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

Fruit Waste as a Matrix of Health-Promoting Compounds in the Production of Corn Snacks

Extrusion is an industrial technology allowing utilization of fruit-based off-products, rich in bioactive and prohealth compounds, in the production of gluten-free snacks. The use of up to 20% fruit waste (apple waste) in the production of such snacks results in significant increases of polyphenols and flavonoids, as well as individual phenolic acids: chlorogenic (36 times) and cryptochlorogenic (4 times). UPLC-PDA-MS/MS method allowed to observe huge increases in phloridzin (25 times), epicatechin (8 times), catechin (up to 6 times), and the end procyanidin (almost 3 times) in corn snacks. The most suitable addition level was 20% because it resulted in the highest increases in the abovementioned compounds and dietary fiber, which provided high antioxidant potential of corn-apple snacks. Therefore, the production of such snacks could be recommended on industrial scale as they have the best organoleptic properties.

The Complex Biological Effects of Pectin: Galectin-3 Targeting as Potential Human Health Improvement?

Galectin-3 is the only chimeric representative of the galectin family. Although galectin-3 has ubiquitous regulatory and physiological effects, there is a great number of pathological environments where galectin-3 cooperatively participates. Pectin is composed of different chemical structures, such as homogalacturonans, rhamnogalacturonans, and side chains. The study of pectin's major structural aspects is fundamental to predicting the impact of pectin on human health, especially regarding distinct molecular modulation. One of the explored pectin's biological activities is the possible galectin-3 protein regulation. The present review focuses on revealing the structure/function relationship of pectins, their fragments, and their biological effects. The discussion highlighted by this review shows different effects described within in vitro and in vivo experimental models, with interesting and sometimes contradictory results, especially regarding galectin-3 interaction. The review demonstrates that pectins are promissory food-derived molecules for different bioactive functions. However, galectin-3 inhibition by pectin had been stated in literature before, although it is not a fully understood, experimentally convincing, and commonly agreed issue. It is demonstrated that more studies focusing on structural analysis and its relation to the observed beneficial effects, as well as substantial propositions of cause and effect alongside robust data, are needed for different pectin molecules' interactions with galectin-3.

Valorization of Bio-Residues from the Processing of Main Portuguese Fruit Crops: From Discarded Waste to Health Promoting Compounds

Food processing generates a large amount of bio-residues, which have become the focus of different studies aimed at valorizing this low-cost source of bioactive compounds. High fruit consumption is associated with beneficial health effects and, therefore, bio-waste and its constituents arouse therapeutic interest. The present work focuses on the main Portuguese fruit crops and revises (i) the chemical constituents of apple, orange, and pear pomace as potential sources of functional/bioactive compounds; (ii) the bioactive evidence and potential therapeutic use of bio-waste generated in the processing of the main Portuguese fruit crops; and (iii) potential applications in the food, nutraceutical, pharmaceutical, and cosmetics industries. The current evidence of the effect of these bio-residues as antioxidant, anti-inflammatory, and antimicrobial agents is also summarized. Conclusions of the revised data are that these bio-wastes hold great potential to be employed in specific nutritional and pharmaceutical applications.

Nutrient digestibility, hindgut metabolites and antioxidant status of dogs supplemented with pomegranate peel extract

The present study assessed the effect of dietary supplementation of pomegranate peel (methanolic) extract (PPE) on the nutrient digestibility, faecal fermentative metabolites and antioxidant status of dogs. Six medium-sized dogs of mixed breeds were allocated to two groups in a replicated cross-over design and fed a basal diet with and without supplementation of PPE at 50 mg/kg body weight. Each of the experimental periods consisted of 30 d, with a 21 d washout period in between. Results indicated that PPE supplementation led to no significant changes in nutrient digestibility except a trend of improvement (P = 0·070) in crude fibre digestibility. PPE supplementation significantly (P < 0·001) influenced faecal pH, ammonia and lactate production, indicative of positive effects of PPE polyphenols. PPE supplementation further increased faecal SCFA concentration accompanied by a reduction (P < 0·01) in branched-chain fatty acids. PPE supplementation also improved (P < 0·05) indices of erythrocytic antioxidants, namely reduced glutathione, catalase, glutathione peroxidase and glutathione S-transferase together with an improvement in lipid peroxidation. Overall, it can be concluded that dietary supplementation with PPE at 50 mg/kg body weight had a positive impact on hindgut fermentation and antioxidant status in dogs, thereby demonstrating its potential as a gut health-promoting nutraceutical.

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 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.

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 β-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 β-glucosidase, β-, 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.

The effects of dietary dried fruit pomaces on growth performance and gastrointestinal biochemistry of turkey poults

One-day-old female turkeys were randomly assigned to five dietary treatments and were fed for 15 weeks diets containing 5% of cellulose (control, C) or 5% of dried fruit pomaces (apple, black currant, strawberry, seedless strawberry; AP, BCP, SP, SSP respectively). In weeks 11-15 of feeding, all diets were supplemented with 2.5% of linseed oil. The crude fibre content of fruit pomaces ranged from 56.5% in AP to 62.9% in SP. In comparison with AP, berry fruit pomaces (BCP, SP and SSP) were characterised by a higher content of neutral detergent fibre - NDF (41.2% vs. 52.7-59.3%) and lignin (13.24% vs. 21.80-25.56%). A monomer analysis revealed that cellulose was the main non-starch polysaccharide (NSP) in fruit pomaces, whereas their pectin content was low. Polyphenol content was determined at below 6 g/kg in AP, at approximately 12 g/kg in BCP and SP, and at 32.8 g/kg in SSP. There were no significant differences (p > 0.05) in final body weight of birds. After 15 weeks of feeding fruit pomaces to turkeys, the relative weight of the small intestine with digesta was higher in group AP, and lower in group SSP, as compared to controls. Dietary fruit pomaces decreased the dry matter (DM) concentration and lowered the pH of the small intestinal digesta, except the AP and SSP treatments respectively. In the caeca, significantly reduced concentrations of ammonia or putrefactive short-chain fatty acids (SCFA) upon dietary fruit pomaces were observed. Fruit pomaces did not influence the concentrations or the total pool of short-chain fatty acids, but led to a significant increase in butyric proportion in the SCFA profile at the expense propionate.

Nutrient digestibility and colonic fermentation processes in species of the families Mustelidae and Canidae fed the same diet

Nutrient digestibility was compared and the influence of colonic fermentation processes on nutrient digestibility was determined in the American mink (Neovison vison) and the silver fox (Vulpes vulpes). It was hypothesized that gut microbiota exert varied effects on digestion processes in the analyzed species. The experiment was performed in December, on a group of 10 male mink and 10 male foxes. All animals were fed identical diets for fur-bearing carnivores, with the following chemical composition (%): dry matter (DM)-33.12, total protein (TP)-12.01, ether extract (EE)-8.64, crude fiber (CF)-12.01, N-free extracts (N-FE)-9.32, and gross energy (GE)-7.313 MJ/kg(-1) . The coefficients of DM, OM, TP and EE digestibility were significantly higher in foxes than in mink. Mink were characterized by significantly higher utilization of N-FE. In foxes, as compared with mink, fermentation rates were higher in the final section of the gastrointestinal tract, which improved nutrient digestibility. In mink, characterized by lower fermentation rates in the colon, increased enzyme secretion by bacterial cells is one of the physiological mechanisms that enable to optimize nutrient absorption in the large intestine.