Combined effects of high hydrostatic pressure and chemical pre‐treatment on physico‐chemical properties of beef, using FTIR and diffuse reflectance spectroscopy

Abstract

AbstractHigh pressure processing (HPP) was combined with a previous short chemical treatment to stabilize the color of beef tissue. Beef samples were treated with a solution containing ascorbic acid, sodium chloride, and a very low concentration of sodium nitrite. The effects of pressure levels (0.1–600 MPa) and preservative solution on: (i) color properties based on diffuse reflectance spectroscopy (DRS), which determines the relative concentrations of muscle pigments, (ii) protein denaturation and changes in the secondary structures by DSC and FTIR‐ATR, were determined.At high pressures, the disappearance of DSC peaks due to protein denaturation, a decrease in the proportion of α‐helix and an increase in the percentage of disordered structures, were evidenced. DRS spectra and Kublelka‐Munk theory equations demonstrated that nitrosilmyoglobin was a more stable chromophore, decreasing discoloration of the tissue. These techniques contribute to the knowledge of the physico‐chemical properties of the tissue submitted to combined preservation processes.Practical ApplicationsThere is an increasing demand from consumers for high‐quality beef products, with significant emphasis placed on color and safety attributes. Extending the shelf life by applying high hydrostatic pressure treatment (HHP) improves food safety and will produce a positive impact on both the industry and consumers. HHP is a non‐thermal preservation technology with generally minimal effects on sensory qualities and nutritional content; however, the direct application of this technology on beef leads to the production of a product with an unacceptable pale coloration. Therefore, it must be remarked that a pre‐treatment stage by immersing the pieces in a preservative solution is essential to improve the color of beef products treated by HHP. In this regard, from a technological point of view, it is very important to know the combined effects of both stages (short chemical treatment and high‐pressure) on the quality of beef products.