Desenvolvimento de metodologia analítica para detecção de adulteração pela adição de leitelho em leite em pó e leite fluido

• Autor(a) principal: Rigueira, Juliana Cristina Sampaio
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2850
• topic: Leite; Leitelho; Fraude; Adulteração e inspeção; Milk; Buttermilk; Adulteration and inspection; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

A quantitative analytical method was developed to detect adulteration of powdered milk and fluid milk by buttermilk addition based on total phospholipids concentration. The samples were subjected to lipids extraction by the methodologies of Röese-Gottlieb, phosphorus derivatization, organic matter calcinations, and spectrophotometer analysis to determine phosphors concentration. Phosphorus concentration was converted to total phospholipids based on the molecular mass of the phosphatidylcholine, a phospholipid present in milk at the highest concentration. The coefficient of variation obtained from thirty repetitions carried out in one single sample of skimmed fluid milk and one single sample of fluid buttermilk derived from cream with fat level standardized by skimmed milk were 3,43 and 3,62, respectively. That is to say, the method showed good accuracy. The maximum limit standard of total phospholipid concentration was recommended on the basis of the mean concentration of total phospholipids from the samples of skimmed and whole milk, both fluid and powdered, added three times the standard deviation. This limit was of 21,66 mg/100 g, 36,19 mg/100 g, 217,38 mg/100 g and 333,05 mg/100 g for skimmed fluid milk, whole fluid milk, skimmed powdered milk, and whole powdered milk, respectively. Samples with total phospholipid concentrations above these limits could be considered as added of buttermilk. These values represented an addition of 2,60 % (m/m) of buttermilk into skimmed fluid milk, 5,46 % (m/m) into whole fluid milk, 6,41 % (m/m) into skimmed powdered milk and 5,86 % (m/m) to whole powdered milk. The developed method, besides being of easy implementation and execution, has low cost when compared to the European Community method, which uses high performance liquid chromatography (HPLC).