HEALTH-PROMOTING COMPOUNDS IN FOOD AND FEED: AN IN VITRO APPROACH TO STUDY DIETARY BIOACTIVES

The main aim of this thesis was to study the functional properties of health-promoting compounds in vitro with an emphasis on milk proteins, vitamin E and micronutrients. The health-promoting effects of intact whey and casein proteins were evaluated after in vitro SGD. Permeate (absorbed fraction) and retentate (intestinal fraction) were obtained and used to study their health-effects in vitro. Soya protein was include as non-animal protein in all the experiments performed. Following SGD, the milk proteins exhibited antioxidant activity, ACE-inhibitory activity and tropho-functional properties at the intestinal cell level. The whey protein permeate exhibited a higher ACE-inhibitory activity compared with the casein and soya protein permeate. SGD increased the ACE-inhibitory activity of whey protein and the antioxidant activity of all the protein tested. At specific concentrations, casein, whey and soya proteins were able to modulate intestinal cell viability and the production of intestinal mucus. Moreover, the proliferation of Lactobacillus casei was increased by specific concentrations of whey and casein proteins. Modulations of mucus production and probiotic bacteria growth were observed, and casein was the primary protein that was able to stimulate MUC5AC gene expression and promote Lactobacillus casei growth. Altogether, the analyses of goblet cell proliferation and prebiotic bacterial growth may represent complementary approaches to study the bioactivities and the functions of food proteins in the gut. Additionally, the comparison of the effect of the two major intact milk proteins performed in this thesis could provide valuable information regarding which is more efficacious in improving health. \u3b1-tocopherol has been demonstrated to play an important role in reducing oxidative stress at cellular level, in different in vitro models. Food toxicants, as OTA, have been found to be able of disrupting the cell monolayer and damaging DNA, which leads to cell death. OTA reduced tight junctions protein localization in cell membranes and influenced cell-cell interactions. The immunofluorescence analyses revealed changes in the patterns of occludin and Zo1 proteins in the presence of OTA, compared with control cells. OTA cytotoxic effects were counteracted by the presence of \u3b1-tocopherol. The pre-treatment with \u3b1-tocopherol blocked the loss of occludin protein in the tight junctions of kidney cells treated with OTA. \u3b1-tocopherol supplementation has demonstrated to counteract short-term OTA toxicity at different cellular levels, supporting the defensive role of this compound in the cell membrane. Finally, the in vitro roles of different micronutrients, specifically choline/methionine and different Zn formulations, were determined. Due to their physiological health-promoting effects, both choline/methionine and Zn are commonly used in animal nutrition. The results of this thesis confirmed that under condition of stress, choline and methionine have important roles in enhancing cell viability and counteracting oxidative stress. Specific concentrations of different Zn sources maintained the viability of human and swine intestinal cells, which underlines the beneficial role of Zn in human and swine intestinal epithelia. Overall, these results contribute to the identification of the roles of different dietary health-promoting compounds in human and animal target tissues by making in vitro models an essential tool. However, further in vivo experiments are necessary to extend these in vitro results and to clarify the contributions of health-promoting components in animal feed and human formulations. The improved knowledge related to milk protein bioactives, antioxidants and micronutrients represents a crucial subject for future systematic efforts to improve food and feed quality

Phenomenological study of the atypical heavy flavor production observed at the Fermilab Tevatron

We address known discrepancies between the heavy flavor properties of jets produced at the Tevatron collider and the prediction of conventional-QCD simulations. In this study, we entertain the possibility that these effects are real and due to new physics. We show that all anomalies can be simultaneously fitted by postulating the additional pair production of light bottom squarks with a 100% semileptonic branching fraction.Comment: 30 pages, 13 figures, 3 tables. Submitted to Phys. Rev.

Review: Insects and former foodstuffs for upgrading food waste biomasses/streams to feed ingredients for farm animals

The increasing global need to find alternative protein/energy sources has triggered research in the field of non-conventional feed ingredients, with insects and former foodstuffs being the most promising. Insects contain high level of protein and fat, whereas former foodstuffs contain high energy in the form of carbohydrates and fats; therefore, both should be considered as promising alternative feed ingredients for livestock production. In addition to the nutritional value, they also represent a way by which food waste biomasses/streams can be upgraded to valuable feed ingredients. This review outlines the main nutritional and safety issues of insects and former foodstuffs, and also considers the legal framework involved. The importance of the type of insect metamorphosis and tailored substrates that could lead to the production of a premium feed is also described. This is also the first time that a review discusses the nutritional quality of former foodstuffs. Energy and the main nutrient content of former foodstuff are compared with the composition of common cereals as the principal energy sources in animal feed. For both ingredients a critical review of the safety issues is provided. Based on the current data available, both insects and former foodstuffs have an excellent potential use as alternative feed ingredients for livestock production. When produced in line with the criteria set by major feed/food authorities, they are characterized by high quality and safety standards. This makes them comparable to other feed materials and ingredients currently available on the market, although their full nutritional, functional, safety and sustainability evaluation cannot be considered complete

Short-communication: a comparison of the in vitro angiotensin-1-converting enzyme inhibitory capacity of dairy and plant protein supplements

The consumption of supplements based on dairy or plant proteins may be associated with bioactive potential, including angiotensin-1-converting enzyme inhibitory (ACE-1i) activity, which is linked with blood pressure reduction in vivo. To gain insight into this proposed mechanism, the ACE-1i potential of protein-based supplements, including a selection of dairy (n = 10) and plant (n = 5) proteins were in vitro digested. The total digest was filtered and permeate and retentate were obtained. ACE-1i activity was measured as the ability of proteins (pre-digestion, 'gastric', permeate, and retentate) to decrease the hydrolysis of furanacroloyl-Phe-Glu-Glu (FAPGG) substrate for the ACE-1 enzyme. Permeate and retentate of dairy proteins exerted a significantly higher ACE-1i activity (mean of 10 proteins: 27.05 ± 0.2% and 20.7 ± 0.2%, respectively) compared with pre-digestion dairy proteins (16.7 ± 0.3%). Plant protein exhibited high ACE-1i in 'gastric' and retentate fractions (mean of five proteins: 54.9 ± 0.6% and 35.7 ± 0.6%, respectively). The comparison of the in vitro ACE-1i activity of dairy and plant proteins could provide valuable knowledge regarding their specific bioactivities, which could inform their use in the formulation of specific functional supplements that would require testing for blood pressure control in human randomly-controlled studies

In Vitro Digestion of Chestnut and Quebracho Tannin Extracts : Antimicrobial Effect, Antioxidant Capacity and Cytomodulatory Activity in Swine Intestinal IPEC-J2 Cells

Quebracho (Qu) and chestnut (Ch) are natural sources of tannins and they are currently used in animal nutrition as feed ingredients. However, to date the bio-accessibility, antimicrobial, antioxidant, and intestinal epithelial cell stimulatory doses of Qu and Ch have not been determined. Our study investigates the antioxidant and E. coli F4+ and F18+ growth inhibitory activity of Qu, Ch, and their combinations after solubilization in water (to evaluate the already bio-accessible molecules) and after simulated gastro-intestinal digestion in vitro. The effect of an in vitro digested Ch and Qu combination was also tested on intestinal epithelial IPEC-J2 cells experimentally stressed with hydrogen peroxide (H2O2) and Dextran Sodium Sulfate (DSS). The results showed that undigested Qu and Ch alone, and in combination, exerted a valuable antioxidant capacity and E. coli F4+ and F18+ growth inhibitory activity. The concentration of 1200 \u3bcg/mL exhibited the highest E. coli growth inhibitory activity for all the samples tested. In addition, after in vitro digestion, Qu and Qu50%\u2013Ch50% maintained E. coli growth inhibitory activity and a modest antioxidant capacity. Three hours pre-treatment with in vitro digested Qu50%\u2013Ch50% counteracted the H2O2 and DSS experimentally-induced stress in the intestinal IPEC-J2 cells. Ch and Qu tannin extracts, particularly when combined, may exert E. coli F4+ and F18+ growth inhibitory activity and valuable antioxidant and cell viability modulation activities

Green tea and pomegranate extract administered during critical moments of the production cycle improves blood antiradical activity and alters cecal microbial ecology of broiler chickens

Phytobiotics are usually tested in feed and throughout the production cycle. However, it could be beneficial to evaluate their effects when administered only during critical moments, such as changes in feeding phases. The aim of the trial was to investigate the effect of a commercial plant extract (PE; IQV-10-P01, InQpharm Animal Health, Kuala Lumpur, Malaysia) on growth performance, blood antiradical activity and cecal microbiome when administered in drinking water to broiler chickens during the post-hatching phase and at each change of diet. In the experiment, 480 1-day-old male broiler chicks were assigned to two groups in a 50-day trial. Broilers received drinking water (C) or drinking water plus PE (T) at a rate of 2 mL/L on days 0 to 4, 10\u201311 and 20\u2013 21. PE did not affect performance and water intake, while total antiradical activity was improved (p < 0.05). A greater abundance of lactic acid bacteria (false discovery rate (FDR) < 0.05) was found in the T group and the result was confirmed at a lower taxonomic level with higher Lactobacillaceae abundance (FDR < 0.05). Our findings suggest that PE administration during critical moments of the production cycle of broiler chickens may exert beneficial effects at a systemic level and on gut microbial ecology