Microbiological quality of minimally processed vegetables sold in Porto Alegre, Brazil

Abstract

Minimally processed vegetables go through various steps during their preparation, with many modifications to their natural structure. However, they must maintain the same quality as the fresh produce. The aim of the present study was to quantify mesophilic and psychrotrophic microorganisms and total and faecal coliforms, and to assess the presence of Escherichia coli, parasites, and dirt material in ready-to-eat minimally processed vegetables. Fifty-six samples of minimally processed vegetables were analysed for the presence of mesophilic and psychrotrophic microorganisms by the plate-count method. Monthly means ranged from 4.7x10 5 to 1.6x10 8 CFU/g and from 7.9x10 6 to 2.7x10 8 CFU/g, respectively for mesophilic and psychrotrophic microorganisms. Coliforms were analysed by the multiple-tube method; total coliforms ranged from <3 to ≥ 2.4x10 4 MPN/g and faecal coliforms from <3 to 1.1x10 4 MPN/g. Escherichia coli was detected in eight samples. Out of 52 samples, eight (15.3%) contained oocysts of Eimeria spp.. Dirt matter, such as insect body parts and young mites, was also found. Contamination of faecal origin was observed in these samples, suggesting that either the sanitisation of the product was unsuccessful, or soil or irrigation water could be the source of these microorganisms.

Minimally processed yellow melon enriched with probiotic bacteria

“…Minimal processing offers consumers highly nutritious, convenient and healthful fruits while maintaining freshness of the non-processed products (WU;WANG, 2012). According to Silva et al (2007), minimally processed fruits and vegetables are products that have undergone cleaning, washing, selection, peeling and cutting, to obtain a 100 % usable product that is packaged and maintained under refrigeration.…”

“…Melon is a kind of fruit having a big market share in minimally processed products (SUPAPVANICH;TUCKER, 2011). Besides, this fruit is cholesterol free and it contains vitamin B1, B2, PP, A and C, being a fruit widely produced and consumed worldwide (NICOLAIS et al, 2011).…”

“…Thus, the nutritional benefits of probiotic bacteria have motivated the increased consumption of minimally processed vegetables in supermarkets and restaurants. Such benefits may be assigned to the control and stabilization of the intestinal microbiota after the use of antibiotics (SOCCOL et al, 2010), increased gastrointestinal resistance to colonization by pathogens (ZHANG et al, 2011), competition for nutrients and adhesion sites (FERREIRA, SILVA, 2010;SAAD;BEDANI;MAMIZUKA, 2011), among others.…”

“…Raw food products have recently been intensively investigated as potential substrates for the production of probiotic non-dairy foods (MARTINS et al, 2013;SOCCOL et al, 2010;CETIN, 2011;PERES et al, 2012;YU et al, 2012). Alegre et al (2011) and Rößle et al (2010a;2010b) found that probiotic strains have the ability to grow in fruit matrices due to fruit nutritional content and internal tissue structures.…”

Aspectos higiênicos-sanitários de vegetais minimamente processados e perfil de resistência das leveduras isoladas frente ao hipoclorito de sódio e ozônio

“…Os principais patógenos causadores destas doenças foram Escherichia coli O157:H7 e Salmonella spp., encontrados em alfaces e brotos; Shigella em salsa e alface e Cyclospora em amoras (SILVA et al, 2003;ARAÚJO, 2006;SILVA et al, 2007a).…”