Effect of different types and concentrations of salts added to Requeson cheese on texture, sensory, and physiochemical characteristics

Structural analysis of whey representation between rural and urban populations in western Mexico

Whey is a by-product derived from cheese making. Despite being rich in nutrients, it is little used, it even represents a problem form the environment in Mexico. In this sense, it is important to know the meanings that are associated with this term, especially when it is intended to develop new products from this by-product. The objective of this work was to analyze the representation of the term whey in rural and urban populations through the Central core Theory. Additionally, the relationship between gender-place of residence with the evoked word is explored. Therefore, three hundred and sixty people (from rural and urban areas) were interviewed face to face in two areas in the western region of Mexico. Word association test was carried out, using "whey" as stimulus; the associated words were ordered according to their importance; the polarity index of each associated word was evaluated. The most frequently mentioned words were analyzed based on their frequency of mention and average importance to identify the conceptual structure of the concept representation. The results show and influence of the place of residence on the conceptual structure. Rural participants tend to generate more words with negative connotations, while the central elements of urban consumers are mainly related to dairy products. When comparing consumers by gender, rural and urban women associate "whey" with aspects of both the production process and dairy products. In the case of men, those from the urban zone, relate to aspects related to nutrition, dairy products and nutrients. In contrast, men from the rural area relate whey mainly to negative aspects such as pollution. The study confirms that there is a link between the place of residence and the conformation of the conceptual structure, where the gender-region relationship influences the definition of the term "whey".

Effect of Packaging and Salt Content and Type on Antioxidant and ACE-Inhibitory Activities in Requeson Cheese

Requeson cheese is obtained from whey proteins. The production of this cheese is the most economical way to recover and concentrate whey proteins, which is why it is frequently made in some Latin American countries. Four requeson cheese treatments were prepared with different concentrations and combinations of salts (sodium chloride and/or potassium chloride) and were conventionally or vacuum packed. Proteolysis, peptide concentration, angiotensin-converting enzyme (ACE) inhibitory and antioxidant (DPPH and ABTS) activities were evaluated over time (one, seven and fourteen days). Requeson cheese presented antioxidant and ACE inhibitory activities, however, these values vary depending on salt addition, type of packaging and time of storage. The highest values of antioxidant activity (ABTS) were found in cheese added with 1.5% NaCl and 1.5% (NaCl/KCl, 1:1). Cheese without added salt and vacuum packed presented the highest ACE inhibition percentage at day seven. Therefore, it can be concluded that requeson cheese elaborated exclusively of sweet whey, presents antioxidant and ACE inhibition activity. However, for a cheese with ACE inhibitory capacity, it is recommended not to add salts or add at 1% (NaCl) and vacuum pack it. Additionally, for a cheese with antioxidant activity, it is recommended to add salt at 1.5% either NaCl or (1:1) NaCl/KCl and pack it either in a polyethylene bag or vacuum. In conclusion, requeson cheese elaborate with 100% sweet whey is a dairy product with antioxidant and ACE inhibition activity, being low in salt and fat.