Effect of processing and cooking on total and soluble oxalate content in frozen root vegetables prepared for consumption

The oxalate content of beetroot, carrot, celeriac and parsnip after freezing by traditional and modified methods (the latter resulting in a convenience food product), and after the preparation of frozen products for consumption was evaluated. The highest content of total and soluble oxalates (105 and 82 mg 100 g-1 fresh matter) was found in beetroot. The lowest proportion (55%) of soluble oxalates was noted in celeriac; this proportion was higher in the remaining vegetables, being broadly similar for each of them. Blanching brought about a significant decrease in total and soluble oxalates in fresh vegetables. Cooking resulted in a higher loss of oxalates. The level of oxalates in products prepared for consumption directly after freezing approximated that before freezing. Compared with the content before freezing, vegetables prepared for consumption by cooking after frozen storage contained less oxalates, except for total oxalates in parsnip and soluble oxalates in beetroot and celeriac. The highest ratio of oxalates to calcium was found in raw beetroot; it was two times lower in raw carrot; five times lower in raw celeriac; and eight times lower in raw parsnip. These ratios were lower after technological and culinary processing. The percentage of oxalate bound calcium depended on the species; this parameter was not significantly affected by the procedures applied. The true retention of oxalates according to Judprasong et al. (2006) was lower than retention calculated taking its content in 100 g fresh matter into account.

Importance of fat reserves in Wilson´s storm petrel chicks

All petrels store large quantities of fat during nesting period. Several hypotheses have offered explanations for the exceptional accumulation of fat by petrels and that stored in smaller amounts by other birds. Fat reserves of Wilson's storm petrel chicks attain 80% of dry mass. Lipid index increases up to value of 2.0 during nesting period . The aim of our study was to explain the role of fat stores in the nestlings. Stable growth of chicks during first three weeks of life suggests that stochastic variation of chick food provisioning arises from unpredictable snow storms rather than fluctuating food availability at the sea. The lack of correlation between body mass and head, tarsal or wing length rejects hypotheses that chicks accumulate lipid in order to increase their rate of intake of a limiting nutrients. Accumulation of excessive lipid reserves may be a consequence of overfeeding of the chicks by their parents. This strategy protects offspring from death during periods of starvation, when nest entrances are covered by snow

Correction: Where have all the petrels gone? Forty years (1978–2020) of Wilson’s Storm Petrel (Oceanites oceanicus) population dynamics at King George Island (Isla 25 de Mayo, Antarctica) in a changing climate

Ausems ANMA, Kuepper ND, Archuby D, et al. Correction: Where have all the petrels gone? Forty years (1978–2020) of Wilson’s Storm Petrel (Oceanites oceanicus) population dynamics at King George Island (Isla 25 de Mayo, Antarctica) in a changing climate. Polar Biology . 2024;47(2):187