Inefficacy of cooking methods on mercury reduction from shark.

Shark and other carnivorous fishes present high potential risk of excessive contamination by mercury. The distribution of mercury throughout the body of blue shark--Prionace glauca--was analysed, and the effects on mercury levels by frying and baking in a laboratory oven, and in a microwave oven, were measured. There was no significant statistical difference in mercury levels in the samples taken from regions near the head, or from central and tail parts, indicating homogeneous distribution of the metal in muscles throughout the body. Frying and baking did not affect original mercury levels present in blue shark. This study indicates that specific studies are needed to define the efficacy or inefficacy of the cooking methods on mercury reduction from fish, in order to clearly resolve divergent opinions in the literature.

Hamburger meat identification by dot-ELISA.

The use of low cost meats to adulterate meats and meat products has been reported. Appropriate methods of analysis then are needed in order to detect this practice. The dot-ELISA method was used to identify the meat of different animal species and to detect adulteration of hamburgers. Antisera to bovine, chicken, swine and horse albumin were produced and they could detect the meat extract of the homologous species at concentrations as low as 0.6%. Thus, the anti-albumin antisera could identify bovine, chicken, swine and horse meat with adequate specificity and sensitivity both in isolation and when added to hamburger. Commercial samples of bovine, chicken and swine hamburgers showed no adulteration with bovine, chicken, swine or horse meats. Our expectation of hamburger adulteration was not confirmed.

Reduction of the bioavailability of fluoride from Antarctic krill by calcium.

The bioavailability of fluoride from krill exoskeleton and the effect of additional calcium on the bioavailability of fluoride from krill paste were evaluated using young rats. Fluoride from the exoskeleton showed a high apparent absorption of 80%. Approximately 3.6% of this fluoride was deposited in the femur, and 44% in the rest of the carcass. The presence of 1.5% and 2.5% calcium (CaCO3) in the diet--1.0 and 2.0% above the minimum recommended content respectively--significantly reduced the bioavailability of fluoride from krill paste. The apparent absorption of fluoride from the paste was reduced by 33.8 and 45.8%, deposition in the femur by 48.1 and 58%, and retention in the rest of the carcass by 44.4 and 55.6%, respectively. The need for further studies using lower amounts of fluoride and calcium and other chemical forms of calcium is indicated.