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.
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.
In this study, the
antibacterial and antioxidant activities of dried fruit extract of cranberry
(gilaburu, Viburnum opulus) were determined. The total phenolic content
was found to be 131.99±2.11 mg
gallic acid equivalent (GAE) g-1 in the cranberry fruit extract
(CFE). The antioxidant activity of the extract was found to be 315.50±8.2 mg g-1 in dried methanol extract. At 2,
5, 10 and 15% concentrations the extracts were tested for their antibacterial
effects by using the agar diffusion method against ten bacteria, some of them
pathogenic and some of them spoilage microorganisms. All bacteria were
inhibited by 10 and 15% concentrations of the CFE. Methanol (control) had no
inhibitory effect on all the tested bacteria. The most sensitive of the
bacteria was A. hydrophila, whereas the most resistant bacterium was Y.
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: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.
Authors:C. Contreras-Castillo, M. Trindade, and P. Felício
The objective of this study was to characterise and compare the quality of the MSMs obtained from carcasses from breeding and laying hens to provide useful information for the processing industry. The composition of the mechanically separated meat (MSM) varied between the two groups. Laying hens contained the most crude protein (P<0.05) and high ash content (P<0.05). Calcium concentrations and bone contents were higher (P<0.05) for laying (448 mg/100 g and 1.25%, respectively) than for breeding hens (299 mg/100 g and 0.78%, respectively). Levels of unsaturated fatty acids for laying and breeding hens (75.89 and 72.82%, respectively) and cholesterol concentrations (73 and 61 mg/100 g, respectively) were higher (P<0.05) for laying hens than for breeding ones.
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.