Comparision of antimicrobial activity of sage (Salvia officinalis L.) and oregano (Origanum vulgare L.) essential oils

Celem pracy było otrzymanie olejków eterycznych z szałwii i oregano, określenie ich składu chemicznego oraz aktywności przeciwdrobnoustrojowej w stosunku do wybranych szczepów bakterii. Olejki otrzymywano za pomocą destylacji z parą wodną przy użyciu aparatu Derynga. Do oceny aktywności przeciwdrobnoustrojowej olejków wykorzystano oznaczenie minimalnego stężenia hamującego (MIC) oraz minimalnego stężenia bakteriobójczego (MBC) olejków. Oznaczano również strefy zahamowania wzrostu metodą krążkowo-dyfuzyjną. Olejek z oregano charakteryzował się największym udziałem karwakrolu (644,89 mg·cm–3), 1,4-cyneolu (1,36 mg·cm–3) i γ-terpinenu (1,35 mg·cm–3), z kolei olejek z szałwii – kamfory (11,62 mg·cm–3), linalolu (6,82 mg·cm–3), R(+) limonenu (4,03 mg·cm–3) i karwakrolu (2,18 mg·cm–3). Olejek z oregano był bardziej skuteczny w hamowaniu wzrostu drobnoustrojów w porównaniu z olejkiem z szałwii.In the recent years, many studies on the effectiveness of activity and possibilities of application of different types of herbs have been conducted using: fragments of dried plants, water and alcoholic extracts and essential oils for food. The aim of this study was to obtain essential oils of sage and oregano, to determine their chemical composition and antimicrobial activity against selected strains of bacteria. Essential oils were investigated for activity against Micrococcus sp., Bacillus subtilis ATCC 6633, Tetracoccus sp., Staphylococcus aureus ATTC 25923, Enterococcus faecalis ATCC 29212, Proteus vulgaris 458, Proteus mirabilis 180, Escherichia coli ATCC 25922, Klebsiella pneumoniae 196 and Salmonella enteritidis ATCC 13076. The essential oils were produced by steam distillation using a Deryng apparatus. To evaluate the antimicrobial activity of essential oils used to defi ne a minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of oils. Also determined zones of inhibition by disk-diffusion method. Both of essential oils (sage and oregano) contain the same compounds but in different amounts. Most of the compounds identifi ed in the oils belonged to the group of monoterpenes. Oregano oil characterized by the highest content of carvacrol (644.89 mg·cm–3), 1.4-cineole (1.36 mg·cm–3) and γ-terpinene (1.35 mg·cm–3), while oil of sage – camphor (11.62 mg·cm–3), linalol (6.82 mg·cm–3), R(+) limonene (4.03 mg·cm–3) and carvacrol (2.18 mg·cm–3). MIC values of essential oil of oregano determined for Gram-positive bacteria were comparable with the values assigned to the Gram-negative bacteria. Oregano essential oil was more effective in inhibiting the growth of microorganisms as compared to the essential oil of sage because all the microorganisms were sensitive to its effects. This was also confi rmed by the diskdiffusion method, which was obtained three times more zone of microorganisms inhibition by the action oil of oregano. The size of the zones of growth inhibition of sage essential oil contained in the range from 6.9 (Bacillus subtilis ATCC 6633) to 8.8 mm (Micrococcus sp.). For essential oil of oregano zones of inhibition were at least three times – the smallest diameter of growth inhibition was determined for strain Enterococcus faecalis ATCC 29212 (17.6 mm) and the highest (42.8 mm) – for bacteria Tetracoccus sp. It can be concluded that the essential oil of oregano is a source of active substances which inhibits the growth and development of selected strains of bacteria

The influence of edible coating on microbiological changes in beef meat under refrigeration

Wykorzystanie powłok jadalnych jest jednym z nowoczesnych rozwiązań technologicznych, pozwalającym na ograniczenie niekorzystnych zmian podczas przechowywania produktów spożywczych. Celem pracy było określenie wpływu powłoki jadalnej wytworzonej na bazie pullulanu, izolatu białka sojowego oraz kwasu stearynowego na zmiany mikrobiologiczne w mięsie wołowym. Próbki mięsa wołowego o masie 10 g pokryte i niepokryte powłoką przechowywano przez 7 dni w warunkach chłodniczych. Bezpośrednio po naniesieniu powłoki (czas „0”) oraz 3 i 7 dniach przechowywania oznaczano ogólną liczbę bakterii: tlenowych mezofilnych, z grupy coli, enterokoków, psychrotrofowych, bakterii kwasu mlekowego oraz drożdży i pleśni. Zastosowanie powłoki jadalnej najskuteczniej zahamowało wzrost liczby bakterii tlenowych mezofilnych, LAB, enterokoków i psychrofilnych, redukując ich liczbę o 1 cykl logarytmiczny w porównaniu z próbkami kontrolnymi (bez powłoki). Stopień zahamowania wzrostu badanych grup drobnoustrojów był jednak zbyt niski, aby można ją było stosować w przypadku surowca mięsnego.The main objective of food packaging is to preserve its freshness and microbial quality for a long period of time. In the meat industry, due to the nature of the product, the type of packaging and packing methods are chosen according barrier against adverse factors. The use of edible coatings is one of the modern technology that allows for the reduction of adverse changes during storage of food products. Edible coatings and fi lms are thin layers made of a single component or multicomponent mixtures which aim is the prevention or reduction biochemical, physicochemical and biological responsible for the spoilage of the product during its storage. The aim of the study was to determine the effect of edible coatings prepared on the basis of pullulan, soy protein isolate, and stearic acid on the microbiological changes occurring in bovine meat during the seven days refrigeration storage. The research material was beef purchased at one of the city’s supermarkets. Pullulan was prepared by the batch culture of Aureobasidium pullulans white mutant B-1. The strain used in the study came from the collection of the Department of Biotechnology and Food Microbiology, Warsaw School of Live Sciences. For the preparation of coatings stearic acid and soy protein isolate SUPRO 595 were used. Beef samples of 10 g weight were coated with an edible coating by immersing in a solution of the emulsion and drying in a laminar fl ow of sterile air at a temperature of 24°C. In parallel control samples without the coating were prepared. The meat samples coated and uncoated edible coating were stored for 7 days under refrigeration (4–6°C). Immediately after application of the coating (time “0”) and after 3 and 7 days of storage destignation for total number of mesophilic aerobic microorganisms, coliforms, enterococci, psychrotrophic bacteria, lactic acid bacteria and yeasts and molds were performed. It has been found that the method for applying the edible coating did not affect the reduce the initial number of microorganisms signifi cantly. There was no presence of mold in the tested samples of beef. During the storing the number of microorganisms identifi ed in the samples increased, however, in the samples coated with an edible coating it was signifi cantly lower. The use of edible coatings effi ciently inhibited the growth of mesophilic aerobic bacteria, LAB, enterococci and psychrotrophic bacteria. Their number, compared with uncoated samples was reduced by 1 log cycle. The same limitation of the number of yeast after 7 days of storage in the coated samples was observed. The degree of inhibition of growth of the tested groups of microorganisms was too low, so it can be used for raw meat

Effect of the addition of pullulan on the quality of low-fat homogenized scalded sausages

This paper presents the study on determination of the effect of pullulan on the quality of low-fat homogenized scalded sausages stored in vacuum packages at 4 ± 1°C for 21 days. Control sausage (PC) contained 20% of pork jowl in recipe composition. In sausages P1, P2 and P3, respectively, 1/4, 1/2 and 3/4 of jowl content was substituted with pullulan. The chemical composition was determined, the color and texture were measured and sensory evaluation was performed in sausages. Microbiological analyses were performed in sausages after 0, 3, 7, 10, 14 and 21 days of storage. It was found that the use of pullulan did not lead to a deterioration in the microbiological quality of sausages during storage. However, no more than 1/4 of the jowl content should be substituted with pullulan due to pullulan-negative effect on the general appearance, taste and texture of scalded sausages with assumed recipe composition

Effect of Meadowsweet Flower Extract-Pullulan Coatings on Rhizopus Rot Development and Postharvest Quality of Cold-Stored Red Peppers

The study involved an examination of the antifungal activity on red peppers of pullulan coating (P) and pullulan coating containing either water-ethanol (P + eEMF) or ethanol extract of meadowsweet flowers (P + eEMF). Pullulan was obtained from a culture of Aureobasidium pullulans B-1 mutant. Both non-inoculated peppers and those artificially inoculated with Rhizopus arrhizus were coated and incubated at 24 °C for 5 days. The intensity of the decay caused by Rhizopus arrhizus in the peppers with P and P + eEMF coatings was nearly 3-fold lower, and in the case of P + weEMF 5-fold lower, than that observed in the control peppers. Additionally, the P + weEMF coating decreased, almost two-fold the severity of pepper decay compared to other samples. The influence of coating of pepper postharvest quality was examined after 30 days of storage at 6 °C and 70%–75% RH. All coatings formed a thin and well-attached additional layer of an intensified gloss. During storage, color, total soluble solid content and weight loss of coated peppers were subject to lower changes in comparison with uncoated ones. The results indicate the possibility of the application of pullulan coatings containing MFEs as an alternative to the chemical fungicides used to combat pepper postharvest diseases

Effect of Meadowsweet Flower Extract-Pullulan Coatings on Rhizopus Rot Development and Postharvest Quality of Cold-Stored Red Peppers

The study involved an examination of the antifungal activity on red peppers of pullulan coating (P) and pullulan coating containing either water-ethanol (P + eEMF) or ethanol extract of meadowsweet flowers (P + eEMF). Pullulan was obtained from a culture of Aureobasidium pullulans B-1 mutant. Both non-inoculated peppers and those artificially inoculated with Rhizopus arrhizus were coated and incubated at 24 °C for 5 days. The intensity of the decay caused by Rhizopus arrhizus in the peppers with P and P + eEMF coatings was nearly 3-fold lower, and in the case of P + weEMF 5-fold lower, than that observed in the control peppers. Additionally, the P + weEMF coating decreased, almost two-fold the severity of pepper decay compared to other samples. The influence of coating of pepper postharvest quality was examined after 30 days of storage at 6 °C and 70%–75% RH. All coatings formed a thin and well-attached additional layer of an intensified gloss. During storage, color, total soluble solid content and weight loss of coated peppers were subject to lower changes in comparison with uncoated ones. The results indicate the possibility of the application of pullulan coatings containing MFEs as an alternative to the chemical fungicides used to combat pepper postharvest diseases