Functional and sensory properties of hen eggs with modified fatty acid compositions.

Foaming, emulsifying, gelling, and sensory properties of fresh and stored hen eggs fed with a diet supplemented with flax oil (FO), rapeseed oil (RO), fish oil (FISH), and by-product from black currant processing (BC) were investigated. With these diets, the ω6/ω3 fatty acid ratio of eggs varied from 1.5 to 5.8, while the ratio for eggs in the control group was 6.2. Compared to eggs in the control group, FO supplementation in the feed had statistically significant influences on the foaming properties of the fresh eggs. Eggs stored for 21 days lost part of their foaming properties in FISH oil supplemented group, but the foaming properties in all test groups were technically acceptable. The emulsifying properties of eggs in FO and FISH supplemented feeding groups were statistically different compared to control group. In boiled eggs, flax oil and fish oil supplementation induced off flavours in eggs, but no changes between the control group and test groups were found in the sensory properties of mayonnaise preparations. These results suggest that the egg processing industry may produce egg-based products using oil-supplemented eggs without major problems in functional or sensory properties.

Screening of lactic acid bacteria from fermented vegetables by carbohydrate profiling and PCR-ELISA.

AIMS: The aim of this study was to identify potential souring agents, isolated from fermented plant material, by API 50 CHL assay and a molecular method based on polymerase chain reaction and colorimetric hybridization (PCR-ELISA). METHODS AND RESULTS: Forty-two strains of lactic acid bacteria derived from plant material were screened by taking advantage of API 50 CHL and PCR-ELISA. Oligonucleotide probes used for hybridization in PCR-ELISA were specific for lactobacilli, the Leuconostoc family, Lactobacillus pentosus/plantarum and Lactobacillus brevis. The hybrides were detected by a colour-developing reaction. Bacteria isolated from fermented cucumbers were identified as Lact. plantarum-related (Lact. plantarum and Lact. pentosus) and Leuconostoc species. Most of the strains isolated from sauerkraut were identified as Lact. pentosus/plantarum. CONCLUSIONS: Complementary results were obtained in the identification of bacterial strains, isolated from fermented cucumbers and sauerkraut, by API 50 CHL and PCR-ELISA. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR-ELISA proved to be suitable for the screening of large numbers of bacterial isolates from fermented vegetables. This will be useful for the identification of strains suitable for the design of starter cultures for the fermentation of plant material.

Red cell function of carp (Cyprinus carpio) in acute hypoxia.

The red cell function of carp, subjected to acute hypoxia, was studied. During hypoxic exposure red cell water content, sodium and chloride concentration and pH increased, whereas plasma sodium and chloride concentrations decreased. Treatment of the animals with a beta-adrenergic antagonist, propranolol, before the onset of hypoxia, largely inhibited the increase in red cell water content, diminished the changes in red cell pH and prevented the changes in red cell and plasma sodium concentration. The red cell chloride concentration increased also in propranolol-treated animals thus illustrating the effect of the deoxygenation of haemoglobin on the ion concentrations of red cells. These data indicate that adrenergic activation of sodium/proton exchange across red cell membrane plays a role in the acute responses of carp to hypoxia.