TITLE:
Detection of Glucomacropeptide in Raw Milk Adulterated with Cheese Whey in Ecuador
AUTHORS:
Byron Humberto Puga-Torres, Samantha Michele Morales-Arciniega, Luis Fabián Núñez Naranjo, David Isaías De la Torre-Duque, Rolando Martin Campos-Vallejo, Silvana Hipatia Santander-Parra, Enrique César Vayas-Machado
KEYWORDS:
Glucomacropeptide, Raw Milk, Whey Cheese, Milk Adulteration
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.8 No.6,
June
7,
2017
ABSTRACT: Milk is one of the products that can
be adulterated in many ways affecting the quality of this and its derivatives.
Glucomacropeptide (GMP) is a protein that is found only in the whey from the
production of fresh cheese, enzymatically obtained from the coagulation of
casein and which is commonly used to adulterate fresh or powdered milk. The aim
of this study was to determine the adulteration of milk with cheese whey
thought a molecular approach, where the glucomacropeptide was collected by sequential
precipitation with trichloroacetic acid (ATC) and detected by polyacrylamidododecylsulfate
gel electrophoresis (PAGE-SDS), using samples of fresh milk, intentionally
adulterated with serum in the proportion of 0%, 1%, 5%, 10% and 15%. The results
obtained showed that the detection of glucomacropeptide by electrophoresis was
positive in all samples of adulterated milk, evidencing a band of 20.9 kDa in
the reading, corresponding to the molecular weight of the GMP, showing that the
technique used determines the adulteration in the milk, in a specific and
sensitive way, also shows that in the evaluation of physical-chemical and
microbiological parameters of milk, there are no significant differences
between treatments, except for the pH that tends to decrease as the percentage
of serum in the milk increases.