Effects of hygiene-sanitary measures on microbiological safety of finished product in butter production plant

This work presents the results of investigations of the effects of hygienesanitary measures at critical points in the technological process of butter production on its quality and microbiological safety. With this object in mind, hygiene safety was checked using the swab method at the machine for churning and packing butter (125 g packages and bulk butter), the equipment, hands and clothing (work aprons) of employees directly engaged on the machines. The evaluation of the safety parameters, as well as of the hygiene of the production process itself, was carried out in keeping with the Regulations on general and special conditions of food hygiene at any stage of production, processing and trade (RS Official Gazette, No.72/2010). The results of the hygiene safety of swabs taken from the 125g-butter packing machine, after sanitation, showed an increased number of mesophilic bacteria (up to 90 cfu/cm2), as well as the presence of bacteria from the Family Enterobacteriaceae (4 cfu/cm2). The results of swabs taken from the hands of workers engaged on the line for wrapping the butter following the churning process and on the packing line reveal the presence of aerobic mesophilic sporogenic bacteria (20 cfu/cm2), while the presence of pathogenic microorganisms was not established. Butter samples packed into 125g portions present more risky forms of commercial packaging than bulk butter, which is a consequence of various handling activities and additional outside contamination that takes place during the production process if continuous production in the plant has not been ensured. Moreover, the established presence of certain microorganisms (aerobic mesophilic microorganisms, lipolytic bacteria, as well as fungi) in packed butter during its shelf life, is largely a result of outside contamination and the hygienic condition of the equipment. The obatined results of the investigations indicate the need for special attention to be paid during the butter production process on meeting the hygiene-sanitary conditions during the production process tself, which primarily implies adequate washing and disinfecting of the equipment, the required temperature regimen for the pasteurization of the cream and similar activities, as well as the immaculate hygiene of the workers engaged in the production process. [Projekat Ministarstva nauke Republike Srbije, br. III 46009: Unapređenje i razvoj higijenskih i tehnoloških postupaka u proizvodnji stočne hrane sa ciljem proizvodnje visokokvalitetnih i bezbednih proizvoda konkurentnih na globalnom tržištu

Effect of bread dough mixing method on rye bread quality

The objective of this study was to evaluate the effect of sourdough (indirect bread dough mixing method) on the quality of rye/wheat bread (TYPE 500 wheat flour and whole grain rye flour - 60:40) and determine its advantages over the straight dough method. Three bread dough mixing methods were used: I - indirect bread dough mixing using flour scalding; II - indirect bread dough mixing without flour scalding; III - straight dough mixing. The study involved the monitoring of the following: microbial characterristics of the flour and dough (yeasts and lactic acid bacteria) and of the bread (presence of Enterobacteriaceae, yeasts and moulds); chemical properties of the dough and the bread (pH and degree of acidity); organoleptic attributes of bread (volume, porosity according to Dallman, crumb elasticity, pore structure fineness, bread crumb score, external appearance, crumb appearance, flavour of both the crust and the crumb). The results showed the highest counts of lactic acid bacteria and yeasts in the indirect bread dough mixing method using rye flour scalding. The rye/wheat bread made with sourdough had a mild sourish flavour, an intense aroma, a prolonged shelf life, and reduced crumbliness. The study suggests that the technological process of sourdough-type rye/wheat bread making is an important requirement in improving bread quality and assortment that can be used in any bakery facility

The presence of undesirable mould species on the surface of dry sausages

Transition from manufacture to the industrial way of meat production and processing, as well as contemporary concept of food quality and safety, have led to the application of starter cultures. Their application leads towards the streamlining of the production process in the desired direction, quality improvement and its harmonization, and thereby to its standardization. Application of moulds in the meat industry is based on positive effects of their proteolytic and lipolytic egzoenzymes which, as a consequence, leads to the creation of characteristic sensory properties ('flavor') of fermented products. Penicillium nalgiovense is a typical representative of moulds used in the production of fermented sausages-salamis from our region. Samples of 'zimska salama' (dry sausage), produced with Penicillium nalgiovense, were evaluated as hygienically unacceptable. Their sensory properties changed due to contamination of this mould during the ripening process. Micological analysis discovered the presence of Penicillium aurantiogriseum, which is a frequent mould contaminant in the meat industry. At the same time, thin layer chromatography revealed no possibility of metabolic activity of this mould in the creation of mycotoxins. However, the presence of this mould on the surface of 'zimska salama' is considered as undesirable due to formation of 'off flavor' in products. Such product is considered as hygienically unacceptable and cannot be used for the human consumption

Antilisterial Activity of Bacteriocin Isolated from Leuconostoc mesenteroides ssp. mesenteroides IMAU:10231 in the Production of Sremska Sausages: Lactic Acid Bacteria Isolation, Bacteriocin Identification and Meat Application Experiments

Bakterije mliječne kiseline imaju ključnu ulogu u proizvodnji fermentiranih mesnih proizvoda. Njihova metabolička aktivnost utječe na proces sazrijevanja, čime nastaje proizvod željenih senzorskih značajki, te se inhibira rast neželjenih mikroorganizama. Bakteriocini su izvanstanični peptidi ili proteinske molekule što suzbijaju rast srodnih vrsta mikroorganizama, a proizvode ih neke bakterije mliječne kiseline. Nastali bakteriocini selektivno i kompetitivno djeluju na okolnu mikrofloru, a tako i na bakterije uzročnike kvarenja ili patogene mikroorganizme, između ostalog i na bakteriju Listeria monocytogenes. Kontrola ove bakterije tijekom proizvodnog procesa važna je zbog velike stope smrtnosti uzrokovane uporabom kontaminiranih proizvoda, rasprostranjenosti bakterije u sirovim proizvodima, te sposobnosti njezina preživljavanja pri različitim uvjetima proizvodnje. Svrha je ovoga rada bila utvrditi mogućnost primjene bakteriocina izoliranog iz bakterije L. mesenteroides ssp. mesenteroides IMAU:10231 na suzbijanje rasta tog soja tijekom proizvodnje tradicionalne Sremske kobasice u Srbiji. Soj bakterije Leuconostoc izoliran je iz tradicionalno proizvedene kobasice, a zatim je taloženjem pomoću amonijeva sulfata izdvojen bakteriocin, čija su svojstva (jačina i spektar djelovanja, utjecaj visokih temperatura i dodatka proteolitičkih enzima) određena u laboratorijskim uvjetima. Osim toga, ispitana je antilisterijska aktivnost bakteriocin dodanog pri proizvodnji tradicionalne Sremske kobasice. Izražena antilisterijska aktivnost bakteriocina omogućuje njegovu primjenu u mesnoj industriji, tj. pri proizvodnji fermentiranih kobasica. Nastavak istraživanja pridonijet će boljem razumijevanju prirode, aktivnosti i mogućoj primjeni bakteriocina, ali i otkrivanju novih sojeva bakterija mliječne kiseline što mogu proizvesti bakteriocin koji se može upotrijebiti kao prirodni konzervans ili bioprotektor hrane.Lactic acid bacteria (LAB) have an essential role in the production of fermented meat products. The metabolic activity of LAB affects the ripening process, leading to the formation of the desired sensory characteristics of the products, while inhibiting the growth of undesirable microorganisms. Bacteriocins are extracellular peptides or protein molecules, produced by some LAB, which possess bactericidal properties against specific species or genera of microorganisms, usually related bacteria. Bacteriocin production by LAB can act in a selective and competitive way against the surrounding microbiota, which may contain spoilage bacteria or pathogenic microorganisms including Listeria monocytogenes. This pathogen is widely distributed in raw products, it survives in different production areas, and human infections have a high mortality rate, all of which makes the control of this microorganism important in food production. The aim of this work is to determine the possibilities of utilizing a novel bacteriocin isolated from Leuconostoc mesenteroides ssp. mesenteroides IMAU:10231 in order to prevent the survival of Listeria monocytogenes in the production of traditional Serbian Sremska sausages. The bacteriocin-producing strain of Leuconostoc originated from the same sausage, which had been produced in the traditional manner. Bacteriocin was isolated using precipitation procedures with ammonium sulphate, and then its properties (strength and range of activities, relationship to high temperatures and proteolytic enzymes) were determined under laboratory conditions. Also, based on the obtained laboratory results, the antilisterial effect of bacteriocin, included as an additive, was examined in the production of traditional Sremska sausages. Expressed antilisterial activity of bacteriocin has an interesting food safety potential which can be used in the meat industry in the production of fermented sausages. Further research will contribute to a better understanding of its nature, activities, opportunities for application, but also to discovering new bacteriocin-producing strains of LAB, which could act as natural food preservatives, or bioprotectors, when used in a specific (controlled) manner

Air quality and impact on food safety

© Published under licence by IOP Publishing Ltd. Air is an important potential source of contamination in different areas of human endeavor (medicine, pharmaceuticals, agriculture, food industry etc.). During the various technological procedures of producing and processing food, its contamination by polluting substances contained in air, such as suspended particles (physical contamination), combustion products and volatile organic substances (chemical contamination) and biological pollutants (bacteria, viruses, molds and mites) very often occurs. Although the sources of air contamination are numerous (poor construction aspects of the building, improper air conditioning and ventilation, etc.), basic and common sources are people and their activities in food production plants. The task of responsible food production is to adequately and continuously implement good production practices, and thereby, prevent potentially harmful practices, to ensure environmental health and safety for the life and work of the staff in that environment, and to create conditions for safe food production, while protecting the environment

Cleaning and disinfection procedures in the dairy industry during COVID-19

The pandemic caused by the coronavirus (SARS-CoV-2) spread to Serbia in March 2020, causing a large-scale outbreak of infection in humans and more than 200 human deaths in two months. Although data on the epidemiology, virology, clinical features, treatment and prevention of this severe respiratory syndrome (COVID-19) are still incomplete, it is certain that the main mode of transmission of the virus is from person to person, through respiratory droplets as the primary transmission route. To date, the World Health Organization has no evidence to suggest that the virus can be transmitted through food, but human infection due to direct contact with contaminated surfaces, tools, equipment and other objects cannot be excluded. The application of good hygiene and manufacturing practices is the most important control measure against this causative agent, primarily involving appropriate employee protection, continuous monitoring of movement and entry restrictions for people and means of transport, and proper targeted sanitation. The choice and use of disinfectants, mostly peroxide, ethanol and hypochlorite based compounds, ensure proper protection of people and an undisturbed production cycle in the food industry in general, and in the dairy industry in particular.Author's versio

Results of mycological and mycotoxicological investigations of corn-based feed for dairy cow diet

In this study, fungal contamination was determined as well as total aflatoxin B1(AB1), ochratoxin A (OTA) and zearalenon (ZEA) levels in corn-based feed samples obtained from four different farms in Serbia (n=35) during one year. Mycotoxins were detected in feed using the VICAM fluorometric method. It was determined that 97.14% of all samples were contaminated with moulds which belonged to following genera: Absidia, Acremonium, Aspergillus, Cladosporium, Geotrichum, Eurotium, Fusarium, Mucor, Mortierella, Oidiodendron, Penicillium, Rhizopus, Scopulariopsis, Syncephalastrum, Trichoderma, Ulocladium and Wallrothiella. A total of 58 different species were identified. Total mould count per 1 g ranged from 1.00 log cfu/g (dried corn silage - autumn, fresh corn silage - summer and corn grain silage - spring) to 7.32 log cfu/g (dried corn silage - winter). Mycotoxins were isolated from 28.5% of samples: ZEA was found in summer (220-240 μg/kg) and in spring (240 μg/kg) in concentrate samples; OTA was detected in winter in dried corn silage (16 μg/kg) and in spring (12 μg/kg); all samples were AB1 free

Identification of mycobiota in Serbian slaughterhouses

Mould growth within slaughterhouses is not acceptable and is considered as both economic and aesthetic problem. Aim of this paper was to determine filamentous moulds in two slaughterhouses by investigating air, water, environment area and equipment. There were a total of 100 samples collected. According to S a m s o n (2004), 6 genera were determined among which Penicillium and Aspergillus were the most frequent. Three Penicillium species were identified; the most frequent were P. brevicompactum and P. solitum. The presence of P. verrucosum was not established. The presence of mycotoxigenic moulds, such as P. brevicompactum, indicates possible contamination of environmental area with mycophenolic acid (MPA). Results of investigation indicated that more comprehensive survey should be made in order to get a better insight of mycobiota in slaughterhouses in Serbia

Assessment of biogenic amine production by lactic acid bacteria isolated from Serbian traditionally fermented foods

The aim of this study was to monitor the production of biogenic amines by 156 selected lactic acid bacteria (LAB) strains isolated from Serbian traditionally fermented sausages and cheeses. The method for the determination of biogenic amines is liquid chromatography tandem mass spectrometry (LC-MS/MS). The measured concentrations of putrescine, cadaverine, tryptamine and spermidine (except in 13 LAB strains) were below the detection limit of the analytical method (0.1 mg/L), whereas those of histamine, tyramine and spermine were above the limit of detection, but still not significant. Tyramine was the only amine that had a measured concentration of 59.89 ± 0.06 mg L-1. Most of the tested LAB strains produced tyramine in broth below 26 mg L-1 with the exception of Enterococcus faecalis strains (59.89 ± 6.66 mg L-1) and Enterococcus faecium strains (47.33 ± 8.58 mg L-1). The low concentrations of biogenic amines are considered non-significant from both a technological and safety point of view.Publishe

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