A Comparative Study on Nutritional Composition, Mineral Content and Amino Acid Profile of the Skin of Four Different Animals

Abstract

The increase in human population comes with it an increase in the demand for protein (and amino acids) from different sources. This study seeks to compare the proximate, mineral, amino acid compositions as well as Mineral Safety Index (MSI) of the skin of four different animals (dog, goat, pig and cane rat). The proximate analysis revealed the values of carbohydrate, fat, crude protein, crude fibre, ash and moisture contents. The protein level in cane rat skin was the highest (40.30%), followed by dog (32.17%) and goat (27.36%) skins respectively, while pig skin (25.36%) had the least protein value. The mineral analysis indicated high Ca, Mg and K contents in pig and cane rat skins, while P content was more concentrated in dog and goat skins. Also, Na, Mn and Zn contents were almost similar in all the skin samples. Leucine was the most concentrated essential amino acid in all the skin samples, with ca skin having the highest content followed by pig, dog and goat skins respectively, while the most concentrated amino acid was glutamic acid, with cane rat and pig skins having the highest value followed by goat and dog skins respectively. The content of total essential amino acids in the animal's skins are 3.56, 5.22, 5.12 and 5.43mg/g for dog, goat, pig and cane rat respectively. All the skin samples were adequate only in Leu, Met + Cys and Phy + Tyr based on FAO/ WHO provisional pattern, while they recorded low activities in some essential amino acids (Val, Thre and Lys). The total amino acid levels being 9.82, 8.81, 9.36 and 11.15mg/g crude protein in dog, goat, pig and cane rat skins respectively. Overall, the findings indicate that all these skins which are usually avoided by some people can contribute useful amount of nutrients, mineral elements and amino acids to human diet. Although, cane rat skin had the highest qualities of them all, followed by dog, pig and goat respectively. There is need, however, to determine the vitamins and fatty acids present in these samples. This will help to adequately establish their importance in human nutrition and provide basis for their maximum utilization.

Extraction of Collagen from the Skin of Kacang Goat and Production of Its Hydrolysate as an Inhibitor of Angiotensin Converting Enzyme

“…The protein analysis of the skin of Kacang goat was obtained at 30.54%, which is lower than that of Ettawa goat (46.89%) (Kasim et al, 2013) and dog (32.17%), but higher than that of the Nigerian goat (27.36%) and leather of pigs (25.36%) (Ajayi & Akomolafe, 2016). Generally, the collagen content of hiding is around 30% of the total body protein (Chuck-Hernández & Ozuna, 2019).…”

“…The physical structure of goat skin is composed of connective tissue, which is a micro component of fibrils and fibroblasts that form collagen and elastin tissue. Moreover, raw goat skin contained 60%-70% water, 25%-32% protein, 2.2%-3.2% fiber protein, and 7%-7.3% crude fat (Ajayi & Akomolafe, 2016) (Naffa et al, 2019). However, the collagen protein of goat skin has low digestibility due to the strong protein-binding bonds in the form of the triple helix.…”