Quality characterisation of strawberries for industrial jam production

Six strawberry varieties were evaluated as raw materials for industrial jam production. The investigation involved chemical, physical and sensory analyses of fresh and frozen/thawed fruits as well as jam at the time of production and after 3 months of storage. Among the varieties studied, Jonsok and Senga Sengana appeared most suitable, followed by Bounty and Tenira. The other varieties, Fructana and Totem, were less satisfactory for this purpose. Based on linear correlation analyses (P<0.05), the relevance of various parameters in evaluating fruits intended for jam production is discussed. The results disclosed pH, titratable acids and sugars of fresh fruits to be less important to jam quality. High contents of soluble solids and ascorbic acid were related to undesirable flavour properties of jams. Further, high levels of ascorbic acid adversely affected colour stability. Colour degradation in jams was parallel to flavour deterioration. It is concluded that the main emphasis should be given to characteristics of the final products rather than to characteristics of the fresh fruits.     

The combined effect of rosemary (Rosmarinus officinalis L.) and modified atmosphere packaging as protection against warmed over flavour in cooked minced pork meat

Rosemary (dried leaves ofRosmarinus officinalis L.) added to cooked meat balls (minced pork) was found to retard the formation of warmed over flavour (WOF) during chill storage. The spice was added to pork meat (Longissimus dorsi) balls in an amount acceptable for the product, as evaluated by a sensory panel (0.05% of total weight). After cooking (water bath, internal temperature 80°C), the meat balls were packed using five atmosphere packaging conditions: (i) air; (ii) 5% O₂/95% N₂; (iii) 3% O₂/97% N₂; (iv) 1% O₂/99% N₂; and (v) 100% N₂. During chill storage (5°C), the sensory quality of the reheated meat balls was evaluated by a trained sensory panel, and lipid oxidation was followed by measurement of thiobarbituric acid reactive substances (TBARS). The combination of decreased O₂ atmosphere in the packages and addition of rosemary resulted in a significantly (p<0.05) lower amount of TBARS and a significantly (p<0.05) better sensory score.     

Invasiveness of Listeria monocytogenes strains of Caco-2 cells in response to a period of extreme salt stress reflecting salt-curing and rehydration of cod (Gadus morhua L.)

Products like salt-cured fish contain approximately 15–21% NaCl and are rehydrated to 2–3% NaCl before preparation and consumption. These products are regarded as safe, but it has been shown that Listeria spp. is able to survive at extreme levels of salt and start to grow after rehydration. Thus, the ability of salt stressed Listeria monocytogenes to cause listeriosis, measured as its ability to invade Caco-2 cells was studied in this paper. Seven strains of L. monocytogenes and one Listeria innocua were cultivated in BHI to early and late stationary phase at 4 °C. At both phases, the strains were exposed to either no salt or to salt stress comparable to that applied in the production of rehydrated salt-cured cod, i.e. 21% NaCl followed by dilution to 2% NaCl. In addition, the eight strains were cultivated in BHI with 2% NaCl, which is similar to the salt content as in rehydrated salt-cured cod and other ready-to-eat (RTE) products as well. The ability of non salt stressed L. monocytogenes strains to enter Caco-2 cells was significant higher (p > 0.05) compared to the corresponding strains exposed to 21% NaCl for 96 h, followed by 2% NaCl for 48 h. On the other hand, L. monocytogenes cultivated in BHI with 2% NaCl showed a higher invasiveness of Caco-2 cells than both the other sample categories. As the ability to invade Caco-2 cells correlates with bacterial virulence, the results suggests that L. monocytogenes represent a lower food safety risk when exposed to salt-curing with extreme NaCl concentrations than exposure of a constant and moderate level of salt commonly used in RTE products.     

Chemical characterization and mutagenicity testing of chlorinated trihydroxybenzenes identified in spent bleach liquors from a sulphite plant

The spent bleach liquors from a sulphite plant have been investigated for their content of phenols. Seventeen phenols were identified by gas chromatography—mass spectrometry analysis and chlorinated trihydroxybenzenes were found to be the main components.The effluent showed mutagenic activity in the Ames' Salmonella test and some of the identified phenols were synthesized to investigate if these compounds could be responsible for the observed effect.     

Effect of pre-slaughter physiological conditions on the oxidative stability of colour and lipid during chill storage of sliced, retail packed roast ham

Pre-slaughter physiological conditions (A serving as control, B subjected to treadmill exercise immediately prior to stunning, C epinephrine injection 15 h prior to slaughter, and D epinephrine injection 15 h prior to slaughter and subjected to treadmill exercise immediately before stunning) were found to significantly affect colour and lipid oxidation of sliced, retail packed roast ham, produced from nitrite-cured (78 ppm nitrite) M. Longissimus dorsi. The pre-slaughter treatment resulted in variations in the level of glycogen, lactate, ATP and IMP and pH development as monitored in Longissimus dorsi muscles, with the lowest ultimate pH (pH(u)) in muscles from non-epinephrine treated pigs (treatments A and B). The initial tristimulus L(?)-value and the L(?)-value during chill storage of sliced roast ham packed in laminates with low or with very low oxygen transmission rate (OTR=40 and <0.5 cm(3)/m(2)/atm/24 h, respectively) were significantly affected by treatment, although the effect of the treatments was different during storage for 28 days (interaction between treatment and storage time). Roast ham from treatments A and B generally had a paler appearance (higher L(?)-values) than from treatments C and D. No differences in the initial tristimulus a(?)-values (redness) were found. During chill storage, a pronounced colour fading (decrease in a(?)-values) was seen for laminate with low OTR, with a tendency of better colour stability for treatment C than A, but with no differences for the other treatments. For laminates with very low OTR, the cured meat pigment was stable with no decreases in a(?)-values during storage. Lipid oxidation (thiobarbituric acid reactive substances, TBARS) in products in laminates with low OTR increased during storage and was significantly higher for roast ham from non-epinephrine treated pigs (A and B) than for ham from epinephrine-treated pigs (C and D). Statistical analysis relating pH and the level of glycogen, lactate, creatine phosphate, ATP and IMP in the individual pigs to the product quality parameters revealed that the ultimate level of lactate was the most important single parameter affecting product quality. After 28 days of chill storage, roast ham from pigs subjected to treatments C and D were more likely to support bacterial growth than from treatments A and B. In conclusion, the results show that pre-slaughter physiological conditions are of importance for chemical as well as for microbiological changes in retail stored roast ham.     

An enzymic method for the determination of starch in meat products

The starch content of meat products is determined as glucose by an enzyme-hydrolytic method using thermo-stable α-amylase and amyloglucosidase for hydrolysis. The method is compared with a polarimetric and an acid-hydrolytic method.The recovery in various cooked and uncooked sausages containing up to 12% starch ranged from 92 to 102% of the starch content estimated from the recipe. The average coefficient of variation was 2%. The presence of lactose did not influence the starch determination. In a collaborative study an average of 103% of the estimated starch value was recovered. The random and systematic errors were of equal size, each amounting to a maximum of 8% of the starch content of the sausages.The application of the method for food inspection purposes is discussed. The method is considered to be suited for starch analysis in meat products.     

Particle backscatter and extinction profiling with the spaceborne high-spectral-resolution Doppler lidar ALADIN: methodology and simulations

The European Space Agency will launch the Atmospheric Laser Doppler Instrument (ALADIN) for global wind profile observations in the near future. The potential of ALADIN to measure the optical properties of aerosol and cirrus, as well, is investigated based on simulations. A comprehensive data analysis scheme is developed that includes (a) the correction of Doppler-shifted particle backscatter interference in the molecular backscatter channels (cross-talk effect), (b) a procedure that allows us to check the quality of the cross-talk correction, and (c) the procedures for the independent retrieval of profiles of the volume extinction and backscatter coefficients of particles considering the height-dependent ALADIN signal resolution. The error analysis shows that the particle backscatter and extinction coefficients, and the corresponding extinction-to-backscatter ratio (lidar ratio), can be obtained with an overall (systematic+statistical) error of 10%-15%, 15%-30%, and 20%-35%, respectively, in tropospheric aerosol and dust layers with extinction values from 50 to 200 Mm(-1); 700-shot averaging (50 km horizontal resolution) is required. Vertical signal resolution is 500 m in the lower troposphere and 1000 m in the free troposphere. In cirrus characterized by extinction coefficients of 200 Mm(-1) and an optical depth of >0.2, backscatter coefficients, optical depth, and column lidar ratios can be obtained with 25%-35% relative uncertainty and a horizontal resolution of 10 km (140 shots). In the stratosphere, only the backscatter coefficient of aerosol layers and polar stratospheric clouds can be retrieved with an acceptable uncertainty of 15%-30%. Vertical resolution is 2000 m.     

Aviation safety and maintenance under major organizational changes, investigating non-existing accidents

The objective of this paper is to discuss the following questions: Do concurrent organizational changes have a direct impact on aviation maintenance and safety, if so, how can this be measured? These questions were part of the investigation carried out by the Accident Investigation Board, Norway (AIBN). The AIBN investigated whether Norwegian aviation safety had been affected due to major organizational changes between 2000 and 2004. The main concern was the reduction in safety margins and its consequences.This paper presents a summary of the techniques used and explains how they were applied in three airlines and by two offshore helicopter operators. The paper also discusses the development of safety related indicators in the aviation industry. In addition, there is a summary of the lessons learned and safety recommendations. The Norwegian Ministry of Transport has required all players in the aviation industry to follow up the findings and recommendations of the AIBN study.     

Antioxidative Properties of Commercial Fruit Preparations and Stability of Bilberry and Black Currant Extracts in Milk Products

ABSTRACT: Nineteen commercial fruit preparations were analyzed for antioxidant capacity (anti-radical power [ARP] and oxygen radical absorbance capacity [ORAC]). ARP and ORAC values of blends with 13% (w/w) bilberry and black currant extract in low-fat milk or low-fat fermented milk were assessed. Antioxidant capacity in 13% berry/fermented milk blends packed in glass or cardboard cartridges and stored for 3 wk in the dark or under fluorescent light was determined. ARP and ORAC values of most fruit preparations greatly exceeded those of plain milk. Milk blends with berry extract increased ARP values 5-fold to 13-fold and ORAC values by 40% to 100%. Packaging material, illumination, and storage period had no consistent effects on antioxidant capacity.     

Strawberry varieties for industrial jam production

Twelve strawberry varieties were investigated for potential use by the jam processing industry. Chemical, physical and sensory analyses were performed with fresh and thawed fruits and with jams made from the fruits. Fresh fruits were analysed for dry matter, soluble solids, pH, titratable acids and ascorbic acid. Total anthocyanin and degradation indexes were determined in both fresh fruits and in jams. Firmness of fresh and thawed fruits, as well as the amount of juice lost upon thawing (drip loss) were tested for each variety. Except for colour, no significant correlation (P<0.05) existed between the chemical analyses and the sensory parameters. There was significant relationship between total anthocyanin content and visual colour as judged by a taste panel. There was no correlation between firmness of fresh and thawed fruits. Drip loss and firmness of fresh fruits and jams gave a negative correlation. There was no relationship between drip loss and texture measurements in thawed fruits. Except for colour, there were no correlations between the chemical analyses. Based on the results, Jonsok, Totem and Bounty varieties appeared suitable for industrial jam production when compared to the Senga Sengana variety now in use.