Authors:J. Karovičová, Z. Kohajdová, and D. Lukáčová
A capillary isotachophoretic (cITP) method to determine the concentration of nitrates and nitrites in vegetables and lactic acid fermented tomato, cucumber and cucumber-onion juices is described. Method characteristics (selectivity, response function, linearity, precision, accuracy and limit of quantification) were determined. The minimal sample pretreatment and relatively low running make isotachophoresis a good alternative to existing methods.
Authors:V. Nanda, A. Kaur, M. B. Bera, B. Singh, and A. K. Bakhshi
In this study honey
samples of Eucalyptus honey (Eucalyptus lanceolatus) were
botanically characterized. Response surface methodology was used to analyze the
effect of temperature, time and pH on the quality responses (hydroxymethylfurfural concentration and diastatic activity)
of Eucalyptus honey. A
central-composite rotatable design was used to develop models for the
responses. At the central value of time (10 min), the maximum concentration of
hydroxymethylfurfural was demonstrated at the highest temperature and pH. The
maximum value of hydroxymethylfurfural concentration was also obtained at the
maximum time and temperature, while keeping the pH at the central value of 5.3.
Diastatic activity decreased as the pH moved away from the central pH value of
5.3 to 5.6 at any level of temperature and time. Three-dimensional response
surfaces were superimposed, and the overlapping regions gave the diastatic
activity (calculated as diastase number 9 to 23.09 °G) and hydroxymethylfurfural
concentration (3 to 10.21 mg kg-1)
at 48±1 °C for
9.5±1 min at
Authors:H.B. Coban, A. Demirci, P.H. Patterson, and R.J. Elias
Alpha keto acids are important food additives, which commonly produced by microbial deamination of amino acids. In this study, production of phenylpyruvic acid (PPA), which is the alpha keto acid of phenylalanine was enhanced in 2-l bench scale bioreactors by optimizing of fermentation medium composition using the Box-Behnken Response Surface Methodology (RSM). Optimum glucose, yeast extract, and phenylalanine concentrations were determined to be 119.4 g 1−1, 3.7 g 1−1, and 14.8 g 1−1, respectively, for PPA production, and 163.8 g 1−1, 10.8 g 1−1, and 9.8 g 1−1, respectively, for biomass production. Under these optimum conditions, PPA concentration was enhanced to 1349 mg 1−1, which was 28% and 276% higher than the unoptimized bioreactor and shake-flask fermentations, respectively. Moreover, P. vulgaris biomass concentration was optimized at 4.36 g 1−1, which was 34% higher than under the unoptimized bioreactor condition. Overall, this study demonstrated that optimization of the fermentation media improved PPA concentration and biomass production in bench scale bioreactors compared to previous studies in the literature and sets the stage for scale up to industrial production.
Authors:K. Szentmihályi, G. Taba, C. Lado, J. Fodor, M. Then, and É. Szőke
Herbal teas may be effective in adjuvant therapy for the prevention of complications of diabetes mellitus II. Agrimoniae herba, Betulae folium, Bursae pastoris herba, Foenigraeci semen, Galegae herba, Maydis stigma, Taraxaci radix, Phaseoli fructus sine seminibus, Urticae folium, and their teas were analysed by ICP-OES for element content. Concentration of the elements of crude drug samples obtained are in good agreement with the average concentrations of plants, although some significantly high concentration has been found for manganese (893 mg kg-1), zinc (275 mg kg-1) and iron (492 mg kg-1) in Betulae folium, for copper (41.2 mg kg-1) in Galegae herba, for iron (2692 mg kg-1) in Taraxaci radix, for calcium (41210 mg kg-1) and magnesium (6275 mg kg-1) in Urticae folium. The common characteristic feature of crude drugs is the relatively high concentration of chromium (0.8-16.3 mg kg-1). Ion concentrations of teas are relatively low. The quantities of metal ions do not cover the daily needs, nevertheless, they may be important as food supplements. According to U.S. Recommended Dietary Allowances (RDA), the following teas are good sources: Agrimoniae herba for chromium, Betulae folium for manganese, Taraxaci radix for copper and chromium, Urticae folium for potassium and calcium. The dissolution of elements from plant drugs varies: potassium (22.5-74.7%), sodium (1.9-60.5%), calcium (6.6-28.1%), magnesium (12.3-52.5%) and copper (3.7-51.4%) are readily dissolved. The dissolution of manganese (6.8-32.3%) and of zinc (0-31%) is lower. The dissolution of chromium from Agrimoniae herba (9.55%) is significantly higher, while the dissolution ranges from other plant drugs are between 0-5.9%.
The adsorption properties of natural zeolite (clinoptilolite) has been studied in order to determine its applicability for copper and zinc removal in acid mine drainage treatment process. For purpose of these experiments the determination of the sorption equilibrium and removal efficiencies were performed under batch conditions using single and dual-component solutions. The experiments were carried out under acidic conditions (pH approx. 4). In general, the obtained results from kinetic experiments showed rapid decrease of the metal concentration during the first 10 min, corresponding to ~80% total removal of ions from both single and dualcomponent solutions. This initial rapid period was followed by a further slow drop in metals concentration caused by ion-exchange in deeper structure of zeolite.Preliminary tests on the real samples of acid mine drainage from Smolnik mine, Slovakia, showed that natural zeolite has a potential as an alternative low cost adsorptive material for acid mine drainage treatment.
Authors:E. Vamanu, A. Vamanu, D. Pelinescu, S. Niţă, N. Rusu, and N. Popa
The synthesis of exopolysaccharides was determined for the Streptococcus sp. IL5 strain in MRS and M17 medium, with carbon sources such as glucose, lactose and sucrose. According to the obtained results, by using glucose as carbon source, the highest quantity of exopolysaccharides was obtained, namely of 400 mg l−1. The influence of various glucose concentrations (5, 10, 15, 20%) on exopolysaccharide production was tested. It resulted in that, at a concentration of 15% glucose, a maximum quantity of synthesized exopolysaccharides was obtained. The influence of temperature and of pH on the exopolysaccharide synthesis capacity of the strain was tested as well. From the tests the temperature of 37 °C and pH 7 proved to be the ideal parameters for obtaining a maximum exopolysaccharides quantity. Based on chromatographic methods, the content of synthesized polysaccharide was determined, consisting of 31.87% anhydrous glucose with a degree of polymerization of 36.7%.
Authors:S. Lamo-Castellví, W. Ratphtagsanti, and V. Balasubramaniam
The objective of this work was to study the effect of nisin, alone or combined with sucrose laurate ester (SL), on enhancing Bacillus amyloliquefaciens Fad 82 spores inactivation by pressure-assisted thermal processing (PATP). Spores of B. amyloliquefaciens (108 CFU ml−1) were suspended in sterile phosphate buffer saline (pH 7.6) with concentrations of nisin (0, 100, 200, 1000, 1500 and 2000 IU ml−1) and 1.0% of SL, and combinations of nisin (1000, 1500 and 2000 IU ml−1) and SL (1.1%), and treated by PATP (700 MPa and 105 °C, for 1 min). Nisin did not show any synergetic effect with PATP in all the concentrations tested. Instead, 1.0% of SL alone was effective in enhancing inactivation.
Authors:L.F. Pérez-Romero, F.T. Arroyo, C. Santamaría, M. Camacho, and A. Daza
The fruit quality parameters of Prunus armeniaca L. cv ‘Ninfa’ grafted on ‘Myrobalan 29C’ (Prunus cerasifera Ehrh.) and ‘Real Fino’ apricot seedling (Prunus armeniaca L.) were analysed in an experimental orchard under organic management. The study was performed between 2010 and 2012 in the province of Seville (SW Spain). Colour, fruit and stone weights, firmness, soluble solid concentration, and acidity were measured for fruit quality evaluation. Trunk cross-sectional area, main branches, and fruit yield were also determined. In general, ‘Myrobalan 29C’ rootstock produced fruit slightly larger in size and with a bigger weight. By contrast, apricots on ‘Myrobalan 29C’ had less firmness and a lower solid soluble concentration than on ‘Real Fino’. There was little difference in the colour, acidity, and stone dry weights. Trees on ‘Real Fino’ had larger areas of trunk and branches but no significant differences were obtained in relation to fruit yields.
Our knowledge on the presence of mycotoxin producing fungi and mycotoxins in food commodities in the last decade in Hungary has been summarized in this review. Among the mycotoxin producing fungi, detailed data are available for Fusarium species in cereals, and mycotoxigenic Aspergillus species in different food commodities including coffee, raisins and spices. Ochratoxin concentrations above the tolerable limit have mostly been detected in imported products such as peanuts and coffee. Ochratoxin levels close to the tolerable limit have been observed in Hungarian red peppers. Besides, ochratoxin A has also been detected in Hungarian wine, beer and raisins. Aflatoxins are usually detected in considerable quantities only in imported agricultural products in Hungary, while patulin concentrations were usually below the allowable limit in Hungarian apple juice concentrates. In the future, continuous sampling and analysis of foods and feeds are required to ensure consumer safety in Hungary.