Strawberry and raspberry seeds were chemically analyzed and added as dietary ingredients to investigate the physiological response of rats. In both cases the main component was dietary fiber and the main polyphenols were ellagitannins (ET). The strawberry ET were mainly constituted by monomers and a dimer, agrimoniin, whereas raspberry ET were mainly constituted by a dimer, sanguiin-H-6, and a trimer, lambertianin-C. The lower content and the less polymerized structure of strawberry ET resulted in a higher cecal metabolites concentration (mainly nasutin and urolithin-A) in comparison to rats fed diet containing raspberry seeds. Dietary raspberry seeds, a source of dietary fiber, despite being richer in polyphenol compounds, were better utilized in fermentation processes, resulting in enhanced production of short-chain fatty acids. As opposed to strawberry seeds, the treatment with raspberry seeds beneficially improved the atherogenic index of a diet, mainly due to reduced triacylglycerol concentration in the serum.

The putative health benefits of raspberries and raspberry-based products are potentially attributable to the presence of polyphenolic compounds, such as ellagitannins, anthocyanins, flavanols, and flavonols. Their content in the products of raspberry processing into juice may be affected by the fruit cultivar, technological process parameters, and the properties of the polyphenolics themselves. The objective of the study was to investigate the composition and quantity of the above polyphenolics in raspberries and the products of their processing (that is, juice and press cake, including its seed and seedless fractions). The study also examined the relationship between the molecular mass of ellagitannins and their transfer to juice. The average percentage contributions of ellagitannins, anthocyanins, flavanols, and flavonols to total polyphenolics in the fruits were 64.2%, 17.1%, 16.9%, and 1.8%, respectively. Analysis of raspberry products showed that the dominant compounds in juice were anthocyanins, with 65.1% contribution to total polyphenolics, while in raspberry press cake, they were tannins (98.0%, mainly ellagitannin including lambertianin C and sanguiin H-6). As shown by our mass-balance calculations, on average, 68.1% of ellagitannins and 87.7% of flavanols were retained in press cake, especially in its seedless fraction. In addition, a significant negative correlation was found between the molecular mass of ellagitannins and their transfer to juice. An increase in molecular mass from 1568 to 2805 Da resulted in a more than 10-fold decrease in ellagitannin transfer.

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The strong acid hydrolysis analysis of galloyl- O -digalloyl-type ellagitannins (ETs), lambertianin C (LC) and sanguiin H-6, and dehydrodigalloyl-type ET, agrimoniin (AM), was performed. A quantitative and qualitative analysis of the degradation products of individual ETs was conducted using high-performance liquid chromatography–diode array detecto–electrospray ionization interface–mass spectrometry (HPLC–DAD–ESI–MS). The data indicate that ETs undergo multidirectional changes in a strongly acidic environment, where the process of successive hydrolysis of ester bonds to form ellagic acid (EA) is the dominant phenomenon in the initial phase of the reaction, followed by the depolymerization process and the formation of low-molecular ETs. Characteristic products of ET hydrolysis were distinguished: for LC: dimeric ET plus one galloyl moiety without one EA moiety ( M = 1736 Da), for all analyzed ETs: sanguisorbic acid dilactone ( M = 470 Da), and for AM: dehydrodigallic acid ( M = 338 Da). The research carried out has allowed to create a database of possible products and routes of transformation of individual ETs, which should facilitate future research on the transformation of ETs, including potential prohealth properties of its breakdown products, under conditions occurring during food processing or digestion.

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Blackberry fiber (BF), extracted blackberry fiber (EBF), defatted blackberry seeds (DBS), and blackberry polyphenols (BP) were added to the diets of rats. A control diet, fiber diets (BF, EBF, DBS) with 6% addition instead of cellulose, and a polyphenol diet (BP) with 1% addition were administered for 4 weeks. BF and DBS contained polyphenols (3.6%); EBF did not. DBS was free of fat. Ellagitannins were the main phenolics, mostly dimers (sanguiin H-6 with isomers) and monomers (pedunculagin, casuarictin isomer, and sanguiin H-2 isomer). Trimers (lambertianin C with isomers) and tetramers (lambertianin D) were in the minority. EBF increased the production of propionate and butyrate in the cecum and improved the blood lipid profile. Polyphenols beneficially decreased the activity of cecal β-glucuronidase, but they may have also increased cholesterol levels in blood. Bacterial metabolism of ellagitannins in the colon gave rise to nasutin A and urolithin A.

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Celem pracy było określenie składu polifenolowego owoców sześciu odmian jeżyny uprawnej, w tym rozpowszechnionych w użytkowaniu: 'Orkan' i 'Gaj' oraz czterech nowych: 'Ruczaj', 'Polar', 'Brzezina', 'Leśniczanka' oraz wyznaczenie zmienności zawartych w nich głównych grup polifenoli. Materiałem do badań były owoce jeżyny wymienionych odmian, które pozyskano z Sadowniczego Zakładu Doświadczalnego Instytutu Ogrodnictwa w Brzeznej. W owocach oznaczono zawartość podstawowych grup polifenoli: antocyjanów, elagotanin i flawan-3-oli z zastosowaniem metody HPLC. W jeżynach stwierdzono zawartość: antocyjanów-210 ÷ 465 mg/100 g ś.m., elagotanin-53 ÷ 320 mg/100 g ś.m. i flawan-3-oli-121 ÷ 282 mg/100 g ś.m., a suma polifenoli wynosiła 556 ÷ 898 mg/100 g ś.m. Istotnie większą zawartością antocyjanów cechowały się owoce odmiany 'Ruczaj' (465 mg/100 g ś.m.), a istotnie mniejszą jeżyny 'Polar' (210 mg/100 g ś.m.), jednak ta odmiana charakteryzowała się istotnie większą zawartością elagotanin (319 mg/100 g ś.m.). Głównym antocyjanem owoców wszystkich odmian był cyjanidynyno-3-O-glikozyd (79 ÷ 91 % sumy antocyjanów). Suma zawartości i wzajemne udziały elagotanin: lambertianiny C i sanguiny H-6 w owocach jeżyny były istotnie zróżnicowane w zależności od odmiany i mogą być rozważane jako kryterium podobieństwa. Duża zawartość sumy polifenoli w jeżynach odmian 'Ruczaj', 'Polar' i 'Gaj' może być dodatkowym czynnikiem wpływającym na upowszechnianie tych odmian w uprawie. Słowa kluczowe: jeżyny, zmienność odmianowa, elagotaniny, antocyjany, flawan-3-ole Wprowadzenie Jeżyna, podobnie jak malina, należy do rodzaju Rubus z rodziny różowatych Rosaceae. Jeżyna Rubus fruticosus jest krzewem o dużej zmienności gatunkowej, tworzącym zarośla i poszycia lasów [3]. Liście oraz owoce jeżyn i malin od dawna stosowane