| 1. |
- Bakeeva, Albina, et al.
(författare)
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Distribution of mycotoxins produced by Penicillium spp. inoculated in apple jam and creme fraiche during chilled storage
- 2019
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Ingår i: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 292, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- Estimations of consumer exposure to mycotoxins through surveillance of mycotoxins in the food trade are well described, but the exposure due to mouldy food in private homes is not known, and may result from removing visible mould on food and eating the rest. In this study, we followed the growth of Penicillium expansum on the surface of apple jam and Penicillium verrucosum on creme fraiche, as well as production and distribution of fungal metabolites throughout the sample (approx. 6 cm high divided into three equal layers), using a multianalyte method, over time (up to 28 days) and at 4, 8 and 15 degrees C.Growth rates and apparent lag times for P. expansum in apple jam at different temperatures were estimated by fitting to the Baranyi model. The growth rates were 1.7, 2.7 and 4.3 mm day(-1) for storage at 4, 8 and 15 degrees C, respectively; apparent lag times decreased with increasing storage temperature and were 10.6, 7.9 and 2.6 days at corresponding temperatures. Patulin and roquefortine C were identified and quantified, among other fungal metabolites. Patulin was detected in all 2-cm layers of the apple jam at 15 degrees C. Concentrations in the upper two layers of the jar corresponded to exposures exceeding the health based guidance value (HBGV) for a normal serving size. Consequently, removal of the mouldy part is insufficient to avoid unhealthy exposure. In contrast to patulin, roquefortine C was also produced at 4 degrees C.The growth of P. verrucosum on creme fraiche was very restricted and could not be modelled. Despite the small colony (8 +/- 0.5 mm in diameter), ochratoxin A and citrinin were detected after 21 days at 15 degrees C in the top 2 cm layer (including the fungal colony), and at concentrations in a normal serving corresponding to an exposure above the HBGV established by EFSA for both mycotoxins. Questiomycin A, an antibiotic, was also produced in creme fraiche but in contrast to the two mycotoxins, was detected throughout all layers of the creme fraiche and was produced also at 4 and 8 degrees C.As a complement to a previous study, we also present production and the distribution of major fungal metabolites in apple jam and creme fraiche for some additional fungal strains (P. crustosum, P. roqueforti and P. verrucosum on apple jam and P. expansum on creme fraiche). A pilot study investigating the effect of inoculation size on toxin production may have implications for the best inoculum to use in experimental studies.
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| 2. |
- Bakeeva, Albina, et al.
(författare)
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Effect of solid-state fermentation with Arxula adeninivorans or Hypocrea jecorina (anamorph Trichoderma reesei) on hygienic quality and in-vitro digestibility of banana peels by mono-gastric animals
- 2017
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 199, s. 14-21
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the effectiveness of solid-state fermentation with Arxula adeninivorans or Hypocrea jecorina to improve hygienic quality and digestibility of banana peels by mono-gastric animals. Green peels of cooking bananas (Musa AAA-group) were solid-state fermented in ziploc plastic bags for 14 d either non inoculated or inoculated with A. adeninivorans or H. jecorina. Colonies of aerobic bacteria, lactic acid bacteria, Enterobacteriaceae, yeasts and moulds were enumerated. In-vitro digestibility (total tract and pre-caecal) of dry matter (DM), organic matter (OM) and crude protein (CP) was also determined. Solid-state fermentation significantly improved (P < 0.05) in-vitro total tract digestibility (9.9% for DM and 10.1% for OM), and in-vitro pre-caecal digestibility (25.0% for DM, 30.9% for OM and 74.5% for CP); however, no significant effect (P > 0.05) due to inoculation was observed. Conversely, inoculation (with A. adeninivorans or H. jecorina) significantly improved (P < 0.05) the hygienic quality; with lower (P < 0.05) aerobic bacteria, Enterobacteriaceae and mould counts than the non-inoculated treatment. However, H. jecorina triggered a significantly superior (P < 0.05) improvement in both hygienic quality and in-vitro pre-caecal digestibility than A. adeninivorans.
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| 3. |
- Bakeeva, Albina, et al.
(författare)
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The Potential of Kluyveromyces marxianus to Produce Low-FODMAP Straight-Dough and Sourdough Bread: a Pilot-Scale Study
- 2021
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Ingår i: Food and Bioprocess Technology. - : Springer Science and Business Media LLC. - 1935-5130 .- 1935-5149. ; 14, s. 1920-1935
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Tidskriftsartikel (refereegranskat)abstract
- Diets low in fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) can help reduce symptoms in 50 to 80% of patients suffering from irritable bowel syndrome. Patients are, therefore, often advised to avoid products contributing to FODMAP intake, such as cereal grain products. However, these products are nutritious staple foods and avoiding their consumption may result in nutritional deficiencies. The development of low-FODMAP, high-fiber cereal grain products is therefore desirable. This pilot-scale study shows that Kluyveromyces marxianus CBS6014 (K. marxianus) results in more fructan hydrolysis and a significantly lower final fructan level in white and whole-grain toast bread as well as in rye sourdough bread compared to a commercial Saccharomyces cerevisiae baking strain. Moreover, combined fructan and fructose levels in white and whole-grain bread prepared with K. marxianus remained well below the threshold concentration for low-FODMAP products. In addition to reducing fructan levels, K. marxianus in rye sourdough bread also positively impacted bread height. Whereas further follow-up studies are needed to assess the potential of K. marxianus for bread production fully, our study suggests that this yeast species may open exciting novel routes for the production of low-FODMAP, high-fiber products.
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| 4. |
- Bakeeva, Albina, et al.
(författare)
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Yeasts and bacteria associated with kocho, an Ethiopian fermented food produced from enset (Ensete ventricosum)
- 2019
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Ingår i: Antonie van Leeuwenhoek. - : Springer Science and Business Media LLC. - 0003-6072 .- 1572-9699. ; 112, s. 651-659
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Tidskriftsartikel (refereegranskat)abstract
- Enset (Ensete ventricosum) is the basis of the staple food consumed by about 20% of the Ethiopian population. Kocho is one of the food products generated from enset by spontaneous fermentation of decorticated and pulverized pseudostem and corm sections. We isolated culturable microbes associated with kocho from different stages of fermentation. Twelve yeast species, six lactic acid bacteria (LABs) species and eleven species of aerobic bacteria were identified by sequencing ITS/D1D2 regions of 26S rDNA of yeasts and 16S rDNA of bacteria, respectively. More yeast species were identified in fresh (fermented for 2-5days) kocho, compared to long-term (7-12months) fermented kocho, while we observed an opposite trend for LABs. In fresh kocho, the most frequently isolated yeast species were Pichia exigua, Galactomyces geotrichum, and Pichia fermentans. From mid-term (3-4months) kocho most frequently Candida cabralensis, G. geotrichum, and Candida ethanolica were isolated. In the long-term fermentations, the most frequently isolated yeast was Saturnispora silva. Lactobacillus plantarum was the most frequently isolated LAB in both fresh and mid-term kocho. In long-term fermented kocho, Acetobacter pasteurianus and L. plantarum were most frequently isolated. L. plantarum was consistently isolated from all the three stages of fermentation. Aerobic bacteria in fresh kocho were mostly gram-negative, with Raoultella planticola and Pantoea agglomerans being the most frequently isolated species. In long-term fermented kocho, mainly gram-positive, spore-forming bacteria of the genus Bacillus were found, among them also species of the Bacillus cereus group, Bacillus anthracis and Bacillus thurigiensis.
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| 5. |
- Cassi, Xavier Fernandez, et al.
(författare)
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Microbial communities and Food safety aspects of crickets (Acheta domestica) reared under controlled conditions
- 2020
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Ingår i: Journal of insects as food and feed. - 2352-4588. ; 6, s. 429-440
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Tidskriftsartikel (refereegranskat)abstract
- In an approach combining microbiological culture methods with high-throughput sequencing, this study investigated the microbial communities (bacteria, moulds and yeasts) in Swedish-produced edible crickets (Acheta domesticus) reared in a controlled environment. The effects of different feeds on microbial loads and populations in crickets were also studied. The crickets used were third-generation offspring from wild-caught individuals from Sweden, which are adapted to grow in a laboratory environment. The efficiency of rinsing to decrease microbial load was evaluated not obtaining a significant decrease of plating counts for total aerobic counts (TAC) and Enterobacteriaceae. Crickets were divided into three batches and fed different diets (control feed, early-cut red clover hay (ECH), late-cut fresh red clover (LCF)) for 62 days. Bacterial numbers (TAC and Enterobacteriaceae) on whole raw crickets ranged between 7 and 8 log cfu/g. Pre-rinsing in water did not reduce these levels (P=0.19). All batches tested negative for the food-borne bacteria Salmonella, Listeria monocytogenes, Bacillus cereus and Clostridium perfringens. The mean mould count for crickets fed control feed was 2.8 log cfu/g, while the values for crickets fed ECH and LCF were 4.2 and 4.5 log cfu/g, respectively. The dominant bacterial communities were Proteobacteria, Bacteroidetes and Firmicutes, with Firmicutes and Proteobacteria dominating in crickets fed control feed, Firmicutes dominating in crickets fed LCF and Proteobacteria dominating in crickets fed ECH. Aspergillus flavus, a fungus that is capable of producing mycotoxins, was detected in control feed and ECH reared crickets. More work is needed to identify specific food-borne pathogens in edible crickets and establish possible bacterial quality reference values, as an important step in developing microbial quality and safety parameters to ensure consumer safety.
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