Effects of Raw and Roasted Cocoa Bean Extracts Supplementation on Intestinal Enzyme Activity, Biochemical Parameters, and Antioxidant Status in Rats Fed a High-Fat Diet.

The aim of the study was to analyze the influence of diet containing the polyphenol-rich material on intestinal enzyme activity, oxidative stress markers, lipid metabolism and antioxidant status of laboratory rats. The animals were fed high-fat diet supplemented with freeze-dried water extracts of raw and roasted cocoa beans of Forastero variety. The observed changes indicated the biological activity of polyphenols and other components of the prepared cocoa beans extracts (CBEs). The presence of raw and roasted CBEs in the diets diversified the activity of the enzymes of the cecal microflora of rats. Both CBEs beneficially affect the antioxidant status of the serum, even in relation to the control standard group. The experimental cocoa bean preparations showed no significant effect on the mass of rats' liver, heart, and kidneys, but varied some parameters of the antioxidant status of their organisms. The raw CBE in rats fed with the high-fat diet shows a high ability to inhibit lipid peroxidation in heart and more effectively increases hepatic reduced glutathione (GSH) concentrations compared to the roasted CBE, which did not show any significant effect. Moreover, supplementation with both CBEs significantly affects the volatile fatty acids concentration in the rats' cecum. Results of this study contribute to the evidence that dietary supplementation with raw and roasted CBEs can exert health-promoting effects, however further studies are necessary.

The effect of different dietary ratios of arginine, methionine, and lysine on the performance, carcass traits, and immune status of turkeys.

The research hypothesis postulated that the optimal dietary inclusion levels and ratios of lysine (Lys), arginine (Arg), and methionine (Met) can increase the growth potential of hybrid turkeys and limit metabolic disorders that weaken immune function. The experiment was carried out in a full rearing cycle, from 1 to 16 wk of age, in a two-factorial randomized design with 3 levels of Arg and 2 levels of Met (90, 100 and 110% of Arg, and 30 or 45% of Met, relative to the content of dietary Lys), with 6 groups of 8 replicates per group and 18 turkeys per replicate. In the first and second month of rearing, a significant dietary Arg-by-Met interaction was noted for daily feed intake and body weight gain, and a more beneficial effect was exerted by higher Met content and medium Arg content. Throughout the experiment, the higher dietary Met level increased the final body weight (BW) of turkeys (P = 0.001). Different dietary Arg levels had no influence on the growth performance of turkeys, but the lowest level decreased dressing yield (P = 0.001), and the highest level increased the percentage of breast muscles in the final BW of turkeys (P = 0.003). The lowest Arg level (90% of Lys content) undesirably increased the concentration of the proinflammatory cytokine IL-6 (P = 0.028) and decreased globulin concentration (P = 0.001) in the blood plasma of turkeys. The higher dietary Met level (45% of Lys content) increased plasma albumin concentration (P = 0.016). It can be concluded that higher dietary levels of Met (45 vs. 30% of Lys content) and Arg (100 and 110 vs. 90% of Lys content) have a more beneficial effect on the growth performance and immune status of turkeys.

Effect of Different Levels and Sources of Dietary Copper, Zinc and Manganese on the Performance and Immune and Redox Status of Turkeys.

The aim of the study was to determine the effectiveness of the combined use of Cu, Zn, and Mn nanoparticles in the diet of turkeys with regard to potential reduction of the levels of these elements added to feed. The experiment was carried out on turkeys' hens assigned to four groups. Turkeys from the PC group received feed with the addition of inorganic forms of Cu, Zn, and Mn in the B.U.T. (British United Turkeys) recommended levels, from group IR received the addition in amounts reduced to 10% of the recommended levels, and from group NR received the addition of elements in the form of nanoparticles in the same amounts as in group IR. The turkeys from group NC received feed without the addition of these elements. The research showed that the addition of Cu, Zn, and Mn to turkey diets, in both inorganic forms and as nanoparticles, in quantities covering only 10% of B.U.T. recommendations had no adverse effect on growth performance or on the antioxidant and immune defense of turkeys. The changes in the redox status of the turkeys whose diet was not supplemented with Cu, Zn, and Mn indicate reduced oxidation processes in the tissues.

The immune response of young turkeys to haemorrhagic enteritis virus infection at different levels and sources of methionine in the diet.

BACKGROUND: Haemorrhagic enteritis (HE) of turkeys was first described in 1937 in the USA, while in Poland it was first diagnosed in 1987. Polish haemorrhagic enteritis virus (HEV) isolates are usually low pathogenic and trigger a subclinical disease. Unfortunately, even the low- pathogenic HEV strains cause severe immunosuppression leading to secondary bacterial infections and huge economic losses. The objective of this study was to evaluate if the influence of Met on HEV infected turkeys immune response can be differentiated by both its level and source. Met is one of the amino acids that not only play a nutritional role but also participate in and regulate key metabolic pathways and immune response. In our study, the birds were assigned to 4 dietary treatments which differed in Met levels (0.55 and 0.78% in weeks 1-4 of age and 0.45 and 0.65% in weeks 5-8 of age, respectively) and sources (DL-methionine (DLM) or DL-methionine hydroxy analogue (MHA)). RESULTS: The HEV added the percentage of CD4+ cells and decreased the percentage of IgM+ cells in the blood, spleen and caecal tonsils (CTs) of turkeys. In addition, it increased the percentage of CD4+CD25+ cells in blood, and interleukin-6 (IL-6) level in plasma. The higher dose of Met led to a significant decrease in the percentages of CD4+, CD8+ and CD4+IL-6+ cell subpopulations in the blood of HEV-infected and uninfected turkeys and to an increase in the percentage of IgM+ B cells in CTs. Turkeys administered feeds with an increased Met content displayed a decrease in plasma IL-6 levels and an increase in plasma IgA levels. CONCLUSIONS: The results of this study indicate that HEV infection impairs the immune function in turkeys. Met content in the feed has a moderate effect on the immune response in HEV-infected turkeys. The source of this amino acid appears not be as important as its dose, because value of the analysed parameters did not differ significantly between turkeys receiving feeds with DLM or MHA. In the uninfected turkeys, the higher by 40% (than recommended by NRC) level of Met in the feeds had a positive effect on humoral immunity parameters.

Influence of Diet Enriched with Cocoa Bean Extracts on Physiological Indices of Laboratory Rats.

Cocoa bean is a rich source of polyphenols, mainly flavonoids which have a wide range of biological properties. The aim of the study was to determine the physiological indices of laboratory rats as a response to diets containing water extracts of raw or roasted cocoa beans of Forastero variety, as well as purified monomeric flavan-3-ols fraction isolated from them. The influence of these extracts on selected parameters was studied during 4 weeks feeding. The samples of rats feces were collected throughout the experiment and after its completion, biological samples (intestines content, blood, and organs) were retrieved individually from each rat and subjected to analyses. The observed changes in the gastrointestinal tract functioning indices and metabolism indicators, determined throughout the study and after its completion, confirm to some extent the biological activity of polyphenol extracts of cocoa beans. The differences in the results obtained for the analyzed parameters of the gastrointestinal tract revealed that the cocoa bean extracts differently affected the physicochemical properties of rats' intestines. The results indicate the beneficial effects of the applied nutrition treatment on the activity of cecal enzymes and the content of volatile fatty acids in the gut.

The effect of copper nanoparticles and copper (II) salt on redox reactions and epigenetic changes in a rat model.

The aim of the study was to evaluate the effects of a diet containing different levels of Cu in two different chemical forms (carbonate and nanoparticles) on redox reactions and epigenetic changes in a rat model. For 4 weeks, five experimental groups (eight rats in each) were fed diets with two dosages of added Cu (standard-6.5 mg/kg or half of the standard dosage-3.25 mg/kg, and as a negative control no additional Cu in the mineral mixture) in two forms (standard-CuCO3 and copper nanoparticles). Addition of Cu nanoparticles resulted in higher Cp (ceruloplasmin) activity and LOOH (lipid peroxides) and MDA (malondialdehyde) content, as well as decrease the CAT (catalase) activity and level of PC (protein carbonyl), 3-NT (3-nitrotyrosine), 8-OHdG (8-hydroxydeoxyguanosine), GSH + GSSG (total glutathione) and DNA methylation. Reducing the dose of copper resulted in a decrease in the level of LOOH and GSH + GSSG as well as CAT activity, but increased the level of PC and methylated DNA. Based on these evidence, we concluded that addition of copper nanoparticles in the diet reduces protein oxidation and nitration as well as DNA oxidation and methylation. Lowering the level of Cu in the diet increases the oxidation of proteins and DNA methylation.

The effect of the source and dose of manganese on the performance, digestibility and distribution of selected minerals, redox, and immune status of turkeys.

The aim of this study was to determine the effect of various levels of manganese added to the diet of growing turkeys in the conventional form of MnO or in the form of NP-Mn2O3 nanoparticles on growth performance, absorption, and accumulation of Mn, Zn, and Cu, and antioxidant and immune status. The experiment was conducted on 1080 one-day-old Hybrid Converter turkeys randomly assigned to 6 groups with 10 replications, in a two-factor design with three dosages of manganese - 100, 50, and 10 mg/kg, and two sources-manganese oxide (MnO) and manganese nanoparticles (NP-Mn2O3). Neither reducing the addition of Mn from 100 to 50 or even 10 mg/kg of the diet nor replacing MnO with NP-Mn2O3 had a negative effect on the growth performance of the turkeys. Replacing MnO with NP-Mn2O3 in the turkey diet improved ileal digestibility of Mn and decreased accumulation of Cu in the liver and breast muscle. The study showed that irrespective of the form used, reducing the level of Mn supplementation of the diet from the 100 mg/kg recommended by British United Turkey to 50 or 10 mg/kg decreased its ileal digestibility and increased its accumulation in the liver, breast muscle, and skin. Reducing the addition of Mn to the turkey diet increased intestinal absorption of Zn and reduced accumulation of Zn and Cu in the liver, breast muscle, and skin. It did not increase oxidation processes in the liver or breast muscle of the turkeys. Reducing the addition of Mn to the turkey diet stimulated the immune system, which was manifested by stimulation of B cells to produce immunoglobulin M and by the release of the cytokine IL-6, but did not intensify apoptosis. The results of the study indicate that the recommended manganese supplement in turkey diets can be reduced. The use of manganese nanoparticles in turkey feeding requires further study.

The effect of different dietary levels of DL-methionine and DL-hydroxy analogue on the antioxidant status of young turkeys infected with the haemorrhagic enteritis virus.

BACKGROUND: The results of experiments involving broiler chickens and turkeys indicate that increased dietary methionine (Met) levels may improve the antioxidant protection of tissues in fast-growing birds. This is an important consideration since viral infections induce oxidative stress. The aim of this study was to verify the hypothesis that turkey diets with increased Met content can suppress oxidation processes induced by infection caused by the haemorrhagic enteritis virus (HEV), and that the noted effect is determined by the chemical form of this amino acid: DL-methionine (DLM) or DL-hydroxy analogue of Met (MHA). RESULTS: Dietary Met content above 40% higher than the level recommended by the NRC (1994) intensified lipid peroxidation in the small intestine, leading to an increase in malondialdehyde (MDA) and lipid peroxide (LOOH) levels, but it also stimulated antioxidant mechanisms in the blood and liver of turkeys infected with HEV. In comparison with DLM, MHA contributed to more severe symptoms of oxidative stress, such as elevated MDA levels in the intestines, and a decrease in glutathione peroxidase (GPx) activity and ferric-reducing ability of plasma (FRAP). CONCLUSIONS: In HEV-infected turkeys, diets with increased Met content did not exert a clear antioxidant effect, which was noted in uninfected birds. The prooxidant activity of Met observed in the small intestinal wall was suppressed in the blood and liver of turkeys, most likely due to intensified synthesis of uric acid and glutathione. In comparison with MHA, DLM had a more beneficial influence on the analysed parameters of the redox status in the small intestine, blood and liver of turkeys.

The effect of manganese nanoparticles on apoptosis and on redox and immune status in the tissues of young turkeys.

The aim of the study was to determine whether the use of Mn nanoparticles would make it possible to reduce the level of this micronutrient added to turkey diets without adversely affecting growth performance, antioxidant and immune status, or apoptosis. The experiment was conducted on 6 groups of turkeys with 10 replications in a two-factor design with 3 dosages of manganese, 100, 50 and 10 mg/kg, and 2 sources, manganese oxide (MnO) and manganese nanoparticles (NP-Mn2O3). The study showed that irrespective of the form of Mn used, reducing the Mn level recommended by British United Turkeys for supplementation of the diet of young turkeys from 100 mg/kg to 10 mg/kg increases the content of this element in the blood with no adverse effect on growth performance or the immune system. The reduction in Mn supplementation in the form of NP-Mn2O3 from 100 to 50 and even to 10 mg/kg of turkey diet has no negative effect on antioxidant defence in young turkeys. A 50% reduction of the recommended Mn level in the form of MnO enhances lipid oxidation processes. Replacing MnO with NP-Mn2O3 in the turkey diet probably can increase apoptosis in young turkeys. On the other hand, irrespective of the form of Mn used, reducing supplementation of the turkey diet with this element from 100 to 50 and even to 10 mg/kg probably can reduce apoptosis.

Influence of diet based on bread supplemented with raw and roasted cocoa bean extracts on physiological indices of laboratory rats.

The aim of the study was to determine the physiological indices of laboratory rats as a response to a diet consisting of a bread supplemented with freeze-dried water extracts of raw and roasted cocoa beans of Forastero variety. The influence of different cocoa extracts on oxidative stress, hyperglycemia, and lipid metabolism was studied during long-term feeding of laboratory rats with bread supplemented with cocoa extracts. During the 4-week experimental feeding samples of rats feces were subjected to analysis and after its completion, biological samples were collected i.e. intestines content, blood, and organs retrieved individually from each rat. The observed changes indicate the biological activity of polyphenol extracts and other components of cocoa beans present in the prepared extracts. The differences in the results obtained for the analyzed parameters of the gastrointestinal tract revealed that the cocoa bean extracts being the subject of this investigation differently affected the physicochemical properties of rats' intestines, including intestinal microflora. The results show the influence of the diet on the activity of both fecal and cecal enzymes. Applied nutrition treatment varied the concentration and total production of volatile fatty acids in the cecum. Furthermore, the diverse composition of the applied diet affected the level of some biochemical indicators of blood serum of rats. Additionally, to a small extent influenced the analyzed indicators of the antioxidative status of rats as characterized by the concentration of substances reacting with thiobarbituric acid in internal organs.

Protective Effects of Ellagitannin-Rich Strawberry Extracts on Biochemical and Metabolic Disturbances in Rats Fed a Diet High in Fructose.

The present study compares the effects of two dietary strawberry extracts rich in monomeric (ME) or dimeric (DE) ellagitannins (ETs) on gastrointestinal, blood and tissue biomarkers in Wistar rats fed high-fructose diets. Both strawberry extracts beneficially affect the antioxidant status and lipid profile of the liver and serum. The ME extract shows a greater ability to inhibit lipid peroxidation in kidneys, more effectively decreases serum and liver triglycerides, and exerts greater anti-inflammatory effects in blood serum than the DE extract. The DE extract significantly reduces the activity of microbial enzymes in the cecum. These effects might be associated with higher cecum and urine levels of ET metabolites in rats fed with ME than in rats fed with DE. In conclusion, the diet-induced fructose-related disturbances observed in biochemical parameters are regulated by both extracts; nevertheless, the beneficial effects of the ME extract are mostly associated with systemic parameters, while those of the DE extracts are associated with local microbial activity.

The effect of administration of copper nanoparticles to chickens in their drinking water on the immune and antioxidant status of the blood.

The aim of this experiment was to determine what dosage of copper (Cu) nanoparticles, added to a standard dietary supplementation with copper sulfate, would improve antioxidant and immune defense in chickens. The experiment was conducted with 126 broiler chickens assigned to seven treatments with three pens per treatment and six broiler chickens per pen. The basal-diet treatment did not receive Cu nanoparticles (nano-Cu) and as shown by analyses it was Cu-deficient (-29% vs. National Research Council (NRC) recommendations; 5.7 vs. 8 mg/kg). Broiler chickens received nano-Cu (0.5, 1.0 or 1.5 mg/kg body weight per day) via a tube into the crop over three 3-day periods (days 8-10, 22-24 and 36-38) or three 7-day periods (days 8-14, 22-28 and 36-42). As a result, in the nano-Cu-treated broilers the total experimental Cu intake was from -11% to +96% versus NRC recommendations. At the age of 42 days of broilers, their blood indices were determined. The obtained results showed that correction of the deficient basal diet of chickens with nano-Cu to a level of copper exceeding the NRC recommendation by 54% increased the antioxidant potential of the organism and inhibited lipid peroxidation. At the dosage of +96% versus NRC, some symptoms of a deterioration in antioxidant status appeared (a decrease in the level of glutathione plus glutathione disulfide and an increase in superoxide dismutase, catalase and ceruloplasmin activity and in lipid hydroperoxide content). Additionally, +7% versus the recommended Cu dietary level was followed by unfavorable results, indicating a deterioration in red blood cell parameters and stimulation of the immune system (an increase in interleukin-6, immunoglobulin A (IgA), IgM and IgY). To conclude, it was shown that it is possible to simultaneously increase antioxidant and immune defense of chickens by supplementing their diets with nano-Cu - up to 12 mg per bird during 6 weeks of feeding, that is to a level no more than 7% over the NRC recommendation for growing broiler chickens.

Ellagitannins from Strawberries with Different Degrees of Polymerization Showed Different Metabolism through Gastrointestinal Tract of Rats.

The present paper describes a comparative study of the metabolism of (1) ellagic acid, (2) monomeric ellagitannins (a mixture of α- and ß-bis-hexahydroxydiphenoyl-d-glucose), and (3) dimeric ellagitannins (mainly agrimoniin with both glucose residues being esterified with hexahydroxydiphenoyl) in rats fed polyphenol-rich diets. Their metabolites were identified and quantified in selected parts of the gastrointestinal tract, i.e., the stomach, small intestine, and cecum, on the second, fourth, and seventh days of the experiment, as well as in the rats' feces, blood serum, and urine. Significant differences between the metabolites of strawberry ellagitannins and ellagic acid were observed in all parts of the gastrointestinal tract. Urolithin A was the predominant polyphenolic metabolite of rats fed a diet supplemented with ellagic acid. On the other hand, in rats fed low degree of polymerization (DP) ellagitannins, the main metabolite was nasutin followed by urolithin A, while ellagitannins with a higher DP led to nasutin only.

Nutritional and Health-Related Effects of a Diet Containing Apple Seed Meal in Rats: The Case of Amygdalin.

Apple pomace includes seeds that are rich in protein, fiber, and oil, which can be extracted from them. However, they can also contain a significant amount of toxigenic amygdalin. We hypothesized that amygdalin is a compound that significantly reduces the nutritional and health quality of defatted apple seeds. An experiment was conducted on rats that were distributed into three groups and fed with high-fructose diets. In the control (C) and amygdalin (AMG) groups, cellulose and casein were the source of dietary fiber and protein, respectively; in the apple seed meal (ASM) group, dietary fiber and protein originated from the endosperm of apple seeds, which were previously defatted and ground. A diet fed to the ASM group also contained 0.24% of amygdalin from the meal, whereas the AMG diet was supplemented with the same amount of synthetic amygdalin. After 14 days of experimental feeding, the body weight of rats was decreased in the ASM group. When compared to the C group, apparent protein digestibility and nitrogen retention were increased in the AMG group, while both were decreased in the ASM group. In the small intestine, mucosal maltase activity was decreased in the AMG and ASM groups, whereas lactase activity was only decreased by dietary amygdalin. The caecal SCFA pool and butyrate concentration were significantly increased in the ASM group compared to the other groups. Moreover, the ASM diet increased plasma concentration of high density lipoprotein (HDL) cholesterol and plasma antioxidant capacity of water-soluble substances (ACW). It also decreased the liver content of thiobarbituric acid-reactive substances (TBARS). In contrast, dietary amygdalin did not affect these indices. Dietary supplementation with apple seed meal can exert beneficial effects on the intestinal tract, blood lipid profile and antioxidant status of rats. In most cases, these effects are not limited by the presence of amygdalin. However, the nutritional value of protein from apple seed meal is relatively low.

The effect of different dietary levels of dl-methionine and dl-methionine hydroxy analogue on the antioxidant and immune status of young turkeys.

The hypothesis postulating that the antioxidant and immunological effects of dietary methionine (Met) in young turkeys (1-8 weeks of age) can be differentiated by level and source of Met was investigated in this study. A total of 544 female Hybrid Converter turkeys were divided into four groups and fed diets in which Met content was tailored through supplementation with dl-methionine (dl-Met) or dl-methionine hydroxy analogue (MHA) to levels recommended by NRC (1994) (Groups dl-MetL and MHAL) and exceeding them by 50% (Groups dl-MetH and MHAH). Regardless of its source, the increased dietary Met content led to significantly higher body weight gains but had no effect on feed conversion rates. Moreover, an increased Met content lowered lipid peroxide concentrations in breast meat and increased selected indicators of the plasma antioxidant status like uric acid levels, activity of superoxide dismutase (SOD), glutathione (GSH) concentrations, the ferric-reducing ability of plasma (FRAP), increased immunoglobulin A (IgA) plasma levels and decreased interleukin 6 levels. In comparison with dl-Met, MHA decreased the activities of SOD and catalase, and GSH concentrations in plasma. A dosage by source interaction revealed that the lower MHA content was associated with the lowest plasma GSH concentrations, FRAP values and activities of SOD and catalase. The higher dietary MHA level resulted for most parameters similar values, except for a decrease in lipid peroxide concentrations and an increase in plasma IgA levels. It can be concluded that an increased dietary dl-Met and MHA content (about 150% of the recommendations given by NRC 1994) not only increased the growth rate of young turkeys but also improved their antioxidant status. MHA appears to be a less desirable source of dietary Met for young turkeys when the inclusion level of Met matches the current recommendations. Therefore, a further debate is needed to establish the dietary requirements for Met in poultry.

Chemical Composition of Blackberry Press Cake, Polyphenolic Extract, and Defatted Seeds, and Their Effects on Cecal Fermentation, Bacterial Metabolites, and Blood Lipid Profile in Rats.

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 ß-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.

Raspberry pomace alters cecal microbial activity and reduces secondary bile acids in rats fed a high-fat diet.

The profile of bile acids (BA) largely depends on the enzymatic activity of the microbiota, but this can be modulated by the dietary addition of biologically active compounds, e.g., polyphenols and polyunsaturated fatty acids. The aim of this study was to examine the effect of dietary raspberry pomace as a rich source of biologically active compounds on microbial activity and the BA profile in the caecum of rats fed a high-fat diet. Wistar rats were fed the standard diet AIN-93, a high-fat diet or a modified high-fat diet enriched with 7% different types of processed raspberry pomaces produced by standard grinding and fine grinding, with or without seeds. Rats fed the high-fat diet for 8 weeks showed some disorders in liver function and cecal BA, as manifested by an increased concentration of cholesterol, total BA in the liver and cholic, deoxycholic, and ß-muricholic acids in the cecal digesta. In general, irrespective of the type of raspberry pomace, these dietary preparations decreased liver cholesterol, hepatic fibroblast growth factor receptor 4, peroxisome proliferator-activated receptor alpha, cecal ammonia and favorable changed BA profile in the cecum. However, among all dietary pomaces, the finely ground preparation containing seeds had the greatest beneficial effect on the caecum by modulating bacterial activity and reducing the levels of secondary BA.

The Fatty Acid Profile and Oxidative Stability of Meat from Turkeys Fed Diets Enriched with n-3 Polyunsaturated Fatty Acids and Dried Fruit Pomaces as a Source of Polyphenols.

The aim of this study was to determine the efficacy of different dietary fruit pomaces in reducing lipid oxidation in the meat of turkeys fed diets with a high content of n-3 polyunsaturated fatty acids (PUFAs). Over a period of 4 weeks before slaughter, turkeys were fed diets with the addition of 5% dried apple, blackcurrant, strawberry and seedless strawberry pomaces (groups AP, BP, SP and SSP, respectively) and 2.5% linseed oil. Pomaces differed in the content (from 5.5 in AP to 43.1 mg/g in SSP) and composition of polyphenols Proanthocyanidins were the main polyphenolic fraction in all pomaces, AP contained flavone glycosides and dihydrochalcones, BP contained anthocyanins, and SP and SSP-ellagitannins. The n-6/n-3 PUFA ratio in all diets was comparable and lower than 2:1. In comparison with groups C and AP, the percentage of n-3 PUFAs in the total fatty acid pool of white meat from the breast muscles of turkeys in groups BP, SP and SSP was significantly higher, proportionally to the higher content of α-linolenic acid in berry pomaces. The fatty acid profile of dark meat from thigh muscles, including the n-6/n-3 PUFA ratio, was similar and lower than 3:1 in all groups. Vitamin A levels in raw breast muscles were higher in group AP than in groups C and BP (P<0.05). The addition of fruit pomaces to turkey diets lowered vitamin E concentrations (P = 0.001) in raw breast muscles relative to group C. Diets supplemented with fruit pomaces significantly lowered the concentration of thiobarbituric acid reactive substances (TBARS) in raw, frozen and cooked meat. Our results indicate that the dietary application of dried fruit pomaces increases the oxidative stability of meat from turkeys fed linseed oil, and strawberry pomace exerted the most desirable effects due to its highest polyphenol content and antioxidant potential.

Anthocyanins in Strawberry Polyphenolic Extract Enhance the Beneficial Effects of Diets with Fructooligosaccharides in the Rat Cecal Environment.

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 ß-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.

Ellagitannins and Flavan-3-ols from Raspberry Pomace Modulate Caecal Fermentation Processes and Plasma Lipid Parameters in Rats.

Raspberry pomace is a source of polyphenols, which nutritional and health promoting properties are not sufficiently known. The aim of this 8-weeks study was to scrutinize if raspberry extracts (REs) with different ellagitannins to flavan-3-ols ratios might favorably affect the caecal fermentation processes and blood lipid profile in rats. Forty male Wistar rats were fed with a standard diet or its modification with two types of REs (E1 and E2) characterized by different ratios of ellagitannins to flavan-3-ols (7.7 and 3.1 for E1 and E2, respectively) and added to a diet at two dosages of polyphenolic compounds (0.15 and 0.30% of a diet; L and H treatments, respectively). Irrespective of polyphenols dietary level, both REs reduced the activity of bacterial ß-glucuronidase, increased production of butyric acid in the caecum and reduced triacylglycerols in blood plasma. The E1 treatment at both dosages caused more effective reduction in the concentration of ammonia and elevated acetate level in the caecal digesta than E2. On the other hand, only the E2 treatment lowered value of the atherogenic index when compared with control group. When comparing dosages of REs, a higher one was more potent to reduce the activity of bacterial ß-glucosidase, ß-, α-galactosidase and lowered value of the HDL profile in plasma. To conclude, REs may favorably modulate the activity of the caecal microbiota and blood lipid profile in rats; however, the intensity of these effects may be related to the dosages of dietary polyphenols and to their profile, e.g., ellagitannins to flavan-3-ols ratio.