Volatiles in a sausage surface model-influence of Penicillium nalgiovense, Pediococcus pentosaceus, ascorbate, nitrate and temperature

Thirty-two agar sausage models were arranged in a 2((5-1)) fractional factorial design to analyse the effects of Penicillium nalgio-vense growth, Pediococcus pentosaceus starter, sodium ascorbate, sodium nitrate and temperature on 79 volatiles produced during incubation. The model focused on the outer 10 millimeters of sausages. Ascorbate addition showed clear antioxidative effects, and reduced the amount of more than half of all volatiles but increased concentrations of 2-methyl-propanal and 3-methyl-butanal. The effects of P. pentosaceus and Micrococcaceae were confounded, but together they had pronounced antioxidative effects, lowering the amount of straight chain aldehydes, 2-alkenals, furanes and ketones. P. pentosaceus and Micrococcaceae growth increased the leucine catabolites 3-methyl-butanal and 3-methyl-1-butanol. P. nalgiovense decreased the concentrations of 2-heptanone, 2-octanone and 2-nonanone, probably because of abnormally high concentration of mycelia. The data indicates that P. nalgiovense converts 2,3-butanedione and 3-hydroxy-2-butanone to 2-butanone. P. nalgiovense increased the concentrations of 1-octene-3-ol and dimethyl disulfide. liberated 2-methyl-furan and 2,4-dimethyl-furan from casing and seemed to liberate chloroform and 1,2-dimethyl benzene from meat. Both 2-methyl-1-propanol and 2-methyl-1-butanol decreased significantly with increasing temperature - this indicated a shift in metabolic pathway. No effects were seen for addition of nitrate.