Effect of dense phase carbon dioxide treatments on physicochemical properties and microbiological quality of cured beef carpaccio

BARRIO YANINA; GAO YUAN; YANG YANG; SANCHO ANA MARÍA.; VAUDAGNA SERGIO R.; ZHANG DE QUAN

Montreal

Congreso; ICEF12: International Congress on Engineering and Food; 2015

Non-thermal technologies can be an alternative for the pasteurization of ready-to-eat fresh meat products such as carpaccio. Dense phase carbon dioxide (DPCD) is a cold pasteurization method that inactivates microorganisms through molecular effects of CO2 under pressures below 50 MPa, without exposing foods to adverse effects of heat. The aim of this study was to evaluate the effect of DPCD treatments on physicochemical and microbiological quality of cured beef carpaccio. Bovine Semitendinosus muscles were rubbed in by hand into plastic bags with curing salts. Then, muscles were vacuum-packed and stored at 4°C for 8 days.  After chill storage, cured muscles were frozen and stored at -20°C until slicing (1.5-2mm). Carpaccio slices were subjected to different DPCD treatments in a HPR Series Reactor 1000 (Supercritical Fluid Technologies Inc., Denmark). The treatments were arranged in a complete randomized 3x3 factorial design with CO2 pressure (5, 8 and 11 MPa) and holding time (5, 10 and 15 min.) as main factors. Untreated samples were used as control. Sample analysis included: chromatic parameters (CIEL*a*b*), absorbance spectrum of myoglobin extracted, Warner-Bratzler shear force, expressible moisture, pH, water activity and microbiota counts. Significant (p<0.05) CO2 pressure effect was observed in the L* parameter (lightness), expressible moisture and lactic acid bacteria (LAB) and Enterobactereaceae counts. However, the effect of holding time was significant (p<0.05) only for Enterobactereaceae counts. CO2 pressure level significantly increased (p<0.05) the lightness and expressible moisture of treated samples. Regarding microbiota, treatments at 11 MPa for 15 min. allowed a significant (p<0.05) count reduction of 1.65 and 1.43 log cycles of LAB and Enterobactereaceae respectively, compared to control samples.  DPCD treatments caused a pale appearance of carpaccio surface and a decrease in water holding capacity that may be related to the denaturation of sarcoplasmic proteins. Also, microbiota reduction was only achieved at the highest CO2 pressure