Chemical and biochemical composition of caviar from different sturgeon species and origins

Abstract

The chemical and biochemical composition of caviar in 22 specimens of wild caught and of 2 farmed animals were measured. The results include grain size, protein and fat content, fatty acid composition of triglycerides and phospholipids, as well as the concentrations of relevant heavy metals and chlorinated hydrocarbons. The average protein content varied between 26.2 and 31.1% (wet weight) and fat from 10.9 to 19.4% (wet weight) with lowest values for caviar from farmed sturgeon. The triglycerides and phospholipids contained more n-3 fatty acids, especially eicosapentaenoic and docosahexaenoic acid than n-6 fatty acids. The copper and zinc concentrations varied between 1.20 and 1.69 and 10.3 and 12.4 mg/kg (wet weight), respectively. These values reflect the elevated requirement of sturgeons for these components. Lead content varied between 0.06 and 0.15 mg/kg (wet weight). The cadmium concentrations were less than 5 micrograms/kg (wet weight) leading to the conclusion that no accumulation took place in the eggs. The concentrations of sigma DDT and sigma PCB were extremely high in caviar from Huso huso compared to the samples of the other species thus reflecting the different food habits leading to increased bio-accumulation.

The chemical and sensorial changes in rainbow trout caviar salted in different ratios during storage

“…Bledsoe et al [11] determined the amount of moisture in raw roe obtained from salmon as 50%, and they reported that the moisture rate of the caviar differed according to the type of salmon, e.g., 50-60% in Oncorhynchus gorbuscha, 55-56% in Oncorhynchus keta, 56-58% in Oncorhynchus nerka, and 51-70% in Oncorhynchus ishawischa. Wirth et al [12] reported the moisture content in caviar obtained from sturgeon as 38-53%. Inal [13] declared the moisture in good-quality caviar as 45%.…”

“…It did not change much during storage and was between 11.48 and 11.57% in 4% salted caviar and between 11.57 and 11.69% in 8% salted caviar. In another study, the fat amount was 10.9-19.4% in caviar obtained from salmon fish [12]. Himelbloom et al [15] detected 11% fat in their salmon caviar (ikura).…”

<b>Caviar substitute produced from roes of rainbow trout (<i>Oncorhynchus mykiss</i>)

“…The rapid heat treatment and 3% of NaCl may have contributed to the lower moisture content, resulting in the highest concentration of ash and energy content in the sample O. Wirth et al (2000) evaluated the composition of caviar from roes of wild and farmed sturgeons, resulting in protein contents of 26.2 to 31.1% and lipids of 19.4% to 10.9. The lowest values were found in caviar from roes of farmed sturgeons.…”

“…The low lipid contents obtained in the current study may be related to the diet composition, with 45% crude protein and 10% crude fat. The protein contents for the raw material and treatments are similar to those obtained by Wirth et al (2000) for caviar of farmed sturgeon. Caloric values obtained are within the limits proposed by Brunner, Marx, and Stolle (1995) for roes of various species, between 130 and 280 kcal 100 g -1 .…”

“…Considered a culinary delicacy, caviar consists of roes of sturgeon, treated with sodium chloride, subjected or not to pasteurization, and the beluga caviar (Huso huso) has the greatest commercial value (Wirth et al, 2000;Flynn, Matsuoka, Reith, MartinRobichaud, & Benfey, 2006). Because of overfishing, most of important sturgeon species are framed as critically endangered in the IUCN Red List of Threatened Species, resulting in reduced supply of caviar and a higher price (Catarci, 2004).…”