International Journal of Food Microbiology 60 (2000) 15–24 www.elsevier.nl / locate / ijfoodmicro Microbial species associated with different sections of broccoli harvested from three regions in Australia a a b b, * Masdiana Padaga , Gillian M. Heard , Jane E. Paton , Graham H. Fleet a CRC for Food Industry Innovation, The University of New South Wales, Sydney, New South Wales 2052, Australia b Department of Food Science and Technology, The University of New South Wales, Sydney, New South Wales 2052, Australia Received 26 October 1999; received in revised form 27 March 2000; accepted 6 April 2000 Abstract The microbial populations associated with the different sections of broccoli harvested from three locations in Australia were studied during storage at 5, 15 and 208C. Bacterial and yeast populations associated with the outer florets and cut surfaces of the stem were generally 10-fold or more higher than those associated with inner florets or non-cut stems, respectively. The predominating bacterial species varied with the origin of the broccoli. Pseudomonas fluorescens, Ps. 5 7 corrugata and Ps. viridiflava predominated at populations of 10 –10 cfu / g on broccoli harvested from Victoria, Ps. 3 6 fluorescens, Ps. mendocina and Ps. fragii and Arthrobacter spp. (10 –10 cfu / g) were prevalent on broccoli harvested from Queensland. Broccoli harvested from New South Wales exhibited a predominance of Ps. fluorescens, Arthrobacter spp. and 3 5 Enterobacter agglomerans (10 –10 cfu / g). Most species grew on broccoli during storage. Similar species were found at the different sections of broccoli, although, for some species there was evidence of strain variation at the different locations and for different temperature of storage.  2000 Elsevier Science B.V. All rights reserved. Keywords: Broccoli; Microbial ecology; Quality 1. Introduction 1990; Forney et al., 1993). Although the onset of some of these disorders is a natural, physiological Broccoli ( Brassica oleracea L. Italica group) is a response of the plant tissue, microorganisms can perishable vegetable. Postharvest storage disorders make a significant contribution to their development include yellowing and opening of florets, loss of and decrease in product shelf life (Lund, 1971, 1992; stem firmness, development of undesirable odours Nguyen-the and Carlin, 1994; Brackett, 1997; Heard, and soft rots (Lebermann et al., 1968a,b; Lipton and 1999). The most obvious and frequently reported Harris, 1974; Shewfelt et al., 1984; Berrang et al., consequence of microbial spoilage is soft rot of the broccoli florets (Ceponis et al., 1987; Liao and Wells, 1987; Brackett, 1989). However, there could *Corresponding author. Tel.: 1 61-2-3855-664; fax: 1 61-2- be the other less obvious but, nevertheless, important 3855-931. E-mail address: g.fleet@unsw.edu.au (G.H. Fleet). influences of microorganisms, since fresh, sound 0168-1605 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0168-1605(00)00329-9