BackgroundAccording to many scientific studies, ellagitannins are beneficial for human health. One of the sources of these compounds is strawberry press-cake. This material can be used for the production of dietary fiber or ellagitannin preparations. The health safety of press cake and the preparations that are rich in ellagitannins obtained from it depend on pesticide residue levels, mainly fungicides, which are used for strawberry protection.AimThe aim of the work was a dietary risk assessment measured by the %ADI (acceptable daily intake) and MOE (margin of exposure) associated with the presence of pesticide residues for the consumption of strawberry processing by-products containing an amount of ellagitannins equivalent to amount present in 100g of fresh strawberries. In our study, we investigated the contents of pesticides that are approved for use against strawberry diseases and pests.ResultsThe total contents of pesticides in strawberry press-cake seeds (SPCS), exhausted strawberry flesh (ESF) and strawberry ellagitannin preparation (SEP) were 2143, 13,464 and 20,225μg/kg, respectively. The analyzed products were dominated by fungicides as 96% of the total content of the tested pesticides. In the tested samples, we detected 11 fungicides and 3 insecticides. The dietary risk to consumer health, which depends on the presence of pesticide residues, in %ADI of daily consumption of ellagitannins (as dried extract (SEP), seeds (SPCS) or flesh (ESF)) ranged from 0.2% to 4.1% in a dose that was equivalent to 100g of strawberries.ConclusionAlthough the pesticide residue contents in strawberry by-products are higher than in fresh fruits, the suggested doses of the by-products are lower. Therefore, the dietary risk to consumers from strawberry by-products is comparable to that from fresh fruits

The administration of fructooligosaccharides (FOS) beneficially modulates gastrointestinal functions and may enhance the metabolism of polyphenols. However, different polyphenolic components in the diet may have different influences on the activities of the digestive enzymes and microbiota in the gastrointestinal tract. Therefore, a 4-week study of forty-eight male Wistar rats was conducted to investigate the physiological response of the rat cecal environment to diets without and with FOS that contained two different strawberry polyphenolic extracts, specifically EP (polyphenolic profile 60, 35, 5, and 0% ellagitannins, proanthocyanidins, flavonols, anthocyanins, respectively) and EPA (polyphenolic profile: 50, 35, 6, and 9%, respectively). When combined with FOS, both extracts beneficially enhanced the acidification of the cecal digesta (P≤0.05 vs the groups without extracts), but the dietary combination of EPA and FOS elicited the greatest reduction in putrefactive short-chain fatty acid production and the lowest fecal β-glucuronidase activity in the cecum (P≤0.05 vs group EP). Moreover, the addition of dietary FOS elevated the metabolism of the examined strawberry extracts in the cecum and thereby increased the concentrations of the metabolites in the cecal digesta and urine (P≤0.05 vs the group with cellulose). Overall, both strawberry extracts modulated the effects of FOS in the gastrointestinal tract; however, the combination with EPA extract that contained anthocyanins exhibited greater beneficial effects in the lower gut environment than the EP extract.