| 1. |
- Hallgard, Elna, et al.
(författare)
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Heterocyclic amine formation during frying of frozen beefburgers
- 2008
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Ingår i: International Journal of Food Science & Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 43:1, s. 62-68
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Tidskriftsartikel (refereegranskat)abstract
- The formation of heterocyclic amines (HCAs) was studied during frying of beefburgers with different fat contents (6.7%, 16.1% and 39%). Beefburgers were fried from the frozen state for 60, 90, 120 s, and until the centre temperature had reached 72 °C (approximately 150 s) in a double-sided pan fryer. The beefburgers were analysed for HCAs with solid-phase extraction and LC/MS detection, and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 1-methyl-9H-pyrido[3,4-b]indole (Harman) and 9H-pyrido[3,4-b]indole (Norharman) were detected in all samples. The concentrations of HCAs ranged between 0 and 2.3 ng g−1. The HCAs concentrations were fitted to a first-order reaction model. The amounts of HCAs in beefburgers fried from the frozen state were in the same range as in beefburgers that have reached room temperature before frying. Furthermore, it was found that the formation of HCAs is not only concentration-controlled but also mass transport-controlled and that kinetic models stated in earlier studies fit relatively well our analysed values on HCAs in fried beefburgers.
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| 2. |
- Shockravi, Soodeh, 1979, et al.
(författare)
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Dephytinisation of Sangak and Barbari bread made from different extraction rate flours increases iron and zinc bioaccessibility in Caco-2 cells
- 2012
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 1365-2621 .- 0950-5423. ; 47:11, s. 2252-2258
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Tidskriftsartikel (refereegranskat)abstract
- Bread is a staple food in many countries and an important source of iron and zinc. The bioavailability of these minerals is generally low because of the content of phytic acid. Traditional Iranian breads were prepared with flours of different extraction rates, Sangak at 93% and Barbari at 82%. Breads were dephytinised by addition of Aspergillus niger phytase during in vitro digestion. The effect upon iron and zinc bioaccessibility in the Caco-2 cell model was investigated. The cellular uptake of iron and zinc was lower from Sangak, compared to Barbari, despite higher mineral content in Sangak. Dephytinisation of both breads increased iron uptake in the Caco-2 cells (0.65 vs. 1.64 in Sangak and 0.77 vs. 1.97 ng mg-1 protein in Barbari). Zinc uptake increased from 0.98 to 2.8 in Sangak and from 1.4 to 2.9 ng mg-1 protein in Barbari. Thus, dephytinisation substantially improves iron and zinc bioaccessibility.
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| 3. |
- Skog, Kerstin, et al.
(författare)
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Effect of different cooking methods on the formation of mutagenic compounds in meat.
- 2003
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Ingår i: International Journal of Food Science & Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 38:3, s. 313-323
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Tidskriftsartikel (refereegranskat)abstract
- Hamburgers and chicken fillets were cooked in convection ovens, deep-fried or contact fried and analysed for mutagenic activity using the Ames test. For the three different convection ovens, the cooking parameters studied included the presence of steam, air velocity, air temperature and holding time. For deep-frying and contact frying, the cooking parameters included cooking temperature and cooking time. In cooked hamburgers, mutagenic activity was only detected in those that had been deep-fried. In chicken fillets, mutagenic activity was detected in samples prepared with all cooking methods, being highest in the deep-fried samples. Factorial analysis indicated that heat transfer was the most important factor affecting mutagenic activity. High temperature and high air velocity in the convection ovens enhanced mutagenic activity. The presence of steam reduced the mutagenic activity, except when high temperature was used in combination with high air velocity. In chicken fillets, high mutagenic activity correlated to high weight loss during cooking. Pan-fried chicken fillets were analysed using high performance liquid chromatography (HPLC) and the mutagenic/carcinogenic heterocyclic amines 2-amino-3,8-dimethylimidazo[4,5-f]-quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo-[4,5-b]-pyridine (PhIP) and the co-mutagenic heterocyclic amine Norharman (9H-pyrido[3,4-b]-indole) were identified. The HPLC fractions were tested for mutagenic activity and, apart from the mutagenic fractions corresponding to MeIQx and PhIP, several mutagenic fractions were detected that did not correspond to known heterocyclic amines.
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| 4. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
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Improvement of active chitosan film properties with rosemary essential oil for food packaging
- 2012
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 1365-2621 .- 0950-5423. ; 47:4, s. 847-853
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Tidskriftsartikel (refereegranskat)abstract
- Rosemary essential oil (REO) was used to develop an active film from chitosan. The effects of REO concentration (0.5, 1.0 and 1.5% v/v) on film properties were studied by measuring the physical, mechanical and optical properties of the REO‐loaded films. Scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy were used to study microstructure and the interaction of the chitosan‐based films. The solubility and water gain of the chitosan film decreased about 25% and 85%, respectively, by REO incorporation, up to 1.5% v/v, because of the interaction between hydrophilic groups of chitosan and REO as confirmed by FTIR. It was determined that REO improved the transparency of the films from 4.97 in neat chitosan up to 7.61; moreover, it reduced the films’ light transmission in UV light more than 25%. Films containing REO showed more antibacterial activity and total phenol content. The films containing REO showed potential to be used as active film in food preservation.
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| 5. |
- Ahrné, Lilia, et al.
(författare)
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Comparison of drying kinetics and texture effects of two calcium pretreatments before microwave-assisted dehydration of apple and potato
- 2003
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Ingår i: International journal of food science & technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 38:4, s. 411-420
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Tidskriftsartikel (refereegranskat)abstract
- The effects on drying rate and texture of treating two plant tissues with calcium, before drying in air with microwave assistance, were studied in this work. The two tissues, potato and apple cubes, which have different structures and composition, were pretreated by immersion in CaCl2 solutions at 20 or at 70 °C before microwave-assisted air dehydration at 50, 60 and 70 °C. The pretreatments with calcium influenced the strength of the plant tissue cell wall, producing products of varying hardness after rehydration. The effect of the two calcium pretreatments was quite different for apples and potatoes. For apples, calcium pretreatment at 20 °C increased the hardness of rehydrated apples compared with untreated apples, but calcium pretreatment at 70 °C had no effect on texture. For potatoes, both calcium pretreatments at 20 and at 70 °C significantly increased the hardness of rehydrated potatoes. The water diffusivity during drying varied mainly because of the type of plant tissue, with secondary effects caused by the drying temperature and the type of calcium pretreatment.
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| 6. |
- Andersson, Thorbjörn, et al.
(författare)
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The effects of selected aldehydes, ketones and carboxylic acids on off-flavours in water
- 2005
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Ingår i: International journal of food science & technology. - : Wiley InterScience. - 0950-5423 .- 1365-2621. ; 40:9, s. 993-1004
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Tidskriftsartikel (refereegranskat)abstract
- The effects of selected aldehydes, ketones and carboxylic acids on the development of off-flavours in water were studied. Combinations of hexanal, octanal, 2-octanone, 5-nonanone, hexanoic acid and nonanoic acid were rated by the off-flavour intensities they created in water at concentrations just at or below the threshold value of each analyte. Two different sensory panels evaluated the off-flavours induced by different combinations of the analytes. The observations of the two panels agreed well. From these studies, it could be concluded that aldehydes play an important role in the development of off-flavours intensities in water. There were synergistic effects between aldehydes and ketones, as well as between aldehydes and carboxylic acids. Small amounts of aldehydes and carboxylic acids – well below their respective threshold values – caused an increase in the off-flavour intensity. No synergism between ketones and carboxylic acids could be observed
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| 7. |
- Bjorklund, Robert, et al.
(författare)
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Continuous monitoring of yoghurt fermentation using a noble metal electrode array
- 2009
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 44:3, s. 635-640
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Tidskriftsartikel (refereegranskat)abstract
- An electrochemical probe containing gold, platinum and rhodium working electrodes was used to monitor yoghurt production in a pilot facility. Three commercial starting cultures at 40, 42 and 44 C transformed milk having 1.5% fat content to mild yoghurt products. The electrochemical changes in the broth during fermentation were recorded as current responses from pulse voltammetry over the electrodes. Principal component analysis of the responses generated two-dimensional score plots describing the qualitative fermentation progressions. Two distinct fermentation pathways were observed leading to similar final products. The pH was recorded during the fermentations and the data was used as reference values for creating a partial least squares model for prediction of pH as an example of a quantitative application for the sensor. The relative mean squared error for validation of the model using four probes interchangeably was about 2%. The probe was constructed of materials approved for use in the food industry and did not require a standard glass reference electrode.
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| 8. |
- Funebo, Tomas, et al.
(författare)
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Microwave and convective dehydration of ethanol treated and frozen apple : Physical properties and drying kinetics
- 2002
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Ingår i: International journal of food science & technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 37:6, s. 603-614
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to examine how the drying kinetics and physical properties of apples are affected by pre-treatment with 95% ethanol or freezing at -18 °C before microwave-assisted air dehydration at 50, 60 and 70 °C. Microwave heating was used to obtain these temperatures in the centre of the apple cubes. After dehydration the shrinkage and rehydration capacity were measured. The texture of dehydrated and rehydrated samples was analysed with a puncture test in a texture analyser. Samples were also analysed with confocal laser scanning microscopy to determine the correlation between physical and microstructural properties. Diffusivity in the different dehydration processes was calculated. Ethanol-treated apples showed both high rehydration and high effective rehydration capacity compared with the other samples. Freezing before dehydration increased the diffusivity and reduced the firmness of rehydrated apples compared with no pre-treatment.
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| 9. |
- Iqbal, Zafar, et al.
(författare)
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Assessment of a mobile phone for use as a spectroscopic analytical tool for foods and beverages
- 2011
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Ingår i: International journal of food science & technology. - : Wiley-Blackwell. - 0950-5423 .- 1365-2621. ; 46:11, s. 2428-2436
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Tidskriftsartikel (refereegranskat)abstract
- A mobile phone was used to perform optical analyses of foods and beverages. The phone’s screen served as illumination source and front view camera recorded images. Reflected intensities were used to discriminate among the different samples analysed by principal component analysis. Samples studied illustrated the technique’s potential analytical capabilities with respect to adulteration and authenticity. Three coloured additives (red, green and blue) in the concentration range 2-10 mg/l in a lemon lime beverage were discriminated. Adulteration by up to 25% water of milk with 3% fat content was detected with an estimated detection limit of about 3% water. Changes occurring on a green onion surface over a 48 h aging period at room temperature were monitored. Five different cuts from lamb carcasses weighing 9 and 14 kg were classified by the method. Considerable additional work with regard to sampling, data treatment and quantifying results is necessary before the goal of using the technique as a point of purchase analytical tool can be realised.
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| 10. |
- Johansson, Sofia, et al.
(författare)
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The availability of soluble oxalates in stir-fried silver beet (Beta vulgaris var. cicla) leaves eaten with yoghurt
- 2011
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 46, s. 2232-2239
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Tidskriftsartikel (refereegranskat)abstract
- Silver beet (Beta vulgaris var. cicla) leaves contain oxalates, and the addition of yoghurt, a food rich in calcium, to stir-fried leaves was investigated as a way of reducing the soluble oxalate content. Fourteen participants ingested 115 g stir-fried silver beet leaves with or without standard yoghurt and low-fat yoghurt, respectively. Stir-fried silver beet leaves contained 209.1 +/- 0.1 mg of total oxalates per meal fresh weight (FW) and 109.2 +/- 0.1 mg of soluble oxalates per meal FW. The proportion of soluble oxalates was reduced from 52% to a mean of 30% of the total oxalates when standard yoghurt or low-fat yoghurt was added. The mean absorption of oxalate was determined by measuring the output of oxalate in the urine over a 6-h period following ingestion of the meals. The mean absorption of oxalate from stir-fried silver beet leaves was 2.41%, which reduced to 1.10% and 0.89% when consumed with standard yoghurt and low-fat yoghurt, respectively.
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