantification (LOQ) were 0.080 and 0.156 μg L−1, respectively. The accuracy of the proposed method was evaluated by measuring the recovery of the spiked samples, which ranged from 82.5% to 110.5% at spiking levels of 0.5–10 μg L−1 with relative standard deviations lower than 5.6% (n = 6). This method was successfully applied to determine the target analytes in canal water, drinking water, and water taken from the inlets and outlets of a wastewater treatment plant. The results demonstrate that the developed method has great potential for determining the two organochlorine pesticides in water samples.

Open access