Evaluation of lamb and muttom quality at retail level in the Tshwane Metropole
Du Plessis, Stephani
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The palatability of meat is determined by tenderness, juiciness and flavour. All over the world consumers consider tenderness as the most important palatability attribute. However, inconsistent quality is one of the biggest problems that have been identified in the meat industry. This ascribed the lack of knowledge about the origin of variation in quality and certain claims regarding consumer satisfaction that do not materialize. Over a period of three months twenty three products were collected from five major retail outlets and twelve smaller butcheries. A total of 14 rounds of purchasing were done representing 14 repetitions. Overall 306 samples were collected. Products varied in type namely Karoo lamb, grass-fed or grain-fed lamb and also in packaging that is modified atmosphere packaging, polyvinyl chloride overwrapping, fresh-cut and on display. Physical, histological and biochemical measurements were performed in an attempt to explain variations in consumer related properties. Data was analyzed with analyses of variance, Tukey-Kramer multiple comparison test, principle component analyses and discriminant analyses to demonstrate differences in meat quality. Price is one of the most influential factors on consumers’ choice of purchase, although they still want good value for their money. The grain-fed products had the lowest/best price with the products from the grass-fed production system being the most expensive. Nevertheless, when considering the meat/fat/bone ratios the grain-fed products had the least amount of meat and the most fat, leaving the products from the Karoo production system as the product with the best value for money. Cooking losses have pointed out problem areas with regards to the grass-fed products as these products had the highest values while being sold as a superior product with the highest price. The Karoo and grass-fed products were associated with healthier FA such as phytanic acid, CLA, total n-3 PUFA and PUFA : SFA ratio. Subsequently, the grain-fed products had healthy oleic acid and MUFA contents as well as a good n-6 : n-3 ratio. This means that the free-range products are regarded as the better option for a healthy diet. No significant differences were found in the TBARS values of the different production systems. It was interesting to find that the samples that were fresh cut had lower TBARS values than the samples with PVC-OW or covered with MAP. Even so all of the products were well below the point where rancidity would start to develop. All of the products in our study were regarded as tender when comparing the WBSF values to preconceived thresholds. However, significant differences were found between the different production systems with the products from the Karoo production system being the most tender. This was in agreement with the sensory tenderness performed by a trained taste panel. Flavour and aroma especially play an important role when discussing lamb/mutton. Some consumers are discouraged by the unique flavour of sheep meat while others embrace it, especially from Karoo lamb. The Karoo and grass-fed production systems was associated with all the intense aromas and flavours (i.e. barnyard, metallic, Karoo ‘bossie’, sour) while the grain-fed production system were superior in terms of the typical lamb and sweet attributes. The factors influencing tenderness have been described as critical control points (CCP’s). From this quality audit it is clear that all the participants do take the CCP’s into account as all the products in our study have been classified as tender. However, there are a few aspects where improvement is still needed with regards to all of the production systems. This include the meat/fat/bone ratio of the grain-fed products, the waterholding capacity of the grass-fed products which might also improve the tenderness and the aroma and flavour of the Karoo products, especially in terms of the sweet attributes that might attract more consumers.