Location: Dairy and Functional Foods
Title: Measuring the antioxidative activities of Queso Fresco after post-packaging high-pressure processing Authors
Submitted to: Advances in Bioscience and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 6, 2012
Publication Date: August 23, 2012
Citation: Paul, M., Van Hekken, D.L., Brewster, J.D., Tomasula, P.M. 2012. Measuring the antioxidative activities of Queso Fresco after post-packaging high-pressure processing. Advances in Bioscience and Biotechnology. 3:297-303. Interpretive Summary: Antioxidants can serve as protective agents against certain disease-causing factors in the body and are found naturally in a number of food products. Some milk-associated proteins have been shown to influence human health through the formation of smaller molecules known as bioactive peptides that protect against problems such as high blood pressure (antihypertensive activity) and oxidative stress (antioxidative activity). Consumption of cheese, such as the increasingly popular Hispanic-style cheese queso fresco, may be a vehicle for delivery of these milk-associated peptides. The effects of a new post-packaging process, which subjects packaged cheese to high pressures, on the antioxidative activity of cheese was measured. The high-pressure treatment had a slight measured effect on the antioxidative activity of cheese at 25 deg C, but warming the cheeses to 40 deg C prior to high-pressure treatment significantly increased the antioxidative activity of the cheese. Understanding the effects of high-pressure processing on the bioactive peptides in cheese will help to develop dairy products that are healthier and combat disease as well.
Technical Abstract: Some milk-associated proteins are known to be nutritionally valuable and form bioactive peptides that exhibit activity against hypertension and oxidative stress. Consumption of cheeses, such as the popular Hispanic-style cheese Queso Fresco (QF), may be a vehicle for delivery of these milk-associated peptides. This paper describes the effects of high-pressure processing (HPP) on the antioxidative activity (ORAC-FL value) of water-soluble proteins extracted from QF samples. QFs were manufactured according to a commercial-make procedure using pasteurized, homogenized milk, without added starter cultures. The cheese was cut into 45x45x150mm3 blocks, double packaged in vacuum bags, and received the following HPP treatments: 200, 400, or 600 MPa for either 0, 5, 10, or 20 min, with warming to an internal temperature of either 22 or 40 deg C prior to HPP treatment. Results show that the core temperature of the cheese during HPP directly affects the ORAC-FL value. The activities of the lower temperature cheeses are time and pressure, and have a median ORAC-FL value of 27 trolox equivalents (TE). The higher temperature cheeses have higher ORAC-FL values ranging from 21.5 to 96.0 TE; the highest activity corresponded to the cheese held at 400 MPa for the longest time under pressure (20 min). The 600 MPa cheeses increase in activity with increasing time under pressure, but are less active than the control cheese. These results indicate that processing temperature and pressure are important factors in the antioxidative activity of these QF samples and further understanding of the roles of these variables may lead to the manufacture of healthier and more nutritious cheeses and dairy products.