The objective of this study was to carry out the physical-chemical characterization of milk, suerocosteño and quesocosteño from the towns of Patillal, Badillo and La Vega.The milk produced in the Department of Cesar is transformed by family businesses located in rural areas without infrastructure, previous standardization processes and hygienic conditions.A physicochemical and chromatographic characterization was carried out in which the analysis of amino acids was included, first performing hydrolysis of the protein and derivation of the sample.Data were analysed using ANOVA analysis of variance and a minimum significant difference test (MSD).It was evidenced that milk and whey from Badillo were the ones that reported the highest protein content, 3.32% and 1.20% respectively.The results showed that Badillo reported the highest protein content for milk with 3.32% and whey1.20%,with Patillal cheese showing the highest percentage of essential amino acids such as isoleucine 31.28%,tryptophan 34.92% and valine with 32.84%.The amino acid content of suerocosteño and quesocosteño can be attributed to the production process, strength, rennet type and storage time.Key words -physicochemical analysis, profile of amino acids, milk and whey. I. INTRODUCTIONMilk is an ideal food in nutritional terms, it is composed on average of approximately 87.3% water, 4.2% fat, 4.6% lactose, 3.25% protein and mineral substances 0.65% [1].This is why it is susceptible to microbial contamination, forcing the dairy industry to employ different processes to preserve its nutritional qualities [1].From the physicochemical point of view, milk is a very complex and complete product containing all the nutrients such as protein, carbohydrates and lipids, indispensable for the individual, particularly the 10 essential amino acids: arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine [2].The milk of the Department of Cesar is characterized physicochemically by its percentage of fat (4.3%) and total solids (12.5 and 14%), which is why multinational and regional companies have been located [3].At present, there is a milk production of over 600.000L day -1 , with a 50% decrease (Fedegan, 2016), which is distributed as follows: 52% is intended for formal processing; 43% is destined for the production of coastal cheese and 5% for local consumption [3].Emphasizing the "suerocosteño", is defined as a milk matrix fermented and commonly elaborated in the Colombian Atlantic Coast, produced by the acidification of raw milk, due to the action of the native microorganisms.It differs from the fermented milks because there is a break of the gel, the waste is produced and sodium chloride is added.The final product is similar to sour cream and is used as a companion.During the fermentation a system of two phases is formed: one liquid and one solid; where the liquid part is called whey and the other is known as "suero" [4].The fermentation temperature of the "suerocosteño" is the most important factor in the growth of microorganisms, followed by the pH, acidity and lactose obtained in the product [4].Another derivative of the milk processing is cheese, which is defined as the product of the coagulation of casein in milk, followed by separation and removal of whey from the curd, is the generic name of a group of products fermented milk-based foods, produced in a wide range of flavours and shapes all over the world.Although the main purpose of making cheese is to conserve the main components of milk, which has evolved into a high-quality food with important qualities, as well as being very nutritious [5].During the elaboration ofquesocosteño, several of the nutritive compounds like vitamins, proteins and milk fats are concentrated in a sub product that is the whey [6], the final fat content in the product is determined by the size of the fat globule, the kinetics of coagulation and the manipulation performed on the curd [7].Likewise, the type of pasteurization used in the hygienization process influences the protein content of the cheeses, so the high temperatures favor the formation of a complex between the K casein and the B lactoglobulin that retains the proteins in the curd [8].Taking into account the above, 43% of the production of quesocosteño is transformed by a guild that develops artisan practices established in rural areas without having a necessary infrastructure, without prior