Caracterização de presuntos crus desossados elaborados com glucona delta-lactona e quitosana

Abstract

Raw ham is a salted and desiccated product obtained from intact hams of pigs whose consumption is increasing in Brazil. Preservatives sodium nitrite and nitrate can be added during processing and natural substances are being sought to replace them, such as chitosan. The objective of this work was to evaluate the use of glucono delta-lactone (GDL) acidulant and chitosan in the preparation of boneless raw hams, aiming at the total or partial replacement of sodium nitrite. In the first experiment, eight treatments were evaluated in a factorial scheme containing two levels of nitrite (75 and 150 mg/kg), two levels of GDL (without and 0.3%) and two levels of chitosan (without and 1.0%). The drying time (18 days) was not affected (P>0.05) by the treatments, as well as the values of humidity (48.89%) and water activity (0.89) and instrumental color indices (L* = 38.57; C* = 9.50; h = 45.98°). The pH values were lower (P<0.05) in the products added with GDL (5.76) and higher in the added chitosan (6.26). Acidity was affected (P<0.05) by treatments, lower values were found in treatments with chitosan (1.64% lactic acid) and higher with 150 mg/kg of nitrite (2.14% lactic acid). TBARS values were different (P<0.05) between treatments, and higher values were found in products added with chitosan (1.88 mg MAD/Kg) and lower in those added with 75 mg/kg of nitrite (1, 59 mg MAD/Kg). The residual concentration of nitrite reduced (P<0.05) during the process (2 mg/kg) in all treatments. The addition of chitosan reduced by up to 4 log cycles the count of aerobic mesophiles and lactic acid bacteria (LAB). In sliced products, the amount of nitrite did not affect (P>0.05) the value of TBARS (2.70 mg MAD/Kg), products with chitosan and GDL reached higher values (2.66 mg MAD/Kg). In the second experiment, six treatments without sodium nitrite were evaluated, in a factorial scheme containing three levels of antioxidants (without; 550 mg/kg of sodium erythorbate; 1.0% of chitosan) and two levels of GDL (without and 0.3 %). Drying time (19 days), humidity (49.29%) and water activity (0.89) were not affected (P>0.05) by the treatments. The pH of the products was affected (P<0.05) by the addition of antioxidants, being higher in those containing chitosan (6.21) and lower in those containing GDL (5.9). Final acidity (2.38% lactic acid) and TBARS values (2.56 mg MAD/Kg) were affected (P<0.05) by all factors, with chitosan added products having the lowest index (1.78 mg MAD/Kg) and the larger control (3.73 mg MAD/Kg). The addition of chitosan reduced the aerobic mesophilic count by 3 log cycles and the BAL count by 2 log cycles. Only the color tone of the products was affected (P<0.05) by the treatments, with lower values (48.03°) in the formulations containing GDL and higher (60.22°) in the control. It was possible to obtain deboned and restructured raw ham with the addition of 0.3% GDL and 1% chitosan, regardless of the level of sodium nitrite, microbiologically stable and with physicochemical characteristics that meet the legislation.