Meat quality characteristics of springbok (Antidorcas marsupialis). 2: Chemical composition of springbok meat as influenced by age, gender and production region

Abstract

The effects of age, gender and production region on the chemical, mineral and amino acid composition of the M. longissimus dorsi (LD) muscle of springbok were investigated. There was a significant gender^∗region interaction for protein content – for the four production regions it varied between 18.80 and 21.16 g/100 g. The intramuscular fat (IMF) content of the LD muscle varied between 1.32 and 3.46 g/100 g. Females (3.13 ± 0.28 g/100 g) had a higher (P < 0.05) fat content than males (1.35 ± 0.08 g/100 g). The IMF content of the adult (2.45 ± 0.26 g/100 g) and sub-adult (2.50 ± 0.28 g/100 g) categories was higher (P < 0.05) in comparison to that of the lambs (1.32 ± 0.11 g/100 g). An inverse correlation was noted between the IMF and moisture content (r = −0.49, P < 0.001) of the meat. The two main amino acids were glutamic and aspartic acid, which contributed 2.47–2.74 and 2.31–2.54 g/100 g of dry matter, respectively. Phosphorous was the predominant mineral in the LD muscle (122.92–159.78 mg/100 g of dry matter), followed by potassium (119.44–131.25 mg/100 g of dry matter) and calcium (6.57–145.18 mg/100 g of dry matter). Production region had a significant effect on the mineral and amino acid composition of the meat, while the effects of age and gender were found to be insignificant.

Introduction

South African game is still untamed and viewed as organic and exotic and is therefore distinguishable from the domesticated game (deer) species from Australia, New Zealand and Europe (Hoffman & Bigalke, 1999). Game meat is healthier because it is much leaner than domesticated meat sources that are fed mainly on cereal products (Viljoen, 1999). Venison also has a low energy and cholesterol profile (Stevenson, Seman, & Littlejohn, 1992). Farmed venison is low in fat, which has been confirmed by the low total energy of the meat, being less than 500 kJ/100 g (Aidoo & Haworth, 1995). The above-mentioned aspects make this meat attractive to the health-conscious consumer (Fisher, 1991) and may therefore be used as a marketing strategy. The low fat content of venison will consequently lead to a higher mean moisture and protein content in comparison with other red meats (Aidoo & Haworth, 1995).

Meat is an important source of protein and is rich in essential amino acids (Higgs, 2000). The amino acid composition of meat has been noted to be influenced by factors such as species, muscle location, age and processing (Lawrie, 1985). If processing conditions are not prolonged, the effect on the amino acid composition of the meat is limited. Meat is high in iron, especially the heam form (50–60%), which is unaffected by several inhibitors that decrease iron absorption in vitro (Higgs, 2000). The mineral composition of meat, however, may be influenced by physiological, genetic and environmental factors (Zarkadas et al., 1987). Other factors, such as the concentration of minerals in the diet of the animal, hormones, age, gender and region may also cause variation in the mineral composition of the meat (Doyle, 1980). Mineral concentrations vary between different muscles due to varying intensity of physical activity and the effects of fibre type (Doornenbal and Murray, 1981, Lin et al., 1989). Factors such as age, gender, muscle type, carcass weight and degree of fatness influence the nutrient content of meat (Sales, 1995) and the effect of these factors on the quality of domesticated meat is well established, but little data exists on how it may affect the quality of game meat (Onyango, Izumimoto, & Kutima, 1998).

Modern consumers want to be informed about the total nutritional composition of the food they consume (Horbañczuk et al., 1998). The chemical attributes of game meat and the factors that may influence these attributes need to be researched extensively and species-specific research is a priority. More than 80% of the game species harvested and exported in South Africa are springbok, yet no data could be sourced on the chemical composition of this species.

The purpose of this study was therefore to determine the chemical, mineral and amino acid composition of the M. longissimus dorsi (LD) of springbok and to quantify the effects of age, gender and production region on the meat quality. Where applicable, correlations between the various attributes of the meat were verified.