Antifungal activities of basil (Ocimum basilicum L.) extract on Fusarium species

The basil extract composition was determined by the GC-MS method and 38 different components were identified. The major components of the basil extract were estragol (86.72%), trans-α-bergamotene (2.91%), eucalyptol (2.67%), trans-ocimene (1.04%), linalool (0.72%), methyl-eugenol (0.71%), etc. The antifungal potential of the basil extract was tested against Fusarium oxysporum, F. proliferatum, F. subglutinans, and F. verticillioides isolated from cakes, using the agar plate method. Extract concentrations of 0.35 and 0.70% (v/v) significantly inhibited the growth of F. proliferatum (33.37 and 44.30%, respectively) and F. subglutinans (24.74 and 29.27%, respectively) whereas other investigated Fusarium species exhibited much lower sensitivity. The basil extract completely inhibited the growth of investigated Fusarium spp. at the concentration of 1.50% (v/v). Higher concentrations (0.35 and 0.70% (v/v)) reduced growth of aerial mycelium in all tested species. Strong medium pigmentation in the case of F. proliferatum and F. verticillioides was observed. The microscopic examination of the samples confirmed the presence of hyphae deformations with a frequent occurrence of fragmentations, thickenings and diminished sporulation. In addition to the basic, sensory, role the extract of basil has in the food product, it exerted significant antifungal properties, depending on its concentration.Key words: Basil (Ocimum basilicum L.) extract, components, antifungal activity, Fusarium spp

Presence of Listeria species in fresh meats from retail markets in Serbia

Listeria spp. are Gram positive, short, non-sporing rods, microaerophilic. Of the six species currently recognized, Listeria monocytogenes is the most important as it causes a range of infections in humans and animals. The organism can be found in a wide variety of habitats including the soil, food processing environments and raw foods. The ability of the organism to grow at refrigeration temperatures is of major importance in food production. This study examines the presence of Listeria species in fresh meat. 29 samples (chicken, pork and beef) meat. This bacteria was found in 82.7% of analyzed samples; 7 L. innocua, 8 L. monocytogenes and 9 L. welshimeri (of all isolates). L. innocua prevailed in pork meat (40%), L. monocytogenes in chicken and pork meat (30%), and L. welshimeri in beef meat (44.4%)

Fermentation temperature and wort composition influence on diacetyl and 2, 3-pentanedione contents in beer

Diacetyl and 2,3-pentanedione are important constituents of beer sensory properties. A new GC/MS method for diacetyl and 2,3-pentanedione content determination was developed. This method was applied for the determination of diacetyl and 2,3-pentanedione contents during beer fermentation (primary fermentation and maturation). Primary fermentations were carried out at different temperatures (8°C and 14°C). Primary fermentation temperature had a great influence on diacetyl and 2,3-pentanedione formation and reduction. Formation and reduction rates increased with the primary fermentation temperature increasment. Diacetyl and 2,3-pentanedione contents also increased with the corn grits increasment. Fermentations were carried out with Saccharomyces cerevisiae pure culture, specially prepared for each fermentation. This GC/MS method for diacetyl and 2,3-pentanedione determination was valuable for analysing the influence of wort composition or fermentation conditions such as primary fermentation temperature on their formation and reduction

Fungal growth during malting of barley

Fungi were isolated and identified in two samples of winter two-row barley (SSK3 and SSK6) harvested in 2003, Kragujevac location, during micromalting. Fungi were isolated and identified in barley before the micromalting, after the 1st, 2nd and 3rd day of steeping, the first day and after the germination after kilning and after malt degermination. The total fungi count was followed in both barley samples, during the mentioned phases. The total count of fungi was also determined in the steeping water, and the isolation and identification was performed after the steeping process. Change of the total count of fungi during barley micromalting was exponentional. During barley micromalting nine fungi genera were isolated: Phoma, Alternaria, Fusarium aspergillus, Cladosporium, Geotrichum, Scopulariopsis, Aureobasidium and Mucor. The most frequent genera were: Phoma, Alternaria and Fusarium. In water for steeping, five genera were identified: Geotrichum, Fusarium, Phoma Cladosporium and Mucor. The most frequent genera was Phoma

Zearalenone production during micro-malting of barley

The zearalenone (ZEA) content was determined during a micro-malting process (after steeping, germination, kilning and degermination, as well as in barley samples before micro-malting process) of two winter two-rowed barley samples, grown at Kragujevac location. In all phases of micro-malting isolation and determination of Fusarium spp. were performed. It was established that barley samples, before malting, were contaminated with zearalenone (barley sample 1-9.7 μg/kg, barley sample 2-9.2 μg/kg). The following Fusarium spp. were isolated: F. avenaceoum, F. culmorum, F. poae F. sporotrichioides, F. tricinctum and F. verticillioides. In both barley samples zearalenone content increased during steeping (86.5 μg/kg and 37.4 μg/kg), decreased during germination (12.5 μg/kg and 26.8 μg/kg), and increased after kilning (62.9 μg/kg and 71.2 μg/kg). In the finished malt the zearalenone content in sample 1 was 35.7 μg/kg dry matter, and in sample 2 was 17.8 μg/kg dry matter

Effect of yeast storage temperature and flour composition on fermentative activities of baker's yeast

Baker's yeast is a set of living cells of Saccharomyces cerevisiae. It contains around 70-72% of water, 42-45% of proteins, around 40% of carbohydrates, around 7.5% of lipids (based on dry matter), and vitamin B-complex. On the basis of yeast cell analysis it can be concluded that yeast is a complex biological system which changes in time. The intensity of the changes depends on temperature. Yeast sample was stored at 4°C i 24°C for 12 days. During storage at 4°C, the content of total carbohydrates decreased from 48.81% to 37.50% (dry matter), whereas carbohydrate loss ranged from 40.81% to 29.28% at 24°C. The content of trehalose was 12.33% in the yeast sample stored at 4°C and 0.24% at 24°C. Loss of fermentative activity was 81.76% in the sample stored at 24°C for 12 days. The composition of five samples of 1st category flour was investigated. It was found that flours containing more reducing sugars and maltose enable higher fermentation activities. The flours with higher ash content (in the range 0.5-0.94%) had higher contents of phytic acid. Higher ash and phytic contents in flour increased the yeast fermentative efficiency. In bakery industry, a range of ingredients has been applied to improve the product's quality such as surface active substances (emulsifiers), enzymes, sugars and fats. In the paper, the effect of some ingredients added to dough (margarine, saccharose, sodium chloride and malted barley) on the yeast fermentative activity was studied. The mentioned ingredients were added to dough at different doses: 0.5, 1.0, 1.5 and 2.0%, flour basis. It was found that the investigated ingredients affected the fermentative activity of yeast and improved the bread quality

THE INFLUENCE OF CARBOXYMETHYLCELLULOSE, XANTHAN AND GUAR-GUM ADDITION IN BREAD DOUGH BEFORE FREEZING ON METABOLISM AND VIABILITY OF Saccharomyces cerevisiae

Doughs were prepared with different concentrations o

Capacity of Fusarium species isolated from brewer's barley to synthesise zearalenone

Fungi of the genus Fusarium, known as toxigenic species, are very of- ten parasites and contaminants of brewer's barley. In this paper, the composition of the genus Fusarium species in brewer's barley samples and their potential in the zearalenone synthesis were investigated. The tests were done on different brewer's barley varieties, crop 2003, samples (SSK1, SSK2, SSK3 SSK4, SSK5, SSK6, SSK7, SSK8, SSK9, SSK10 and SSK12) from Kragujevac locality. The isolation and identification of the Fusarium species were done according to the methods described by N e l s o n et al. (1983). The identified Fusarium species (6) were tested for their capacity to synthesise zearalenone. The isolates were cultivated on sterilised barley grains at the temperature of 25°C for 14 days, and then the zearalenone concentration was determined by the fluorometric method on the fluorometer "VI- CAM" series 4. The following seven Fusarium species were isolated from barley samples: F. acuminatum, F. avenaceum, F. culmorum, F. equiseti, F. poae, F. sporotrichioides and F. tricinctum. F. poae was the most distributed species (10.26%). The zearalenone concentration within the range of 12.0 to 430.0 g kg-1 was determined in cultures of barley grain inoculated with F. avenacuem (SSK6 and SSK12), F. culmorum (SSK8), F. tricinctum (SSK1), F. sporotrichioides (SSK7 and SSK12) and F. poae (SSK5, SSK9 and SSK10). Isolates of F. equiseti (SSK2) and F. poae (SSK6) did not express capacity to synthesise this toxic metabolite

Determina tion of diacetyl and 2,3-pentanedione in beer by gc/ms using solid-phase extraction columns

A new GC/MS method for the determination of diacetyl and 2,3-pentanedione was investigated. Diacetyl and 2,3-pentanedione were derivatized with 1,2-diaminobenzene to form 2,3-dimetylquinoxaline and 2-ethyl-3-methylquinoxaline. respectively. The amounts of formed 2.3-dimetylqu:inoxaline and 2-ethyl-3,.methylquinoxaline were proportional to the concentrations of diacetyl and 2,3-penianedione present in the sample. 2,3-Dimetylquinoxaline and 2-ethyl-3-methylquinoxaline were extracted by solid-phase extraction (SPE) columns and determined by gas chromatography using a mass selective detector. This method was applied for the determination of diacetyl and 2,3-pentanedione concentrations in beer. Extraction by SPE columns proved to be very simple and reliable. The method can be used for simultaneous determination of diacetyl and 2,3-pentanedione concentrations in beer in a great number of beer samples

Reduction of sterigmatocystin biosynthesis and growth of food-borne fungi by lactic acid

© 2020 BMFH Press. Food contamination by fungi and mycotoxins presents a problem for food safety even today. Since lactic acid (LA) has Generally Recognized As Safe (GRAS) status, the aim of this research was to determine its potential in protection of food against mycological and mycotoxicological contamination. In this study, LA showed an inhibitory effect on the growth of food-borne fungi (Penicillium aurantiogriseum K51, Aspergillus parasiticus KB31, Aspergillus versicolor S72, and Aspergillus niger K95) and on biosynthesis of sterigmatocystin (STE). For the antifungal effect of LA on the growth of food-borne fungi, the disc diffusion and microdilution methods were performed. The effect of LA on the STE biosynthesis by A. versicolor was determined using an LC-MS/MS technique. The largest inhibition zone was observed for A. versicolor (inhibition zone of 24 ± 0.35 mm), while there were no inhibition zones for A. niger and A. parasiticus at all tested LA concentrations. The minimal inhibitory concentration (MIC) of LA on fungi ranged from 25.0 mg/mL to 50.0 mg/mL, while the minimum fungicidal concentrations (MFCs) ranged from 50.0 mg/mL to 100.0 mg/mL. Complete inhibition of STE biosynthesis by A. versicolor was observed at an LA concentration of 50.0 mg/mL. The obtained results showed that LA could be efficient for protection of food against mycological and STE contamination