Does dietary inulin affect biological activity of a grapefruit flavonoid-rich extract?

<p>Abstract</p> <p>Background</p> <p>The aim of the study was to verify that the concomitant presence of grapefruit flavonoid extract with inulin in a Western-type diet may provide synergistic effects to the hindgut metabolism, as well as blood lipid and mineral profiles.</p> <p>Methods</p> <p>Forty male Wistar rats were distributed into 4 groups and fed for 28 days with diets rich in fat, cholesterol and protein. A two-way repeated measures ANOVA was applied to assess the effects of inulin (v. sucrose, 5% of the diet), the addition of dietary grapefruit flavonoid extract (diets without or with 0.3% of an extract from hard parts of grapefruit) and the interaction between these two dietary factors.</p> <p>Results</p> <p>When compared to the control sucrose-containing diet, the diet enriched with inulin led to typical changes within the caecum, the main part of hindgut fermentation in rats, such as acidification of the digesta, support of bifidobacteria growth and increase of propionate and butyrate production. The dietary grapefruit flavonoid extract without inulin increased the bulk and pH value of caecal digesta, whereas short-chain fatty acid concentration and the bifidobacteria population were lowered compared to the extract-free diets. Simultaneous dietary addition of both tested components decreased slightly the pH value and increased somewhat the bifidobacteria number and the propionate concentration, however to the level observed with the control sucrose-containing diet. With regard to blood lipids, dietary grapefruit flavonoid extract decreased the triglyceride concentration regardless of the dietary carbohydrate type.</p> <p>Conclusion</p> <p>Inulin does not provide any additional benefit to the blood lipid profile caused by the dietary application of grapefruit flavonoid extract and it does not counteract clearly detrimental effects of the extract in the hindgut. Adding grapefruit extract to the diet must be performed with caution due to possible adverse hindgut responses with overdoses.</p

Effects of Dietary Addition of a Low-Pectin Apple Fibre Preparation on Rats

The aim of this study was to scrutinise if the dietary addition of a low-pectin fibre preparation obtained from apple pomace, the by-product of apple concentrate processing, is able to favourably affect the gut metabolism, antioxidant status and blood bio-markers of the organism, as it takes place when apple fibre is present in the diet as an unprocessed ingredient. The nutritional experiment was performed on rats allocated to 2 groups of 10 animals each and fed for 2 weeks with either a control cellulose-containing diet or an experimental low-pectin apple fibre-containing diet. To induce metabolic disorders a diet rich in saturated fat and fructose was used in both diet-specific groups. The dietary apple fibre preparation (AFP) significantly reduced the activity of sucrase and maltase in the mucosa of the small intestine. In the caecal digesta, the dietary AFP significantly increased bacterial α-glucosidase and α-galactosidase activity, whereas bacterial β-glucuronidase activity was significantly reduced. Also, the content of short chain fatty acids in the caecal digesta was significantly increased after the AFP supplementation. In the blood serum, the dietary AFP significantly reduced the glucose concentration, and decreased the ratio of total cholesterol to HDL cholesterol. In conclusion, the tested dietary AFP is still able to favourably affect the gut metabolism and can also ameliorate blood glucose concentration, which seems to be related to the inhibition of mucosal disaccharidase activities. However, the analysed preparation has no influence on the antioxidant status of the organism and may trigger adverse effects on cholesterol metabolism

Hranjiva vrijednost i fiziološki učinak hrane za štakore s dodatkom sirovih sjemenki lupine te sjemenki fermentiranih s pomoću kvasca Candida utilis

The growth and physiological responses of the rats to diet supplemented with raw and Candida utilis-fermented yellow and blue lupin seeds were determined. The diets containing soya bean meal, raw and fermented blue and yellow lupin were administered to eight rats in each diet group for four weeks. Yellow lupin seeds in the diets of rats improved significantly (p<0.05) feed intake, protein digestibility, body mass gain and protein efficiency ratio in comparison with blue lupin seeds. On the contrary, blue lupin seeds affected significantly (p<0.05) gastrointestinal fermentation processes in comparison with yellow lupin seeds. Fermentation of lupin seeds increased crude protein content and reduced phytate and oligosaccharide content. In the fermented products, a higher number of lactic acid bacteria and yeasts but reduced number of coliform bacteria was found. Fermentation by Candida utilis positively (p<0.05) aff ected protein digestibility of feed, body mass gain and protein efficiency ratio of rats, as well as the activity of some bacterial enzymes and cholesterol concentrations in the blood serum.U radu je ispitan utjecaj hranidbe štakora sjemenkama žute i plave lupine, sirovim ili fermentiranim s pomoću kvasca Candida utilis, na njihov rast i fiziološke promjene. Štakori su u grupama po osam jedinki hranjeni sojinom sačmom, te sirovim ili fermentiranim sjemenkama plave i žute lupine tijekom četiri tjedna. Sjemenke žute lupine znatno su povećale (p<0,05) unos hrane, probavljivost proteina i tjelesnu masu, te povećale omjer proteinske djelotvornosti u usporedbi sa sjemenkama plave lupine. Sjemenke su plave lupine pak bitno utjecale (p<0,05) na fermentacijske procese u gastrointestinalnom traktu, za razliku od žute lupine. Fermentacijom se u sjemenkama lupine povećao udjel sirovih proteina, a smanjio udjel fitata i oligosaharida. U fermentiranim je proizvodima pronađeno više bakterija mliječno-kiselog vrenja te kvasaca, a manje koliformnih bakterija. Fermentacija s pomoću kvasca Candida utilis pozitivno (p<0,05) je utjecala na probavljivost proteina, povećanje tjelesne mase i omjer proteinske djelotvornosti, koncentraciju kolesterola u krvi, te na aktivnost nekih bakterijskih enzima

Sastav i biološka svojstva etanolnih ekstrakata korijena, kore, sjemenja i listova cikorije

The chemical composition of the ethanol extracts of chicory root, peel, seed and leaf has been determined, in particular their inulin and phenolic fractions. The root and peel extracts were characterized by large mass fractions of inulin (60.1 and 46.8 g per 100 g of fresh mass, respectively), predominantly with degree of polymerization in the range from 3 to 10, while phenolics, determined as caffeoylquinic acids, made up 0.5 and 1.7 g per 100 g of fresh mass, respectively. The leaf and seed extracts had decidedly lower mass fractions of inulin (1.7 and 3.2 g per 100 g of fresh mass, respectively) and higher mass fractions of phenolics (9.6 and 4.22 g per 100 g of fresh mass, respectively) recognized as caffeoylquinic acids, chicoric acid and quercetin glucuronide. The biological properties of a non-inulin fraction from each extract were determined on Wistar rats fed with diets rich in fructose and saturated fat, as a model of metabolic changes related to westernization of human eating habits. The diets contained the same amount of inulin (6 %) with various phenolic fractions. Some changes were noted in the microbial enzymatic activity of the caecum after feeding for 4 weeks with the diet containing the highest mass fraction of phenolics (0.208 %), derived from the mixture of peel and seed extracts (decreased activity of β-galactosidase and β-glucuronidase), as well as with the diet containing leaf extract (decreased β-glucuronidase activity). All the diets showed no essential influence on the caecal concentration and profile of short-chain fatty acids, except acetate, whose concentration decreased significantly in rats fed with the diet enriched with root extract. The addition of peel and leaf extracts to the fructose diets significantly increased the serum antioxidant capacity of lipophilic substances. The study indicates that parts of chicory and its byproducts might be a source of valuable compounds to improve the physiological activity of inulin.Određen je kemijski sastav etanolnih ekstrakata (tj. udjeli inulina i fenola) korijena, kore, sjemenja i listova cikorije. Ekstrakti korijena i kore sadržavali su velike masene udjele inulina, i to u 100 g svježe tvari: korijen 60,1 g i kora 46,8 g, pri čemu je stupanj polimerizacije bio od 3 do 10. Maseni udjel fenola (derivata kofeinske kiseline) u 100 g svježe tvari bio je u ekstraktu korijena 0,5 g, a u ekstraktu kore 1,7 g. Ekstrakti lišća i sjemenja imali su kudikamo manji udjel inulina u 100 g svježe tvari (ekstrakt lišća 1,7 g i ekstrakt sjemenja 3,2 g) i veći maseni udjel fenola u 100 g svježe tvari (ekstrakt lišća 9,6 g i ekstrakt sjemenja 4,22 g). Biološka svojstva fenola, tj. njihov utjecaj na metaboličke promjene prouzročene zapadnjačkim načinom prehrane, ispitana su na štakorima Wistar kojima je davana hrana bogata fruktozom i zasićenim masnim kiselinama. Hrana je sadržavala isti udjel inulina, a različite masene udjele fenola, ovisno o dodanom ekstraktu. Nakon 4 tjedna prehrane hranom s najvećim udjelom fenola od 0,208 % uočene su promjene u aktivnosti enzima mikrobnog podrijetla, izoliranih iz slijepoga crijeva štakora. Utvrđeno je da hrana koja sadržava mješavinu ekstrakata kore i sjemenja smanjuje aktivnost β-galaktozidaze i β-glukuronidaze, dok hrana koja sadržava ekstrakt lišća smanjuje aktivnost samo β-glukuronidaze. Prehrana nije utjecala na koncentraciju i sastav masnih kiselina, osim što je hrana s dodatkom ekstrakta korijena bitno smanjila koncentraciju acetata u slijepom crijevu. Dodatkom ekstrakata kore i lišća hrani bogatoj fruktozom znatno se povećala antioksidativna aktivnost seruma. Studija je pokazala da dijelovi cikorije i njezine prerađevine mogu poslužiti kao izvor vrijednih sastojaka koji poboljšavaju fiziološku aktivnost inulina

Enhancing the nutritional profile of regular wheat bread while maintaining technological quality and adequate sensory attributes

Plant proteins, and legume proteins in particular, have become the centre of attention moving towards a more sustainable and, therefore, more plant-based human diet. Especially hybrid products, containing wheat and legume proteins, promise a balanced amino acid composition and an upgraded nutritional value of both protein sources. This study investigates a high-protein hybrid bread (HPHB) formulation, where wheat flour was partially replaced by high-protein ingredients from faba bean, carob and gluten. In addition to a detailed characterisation of technological quality and sensory profile, also the formulation's nutritional value was examined in comparison to regular wheat bread. Therefore, macronutrient composition, antioxidant potential, amino acid profile and contents of antinutritional compounds were analysed. Furthermore, protein digestibility was determined in an in vitro model and in vivo. Dough analysis revealed significant differences of the HPHB formulation compared to regular wheat dough. However, results obtained for bread quality characteristics prove HPHB to be equal to regular wheat bread and sensory results and the determined sensory attributes suggest high consumer acceptance. Nutritional analyses of HPHB showed a more favourable macronutrient composition in comparison to regular wheat bread; as well as low contents of antinutritional compounds and high antioxidant potential linked to high levels of phenolics. Also an improved amino acid profile, increased nitrogen utilisation rate (by 69%) and higher protein efficiency ratio were determined, which are associated with enhanced protein quality. This suggests HPHB, and similar formulations of its kind, as a valuable and healthy food choice, which can contribute to adequate protein supply in predominantly plant-based diets

The Effect of the Restrictive Ketogenic Diet on the Body Composition, Haematological and Biochemical Parameters, Oxidative Stress and Advanced Glycation End-Products in Young Wistar Rats with Diet-Induced Obesity

Over the past few years, the interest in the application of the ketogenic diet (KD) for obesity management is growing. Although many studies have been performed on the effects of KD, the metabolic and physiological impact of KD is still not fully understood. Therefore, this study aimed to evaluate the effect of calorie-restricted KD on the body weight and composition, oxidative stress, and advanced glycation end products (AGEs) assessed in an animal model with young Wistar rats. KD was followed for 4 weeks in maturity after an obesity-inducing high-fat diet during adolescence, resulting in a slowing down of the weight gain but higher adiposity compared to a standard diet. Increased adiposity resulted in an deterioration of liver parameters, suggesting negative changes in this organ. No adverse effects of KD were determined in haematological parameters in young rats. KD did not affect AGEs; however, a decrease in oxidative stress was observed. Based on the presented results, it can be concluded that KD applied for weight loss in obesity induced in adolescence may reduce oxidative stress without compromising the haematological status; however, caution may be required to control adiposity, glucose level and liver health. Thus, KD therapy should be carefully controlled, especially in young subjects

Nutritional properties of tubers of conventionally bred and transgenic lines of potato resistant to necrotic strain of Potato virus Y (PVYN)

The potential effect of genetic modification on nutritional properties of potatoes transformed to improve resistance to a necrotic strain of Potato virus Y was determined in a rat experiment. Autoclaved tubers from four transgenic lines were included to a diet in the amount of 40% and compared with the conventional cv. Irga. The experiment lasted 3 weeks and special attention was paid to nutritional properties of diets, caecal metabolism and serum indices. Genetic modification of potato had no negative effect on the chemical composition and nutritional properties of tubers, ecosystem of the caecum, activity of serum enzymes and non-specific defence mechanism of the rats. Obtained results indicate that transgenic potato with improved resistance to PVYN: line R1F (truncated gene coding for PVYN polymerase in sense orientation), R2P (truncated gene coding for PVYN polymerase in antisense orientation), and NTR1.16 (non-translated regions of PVYN genome in sense orientation) are substantial and nutritional equivalence to the non-transgenic cultivar. Tubers of transgenic line NTR2.27 (non-translated regions of PVYN genome in antisense orientation) increased the bulk of caecal digesta and the production of SCFA as compared to tubers of the conventional cultivar and the other transgenic clones. Taking into account some deviations, it seems reasonable to undertake a long-term feeding study to confirm the nutritional properties of tubers of transgenic lines

Using the SPE and Micro-HPLC-MS/MS Method for the Analysis of Betalains in Rat Plasma after Red Beet Administration

The objective of this study was to develop a simple and reproducible method for the qualitative and quantitative analysis of betalains in plasma samples, based on Solid Phase Extraction (SPE) and micro-high performance liquid chromatography coupled with mass spectrometry (micro-HPLC-MS/MS). The eight betalain compounds detected and quantified were characterized in the fortified rat blood plasma samples. The developed method showed a good coefficient of determination (R2 = 0.999), good recovery, precision, and appropriate limits of detection (LOD) and quantification (LOQ) for these compounds. Application of this method for the treatment of rat plasma samples collected after the betalain preparation administration, for the first time, revealed the presence of native betalains and their metabolites in plasma samples. Moreover, among them, betanin (2.14 ± 0.06 µmol/L) and isobetanin (3.28 ± 0.04 µmol/L) were found at the highest concentration. The results indicated that the combination of an SPE method with a micro-HPLC-MS/MS analysis may be successfully applied for the determination of betalains in the blood plasma