Traceability of grass feeding in beef: terpenes, 2,3-octanedione and skatole accumulation in adipose tissue of young bulls

Abstract

The development of analytical methods to verify the production system of meat products requires the identification of biomarkers that can trace the product's origin, and secondly the factors that govern the deposition of these markers in animal tissue need to be defined. In this study, 2,3-octanedione, skatole and terpenes were selected as biomarkers, and their deposition was investigated in bull calves reared under three different strategies. All of the animals were reared indoors until approximately 150 days of age. They were suckled twice a day by their mothers, and both calves and cows had free access to cocksfoot hay. Then the first two groups of animals were kept indoors, suckled by their mothers twice a day and received either cocksfoot hay (HL) or freshly cut-green herbage (GL) and a limited quantity of concentrate. The third group of calves (PH) was kept on pasture with their mothers and offered concentrate ad libitum. The pasture supporting the PH animals was highly diversified, containing several terpene-rich plant species, whereas the herbage for the GL animals contained no species known to be aromatic. Perirenal and subcutaneous adipose tissues were analysed for volatile compounds. The perirenal fat was found to be more responsive to the treatment and a more reliable substrate than the subcutaneous adipose tissue. Higher levels of 2,3-octanedione ( P , 0.05) were found in PH and GL than in HL fat (6.56, 6.51 and 5.77 area arbitrary units, respectively, in perirenal fat), confirming the ability of this molecule to trace green herbage feeding. Skatole was detected in the perirenal and subcutaneous fat of all the animals. Animals receiving high concentrate level (PH group) presented lower ( P , 0.05) skatole values (5.83 area arbitrary units in perirenal fat) than animals receiving low concentrate level (HL and GL groups, 6.23 and 6.71 area arbitrary units, respectively, in perirenal fat). Terpenoids, and especially sesquiterpenes, were found at higher levels and diversities in the PH than in the GL and HL animals. Two monoterpenoids allowed group discrimination considering perirenal or subcutaneous fat without distinction, whereas 11 and 5 sesquiterpenoids from perirenal and subcutaneous fat, respectively, allowed it.

Volatile compounds in the perirenal fat from calves finished on semiextensive or intensive systems with special emphasis on terpenoids

“…Prache et al (2005) suggested that terpenoids could be used not only to recognize the type of diet animals consume but also to localize the geographical origin of pasturefed animals. Furthermore, Serrano et al (2011) reported that a higher accumulation of terpenoids was observed in perirenal and intraperitoneal fat compared to intermuscular and subcutaneous fat.…”

“…Recent studies have managed to find compounds in beef that could be used as herbage feeding tracers, based on the significant effect of the feeding system on the volatile composition of beef (Prache et al, 2005;Serrano et al, 2011;Vasta et al, 2012). Higher levels in the volatile fraction of meat and fat of skatole, 2,3-octanodione and several terpenoids, especially sesquiterpenes, such as aromadendrene, γ-cadinene or germacrene D, among others, led to the conclusion that those compounds could be used as indicators of pasture diets in cattle (Vasta and Priolo, 2006;Serrano et al, 2011;Vasta et al, 2012).…”

“…Higher levels in the volatile fraction of meat and fat of skatole, 2,3-octanodione and several terpenoids, especially sesquiterpenes, such as aromadendrene, γ-cadinene or germacrene D, among others, led to the conclusion that those compounds could be used as indicators of pasture diets in cattle (Vasta and Priolo, 2006;Serrano et al, 2011;Vasta et al, 2012). The ketone 2,3-octanedione could originate from the lipoxygenase activity of leafy plants during the mastication of green forages and then accumulate in the fat via absorption from the rumen or the lungs (Young et al, 1997).…”

Potential of n-alkanes as grass-feeding biomarkers in steers

“…Efforts have been made to use the profiles of stable isotopes, fatty acids and other organic compounds in the meat and adipose tissue of animals (Serrano et al, 2011), DNA (Nicoloso et al, 2013), carotenoids and vitamin A in plasma; additionally, other biological fluids (Álvarez et al, 2015) could be used as discriminators of geographic origin, type of diet or production system of meat. Indirect authentication systems usually require slaughtering the animal to take samples, and to some degree, they are subject to adulteration in the results.…”

Comparison of visible and near infrared reflectance spectroscopy on fat to authenticate dietary history of lambs

“…A number of specific compounds in the meat have been identified as biomarkers of pasture-feeding, such as carotenoid pigments (Prache and Thériez, 1999;Serrano et al, 2006;Alvarez et al, 2014), fatty acid composition (Aurousseau et al, 2004 and2007) and volatile compounds Serrano et al, 2011). Assay of these different components necessitates various analytical techniques, and the data often have to be further combined to overcome confounding factors and the possibility of fraud (Prache et al, 2009).…”