Effects of the diameter on physico-chemical, microbiological and volatile profile in dry fermented sausages produced with two different starter cultures

Four batches of Milano-type dry fermented sausages were industrially produced to evaluate the effects of two different lactic acid bacteria starter cultures (Lactobacillus sakei and Pediococcus pentosaceus) and diameter on physico-chemical, microbiological and aroma characteristics during processing and in the final products. Values of awand pH were similar in the final sausages. Lactic acid bacteria counts were high and slightly influenced by the diameter, while higher concentrations of staphylococci were found in small sausages. The diameter had a strong influence on the formation of volatile organic compounds, as revealed by PCA analysis. The main differences regarded ketones (acetone, 2-butanone, 3-hydroxy-2-butanone and 2,3-butandione) and aldehydes (mainly hexanal). The influence of starter cultures was less evident, also due to the presence of indigenous L. sakei in the sausages inoculated with pediococci. Nevertheless, the choice of L. sakei or P. pentosaceus as starter culture showed a direct effect on some of the main process parameters (fermentation and acidification rate) and generation of volatile compounds. The results evidenced the need to optimize the process to increase starter culture performances.