The main objective of this thesis-work was to document the management of milk and colostrum on farms around the cantons of Guano and Chambo, in the Province of Chimborazo (Riobamba, Ecuador), and to evaluate the effect of the presence of colostrum on the physicochemical characteristics, technological suitability and microbiological quality of cheese milk, the characteristics of fresh cheese during its shelf life and the resulting cheese whey. The first study focused on the evaluation of the effect of the presence of different concentrations of colostrum in the technological suitability of cheese milk. The milk was subdivided into four parts to be mixed with colostrum at different concentrations (0, 1, 5 and 10%, v/v), to which were applied 2 types of discontinuous heat treatments (56 °C × 1 h and 63 °C ×30 min). The presence of colostrum modified the composition and the physicochemical characteristics of the milk, on the contrary, the cheese-making properties of the milk were not affected by the presence of colostrum. In a second study, a protocol (shapes, dimensions, speeds) of the texture profile analysis (TPA) of parameters applied to fresh cheese was standardized. For this, different TPA protocols were applied in a texturometer, varying the speed of the test (0. 30; 0. 70 and 1 mm/s), and using different shapes and dimensions of the cheese sample, in order to evaluate its effect on the results of the TPA. Cylindrical samples with a diameter of 3 cm were the candidates to be used in the TPA tests, with speeds of 0. 3 and 0. 7 mm/s. In a third study, the effect of the presence of different concentrations of colostrum (0, 1, 5 and 10%) in cheese milk on the quality of the cheese and the resulting cheese whey was evaluated. An analysis of physicochemical characteristics, microbiological quality, color and determination of immunoglobulins was performed on the raw materials. The fresh cheeses obtained from milk with different concentrations of colostrum were stored for 21 days at 4 °C, and a compositional analysis, physicochemical characteristics, instrumental texture, microbiological quality, color, determination of immunoglobulins, sensory analysis, and the biochemical processes of lipolysis and proteolysis were studied. The resulting serum was analyzed for its physicochemical characteristics and the concentration of immunoglobulins was determined. The presence of colostrum in the milk tank, intentionally or accidentally, causes changes in the composition, microbiological, color, sensory and texture characteristics in the production of fresh cheese. IgG concentration increased significantly in serum after cheesemaking when colostrum was added to cheese milk at concentrations of 5 and 10%. A fourth study was born from the need of milk producers in the province of Chimborazo to do good management of cattle around milking practices and colostrum management. For this work, we designed a questionnaire, and it was reviewed by researchers from Universidad Nacional de Chimborazo, Universidad Autónoma de Barcelona and the Universidad de Las Palmas de Gran Canaria. The validation of the questionnaire was carried out with 5 milk producers in the area, subsequently was applied to 90 dairy farmers in the province, and finally the information was gathered and processed. Finally, in this research, recommendations are offered according to risk factors, in order to improve colostrum management and milk quality, raising the productive and competitive level of our farmers in the dairy market.
| Date of Award | 29 Nov 2022 |
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| Original language | Spanish |
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| Supervisor | Antonio José Trujillo Mesa (Director) & Davinia Sánchez-Macías (Director) |
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