Egg white hydrolysate inhibits oxidation in mayonnaise and a model system

The flavor deterioration of mayonnaise is induced by iron, which is released from egg yolk phosvitin under acidic conditions and promotes lipid oxidation. To prevent oxidative deterioration, natural components, rather than synthetic chemicals such as ethylenediaminetetraacetic acid have been required by consumers. In the present study, we evaluated the inhibitory effects of three egg white components with the same amino acid composition, namely egg white protein, hydrolysate, and the amino acid mixture, on lipid oxidation in mayonnaise and an acidic egg yolk solution as a model system. We found that the hydrolysate had the strongest inhibitory effect on lipid oxidation among the three components. The mechanism underlying the antioxidant effect was associated with Fe²⁺-chelating activity. Thus, egg white hydrolysate may have the potential as natural inhibitors of lipid oxidation in mayonnaise.     

Community dynamics of evergreen broadleaf forests in southwestern Japan. II. Species composition and density of seeds buried in the soil of a climax evergreen oak forest

The species composition and density of seeds in the soil of a climax evergeen oak forest in the Kasugayama Forest Reserve, Nara, Japan were studied by directly extracting seeds from soil samples and using soil samples in planting boxes as the basis of germination tests. A total of 33 species were identified from all seeds collected in 6 stands: 11 evergreen broadleaf, 15 deciduous broadleaf, 2 coniferous, 2 liana, 1 herb, and 2 grass species. Species producing sap fruits and dry fruits accounted for 60% and 40% of the total number of species, respectively. The species composition of all the seeds was independent of the species composition of the forest vegetation. The mean density of the seeds was 22,134 seeds/m²·5 cm.Eurya japonica, of which seeds were found in all soil samples, was the most abundant species, followed byCryptomeria japonica, Ilex micrococca, andBoehmeria longispica. Pioneer species such asMallotus japonicus, Zanthoxylum ailanthoides, andAralia elata were found in all soil samples in spite of the paucity of adult trees in the forest. Seeds of evergreen oaks were relatively aboundant but no viable seeds were found. ViableE. japonica, I. micrococca, Symplocos prunifolia, andB. longispica seeds were abundant.     

A short note on an Adélie penguin feeding its own mate

An adult Adélie penguin (Pygoscelis adeliae) raising two chicks in the colony of Petrel Island, Adélie Land was observed feeding food to its own mate. Electronic Supplementary Material is available if you access this article at http://dx.doi.org/10.1007/s00300-002-0429-0. On that page (frame on the left side), a link takes you directly to the supplementary material.