Researchers have found Cronobacter in samples of nuts, seeds and dried fruit in Poland.

The study determined the microbiological quality of commercial ready-to-eat food products of plant origin with a focus on Cronobacter.

Analyses were carried out on 64 samples of nuts, dried fruits, candied fruits, seeds, and mixes of seeds, dried fruits and nuts. Samples were tested for the total plate count of bacteria (TPC), counts of yeasts and molds, and the occurrence of Cronobacter.

Cronobacter demonstrate a range of properties which enable survival in various food products and allow them to adapt to a changing environment during the manufacturing process, according to the study published in the journal Pathogens.

TPC, yeast and mold
The level of TPC in nuts is believed to be an indicator of postharvest contamination of these products. TPC were not found in samples of seeds and candied fruits.

Five samples, including dried fruits, seeds and mixes of dried fruits, nuts and seeds, had excessive counts of mold based on international guidelines but yeast levels were satisfactory and not detected in seeds and candied fruits.

Samples were bought in Warsaw, Poland, at different supermarkets, from September 2018 to February 2019. They came from seven producers.

The 20 nut samples included Italian and Brazil nuts, hazelnuts, almonds, pecans, cashews, pine nuts and macadamias. The 24 samples of dried fruit were prunes, raisins, cherries, sour cherries, figs, bananas, dates, apricots, blackcurrants, cranberries, goji and chia berries.

Eight samples were candied fruit like mango, pineapple, jackfruit, plums, and passion fruit. Another eight were mixes in various proportions of raisins, dried cranberries, walnuts, hazelnuts, cashews, almonds, and sunflower seeds. Four were samples of sunflower and pumpkin seeds.

Cronobacter findings
There are no regulations for Cronobacter in foodstuffs except for powdered infant formulas.

Ten samples of nuts and two mixes were contaminated with Cronobacter. It was not detected in dried or candied fruits, and seeds. The prevalence of Cronobacter in nuts and in mixes of dried fruits, seeds and nuts accounted for 50 percent and 25 percent respectively.

Three Cronobacter species were isolated from nuts and mixes of nuts, dried fruits and seeds.

Presence of Cronobacter sakazakii was confirmed in some Brazil nut samples and certain mixes of dried fruits, seeds and nuts. Cronobacter turicensis was detected in 20 percent of almonds and hazelnuts. Cronobacter malonaticus was found in 20 percent of hazelnuts, cashews, pine nuts and macadamias and in 12.5 percent of the samples of mixes of dried fruits, seeds and nuts.

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