Assessment of milk quality during storage based on DNA extracted from milk

Abstract

This study investigated the changes of DNA and milk quality during storage at temperatures of 2°C, 10°C and 20°C. Milk quality was assessed by measuring the milk protein, milk fat, lactose, pH and acidity. The quality of DNA extracted from milk was evaluated by monitoring DNA content, purity, and degradation as well as by amplifying target sequences from mitochondrial and nuclear genes. In addition, nonlinear regression models were used to analyze the correlations between DNA content and milk quality. As expected, the deterioration was observed in both DNA and milk quality during storage. Mathematical models showed the high correlations (R 2 > 0.9) between DNA content and milk quality. These established mathematical models hold the potential to evaluate the milk quality and may be applied practically in the process design and quality control of dairy products in the future.Valoración de la calidad de la leche durante su almacenamiento basada en el ADN extraído de la leche RESUMEN El presente estudio investigó los cambios que se producen en el ADN y la calidad de la leche durante su almacenamiento a temperaturas de 2°C, 10°C y 20°C. Al respecto, la calidad de la leche fue valorada a partir de la medición de la proteína láctea, la grasa láctea, la lactosa, el contenido de ADN, su pureza y su degradación, y de la amplificación de las secuencias objetivo de los genes mitocondriales y nucleares. Asimismo, se utilizaron modelos de regresión no lineales para analizar las correlaciones entre el contenido de ADN y la calidad de la leche. Como se esperaba, durante el almacenamiento se produjo el deterioro tanto del ADN como de la calidad de la leche. Los modelos matemáticos dieron cuenta de elevadas correlaciones (R 2 >0.9) entre el contenido de ADN y la calidad de la leche. Estos modelos matemáticos establecidos posibilitan evaluar la calidad de la leche y en el futuro podrán ser aplicados de manera práctica a la hora de diseñar su procesamiento y realizar el control de calidad de productos lácteos. ARTICLE HISTORY

Dietary Compounds Influencing the Sensorial, Volatile and Phytochemical Properties of Bovine Milk

“…The study by O'Callaghan, et al [16] investigated the influence of four supplemental feed choices for pasture-based cows on the fatty acid and volatile profile of milk. Some studies have also evaluated the effect of storage conditions on the microbiological quality of milk [17,18]. In the present study, the volatile profile and free fatty acid (FFA) content of the milk samples were evaluated over a 14-day storage period at 4 • C in order to ascertain the level of lipid oxidation occurring within the milk, and to track volatile compounds forming or changing during refrigerated storage.…”

Comparison of PCR Techniques in Adulteration Identification of Dairy Products

“…The quality and quantity of the DNA extracted from dairy production is the key factor to the success of PCR methods used in dairy adulteration identification. Many factors, such as somatic cell number, milk composition, and DNA extraction methods, can affect the quality and quantity of the DNA used in PCR methods, and in turn, affect the adulteration detection effectiveness [19,20]. Many factors might affect the concentration of somatic cells in dairy products such as milk-producing animal breeds, lactation stage, and health as well as environments [21,22].…”

Extraction and detection of DNA from UHT milk during storage

“…So the UHT treatment may also result in DNA degradation and subsequently increase the difficulty of DNA detection. On the other hand, it was suggested that storage shows a significant influence on the DNA extracted from raw milk (Liao et al, 2018c), so there might be DNA degradation during the storage of UHT milk. Considering that monitoring the changes of DNA in UHT milk during storage not only contributes to optimizing DNA-based analysis methods but also provides a way to distinguish UHT milk composition in other dairy products.…”