Relationship of the time of year with the characteristics of milk, yield and shelf life of cheese in a hot climate.

Abstract

The objective of the study was to determine if there is a relationship between environmental conditions on cheese yield and shelf-life of pasta filata cheese (Oaxaca) made in a production unit in the Valle de  Mexicali, Baja California, Mexico. In this geographical zone, there is a desert climate with extreme temperatures that are delimited in two seasons of the year, cold with a temperature and humidity index (THI) lower than 77 and hot. To assess whether there is a relationship, environmental data (temperature and relative humidity), characteristics of the milk used at the time of reception (temperature, acidity, density, cheese yield, somatic cell count and microorganism count) were recorded for eleven months. and the shelf life of Oaxaca-type pasta filata cheese. The variables recorded were evaluated by analysis of variance (α=0.05), the difference between means with Tukey's test (p<0.05) and the relationship of the season of the year using Pearson's correlation. Significant differences were observed in density, acidity, temperature, somatic cell count of milk and cheese yield. In addition, a decrease of approximately 11% in cheese yield was recorded as the maximum ITH exceeded 77 units. For its part, the useful life did not present differences due to the ITH, but due to the pasteurization of the milk. Therefore, it is concluded that there is a negative relationship in the yield of milk for the production of Oaxaca cheese, during the warm season. What emphasizes the mitigation of heat stress of dairy cattle during that time.