Effects of moulds on the safety and processing quality of Triticum aestivum

Wheat and wheat products are frequently subjected to mould infestations. Many of them are potential producers of various mycotoxins. Some of the consequences, due to the infestations by genus Fusarium and Alternaria, are mostly: yield loss, decrease of biological and technological quality, and unacceptable quality of infected kernels for the production and processing into human food because of the possible presence of mycotoxins. It is unknown whether and how the contaminated grains are distributed during milling into various flour streams and finished products. Wholegrain flours and related products contain all anatomic parts of kernels, including mycotoxins. It is a known fact that mycotoxins are resistant to thermal degradation, so they do not loose their toxicity during processing. Moulds from genus Fusarium spp. and Alternaria spp. synthesize mycotoxins, mostly zearalenon and ochratoxin A. The aim of the investigation was to examine mould contamination of wheat grain, as well as to identify the isolated species, especially those capable of producing toxins, and to determine their impact on technological quality, safety and sanitary condition of wheat. Six varieties of wheat, contaminated with moulds, were investigated. Each sample was separated manually into four fractions: sound kernels, black germ kernels, kernels infected slightly and those infected severely with Fusarium spp

Exo-polygalacturonase production by Penicillium roqueforti on pumpkin oil cake in solid state fermentation

The feasibility of using pumpkin oil cake (PuOC), individual and in combination with wheat bran (WB), as substrate for the production of Exo-polygalacturonase (Exo-p) by starter culture Penicillium roqueforti in solid state fermentation (SSF) has been evaluated. The kinetics of enzyme production was investigated using PuOC alone in the range from 13 to 168 h, with moisture contents varying from 44% the ability to grow and produce Exo-p activity on this substrate, reaching a maximum value of 1451.75 U/g.d.w PuOC by the 5th day of fermentation. Fermentation experiments indicated that the water activity (aw) influenced the enzyme production. A medium with aw 0.932 and the fermentation time of 5 days were selected, as these conditions resulted in the highest pectolytic activity and were used for further investigation. A next step in this research was to examine the effect of the substrate combination, PuOC with wheat bran (WB), in different ratios. The addition of WB as carbon sources was found to have a significant influence on the enzymes yields. Exo-p activities were the highest with initial water activity of a w 0.932 and PuOC supplementation with WB (1:0.67)

Air mycopopulations in Petrovská klobása producing facility

Different types of filamentous fungi periodically cause problems in small-scale facilities for traditional dry fermented sausages, such as Petrovská klobása from Vojvodina province (Serbia). Mould contamination can be observed during processing, ripening, and storage. Sausages may become spoiled due to visible mould colonies on the surface and off-flavours they produce. The most important - if mycotoxin production occurs it might promote a number of health disorders. Knowledge and control of filamentous fungi are, therefore, essential to produce sausages that satisfy the criteria of hygienic quality, sensorial characteristics, and food safety. The aim of this study was to survey mycoflora of a small-scale facility producing traditional dry fermented sausage - Petrovská klobása. The mould contamination of the air in processing unit and ripening chambers was investigated, in order to determine the important fungi in terms of spoilage of the products and ability to produce mycotoxins. The mould contamination of air in processing unit and ripening chambers examined was in range 0.22 - 1.89 log CFU/P.d. Isolated moulds belong to 6 genera: Aspergillus (3 species), Cladosporium (1 species), Eurotium (2 species), Fusarium (1 species), Penicillium (12 species) and Scopulariopsis (1 species). The most abundant were species of Penicillium genus, many of which are capable for mycotoxin production. The level and diversity of fungal contamination of air varied between samples, influenced by the general hygiene, the buildings, the airflow, the outdoor environments, and the time of year. This knowledge is crucial for the improvement of hygiene control systems in small-scale processing units

Effect of Origanum heracleoticum L. essential oil on food-borne Penicillium aurantiogriseum and Penicilium chrysogenum isolates

Molds are ubiquitously distributed in nature and their spores can be found in the atmosphere even at high altitudes. The difficulty of controlling these undesirable molds, as well as the growing interest of the consumers in natural products, have been forcing the industry to find new alternatives for food preservation. The modern trends in nutrition suggest the limitation of synthetic food additives or substitution with natural ones. Aromatic herbs are probably the most important source of natural antimicrobial agents. Origanum heracleoticum L. essential oil has been known as an interesting source of antimicrobial compounds to be applied in food preservation. In the this work, we have investigated the effect of essential oil obtained from O. heracleoticum on growth of six isolates of Penicillium aurantiogriseum and four isolates of Penicillium chrysogenum isolated from meat plant for traditional Petrovacka sausage (Petrovská klobása) production. The findings reveal that the essential oil of O. heracleoticum provides inhibition of all of fungal isolates tested. O. heracleoticum L. essential oil exhibited higher antifungal activity against the isolates of P. chrysogenum than the isolates of P. aurantiogriseum. O. heracleoticum essential oil showed a MIC value ranging from 25 to 100 μL/mL. The fungi cultivated in the medium with higher concentration of essential oil showed certain morphological changes. The alterations included lack of sporulation and loss of pigmentation

Mycopopulations and ochratoxin A: Potential contaminants of Petrovská klobása

Petrovská klobása is traditionally produced dry fermented sausage from the area of Bački Petrovac (Vojvodina Province, Serbia) that has been protected with designation of origin (PDO) according to Serbian legislation. Contamination of this kind of sausage casings by different mould species often occur during the production process, mainly during the ripening and storage. The aim of this study was to isolate and identify moulds that contaminate ingredients used for Petrovská klobása production and its casings during different phases of ripening and storage. Sampling was done during the production process and after 2, 6, 9, 11, 14, 34, 65, 90, 120, 217 and 270 days. Total mould counts in components ranged from 1.60 (mechanically mixed filling) to 4.14 (red hot paprika powder) log10 CFU/g, while the number of moulds isolated from sausage casing surfaces ranged from 0.01 (C3 sausage, 217th day) to 1.60 (C1 sausage, 270th day) log10 CFU/cm2. After total mould counts were determined, isolates were identified and classified in five genera for components (Penicillium - 7 species; Fusarium - 2 species; Aspergillus - 1 species; Alternaria - 1 species; Verticilium - 1 species) and 3 genera for casings surfaces (Penicllium - 3 species; Aspergillus - 1 species; Eurotium - 1 species). It was appointed that 83.33% of isolated species are potential producers of toxic metabolites. The analyses of ingredients and sausages on the presence of ochratoxin A, following the ELISA method, gave the negative results

Kserofilne mikopopulacije izolovane iz semena uljane repice

This paper presents the results of an investigation related to mycological populations of rapeseed samples produced in the Institute of Field and Vegetable Crops in Novi Sad (location: Rimski Šančevi, Novi Sad), with a special emphasis on the potentially toxigenic mycopopulations. Mycological investigations were performed on the samples that were treated with 4% solution of Na-hypochlorite, and on the ones that were not submitted to this treatment. Isolation and determination of total mould count was carried out using Dichloran Glycerol Agar (DG18). The identification of isolated moulds was done according to modern keys for fungal determination. From 20 untreated tested samples, 17 were contaminated with moulds (10.0 to 4.7x102 cfu/g). When the samples were treated with 4% solution of Na-hypochlorite, moulds were isolated only form 4 samples, and the total mould count ranged from 10.0 to 60.0 cfu/g. In the isolated mycopopulations, xerophilic moulds dominated, especially those from the genera Aspergillus, Eurotium and Penicillium. In the isolated mycopopulations, high degree of isolated species belonged to toxigenic species from the genera Alternaria, Aspergillus, Fusarium, Eurotium and Penicillium.U radu su data istraživanja vezana za mikološku populaciju u uzorcima uljane repice proizvedene u Institutu za ratarstvo i povrtarstvo (lokacija Rimski Šančevi, Novi Sad), sa posebnim osvrtom na potencijalno toksigenu mikopopulaciju. Mikološka ispitivanja su izvedena u uzorcima koji su tretirani sa Na-hipohloritom, kao i u uzorcima koji nisu podvrgnuti ovom tretmanu. Izolacija i određivanje ukupnog broja plesni izvedeno je na Dixloran Glicerol agaru. Identifikacija izolovanih vrsta plesni izvedena je prema ključevima za determinaciju koji su opisani u literaturi. Od 20 ispitanih uzoraka u 17 je utvrđeno prisustvo plesni i ukupan broj se kretao do 10 do 4,7x102 cfu/g. Kada su uzorci tretirani 4% rastvorom Na-hipohlorita plesni su izolovane iz 4 uzorka, a ukupni broj plesni se kretao od 10,0 do 60,0 cfu/g. U izolovanoj mikopopulaciji dominirale su kserofilne vrste iz rodova Aspergillus, Eurotium i Penicillium. Izolovanu mikopopulaciju u visokom procentu činile se potencijalne toksigene vrste iz rodova Alternaria, Aspergillus, Fusarium, Eurotium i Penicillium

PRESENCE OF AFLATOXINS IN CEREALS FROM SERBIA

ABSTRACT: Aflatoxins (AFs), one of the most toxic and the strongest natural carcinogens can be found in a variety of food commodities, including cereals. For that purpose, the aim of this study was to investigate occurrence of AFs (AFB1, AFG1, AFB2 and AFG2) in 130 cereal samples

Mycological and mycotoxicological quality of wheat and flour fractions

The seed infection is a result of complex factors influence: weather conditions, health conditions of used seed, quantity of infective potentila in soil, etc. By visual evaluation, initial wheat sample has been divided in four fractions: healthy, dark germed, slightly and very fusarious. Three varietes from two localities 1 and 2 have been included in analyses. Beside the wheat, the mycotoxicological contamination of flour produced by grounding of given samples was monitored, too. The representatives of genera Fusarium were dominating, and the most frequent was F. oxysporum. The wheat and flour samples have also been analysed on presence of aflatoxin B1 "AB1" and G1 "AG1", ochratoxin A "OA" and zearalenone "F-2" toxin. AG1 had the lowest representation (2,3 g/kg) and the highest representation was of F-2 toxin (even 500 g/kg)

Production of exo-pectinase by Penicillium roqueorti using pumpkin oil cake

Submerged fermentation (SmF) was carried out using the pumpkin oil cake (PuOC) as a substrate for the production of exo-pectinase (exo-p) by Penicillium roqueforti. PuOC was used as carbon, nitrogen and mineral source for fungi growth and exo-p production. SmF was carried out in the production medium containing 0.2% KH2PO4, 0.1% MgSO4 and 0.1% NaCl, supplemented with PuOC at 2% concentration. The obtained results show that P. roqueforti cultivated in a liquid medium in the presence of PuOC as a source of nitrogen, produced significant amount of exo-p, activity 161.03 U/ml

Sunflower seed for human consumption as a substrate for the growth of mycopopulations

These mycological investigations are implicating samples of protein sunflower seed from regular cultivation in the Vojvodina Province. Samples are examined in different stages of production: reception in the silo, separation of massive fraction on peeler and then peeling, kernel after peeling, hull, final product, i.e. kernels separated from visible impurities on conveyor bel, that are later manually divided in two fractions - a) seemingly whole, undamaged kernels, without change of colour, and b) seemingly damaged kernels, broken, with change of colour. For the determination of viable count of moulds and their isolation, two different media are used in parallel: Sabouraud maltose agar (SMA) and malt/yeast extract with 50% of glucose (MY50G), favourable for growth of xerophilic moulds. All samples tested were contaminated with fungi. Total viable mould count per seed varied from 1.6 (SMA) respecting 1.3 (MY50G) on reception, to 5.6 (SMA) and 7.5 (MY50G) cfu/seed in visually damaged sunflower kernels (final product). From seeds, kernels and hull, numerous moulds were isolated, belonging to 8 genera and 13 species (Alternaria alternata, Arthrinium phaeospermum, Aspergillus candidus, A. flavus, A. niger, A. ochraceus, A. versicolor, A. wentii, Cladosporium cladosporioides, Eurotium herbariorum, Penicillium aurantiogriseum, Rhizopus stolonifer and Trichoderma harzianum). Alternaria alternata, Aspergillus flavus, A.ochraceus, A. versicolor and Eurotium herbariorum were isolated on both media. Aspergillus candidus, A. versicolor, C. Cladosporioides, P. aurantiogriseum and T. harzianum were isolated only on SMA, while A. niger, A. wentii and R. stolonifer were exclusively isolated on MY50G. Most ubiquitous species is A. alternata, which is isolated from all tested samples, while A. candidus, C. cladosporioides and T. harzianum were isolated from sunflower seed on reception in silo, using SMA medium