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:  modified atmosphere packaging
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. Modified atmosphere packaging (MAP) is an important technology to extend mushrooms shelf-life, with maintenance the characterisation as “fresh product”, since allows reducing losses and maintaining quality, once they belong to highly perishable commodities. The aim of this study was to evaluate the potential storage conditions on the properties of fresh cultivated mushrooms - Pleurotus ostreatus when placed in polyethylene trays heatsealed with different polymeric films, passive modification mode, at 4°C. Material and methods. The process was carried out using fresh mushrooms of the first flush, produced under controlled conditions. Investigations were conducted for 11 days. The mushrooms shelf-life was assessed through quality parameters, namely physiological, physicochemical, microbial and sensorial analysis. The marketability was assessed by visual appearance and sensory characteristics change, namely, softening and off-odours and off-flavours development. Results. The factorial discriminate analysis allowed observing the influence of the different polymeric films permeability on the mushrooms storage. On the second day, similar mushrooms behaviour, with all film packages, was observed. From the seventh to the eleventh day, the packages showed an identical storage state, two to two, just the ninth day. This behaviour is related with O2 levels (A and B films) and with CO2 levels (C and D films). Conclusions. The results leads to conclude that PE 65S Cryovac (C) and PD 961 Cryovac (D) films, improve storage mushrooms preservation with good stability during 11 days, showing the beneficial effect of MAP conditions. It is a valuable starting point in order to design a commercial application of modified atmosphere packaging technology with these products
Wild caught shrimp can have a shortened shelf life compared to farm raised shrimp due to handling and on-ship limitations. The loss of freshness in shrimp is partly due to autolytic reactions caused by endogenous enzymes such as polyphenol oxidase. The objective of this study was to determine the effect of sulfi tes combined with Modified atmosphere packaging (MAP) on the shelf life of non-frozen shrimp. Fresh South Atlantic white shrimp were subjected to one of four treatments, no bisulfite rinse-air packaged, 1.25% bisulfite rinse-air packaged, 1.25% bisulfite rinse-MAP (60% CO2, 18% O2, 22% N2) and 1.25% bisulfite rinse-MAP (36% CO2, 64%N2). The quality and freshness of shrimp was measured by determining total aerobic bacterial populations, package gas headspace analysis, shrimp volatiles (GC-MS), meat pH, nucleotide degradation, and visual analysis. Fresh non-frozen shrimp treated with a combination of sulfites and MAP maintained the shelf life of fresh shrimp up to 10 days while shrimp in non-MAP without sulfite and non-MAP with sulfite developed black spots within 2 and 6 days, respectively. Both MAP treatments slowed bacterial growth while the MAP with high CO2 and with O2 was more effective in preventing off odors and nucleotide degeneration.
The study compares different conditions of packaging apple slices subjected to vacuum impregnation with ascorbic acid, 4-hexylresorcinol, calcium chloride and sucrose. Packaging in modified atmosphere (MA) containing: 2, 4, 6, 8 and 10% CO2, 2% O2 (nitrogen to 100%), packaging in nitrogen atmosphere with 2% O2, vacuum packaging and air packaging were applied. Vacuum packaging of apple slices subjected to processing made it possible to obtain the product with best sensory quality among all the tested packaging methods. The most effective method in terms of microflora growth inhibition on apple slices turned out to be modified atmosphere containing 4% CO2 and nitrogen atmosphere packaging. In case of vacuum packaging and air packaging counts of some groups of microorganisms during the storage of apple slices increased slightly, which however did not have a decisive effect on the microbiological quality of the product.
The growth of pathogenic microflora was monitored in fresh white cheeses stored for 7, 14 and 21 days at a temperature of 5oC±0.5oC, packed under vacuum, modified atmosphere and air atmosphere conditions. The fresh and stored white cheeses were determined for the numbers of Listeria monocytogens, Enterococcus spp, coli group bacili, and Escherichia coli. The results obtained indicated that the method of packaging had no effect on the development of those microorganisms in white cheeses during their chilled storage.
Modified atmosphere packaging (MAP) is an effective system for extending the shelf-life of meat and its products stored under refrigeration conditions. By the use of that system the shelf-life of raw meat can be two or three times longer and of meat processed products several times longer. Packaging system under vacuum or modified gaseous atmosphere has no significant effect on the quality and shelf-life of packaged whole products. Packaging under vacuum of sliced products, manufactured from finely comminuted meat is not recommended due to their deformation. Modified atmosphere packaging extends the lag phase of bacteria and slows down enzyme activity of bacteria, e.g. oxidases, exolipases, reduces degradation of muscle tissue proteins and meat lipids oxidation during storage. The effectiveness of modified atmosphere packaging is dependent on many factors such as: initial microbial contamination of the raw materials or finished products; type and properties of the packaged market commodity; the composition of the gaseous atmosphere in the packaging; properties of packaging materials used: storage temperature and prcessing hygiene. The most important prerequisite for high quality and microbial safety of meat and its processed products packaged under modified atmosphere is the storage temperature maintained at the constant level from 0 to 2°C.
This study was conducted to investigate the effects of pre-harvest Harpin treatments and post-harvest MAP treatments on fruit quality attributes and bioactive compounds of ‘0900 Ziraat’ cherry cultivar throughout cold storage and shelf life of the fruits. Weight loss and decay ratios were significantly reduced with Harpin and MAP treatments. In general, lower L* and chroma values were measured in Harpin-treated fruits. As compared to control fruits, higher firmness, titratable acidity and vitamin C contents were measured in MAP and Harpin + MAP treated fruits throughout the cold storage and shelf life. On the other hand, lower solible solids content (SSC) values were observed in the same treatments. At harvest and shelf life measurements, higher total monomeric anthocyanin (TMA) and total phenolics (TPs) were measured in Harpintreated fruits than in control fruits. Although lower anthocyanin contents were obtained from MAP-treated fruits throughout the cold storage, higher values were observed throughout shelf life. Throughout cold storage and shelf life, MAP-treated fruits had lower total phenolics and total antioxidant activity (according to FRAP and TEAC assay) values than the control and Harpin-treated fruits. It was concluded that Harpin and MAP treatments could be used reduce weight losses and decays throughout the cold storage.
The effect of two types of modified atmosphere (MA1: 69% N2, 25% CO2, 5%O2, 1% CO; MA2: 70% N2, 30% CO2) on changes in physical and chemical parameters (pH, aw - water activity, TVBN - total volatile basic nitrogen, TMA - trimethylamine, FFA - free fatty acids, PV - peroxide value, TBA - thiobarbituric acid) in muscle tissues of the silver carp was monitored in the study. The samples were stored at temperatures +2 ± 2oC for 18 days. Changes in gas volumes (CO2 and O2) in MAs were also monitored. CO2 levels increased in MA1 but decreased in MA2. At the end of 18 days of storage, a significantly (P < 0.01) lower water activity (aw) levels were found in samples packaged under MA1, in contrast to samples packaged under MA2 where water activity values showed considerable fluctuation. Variations in pH values in the two types of MA showed similar trends. Sample pH gradually decreased until day 9 of storage. On day 11, muscle tissue pH increased markedly and then began to decrease again. The overall decrease in pH values was more profound in samples packaged under MA1. TVBN and TMA levels in samples packaged under the two types of MAs remained almost identical until day 9 of the experiment. Later, however, significantly (P < 0.01) higher levels of both parameters were found in muscle tissues packaged under MA1. FFA concentrations in silver carp samples in MA1 were significantly lower (P < 0.01) throughout the experiment. The PV increased significantly in both muscle samples tested. Greater fluctuations in this parameter’s values throughout the experiment were observed in samples packaged under MA2. Faster rates of oxidation (P < 0.01) were found in samples packaged under MA1 starting on day 9. Maximum TBA values in MA1 and MA2 were observed on days 14 and 18 of the experiment, respectively. From the course of proteolytic and oxidative changes point of view, the more appropriate combination of gases for silver carp storage seems to be the mixture of 70% N2 and 30% CO2 (MA2), which allows for muscle storage of up to 9 days. We recommend TVBN as a suitable indicator of freshness, and TBA assay as a suitable indicator of the extent of oxidative processes.
The present study was conducted to investigate the effects of different package types and ozone treatments on post-harvest quality of figs. Three different package types (classical-type, modified atmosphere –MAP, consumer-type) and different ozone treatments (0, 5, 10 and 15 minutes) were used in experiments. Purple figs grown in Tekkeköy town of Samsun province were used as the experimental material of the study. Fruits harvested at optimum harvest period were subjected to pre-cooling for a day and then stored in a cold storage at 4°C temperature and 85–90% relative humidity. At the beginning of cold storage and each week of storage, fruits removed from the storage were subjected to weight loss, water soluble dry matter content, titratable acidity, wrinkle, leakage, mold spots, peeling and degustation analyses. Current findings revealed that MAP and 10 or 15-minute ozone treatments had positive impacts on weight loss prevention in figs. While there were not significant differences in other characteristics of treatments, 10 and 15-minute ozone treatments retarded mold spots and leakage in consumer and modified packages.
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.