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%.
Authors:K. Jurica, I. Brčić Karačonji, D. Lasić, D. Vukić Lušić, S. Anić Jurica, and D. Lušić
Phthalates are ubiquitous environmental contaminants that, due to their lipophilicity, migrate more readily into beverages with higher ethanol content. The aim of this work was to study the occurrence of phthalates in samples during the plum spirit production and in the final product, plum spirit manufactured by registered producers from five European countries, using gas chromatography-mass spectrometry (GC-MS). A decreasing trend of mean values was observed for diethyl phthalate (DEP), di-iso-butyl phthalate (DiBP), and di-n-butyl phthalate (DBP) as the distillation process went on. Levels of benzyl-butyl phthalate (BBP) and di-(2-ethylhexyl) phthalate (DEHP) increased in the distillation phase compared to concentrations in the preceding phases. In commercial plum spirits, DEHP and DiBP were detected in the highest concentrations. Results also indicated that a moderate daily consumption of plum spirit does not pose a health risk regarding the Tolerable Daily Intake of BBP, DEHP, and DBP
Authors:L. Körmendy, E. Zukál, I. Csapó, and N. Török
The aim of this study was a survey of relationships used for calculating ‘meat content’ with respect to the QUID regulation (Commission Directive
, 2001). The recommended equations are presented in a concise form. The advantages of a possible introduction of the meat equivalent concept are also treated [assessment of lean content of the meat ingredient(s)]. A non-negligible condition for applying the QUID equations is, in principle, the equality of the fat-free protein concentrations of the various tissue types in the raw meat materials. This needs an adjustment of the protein concentrations of the recipes to a reference value (PFFref), which can be achieved by effective or virtual addition of water to the formulation or ‘removal’ of water from it. The influence of moisture loss during meat processing on QUID is also discussed. The results of various calculation methods are presented with examples.
The aim of the present study was to test the antioxidant activity of rosemary extract and its mixture with propylene glycol on the stability of fat in butter. Rosemary extract was added at a concentration of 0.02% (w/w) and mixture of rosemary extract with propylene glycol at a concentration of 0.25% (w/w) to the cream before churning. For comparison, control samples without added antioxidant were also prepared and tested. Samples were stored at 4 °C and at 20 °C for 27 days and their peroxide values were determined periodically. The measurement of peroxide values for butter at 60 and 98 °C was also performed. Activity of rosemary extracts was compared with synthetic antioxidant BHT. The rosemary extract and its mixture with propylene glycol exhibited strong antioxidant activity in butter when added to a cream before churning and in an aqueous emulsion system of β-carotene and linolenic acid.
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.
Authors:Cs. Mohácsi-Farkas, G. Kiskó, L. Mészáros, and J. Farkas
Laboratory batches of fresh tomato juices were treated in several experimental trials by high hydrostatic pressure alone or in combination with various concentrations of oregano, thyme or dill seed oils. Lactic acid bacteria formed the dominating component of the spoilage microbiota during post-processing storage at 15 °C causing spoilage of the untreated samples within 4 days. One tenth of a percent oregano or thyme oils at least doubled the microbiological shelf life, while their respective concentrations of 0.5% alone, or 400 MPa 5-20 min high hydrostatic pressure treatment alone resulted in microbial stability for at least two weeks. Two hundred MPa for 10 min resulted only in an approx. 3 days delay of spoilage, whereas 0.1% thyme oil increased the efficiency of this moderate UHP-treatment, resulting in a microbiologically stable product for at least 3 weeks at the storage temperature applied.
Authors:V. Stehlik-Tomas, S. Grba, D. Stanzer, N. Vahčić, and V. Gulan Zetić
Procedures for the production of Saccharomyces cerevisiae biomass enriched with iron and the effects of the iron ions addition into the molasses medium on the yeast growth and the production of ethanol were studied. The growth of the yeast S. cerevisiae and the ethanol production in media with different concentrations of Fe were monitored in the batch process under semiaerobic and anaerobic conditions. The highest biomass concentration and ethanol production were achieved in the medium with 0.6-0.8 g l-1 of Fe under both (semiaerobic and anaerobic) conditions. Kinetics of the iron ions accumulation in yeast cells during 24 h of growth in the batch process under semiaerobic and anaerobic conditions were monitored. In anaerobic conditions the maximum uptake (10 mg g-1 d.m. yeast biomass) was obtained after 12 h of fermentation, while in semiaerobic conditions a four times lower uptake (2.5 mg g-1 d.m. yeast biomass) was obtained after 16 h of fermentation.
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%.