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Highlights • Occurrence of ochratoxin A (OTA) in the selected food products as studied by HPLC. • In this study 473 food products have been tested for content of ochratoxin A. • Monitoring and evaluation of OTA levels in food products should be advisable. Abstract The aim of this study was to determine the content of ochratoxin A (OTA) using high-performance liquid chromatography (HPLC) in selected food products, in the aspect of consumer health hazards. In the study 473 samples of food products, available on the Silesia market in Poland, were analyzed. For the determination of ochratoxin A in food, high performance liquid chromatography (HPLC) with fluorescence detection was used. Almost 22% of the samples were contaminated with ochratoxin A. The highest concentration of OTA was determined in raisins (34.0 μg/kg), which exceeds the permissible level 3.5 times. In one of the analyzed rye flour samples ochratoxin A was determined at level 19.5 μg/kg, where the maximum level is 3 μg/kg. For the general population, there is a risk of exposure to ochratoxin A from food, which justifies the need to monitor the quality of products for mycotoxin contamination. [ABSTRACT FROM AUTHOR]

Ochratoxin A (OTA) is a nephrotoxic mycotoxin naturally found in a wide range of food commodities throughout the world. Aspergillus carbonarius is the most important source of OTA in food commodities such as wine, grapes and dried vine fruits and is also responsible for the formation of OTA in coffee. The aim of this study was to determine the simultaneous effect of three culture media (Czapek Yeast Extract Broth (CYB); Synthetic Grape Juice Medium (SGM) and White grape juice (WGJ)) at three water activity (a w) levels (0.90; 0.95 and 0.98–0.99), and three incubation temperatures (15 °C, 25 °C and 35 °C) on the growth and OTA production by 16 strains of A. carbonarius. The strains were mainly isolated from grapes from areas with a Mediterranean climate. All the strains were confirmed for identity by sequencing of the calmodulin gene. The assay was performed in microtiter plates, determining the absorbance at 530 nm and the concentration of OTA after 1, 2, 4 and 10 days of incubation. No significant differences were observed in absorbance values between the strains. The highest absorbance values were recorded in CYB at 0.99 a w and at 0.95 a w after 10 days of incubation at 25 °C and 35 °C. None of the strains were able to grow at 0.90 a w and 15 °C in any culture media after 10 days of incubation. OTA concentration was statistically higher at 15 °C than at 25 °C or 35 °C. The highest significant OTA values were obtained at 0.98–0.99 a w and the best culture media for OTA production was CYB, followed by WGJ and SGM. While strains isolated from Mediterranean climate foods had a similar behavior despite being isolated from different geographical areas, OTA concentration produced by one Robusta coffee strain from Thailand was statistically higher at 25 °C than at 15 °C. This would suggest that the type of food matrices and consequently the adaptation of A. carbonarius strains to different climatic conditions would have a greater influence on the ecophysiology of the strains than only their geographical origin. • A. carbonarius strains from Mediterranean climate areas had similar behavior. • Optimum temperature for OTA production was 15 °C for grapes and raisins strains. • Optimum temperature for OTA production was 25 °C for the tropical coffee strain. [ABSTRACT FROM AUTHOR]

Background: Dried fruits, such as raisins, contain phytochemicals and dietary fibers that contribute to maintaining health, potentially at least partially through modification in gut microbiota composition and activities. However, the effects of raisin consumption on gut microbiota have not previously been thoroughly investigated in humans. Therefore, the objective of this study was to determine how adding three servings of sun dried raisin/day to the diet of healthy volunteers affects gut microbiota composition.Methods: A 14-day exploratory feeding study was conducted with thirteen healthy individuals between the ages of 18 and 59 years. Participants consumed three servings (28.3 g each) of sun dried raisins daily. Fecal samples were collected prior to raisin consumption (baseline) and after the addition of raisins to the diet (on days 7 and 14). To determine the effects of raisin intake, fecal microbiota composition before and after raisin consumption was characterized for each participant by 16S rRNA gene sequencing.Results: Overall microbiota diversity was not significantly affected by adding raisins to the diet. However, upon addition of raisins to the diet specific OTUs matching Faecalibacterium prausnitzii, Bacteroidetes sp. and Ruminococcus sp. increased in prevalence while OTUs closest to Klebsiella sp., Prevotella sp. and Bifidobacterium spp. decreased.Conclusion: Our findings suggest that adding raisins to the diet can affect the prevalence of specific bacterial taxa. Potential health benefits of the observed microbiota changes should be determined in future studies in populations for which specific health outcomes can be targeted.Trial Registration: http://www.clinicaltrials.gov ; Identifier: NCT02713165 . [ABSTRACT FROM AUTHOR]

Interest in natural ingredients with multifunctions in food has led to the investigation of the antimicrobial activity of raisins, a traditional baking ingredient. Water and 60% ethanol extracts, and raisin juice concentrate (RJC, a commercial food ingredient) were assessed for their ability to inhibit the growth of ropy-bread-causing Bacillus species. The ability of these additives and raisin paste were tested for antifungal activity in liquid bread model system and bread. In the liquid bread model, concentrations as low as 20 and 36 mg crude extract or RJC per gram media significantly ( P < 0.05) reduced the populations of B. licheniformis and B. subtilis, respectively. A significant reduction in the population of Aspergillus flavus and Penicillium chrysogenum was achieved at 80 and 470 mg crude extract per gram media, respectively. Bread formulas containing 7.5% of a water extract (equivalent to 70 mg extract per gram dough) or RJC (70 mg/g dough) produced bread that had equivalent mold-free shelf life. The mean mold-free shelf life of the bread containing 7.5% water extract was 18.1 ± 3.3 d at room temperature while the negative control was mold free for 9.4 ± 2.4 d. The antifungal efficacy of the extracts in bread was equivalent to 0.24% calcium propionate in 21 d of storage. Doubling the concentration of the extract did not improve the mold-retarding property in bread. The bread containing raisin paste, the percentage of which in dough was equivalent to 15% raisin extract, exhibited a stronger antifungal activity than did the extracts in bread. [ABSTRACT FROM AUTHOR]