Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 15

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  food spoilage
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Background. Food spoilage is a process in which the quality parameters decrease and products are no longer edible. This is a cumulative effect of bacteria growth and their metabolite production, which is a factor limiting shelf life. Thus, the aim of the study was to evaluate whether microbiological growth models for total viable count (TVC) and Clostridium strain bacteria are reliable tools for prediction of microbiological changes in spreadable processed cheese. Material and methods. Investigations were conducted for two types of bacteria: TVC and Clostridium in following temperature: 8°C, 20°C and 30°C. A total number of aerobic bacteria was determined based on standard PN-EN ISO 4833:2004 and Clostridium was detected by using microbiological procedure for sulphite-reducing anaerobic spore-bacteria with a selective nourishment. During the analysis nonlinear regression and Baranyi and Roberts primary model were used. Results. For temperatures 20°C and 30°C, Baranyi and Roberts model, for total viable count showed determination coefficient of 70%. The models prepared for Clostridium, in these temperatures, showed much lower R2, respectively 25% and 30%. At the abovementioned temperatures also the expiration of product shelf life was much shorter and amounted 70 days at 20°C and 7 days at 30°C. For both types of bacteria incubated at 8°C the numbers of bacteria decrease until the expiration of product shelf life. Conclusions. Models used in the analyses, Baranyi and Roberts and nonlinear regression, poorly matched the experimental data, hence they are not reliable tools. Nevertheless, they gave information about dynamic of microbiological changes in spreadable processed cheese.
Alicyclobacillus spp. is an important thermoacidophilic, spore-forming spoilage bacterium that is a major concern for beverage and juice industries. This study was undertaken to: (i) estimate the incidence of Alicyclobacillus spp. and A. acidoterrestris in Polish apple and dark berry juice concentrates, and (ii) evaluate the ability of isolated A. acidoterrestris strains to spoilage of these juices after dilution to single strength. Polish apple and berry juice concentrates were screened for the presence of Alicyclobacillus spp. between 2002 and 2015. Incidence of Alicyclobacillus spp. in apple juice concentrates (n=1164) range from 27.3 to 86.8%, depending on the year. The species A. acidoterrestris accounted, depending on the year, from 12.7 to 100.0% of all isolated strains. Among the dark berry juice concentrates (n=146), approximately 60.0% were contaminated by Alicyclobacillus spp. Incidence of A. acidoterrestris strains in dark berry juice concentrates range from 4.2% in blackcurrant up to 40.0% in raspberry. Single strength apple juice promoted the growth of eight of the tested A. acidoterrestris strains (> 7 log cfu/ml) when was incubated at 45°C. No A. acidoterrestris growth was observed in single strength chokeberry, raspberry, strawberry, cherry and blackcurrant juices during 28 days incubation at 45ºC.
Próbki mięsa z mięśni piersiowych i mięśni udowych kurcząt broilerów paskalizowano ciśnieniem 200-400 MP a i przechowywano w warunkach chłodniczych do czasu wystąpienia objawów zepsucia. W określonych odstępach czasu próbki poddawano badaniom mikrobiologicznym, fizykochemicznym i sensorycznym. Ciśnienie 400 MPa obniżało ogólną liczbę drobnoustrojów (OLD) o 2 cykle logarytmiczne. Zmiany cech sensorycznych mięsa przebiegały szybciej, niż zmiany mikrobiologiczne.
The results of the works over thermal inactivation of the Bacillus stearothermophilus spores are presented in the paper. The inactivation process was performed in the water milieu with the presence of the citric acid. The influence of the citric acid on the sprout and growing of the spores was analyzed. Before this process the spores were stored in the sterilization temperature.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.