Factors influencing the¹⁸O/¹⁶O-ratio in meat juices

Abstract

With respect to the question of whether the 18O/16O-ratio of meat water could be used for meat origin analysis, factors influencing its delta18O-value have been examined. The 18O/16O-ratio of meat water differs geographically, similar to known differences in precipitation and ground water. In Great Britain higher enrichments in 18O were found in southern samples and in Germany in northern samples. However, it was not possible to distinguish between British and German beef: their 18O/16O-ratios overlapped. British bovine samples the variation range of delta18O-values was 2.8 per thousand; in porcine samples it was 2.0 per thousand. British meat liquids from beef were enriched in 18O by 1.3 +/- 0.3 per thousand compared with pork. In porcine samples of litter mates with identical breeding and age at slaughter, the range in the delta18O-values among individuals was 2.4 per thousand. Experiments revealed significant influences of the meat's storage and handling conditions on the 18O/16O-ratio. After 10 h at 21.5 or 18.5 degrees C the delta18O-value increased by 0.4 or 0.3 per thousand per h, respectively, in samples (50 g) of chopped meat. The observed magnitude of changes might compensate for the geographical and seasonal differences. A precise origin assignment of the affected specimen on the base of delta18O-values of meat water is hence bound to be impossible.

Oxygen isotope fractionation between human phosphate and water revisited

“…Some food (cereals, legumes) contains only a few wt % water, whereas most vegetables are up to 95% water by weight (Table 4). Plants and meat are 18 O-enriched compared to meteoric water (e.g., Schmidt et al, 2001;Thiem et al, 2004). Therefore, the total water ingested by consumers may be 18 O-enriched compared to the meteoric water of their living place.…”

The use of multi‐element stable isotope analysis to monitor the origin of chondroitin sulfates

“…The application of stable isotope analysis for origin assignment of animal products has been applied since 1995 to an increasing number of animal products such as milk, cheese, butter, meat, eggs and fish . More recently, studies on fine chemicals used in the cosmetic and pharmaceutical area have been published, demonstrating that SIRA (Stable Isotope Ratio Analysis) can also provide useful information to check their origin …”

Tracing the geographic origin of poultry meat and dried beef with oxygen and strontium isotope ratios

“…18 O with increasing storage time in a simulated storage experiment [46]. However, samples of Brazilian raw meat origin (processed in Austria and canton Grissons) could not be separated from dried beef made from Swiss raw meat (processed either in canton of Grissons or Valais).…”

“…Due to the fact that 18 O preferentially remains and gets enriched during evaporation [19,30,44,46], it was expected that the drying process would affect the final oxygen isotope ratio of the meat product. Unpublished preliminary data suggest that the d-values increase with drying as do studies describing an elevated d…”

“…One further relevant factor influencing d 18 O might be the evaporative water losses from the body of livestock (via lung and skin), where 16 O is lost at higher rates than the heavier 18 O, thus enriching the body water pool of terrestrial animals with 18 O relative to that of the ingested water [18,39,46]. Moreover, some water is produced from feed nutrient oxidation (metabolic water), and this does influence the 18 O enrichments as well.…”