title: Effect of γ-irradiation on the sensory quality of moist beef biltong.
abstract: Moist beef biltong (mean moisture content=46.7% and a(w)=0.919) was vacuum packaged and irradiated to target doses of 0, 2, 4, 6, and 8kGy. Thiobarbituric acid reactive substance (TBARS) measurements and sensory difference and hedonic tests were performed to determine the effect of γ-irradiation on the sensory quality of the biltong. TBARS values only increased significantly (P<0.05) if biltong was irradiated to at least 8kGy, indicating a low degree of lipid oxidation. This can be attributed to the low fat content (on average 1.53%) of the biltong used in this study, as well as irradiation under vacuum conditions. All irradiated samples could be discriminated (P<0.05) from non-irradiated biltong, but none was rated as less acceptable. Dissipation of volatiles before tasting (by exposing the product to aerobic conditions before consumption), a low degree of lipid oxidation and liking of distinct 'irradiation flavours' possibly all attributed to the flavour of irradiated biltong not being regarded as unacceptable compared to controls. Biltong irradiated at 2 and 4kGy was however liked significantly more (P<0.05) than other samples, indicating that slight, non-oxidative irradiation-induced flavour changes may contribute to flavour development in the usually more bland moist beef biltong. Although lean moist beef biltong can thus be irradiated to doses up to 8kGy without adversely affecting the sensory acceptability, low dose irradiation (⩽4kGy) is most feasible to optimise the sensory quality.
authors: Department of Food Science, University of Pretoria, Pretoria 0002, South Africa.
authors: K
authors: K
authors: Nortjé
authors: E M
authors: EM
authors: Buys
authors: A
authors: A
authors: Minnaar