Changes in Quality of Minced Meat From Goat Due to Gamma Irradiation

Abstract

Thigh muscles from aged (3-4 years) goat were minced, packed in polyethylene bags (250 g each), gamma irradiated with a dosage of 4 kGy and the packets held at 3 Ϯ 1C for 8 days. Nonirradiated muscle mince packed and stored similarly were treated as control. Both irradiated and nonirradiated muscle mince were sampled on 0, 5 and 8 days of storage and analyzed for physicochemical, microbiological and sensory quality attributes. Irradiation resulted in lower (P Յ 0.05) muscle pH (3.5-5.1%), water holding capacity (4.5-6.7%), thiobarbituric acid values (19.4-34.9%) and higher (P Յ 0.05) free fatty acid (26.9-61.0%) and Hunter a* (3.3-17.3%) values compared with nonirradiated control muscle samples. A reduction (P Յ 0.05) of 2 log cfu/g in total aerobic bacteria and psychrotrophs, and 1 log cfu/g in total staphylococci, yeast and molds were also observed in irradiated samples while enterococci, Escherichia coli and Staphylococcus aureus could not be detected in irradiated and stored muscles. Sensory quality scores on a 9-point hedonic scale decreased from 7.5-8.3 to 7.1-7.9 during storage at 3 Ϯ 1C for 8 days and were marginally influenced by irradiation. The results establish that a 4-kGy dosage is appropriate for irradiation to maintain fresh meat quality under chilled condition. PRACTICAL APPLICATIONSMuscles are highly perishable primarily because high microbial load and irradiation effectively reduces the microbial counts and helps extension of shelf life of muscle foods. Production and retention of free radicals produced 1 Corresponding

Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

“…1). The statistically significant decrease (Po0.05) of aerobic mesophilic bacteria population by irradiation in this study is in agreement with the scientific literature for different food commodities (Gomes and da Silva, 2006;Sedeh et al, 2007;Yusof et al, 2007;Adu-Gyamfi et al, 2008;Modi et al, 2008;Ż egota and Ma"olepszy, 2008;Mbarki et al, 2009;Kim et al, 2010). When the data for aerobic mesophilic bacteria (at day 1) is fitted into a linear regression model, a D 10 value of 0.83 kGy is found.…”

Effect of gamma irradiation on the microbial load, chemical and sensory properties of goat meat

“…Even though irradiation is a prospective technology, its application causes physico-chemical and biochemical changes that affect the nutritional value and sensory characteristics of irradiated food (sohn et al, 2009). The advantages of irradiation in controlling microorganisms and improving the shelf-life of different kinds of red meat, such as fresh beef (chen et al, 2007), lamb meat (KAnAtt et al, 2007), and camel meat (Al-BAchir & Zeinou, 2009), are well known, but there is only limited information in the literature on the effect of ionizing irradiation on the safety and shelf-life of goat meat (Modi et al, 2008). Knowledge of meat yield and quality of indigenous goats is limited.…”

Effect of radiation processing on meat tenderisation

“…Similar results were reported by Xavier et al (2014), who found that irradiation (2-5 kGy) had no effect on the pH of beef trimmings. On the other hand Modi et al (2008), reported that the pH of irradiated minced goat meat was 0.2-0.3 units lower as compared to non-irradiated control samples. Yook et al (2001), reported that in Korean cattle meat irradiated one day after slaughter, pH decreased more rapidly in irradiated muscle than in non-irradiated samples during storage at 4°C.…”

“…Low WHC can negatively affect appearance of meat and thus influence consumer's willingness to purchase the product. Modi et al (2008) have also reported lower WHC in irradiated (4 kGy) goat minced meat. Zabielsky et al (1984), found that myosin solubility that goes down with increasing irradiation dose up to 10 kGy may result in reduced WHC.…”

“…In irradiated chicken meat there was a dose dependant increase in a n (redness) values and a corresponding decrease in L n (lightness) values. Many other studies have reported the increase in redness of raw and cooked meat after irradiation (Jouki and Yazdi, 2014;Modi et al, 2008;Bagorogoza et al, 2001). In buffalo meat, irradiation did not alter the L n and a n values significantly.…”