This review delves into the concept of nutrition by design, exploring the relationship between poultry production, the utilization of dietary by-products to create functional foods, and their impact on human health. Functional foods are defined as products that extend beyond their basic nutritional value, offering potential benefits in disease prevention and management. Various methods, including extraction, fermentation, enrichment, biotechnology, and nanotechnology, are employed to obtain bioactive compounds for these functional foods. This review also examines the innovative approach of enhancing livestock diets to create functional foods through animal-based methods. Bioactive compounds found in these functional foods, such as essential fatty acids, antioxidants, carotenoids, minerals, vitamins, and bioactive peptides, are highlighted for their potential in promoting well-being and mitigating chronic diseases. Additionally, the review explores the functionality of food components within these products, emphasizing the critical roles of bioaccessibility, bioactivity, and bioavailability in promoting health. The importance of considering key aspects in the design of enhanced poultry diets for functional food production is thoroughly reviewed. The safety of these foods through the establishment of regulations and guidelines was reviewed. It is concluded that the integration of nutrition by design principles empowers individuals to make informed choices that can prioritize their health and well-being. By incorporating functional foods rich in bioactive compounds, consumers can proactively take steps to prevent and manage health issues, ultimately contributing to a healthier society and lifestyle.

As global demand increases for poultry products, innovative feeding strategies that reduce resource efficiency and improve food safety are urgently needed. This paper explores the potential of alternative sustainable poultry feeding strategies aimed at achieving SDG2 (Zero Hunger) while increasing production performance and food quality, focusing on the potential recycling of by-products, plants, and food waste derived from fruits, vegetables, and seeds, which account for up to 35% annually. The paper provides a review analysis of the nutritional (protein, fat, fiber, and ash) and minerals (i.e., calcium, phosphorus, zinc, manganese, copper, and iron) content as well as the bioactive compounds (polyphenols, antioxidants, carotenoids, fatty acids, and vitamins) of alternative feed ingredients, which can contribute to resource efficiency, reduce dependency on conventional feeds, and lower production costs by 25%. The nutritional benefits of these alternative feed ingredients, including their effects on poultry production and health, and their potential for improving poultry product quality, are presented. Carrot, paprika, rosehip, and some berry waste represent a great source of carotenoids, polyphenols, and vitamins, while the seed meals (flax, rapeseed, and sea buckthorn) have been reported to enhance the essential fatty acid composition in eggs and meat. Numerous plants (basil, sage, rosemary, and lettuce) are natural reservoirs of bioactive compounds with benefits for both animal and food products. Some challenges in implementing these alternative sustainable feeding strategies, including inconsistencies in quality and availability, the presence of anti-nutrients, and regulatory barriers, are also explored. In conclusion, future research directions in sustainable poultry feeding with alternative feed ingredients should be considered to achieve SDG2.

The study aims to compare the nutrient composition, antioxidant potential, and polyphenol bioaccessibility of the fruit, leaves, and pomace of black chokeberry. Phytochemical characterization, antioxidant activity, and the effect of in vitro gastrointestinal digestion on the individual phenolic compounds of fruit, leaves, and pomace of black chokeberry were assessed. Results showed that leaves had a higher content of polyphenols (61.06 mg GAE/g dw), flavonoids (8.47 mg QE/g), and tocopherols (1172.20 mg/kg) than fruit (27.99 mg GAE/g dw polyphenols, 5.23 mg QE/g flavonoids, 38.48 mg/kg tocopherols) and pomace (22.94 mg GAE/g dw polyphenols, 1.89 mg QE/g flavonoids and 157.19 mg/kg tocopherols), with superior in vitro antioxidant activity. Chlorogenic acids were the dominant phenolic compounds in black chokeberry undigested samples (2.713 mg/g in fruit, 17.954 mg/g in leaves, and 1.415 mg/g in pomace) but are poorly absorbed (bioaccessibility index in intestinal phase of 28.84% for fruit, 8.81% for leaves, and 31.90% for pomace). Hydroxybenzoic acids were highly stable in leaves and fruit during simulated digestion and had high bioaccessibility. In conclusion, residues from black chokeberry processing are also valuable sources of bioactive compounds, but the pomace had higher polyphenol bioaccessibility than leaves and might be a promising supplement for the food industry.

Inflammatory Bowel Diseases (IBD) are chronic inflammations associated with progressive degradation of intestinal epithelium and impairment of the local innate immune response. Restoring of epithelial integrity and of the mucosal barrier function, together with modulation of inflammatory and innate immune markers, represent targets for alternative strategies in IBD. The aim of our study was to evaluate the effects of a diet including 8% grape seed meal (GSM), rich in bioactive compounds (polyphenols, polyunsaturated fatty acids (PUFAs), fiber) on the markers of colonic epithelial integrity, mucosal barrier function, pro-inflammatory, and innate immunity in DSS-treated piglets used as animal models of intestinal inflammation. Our results have demonstrated the beneficial effects of bioactive compounds from dietary GSM, exerted at three complementary levels: (a) restoration of the epithelial integrity and mucosal barrier reinforcement by modulation of claudins, Occludin (OCCL) and Zonula-1 (ZO-1) tight junction genes and proteins, myosin IXB (MYO9B) and protein tyrosine phosphatase (PTPN) tight junction regulators and mucin-2 (MUC2) gene; (b) reduction of pro-inflammatory MMP-2 (matrix metalloproteinase-2) and MMP-9 (matrix metalloproteinase-9) genes and activities; and (c) suppression of the innate immune TLR-2 (Toll-like receptor-2) and TLR-4 (Toll-like receptor-4) genes and attenuation of the expression of MyD88 (Myeloid Differentiation Primary Response 88)/MD-2 (Myeloid differentiation factor-2) signaling molecules. These beneficial effects of GSM could further attenuate the transition of chronic colitis to carcinogenesis, by modulating the in-depth signaling mediators belonging to the Wnt pathway.

Blackcurrant (Ribes nigrum L.) is a berry bush widely cultivated in Europe for producing juices, jams, jellies, and syrups. In addition to berries, blackcurrant leaves and pomace, as byproducts, have also been shown to have health-promoting effects. Static digestion, simulating oral, gastric, and small intestinal digestion, was applied, and blackcurrant leaves, fruits, and pomace and the polyphenol bioaccessibility were evaluated in terms of recovery index. The results were related to sample type, and the recovery index presented higher values in the case of fruits, indicating this morphological part of blackcurrant as the most bioaccessible. The antioxidant potential of blackcurrant was evaluated using four different methods, with the leaves proving to be a significant and powerful antioxidant compared to fruits and pomace. The counteracting potential of inhibiting the oxidation process was evaluated using in vitro-induced lipid peroxidation and the inhibition potential of superoxide and hydroxyl anions. The antioxidant evaluation and the inhibition of biological and non-biological radicals indicate the leaf extract is the most powerful antioxidant studied. Also, the results proved that not only fruits but also the blackcurrant byproducts (pomace and leaves) are promising sources of bioaccessible antioxidants with potential benefits in animal nutrition.

The goal of this research was nutritional evaluation through the phytochemical analysis of blackberry and raspberry leaves, the screening of their biological activity (antioxidant capacity and inhibition of lipid peroxidation), and the investigation of the effect of in vitro gastrointestinal digestion (GID) of blackberry and raspberry leaves on the bioaccessibility of polyphenol subclasses. The concentrations of the analyzed liposoluble antioxidants were higher (p < 0.05) in blackberry leaves compared to raspberry leaves, while a significant (p < 0.05) higher content of water-soluble antioxidants was registered in raspberry leaves (with a total polyphenol content of 26.2 mg GAE/g DW of which flavonoids accounted for 10.6 mg/g DW). Blackberry leaves had the highest antioxidant capacity inhibition of the superoxide radicals (O₂^•−), while raspberry leaves registered the highest inhibition of hydroxyl radicals (^•OH), suggesting a high biological potency in scavenging-free radicals under in vitro systems. The maximum inhibition percentage of lipid peroxidation was obtained for blackberry leaves (24.86% compared to 4.37% in raspberry leaves), suggesting its potential to limit oxidative reactions. Simulated in vitro digestion showed that hydroxybenzoic acids registered the highest bioaccessibility index in the intestinal phase of both types of leaves, with gallic acid being one of the most bioaccessible phenolics. The outcomes of this investigation reveal that the most significant release of phenolic compounds from blackberry and raspberry leaves occurs either during or after the gastric phase. Knowledge about the bioaccessibility and stability of polyphenol compounds during digestion can provide significant insights into the bioavailability of these molecules and the possible effectiveness of plant metabolites for human health.