Nutritional Characterization of Different Cuts in Goat Kid Meat
Compared to the other frequently-consumed red meat like beef and lamb, goat meat occupies a narrow market and is cheap in price due to the historical prejudice towards tough and stringy goat meat. However, nutritionally, goat meat has been proven not to be inferior to beef and lamb, and it is regarded as a lean meat with low fat content. Perceptually, goat kid meat can satisfy consumers’ organoleptic requirements of a tender and juicy meat. Hence the under-utilized goat kid meat can make a great contribution to the growing need of meat worldwide. Within goat kid carcasses, the nutritional value differs among various goat cuts. Therefore, the aim of the current study is to characterize the differences of nutritional composition in goat cuts to provide a thorough information for consumers when purchasing goat meat.
The proximate composition in terms of moisture, crude fat, crude protein and ash content of 14 cuts (longissimus dorsi, tenderloin, flap, knuckle, rump, outside round, hind shank, inside, cube roll, neck, fore shank, blade roll, cross cut and bolar) from milk-fed Saanen male goat kids (aged 31 days with a living weight of approximate 8.2 kg) were determined using the Official Methods of Analysis (AOAC). The in vitro gastrointestinal digestion was simulated to compare the protein digestibility of the 14 cuts. The free amino acids (FAAs) were measured quantitatively by LC-MS in three phases (prior to digestion, at the end of the gastric digestion phase and the intestinal digestion phase). Protein and peptides were determined qualitatively by SDS-PAGE in these three phases as well.
The flap was found to have a significantly low moisture content (P < 0.001). The ventral trunk (flap and bolar) was found to have a relatively high fat content (P < 0.001). All of the other cuts did not show statistical differences in moisture and fat content (P > 0.05), varying around 75% and 2.5% of the raw meat, respectively. The protein content was around 20% for all of the 14 cuts with small variance. But statistically, the longissimus dorsi (LD) and the tenderloin possessed a higher protein content than that of the ventral trunk (flap and bolar), knuckle, cube roll, fore shank and blade roll (P < 0.001). Ash content was around 1% and did not show significant difference in all of the cuts. After the simulation of in vitro gastrointestinal digestion, the fore shank had the highest digestibility in respect of the release of the total free amino acids (TAAs) at the end of intestinal digestion, which was not significantly different with the digestibility of the cross cut, blade roll, tenderloin and knuckle, but higher than that of all of the remaining cuts (P < 0.001). As for SDS-PAGE profile, the proteins and large peptides showed sparser and lighter bands in molecular weights over 14 kDa with the progression of in vitro digestion, indicating the degradation and disintegration of meat proteins by digestive enzymes.
The result of the current study indicates the less preferred goat kid cuts like the fore shank and the cross cut do not have an inferior nutritional attributes than those highly preferred cuts like the LD, especially in terms of the protein digestibility. Further investigations on sensory attributes of these cuts could be applied to better understand the differences in cuts so that consumers can make a better choice when purchasing goat kid meat cuts, or even the red meat cuts.