| 1. |
- Andersson, Mats, et al.
(author)
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Toward an enzyme-based oxygen scavenging laminate. Influence of industrial lamination conditions on the performance of glucose oxidase
- 2002
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In: Biotechnology and Bioengineering. - : Wiley. - 1097-0290 .- 0006-3592. ; 79:1, s. 37-42
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Journal article (peer-reviewed)abstract
- The laminate consisted of several polymer layers, aluminium, and one cellulose-based layer containing the active enzymatic system (e.g., glucose oxidase, catalase, glucose, and CaCO3). During the industrial lamination process, the enzyme layer was exposed to three temperature spikes up to 325degreesC without significant enzyme inactivation. Ninety-seven percent of the glucose oxidase activity still remained after the lamination process. The best laminate had an oxygen absorbing capacity of 7.6 +/- 1.0 L/m(2). A reference that was not laminated expressed a corresponding oxygen absorbing capacity of 7.1 +/- 0.8 L/m(2).
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| 2. |
- Jacobsson, Annelie, et al.
(author)
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Effects of type of packaging material on shelf-life of fresh broccoli by means of changes in weight, colour and texture
- 2004
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In: European Food Research and Technology. - : Springer Science and Business Media LLC. - 1438-2377 .- 1438-2385. ; 218:2, s. 157-163
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Journal article (peer-reviewed)abstract
- Five polymeric films were studied to determine their ability to retain the colour, weight and texture of broccoli (Brassica oleracea L. var. Italica "Monterey"). The materials were oriented polypropylene (OPP), polyvinyl chloride (PVC) and two different low-density polyethylenes (LDPE), one of which contained a sachet reported to absorb ethylene. The broccoli was packaged and stored at 4 and 10 °C for 4 weeks. The weight, colour, chlorophyll content and texture were monitored during storage as well as O 2 and CO2 concentrations inside the packages. Packaging prolonged the broccoli shelf-life by up to 14 days. The shelf-life varied depending on the packaging material and quality parameter considered. The atmosphere was modified inside the packages; however, no package provided the recommended atmosphere (O2 1-2% and CO2 5-10%) for broccoli. Packaging in OPP resulted in the highest CO2 concentration, 6%, while the lowest O2 concentration, 9%, was created in the LDPE package without a sachet for ethylene absorption. Storage in LDPE without ethylene absorber resulted in the overall longest shelf-life. Broccoli stored in PVC deteriorated faster than broccoli packaged in the other materials. The influence of packaging material was greater at the higher temperature.
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| 3. |
- Jacobsson, A, et al.
(author)
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Influence of packaging material and storage condition on the sensory quality of broccoli
- 2004
-
In: Food Quality and Preference. - 0950-3293 .- 1873-6343. ; 15:4, s. 301-310
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Journal article (peer-reviewed)abstract
- The sensory quality of broccoli stored in modified atmosphere packages was studied. Oriented polypropylene (OPP), polyvinyl chloride (PVC) and low-density polyethylene (LDPE) were used as packaging materials. The LDPE contained an ethylene-absorbing sachet. The samples were stored for I week, either at a constant temperature of 10 degreesC or for 3 days at 4 degreesC, followed by 4 days at 10 degreesC. The atmospheres that were developed inside the different packaging materials during storage differed significantly. After storage, the broccoli was evaluated both raw and cooked using a triangle test and a quantitative descriptive analysis. The triangle test showed significant differences in the smell of broccoli stored in different packaging materials after cooking. No differences were detected in the raw broccoli. The quantitative descriptive analysis showed significant differences in the fresh smell and flavour, the chewing resistance, and the crispness, between samples after cooking. Overall, including all the sensory properties studied, broccoli packaged in LDPE (5% O-2 7% CO2) that contained an ethylene absorber was perceived to be the sample most similar to fresh broccoli. There were no differences in weight loss between broccoli stored in the different packaging materials. (C) 2003 Elsevier Ltd. All rights reserved.
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| 4. |
- Jacobsson, A., et al.
(author)
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Influence of packaging material and storage temperature on texture, colour, and weight of broccoli.
- 2003
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In: ISHS Acta Horticulturae. - 0567-7572. ; 600, s. 323-323
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Conference paper (peer-reviewed)abstract
- Sophisticated packaging solutions can be used in order to preserve vegetables during storage and transport. Polymeric films with selective barriers matching the respiration of the produce, thereby creating an ideal atmosphere inside the package, are available on the market. Fresh broccoli (Brassica oleracea L. var. italica ‘Monterey’) heads were packed in 4 different commercially available polymeric films, and stored at 4 and 10°C respectively. During storage the weight, colour, chlorophyll content and texture were monitored. The investigated polymer materials were oriented polypropylene (OPP), polyvinyl chloride (PVC) and two types of polyethylene (PE) packagings. The choice of packaging material had an impact on the measured quality parameters of broccoli. Storage in OPP resulted in the longest storage life. Broccoli stored in PVC film deteriorated faster than broccoli packaged in the other materials. It was also observed that the influence of the type of packaging material was more important at the higher temperature. The implications of this work for the packaging and storage of fresh broccoli will be discussed.
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| 5. |
- Jacobsson, A, et al.
(author)
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Influence of temperature, modified atmosphere packaging, and heat treatment on aroma compounds in broccoli
- 2004
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In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 52:6, s. 1607-1614
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Journal article (peer-reviewed)abstract
- The aroma compounds in broccoli stored in different modified atmospheres were studied. The packaging materials used were oriented polypropylene (OPP), poly(vinyl chloride) (PVC), and low-density polyethylene (LDPE) containing an ethylene-absorbing sachet. All samples were stored for either 1 week at a constant temperature of 10 degreesC or for 3 days at 4 degreesC, followed by 4 days at 10 degreesC. The atmospheres that developed inside the packaging materials differed significantly. The broccoli samples were analyzed raw and after cooking, with regard to volatile compounds, using gas-phase (headspace) extraction followed by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry. Dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), hexanal, 3-cis-hexen-1-ol, nonanal, ethanol, and a group of thiocyanates were selected for a detailed study because these compounds cause off-odor and can be used as indicators of stress. Significant differences were found in the aroma profiles of the broccoli samples relative to the packaging materials used for storage. Storage in OPP (14% O-2, 10.5% CO2) resulted in most of the off-odors, while storage in LDPE (6% O-2, 7% CO2) and PVC (17.9% O-2, 4% CO2) was found to maintain the concentration of DMS, DMDS, and DMTS during storage. Heat treatment of the broccoli increased the content of aroma compounds as well as the number of compounds containing sulfur.
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| 6. |
- Jacobsson, A., et al.
(author)
-
The effect of packaging material on the sensory properties of broccoli.
- 2003
-
In: ISHS Acta Horticulturae. - 0567-7572. ; 599, s. 323-323
-
Conference paper (peer-reviewed)abstract
- Three different commercially available polymeric films were studied to determine their effect on the sensory properties of fresh broccoli (Brassica oleracea L. var. Italica cv. ‘Marathon’). The polymer materials investigated were oriented polypropylene (OPP), polyvinyl chloride (PVC) and one low density polyethylene (LDPE) which contained an ethylene absorber. The fresh broccoli was packaged and stored for one week at 10°C or 3 days at 4°C followed by 4 days at 10°C. The oxygen and carbon dioxide concentrations inside the packages were monitored during storage. After storage the broccoli was evaluated according to sensory analyses, i.e. triangle test and quantitative descriptive analysis, by an analytical panel. The panel judged the broccoli according to smell, taste, texture and appearance. The triangle test showed significant differences between the smell of the broccoli samples, stored in the different packaging materials, when cooked. However, no differences between the raw broccoli, stored in the different packaging materials could be detected. The quantitative descriptive analysis showed that the following attributes; fresh smell and taste, chewing resistance, and crispness, differed significantly between the packaged broccoli when cooked. The appearance was shown to be the sensory property of broccoli most affected by the storage conditions, i.e. packaging material used and storage temperature. The results indicated the importance of the packaging material for maintaining the broccoli quality. However, one packaging material that was able to maintain all the studied sensory properties could not be identified.
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| 7. |
- Wessling, C., et al.
(author)
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Antioxidant ability of bht- and ?-tocopherolimpregnated ldpe film in packaging of oatmeal
- 2001
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In: Journal of the Science of Food and Agriculture. - 0022-5142 .- 1097-0010. ; 81:2, s. 194-201
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Journal article (peer-reviewed)abstract
- Cereals in general, and particularly oatmeals, are considered rather sensitive to oxidation owing to their relatively high fat content. The addition of antioxidants can sometimes prolong the shelf-life of products. The aim of the present study was to investigate how the rate of lipid oxidation ora packaged oatmeal product was affected by the nature and level of antioxidants incorporated in an LDPE film structure. The stability of the product, which was determined by hexanal analysis using GC-MS and by electronic nose analysis, showed very small variations over the chosen storage period. No oxidation, as determined by hexanal levels in the oatmeal, was initiated during storage, but small variations in volatile profile were seen among the samples analysed by the electronic nose. The product stored in the BHT-impregnated LDPE film had undergone the least change during 10 weeks of storage at 20°C. ?-Tocopherol-impregnated LDPE film did not appear to prolong the shelf-life of the oatmeal at all. © 2000 Society of Chemical Industry.
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| 8. |
- Wessling, C., et al.
(author)
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Influence of ?-tocopherol concentration on the stability of linoleic acid and the properties of low-density polyethylene
- 2000
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In: Packaging technology & science. - 0894-3214 .- 1099-1522. ; 13:1, s. 19-28
-
Journal article (peer-reviewed)abstract
- In food packaging applications where low-density polyethylene (LDPE) film containing ?-tocopherol is used, the antioxidant may have a dual function, i.e. to protect the polymer from oxidative degradation during processing, and to delay the onset of oxidation of the packaged foodstuff during storage. Incorporation of high levels of ?-tocopherol into LDPE film was found to inhibit oxidation of a linoleic acid emulsion stored in contact with the film at 6°C. However, the presence of 360 ppm caused changes in mechanical properties and an increase in oxygen transmission. Levels as high as 3400 ppm ?-tocopherol also caused yellowing and reduction in crystallinity of the material. Thus, the use of high amounts of ?-tocopherol in LDPE, which might be needed in active packaging applications, requires careful consideration of the protective requirements for each specific food and the maintenance of the desired properties of the packaging material.
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| 9. |
- Wessling, C., et al.
(author)
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Influence of trace metals, acids and ethanol in food-simulating liquids on the retention of ?-tocopherol in low-density polyethylene film
- 2000
-
In: Food Additives and Contaminants. - 0265-203X .- 1464-5122. ; 17:8, s. 713-719
-
Journal article (peer-reviewed)abstract
- The retention of ?-tocopherol (vitamin E) in low-density polyethylene (LDPE) film was investigated when in contact with different food-simulating liquids. Variations of the aqueous food simulants approved by the EU for testing of interactions between packaging materials and food, and an alternative fatty food simulant (95% aqueous ethanol) were used to study the influence of trace metals and acids, as well as variation in pH and ethanol concentration, on the stability of ?-tocopherol in the LDPE film. The presence of trace metals in aqueous media accelerated loss of ?-tocopherol from the film, while the addition of citric or ascorbic acid counteracted this loss. In contact with aqueous ethanol at a concentration of 50% or higher, the less of ?-tocopherol from the film was total. However, with solutions containing less than 50% ethanol, the antioxidant was almost completely retained in the film, unless the temperature was increased from 6 to 40°C. For contact with solutions containing ethanol or trace metals, an increase in temperature resulted in a greater loss of ?-tocopherol from the LDPE film.
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| 10. |
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| 11. |
- Widén, Heléne, et al.
(author)
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Migration of model contaminants from PET bottles : Influence of temperature, food simulant and functional barrier
- 2004
-
In: Food Additives and Contaminants. - : Informa UK Limited. - 0265-203X .- 1464-5122. ; 21:10, s. 993-1006
-
Journal article (peer-reviewed)abstract
- To simulate post-consumer recycled plastics, selected model contaminants were incorporated into PET bottles using a time saving method. Migration into 3% acetic acid, a cola-type beverage and 95% ethanol was followed during 1 year of storage at 20 and 40°C. Aroma compounds previously found in post-consumer PET material were used as model contaminants. Benzaldehyde was found to migrate to the highest extent. Storage at 40°C affected the bottle material and this might be one reason for the high migration values of these bottles. Migration into ethanol was up to 20 times higher than into 3% acetic acid or a cola-type beverage. Bottles with a functional barrier resisted migration into food simulants even when filled with 95% ethanol and stored for 1 year at 40°C. Differential scanning calorimetry measurements showed that ethanol was interacting with the plastic material. This resulted in a lower glass transition temperature of bottles stored with ethanol compared with bottles stored empty or with other food simulants.
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