Data driven prediction of dairy cattle lifetime production and its use as a guideline to select surplus youngstock.

The lifetime production of dairy cows is a complex trait influenced not only by genetics, but also by the environment in which a cow lives and the management practices of the farmer. Moreover, these influential factors show complex interactions with each other, making it difficult to reliably predict the lifetime production of individual animals at birth. However, since well managed dairy farms often have a surplus of youngstock, reliable lifetime production predictions would offer the opportunity to make more substantiated decisions when selecting calves or heifers to sell. Therefore, using data from Dutch herds, we constructed a data set capturing information on genetics, environment and management practices to develop multiple machine learning models capable of predicting the lifetime production of dairy cattle soon after birth. We found that a coupling of trends observed at the country level with farm-specific models largely outperforms off-the-shelf approaches. At birth, our best model could explain up to 47% of the variance in lifetime production, a considerable improvement in comparison with linear regression on the breeding values supplemented with the average lifetime production at farm level, which could only explain 21.7% of the variance in lifetime production. Moreover, we demonstrated surplus youngstock selection according to our model could more than double the surplus animal selection effect in comparison with the benchmark methodology, offering opportunities to increase the average (future) potential lifetime production of the retained heifers significantly. Assuming a static 20% surplus liveborn heifer scenario and random surplus animal selection as the default, our best model for surplus animal selection resulted in a 9.4% greater lifetime production in the retained animals compared with the current Dutch average lifetime production.

Early life jumping traits: Are they good proxies for success in show jumping competitions in Belgian warmblood horses?

The main goal of the Belgian Warmblood horse studbook (BWP) is to breed successful competition horses, with emphasis on show jumping. However, competition results are only available later in life and competition traits are lowly heritable. Hence, the use of phenotypes that record performance-related traits at an early life stage could help increase genetic progress. In this study, we evaluated the potential of eleven linear scored early life jumping traits assessed during jumping in freedom (2-5 years old) or under the saddle (4-6 years old) as proxies for later success in show jumping competitions. To this end, we estimated their heritabilities and genetic correlations with the competition trait, adjusted fence height, by using 2170 free jumping records, 1588 jumping under saddle records, 674,527 show jumping competition records and almost 81,000 informative horses in the pedigree. As participation of young horses in these contests is on a voluntary basis, a pre-selection most probably exists. To verify this hypothesis, we investigated the association between participation to young horse contests and participation to show jumping competitions later on (called here start status phenotype). We also estimated heritabilities for "start status in free jumping contest", "start status in jumping under saddle contest" and "start status in free jumping or jumping under saddle contest" by fitting threshold models. Furthermore, we calculated genetic correlations between these traits and adjusted fence height and calculated the correlations between EBVs for start status in young horse contests and EBVs for success in competitions. Estimated heritabilities of early life jumping traits ranged between 0.05 and 0.30. Their genetic correlations with adjusted fence height were moderate to high (rg = 0.37-0.63). Relatively more horses that participated in young horse contests competed later on compared to horses that did not participate in young horse contests (p-value < 0.001). They were also significantly more successful in show jumping competitions. Furthermore, start status in young horse contests was moderately heritable in BWP horses (h2 = 0.56-0.65) and moderately to highly correlated with later success in competitions (rg = 0.30-0.77). Hence, we showed that ELJ traits are good proxies for later success in competitions and that a pre-selection of horses occurs in young horse contests. It is suggested to stimulate participation to young horse contests to achieve a more representative sample of the population. Early life jumping traits can therefore optimize the genetic progress for show jumping performance.

Effect of vitamin E level and dietary zinc source on performance and intestinal health parameters in male broilers exposed to a temperature challenge in the finisher period.

The objective of this study was to evaluate the interaction of zinc source (ZnSO4 vs. zinc amino acid complex) and vitamin E level (50 IU vs. 100 IU) on performance and intestinal health of broilers exposed to a temperature challenge in the finisher period. A total of 1224 day old male Ross 308 broilers were randomly distributed among 4 dietary treatments (9 replicates per treatment). Dietary treatments were organized in a 2 × 2 factorial arrangement: two sources of zinc, 60 mg/kg of Zn as ZnSO4 .7H2 O or 60 mg/kg of Zn as zinc amino acid complexes (ZnAA) combined with two levels of vitamin E (50 or 100 IU/kg). Zinc and vitamin E were added to a wheat/rye-based diet that was designed to create a mild nutritional challenge. From day 28 until day 36 (finisher period), all birds were subjected to chronic cyclic high temperatures (32°C ± 2°C and RH 55-65% for 6 h daily). The combination of ZnAA and 50 IU/kg of vitamin E improved weight gain in the starter (day 0-10), finisher (day 28-36) and overall period (day 0-36) and feed conversion ratio in the starter (day 0-10) and finisher phase (day 28-36). Providing Zn as ZnAA significantly improved villus length and villus/crypt ratio in the starter, grower and finisher period and decreased infiltration of T-lymphocytes and ovotransferrin leakage in the finisher period. In conclusion, providing broilers with a diet supplemented with ZnAA and a vitamin E level of 50 IU/kg, resulted in better growth performance as compared to all other dietary treatments. Interestingly, under the conditions of this study, positive effects of ZnAA on performance did not occur when vitamin E was supplemented at 100 IU/kg in feed. Moreover, providing zinc as zinc amino acid complex improved intestinal health.

Weaning affects the glycosidase activity towards phenolic glycosides in the gut of piglets.

Phenolic compounds in pig diets, originating either from feed ingredients or additives, may occur as glycosides, that is conjugated to sugar moieties. Upon ingestion, their bioavailability and functionality depend on hydrolysis of the glycosidic bond by endogenous or microbial glycosidases. Hence, it is essential to map the glycosidase activities towards phenolic glycosides present along gut. Therefore, the activity of three key glycosidases, that is α-glucosidase (αGLU), ß-glucosidase (ßGLU) and ß-galactosidase (ßGAL), was quantified in small intestinal mucosa and digesta of piglets at different gastrointestinal sites (stomach, three parts of small intestine, caecum and colon) and at different ages around weaning (10 days before and 0, 2, 5, 14 and 28 days after weaning). Activity assays were performed with p-nitrophenyl glycosides at neutral pH. The αGLU activities in mucosa and digesta were low (overall means 1.4 and 60 U respectively) as compared to ßGLU (15.2 and 199 U) and ßGAL (23.4 and 298 U; p < .001). Moreover, αGLU activity in mucosa was unaffected by age. Conversely, ßGLU and ßGAL activities dropped significantly after weaning. Minimal levels, ranging between 18% and 54% of the pre-weaning values, were reached at 5 days post-weaning. Similarly, in small intestinal digesta, reductions from 60% up to 90% were observed for the three enzyme activities on day five post-weaning as compared to pre-weaning levels. In caecal contents, activities were lowest at 14 days post-weaning, while in stomach and colon no clear weaning-induced effects were observed. Our data suggest that weaning affects the glycosidase activity in mucosa (mainly endogenous origin) and digesta (primarily bacterial origin) with the most pronounced effects occurring 5 days post-weaning. Moreover, differences in activities exist between different glycosidases and between gut locations. These insights can facilitate the prediction of the fate of existing and newly synthetized glycosides after oral ingestion in piglets.

Differences in muscle histidine-containing dipeptides in broilers.

BACKGROUND: Poultry meat has high levels of histidine-containing dipeptides (HCD) and consumption of meat rich in HCD may elicit certain health benefits. The aim of this work was to compare the HCD content (anserine and carnosine) in the breast and thigh muscles of two broiler strains differing in growth rate, feeding regime, and age at slaughter. A 3 (production system) × 2 (sex) × 2 (age at slaughter) full factorial arrangement was applied with fast-growing Ross 308 chicks fed ad libitum (ROSS-AL), slow-growing Sasso T451 chicks fed ad libitum (SASSO-AL), and Ross 308 chicks given limited feeding (ROSS-LIM). At the age of 40 and 62 days, eight birds per production system × sex combination were randomly selected for sampling of the breast and thigh muscle. Muscle HCD content was determined by high-performance liquid chromatography (HPLC). RESULTS: Across treatments, levels of anserine were 2.5- and 1.9-fold higher than carnosine in breast and thigh muscle respectively (P < 0.001), and levels of anserine and carnosine were 2.2- and 2.8-fold higher respectively in breast versus thigh muscle (P < 0.001). In breast muscle, SASSO-AL had higher levels of HCD than ROSS-AL and ROSS-LIM (P < 0.001). Considering different market meat types, breast muscle of 62-day-old SASSO-AL birds had more than threefold higher content of HCD compared to thigh muscle of 40-day-old ROSS-AL birds (P < 0.001). CONCLUSION: Large differences in muscle HCD content were found, varying according to type of muscle and broiler. © 2019 Society of Chemical Industry.

Effect of temperature and pH on the community dynamics of coagulase-negative staphylococci during spontaneous meat fermentation in a model system.

Coagulase-negative staphylococci (CNS) contribute to the product quality of fermented meats. In spontaneously fermented meats, CNS communities are variable and difficult to predict, as their compositions depend on a superposed combination of different processing factors. To partially disentangle this superposition, a meat model system was used to study the influence of temperature and pH on the CNS community dynamics. Therefore, cured pork mince was prepared that was divided into three batches of different initial acidity levels, namely pH 5.7, pH 5.5, and pH 5.3. These three batches were incubated at three different temperatures, namely 23 °C, 30 °C, and 37 °C. Hence, the experimental set-up resulted in nine combinations of different temperature and initial pH values. Samples were analysed after 3 and 14 days to monitor pH, colony counts, and species diversity of the CNS communities, based on mannitol-salt-phenol-red agar (MSA) medium. At conditions of mild acidity (pH 5.7) and low temperature (23 °C), as often encountered during artisan-type meat fermentations, a co-prevalence of Staphylococcus xylosus, Staphylococcus equorum, and Staphylococcus saprophyticus occurred. At the same initial pH but higher incubation temperatures (30 °C and 37 °C), Staphylococcus lugdunensis became the prevailing CNS species, besides S. saprophyticus (30 °C) and the coagulase-positive species Staphylococcus aureus (37 °C). When the initial pH was set at 5.5, S. saprophyticus was the prevailing CNS species at both 23 °C and 30 °C, but it was replaced by Staphylococcus epidermidis and Staphylococcus simulans at 37 °C after 3 and 14 days, respectively. At the most acidic conditions (pH 5.3), CNS counts declined and many of the MSA isolates were of non-staphylococcal nature. Among others, Staphylococcus carnosus (23 °C), Staphylococcus warneri (30 °C), and S. epidermidis (37 °C) were found. Overall, the results of the present study indicated that the processing factors temperature and pH had a clear impact on the shaping of staphylococcal communities during meat fermentation.

Nutrients Composition in Fit Snacks Made from Ostrich, Beef and Chicken Dried Meat.

The aim of the study was to compare three types of meat snacks made from ostrich, beef, and chicken meat in relation to their nutrients content including fat, fatty acids, heme iron, and peptides, like anserine and carnosine, from which human health may potentially benefit. Dry meat samples were produced, from one type of muscle, obtained from ostrich (m.ambiens), beef (m. semimembranosus), and broiler chicken meat (m. pectoralis major). The composition of dried ostrich, beef, and chicken meat, with and without spices was compared. We show that meat snacks made from ostrich, beef, and chicken meat were characterized by high concentration of nutrients including proteins, minerals (heme iron especially in ostrich, than in beef), biologically active peptides (carnosine-in beef, anserine-in ostrich then in chicken meat). The, beneficial to human health, n-3 fatty acids levels differed significantly between species. Moreover, ostrich jerky contained four times less fat as compared to beef and half of that in chicken. In conclusion we can say that dried ostrich, beef, and chicken meat could be a good source of nutritional components.

Modelling postmortem evolution of pH in beef M. biceps femoris under two different cooling regimes.

A model based on enzyme kinetics was developed to predict differences in postmortem pH change in beef muscles as affected by cooling rate. For the calibration and validation of the model, pH and temperature measurements were conducted at different positions in M. biceps femoris following conventional carcass cooling or faster cooling of the muscle after hot boning. The glycogen conversion, and, hence, the pH fall, was observed to significantly vary with position and cooling regime but only during the initial hours of cooling. Comparison of the cooling regimes indicated that fast cooling following hot boning avoids heat shortening induced by the combined effect of high temperature and low pH.

Reduction in circulating bile acid and restricted diffusion across the intestinal epithelium are associated with a decrease in blood cholesterol in the presence of oat ß-glucan.

Although oat (1,3:1,4)-ß-glucan (BG) has been shown to decrease blood cholesterol in intervention trials, the detailed mechanism is not yet defined, but restricted reabsorption of bile acids (BAs) has been hypothesized. Using pigs as a model for humans we demonstrated that, compared to the control, BG added to the diet for 26 d caused decreases of 24% in blood total BAs (TBAs), 34% in total cholesterol (TC), and 57% in LDL cholesterol (LDL-C) (P < 0.01); decreases of 20% TBA in the midjejunum and terminal ileum (P < 0.01); increases of 80% in cecal total neutral sterols (TNSs) including cholesterol (P < 0.01); a 50% reduction in BA active transport across ex vivo ileum after 40 min (P < 0.001); and 32% decrease in jejunal microvillus heights with apparent increased goblet cell activity. The results suggest that BG not only physically hinders the active reabsorption of BAs and uptake of cholesterol, but also changes the BAs profile with lower circulating levels without excess excretion in the feces, thus resulting in reduced blood TC and LDL-C. Fermentation of sterols reaching the colon enhanced production of therapeutic ursodeoxycholic acid, suppressed toxic lithocholic acid, and decreased the possibility of cholesterol absorption by transforming the latter into coprostanol, a nonabsorbable NS.-Gunness, P., Michiels, J., Vanhaecke, L., De Smet, S., Kravchuk, O., Van de Meene, A., Gidley, M. J. Reduction in circulating bile acid and restricted diffusion across the intestinal epithelium are associated with a decrease in blood cholesterol in the presence of oat ß-glucan.

Intrauterine growth restriction in neonatal piglets affects small intestinal mucosal permeability and mRNA expression of redox-sensitive genes.

Neonates with intrauterine growth restriction (IUGR) show lower efficiency of nutrient utilization compared to normal birth weight (NBW) newborns. This study was conducted using neonatal piglets as a model to test the hypothesis that IUGR affects the intestinal barrier function, intestinal structure, and antioxidant system development during the suckling period. The small intestinal mucosae were obtained from IUGR and NBW littermates in the suckling period (d 0, 3, 8, and 19 postnatal). The epithelial barrier function was assessed by FITC-dextran 4 (FD4) and horseradish peroxidase (HRP) fluxes across the epithelium, histomorphologic measurements, and expression of tight-junction proteins. Redox status represented by the glutathione disulfide/glutathione ratio and malondialdehyde concentrations was determined, whereas mRNA expressions of some redox-sensitive proteins were quantified. Results showed that IUGR piglets exhibited a 2-fold higher intestinal permeability in the proximal small intestine on d 0 (P < 0.05), and this difference between IUGR and NBW piglets was widened to 3 and 4 times for FD4 and HRP, respectively (P < 0.05), on d 3. In accordance, expression of occludin was down-regulated at the transcriptional level in IUGR piglets at d 0 and 19 (P < 0.01). Furthermore, the transcription of heme oxygenase 1, catalase, and thioredoxin reductase genes was down-regulated in IUGR piglets, mainly on postnatal d 0 and 19 (P < 0.01). It appears that IUGR subjects have a lower capacity to mount an antioxidant response in the early postnatal period. Collectively, these results add to our understanding of the mechanisms responsible for intestinal dysfunction in IUGR neonates.

Factors related to the quality of life of older prisoners.

PURPOSES: There is evidence of an increasing emphasis on the relevance of the quality of life-paradigm as an outcome measure for clients in geriatric, forensic, as well as correctional care. This paper aims to explore to what extent variables that were categorized according to the main areas of the Good Lives Model ('the self', 'the body' and 'social life') are related to the quality of life domains of older imprisoned offenders. METHODS: Data were collected by means of a structured questionnaire administered in individual interviews with 93 older prisoners aged 60 years and over in 16 prisons of the Dutch-speaking region in Belgium. Characteristics of the main GLM-areas were identified by specifically designed items as well three validated instruments (psychiatric disorders, loneliness, and frailty). Dependent variables consisted of the four sub-domains of the WHOQOL-BREF instrument which measures quality of life in four domains, namely: (1) physical health, (2) psychological health, (3) social relationships, and (4) environment. Structural equation modelling (SEM) was used for statistical analysis. RESULTS: Individual variables, such as satisfaction with activities, were related to the older prisoners' QoL in several domains simultaneously. Other than suicidal ideation, psychopathological symptoms had no significant relation to quality of life. CONCLUSIONS: Approaches enabling older prisoner to disclose their interests, experiences, and feelings are important in prison. Special attention should be given to psychiatric and age-related symptoms of older prisoners, since they may not be noted by the prison staff, as older prisoners seem to be poorer self-advocates as compared to their younger peers.

Nutritional composition of black soldier fly (Hermetia illucens) prepupae reared on different organic waste substrates.

BACKGROUND: Black soldier fly larvae are converters of organic waste into edible biomass, of which the composition may depend on the substrate. In this study, larvae were grown on four substrates: chicken feed, vegetable waste, biogas digestate, and restaurant waste. Samples of prepupae and substrates were freeze-dried and proximate, amino acid, fatty acid and mineral analyses were performed. RESULTS: Protein content of prepupae varied between 399 and 431 g kg-1 dry matter (DM) among treatments. Differences in amino acid profile of prepupae were small. On the other hand, the ether extract (EE) and ash contents differed substantially. Prepupae reared on digestate were low in EE and high in ash (218 and 197 g kg-1 DM, respectively) compared to those reared on vegetable waste (371 and 96 g kg-1 DM, respectively), chicken feed (336 and 100 g kg-1 DM, respectively) and restaurant waste (386 and 27 g kg-1 DM, respectively). Prepupal fatty acid profiles were characterised by high levels of C12:0 in all treatments. CONCLUSION: Since protein content and quality were high and comparable for prepupae reared on different substrates, black soldier fly could be an interesting protein source for animal feeds. However, differences in EE and ash content as a function of substrate should be considered. © 2016 Society of Chemical Industry.

Oxidation During Digestion of Meat: Interactions with the Diet and Helicobacter pylori Gastritis, and Implications on Human Health.

The last decade has seen epidemiological evidence of a positive association between high consumption of red meat and processed meat and the risk of developing a range of chronic diseases, such as colorectal cancer, cardiovascular disease, and type 2 diabetes. Oxidative stress is potentially involved in this association; however, oxidative stress is likely limited if red meat and processed meat are consumed in moderation, and combined with high intake of fruits and vegetables and low intake of refined sugars. In addition, it appears that some subgroups of the population are more prone to developing oxidative stress-related diseases as a consequence of high red and processed meat consumption. For example, the gastric juice in the inflamed stomach of individuals infected with Helicobacter pylori may be an excellent site for enhanced oxidation following meat consumption. Similarly, patients with inflammatory bowel disease may be at increased risk. Oxidative stress resulting from red or processed meat consumption may mediate the onset and/or progression of a wide range of diseases through various mechanisms, which are discussed in this review.

Mechanisms Linking Colorectal Cancer to the Consumption of (Processed) Red Meat: A Review.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The vast majority of CRC cases have been linked to environmental causes rather than to heritable genetic changes. Over the last decades, epidemiological evidence linking the consumption of red and, more convincingly, of processed red meat to CRC has accumulated. In parallel, hypotheses on carcinogenic mechanisms underlying an association between CRC and the intake of red and processed red meat have been proposed and investigated in biological studies. The hypotheses that have received most attention until now include (1) the presence of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines, two groups of compounds recognized as carcinogenic, (2) the enhancing effect of (nitrosyl)heme on the formation of carcinogenic N-nitroso compounds and lipid peroxidation. However, none of these hypotheses completely explains the link between red and processed red meat intake and the CRC risk. Consequently, scientists have proposed additional mechanisms or refined their hypotheses. This review first briefly summarizes the development of CRC followed by an in-depth overview and critical discussion of the different potential carcinogenic mechanisms underlying the increased CRC risk associated with the consumption of red and processed red meat.

Determination of α-tocopherol by reversed-phase HPLC in feed and animal-derived foods without saponification.

BACKGROUND: The analysis of α-tocopherol in feed and animal-derived foods usually involves a saponification step. However, since saponification often leads to losses of α-tocopherol, a method for the determination of α-tocopherol in feed and in animal-derived foods was developed without a saponification step. RESULTS: In this method, α-tocopherol is extracted with hot ethanol and the co-extracted fat is removed by centrifugation. Removal of the fat fraction is made possible by the addition of water, to achieve an ethanol:water ratio of 40:7, followed by cooling on ice before centrifugation. This procedure allows removal of the fat fraction, while α-tocopherol is retained. Matrices differing in gross composition and α-tocopherol content were analyzed: fresh pork, cooked ham, subcutaneous fat, liver, egg yolk, milk and a compound pig feed. Higher α-tocopherol concentrations were found for this novel method compared to a conventional method with saponification, particularly for subcutaneous fat (P < 0.05). Recoveries were higher (P < 0.05) for the novel method (82-103%), compared to the saponification method (66-90%; for subcutaneous fat < 25%). CONCLUSION: Determining α-tocopherol in feed and animal-derived foods using pure ethanol without saponification results in higher extraction yields and recoveries compared to the saponification method.

Supra-nutritional levels of α-tocopherol maintain the oxidative stability of n-3 long-chain fatty acid enriched subcutaneous fat and frozen loin, but not of dry fermented sausage.

BACKGROUND: Meat products enriched with n-3 fatty acids are more prone to oxidation. The aim was to investigate whether supra-nutritional levels of α-tocopherol can enhance the colour and lipid oxidative stability of n-3 fatty acids enriched dry fermented sausages, frozen loins and subcutaneous fat. Pigs were fed a diet supplemented with 18 g kg(-1) fish oil and 50, 150 or 300 mg kg(-1) α-tocopheryl acetate. The control group received 12 g kg(-1) soy oil and 150 mg kg(-1) α-tocopheryl acetate. RESULTS: α-Tocopherol levels of the frozen loin, dry fermented sausage and subcutaneous fat were elevated as a result of the dietary α-tocopherol supplementation. Lipid oxidation occurred to the same extend in the n-3 fatty acid enriched frozen loins when compared to the control group. In the subcutaneous fat enriched with n-3 fatty acids reduced lipid oxidation was found when comparing 50 mg kg(-1) versus 150 and 300 mg kg(-1) . However, in the dry fermented sausages no such effect was observed and higher TBARS values were found in the n-3 fatty acid enriched sausages compared to the control group. Colour parameters of the loin and subcutaneous fat were not affected, whereas some significant differences in the dry fermented sausages were found. The colour stability of the frozen loins was not affected by the dietary treatments. CONCLUSION: Supra-nutritional levels of α-tocopherol maintain the oxidative stability of n-3 fatty acid enriched frozen loins and subcutaneous fat, but not of dry fermented sausages. © 2016 Society of Chemical Industry.

Arabinoxylan in wheat is more responsible than cellulose for promoting intestinal barrier function in weaned male piglets.

BACKGROUND: The effect of dietary fiber on intestinal function primarily has been ascribed to its interaction with intestinal bacteria in the hindgut, whereas changes in intestinal bacteria in the host have been considered to depend on fiber composition. OBJECTIVES: The objectives of this study were to determine the contribution of the major fiber components to the health-promoting effects of wheat bran on intestinal mucosal barrier function and to elucidate the involvement of microbiota changes in weaned piglets. METHODS: Thirty freshly weaned male piglets were assigned to 5 dietary treatment groups (n = 6) according to litter and weight. The piglets consumed synthetic diets ad libitum for 30 d, including a basal control diet (CON) without fiber components, a wheat bran diet (WB) as reference diet (10% wheat bran), and 3 other diets containing amounts of fiber components equivalent to those in the WB, i.e., an arabinoxylan diet (AX), a cellulose diet (CEL), and a combined arabinoxylan and cellulose diet (CB). RESULTS: The groups consuming diets containing arabinoxylans (i.e., the WB, AX, and CB groups) had increased intestinal secretory immunoglobulin A concentrations, goblet cell number and cecal short-chain fatty acid concentrations, and reduced branched-chain fatty acid concentrations and pH values compared with the CON group. In the WB group, the stimulated secretion of Cl(-) was suppressed (60.8% and 47.5% change in short-circuit current caused by theophylline and carbachol, respectively) in the distal small intestine compared with the CON group. The AX and CB groups also had increased intestinal alkaline phosphatase activities and reduced intestinal transcellular permeability (by 77.3% and 67.2%, respectively) compared with the CON group. Meanwhile, in the WB group, cecal Bacteroidetes and Enterobacteriaceae populations were lower, and the growth of Lactobacillus was higher in the AX and CB groups than in the CON group, whereas no positive effect on intestinal barrier function was observed in the CEL group. CONCLUSION: Arabinoxylan in wheat bran, and not cellulose, is mainly responsible for improving various functional components of the intestinal barrier function and the involvement of microbiota changes.

Bacterial production of conjugated linoleic and linolenic Acid in foods: a technological challenge.

Conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) isomers are present in foods derived from ruminants as a result of the respective linoleic acid (LA) and α-linolenic acid (LNA) metabolism by ruminal microorganisms and in animals' tissues. CLA and CLNA have isomer-specific, health-promoting properties, including anticarcinogenic, antiatherogenic, anti-inflammatory, and antidiabetic activity, as well as the ability to reduce body fat. Besides ruminal microorganisms, such as Butyrivibrio fibrisolvens, many food-grade bacteria, such as bifidobacteria, lactic acid bacteria (LAB), and propionibacteria, are able to convert LA and LNA to CLA and CLNA, respectively. Linoleate isomerase activity, responsible for this conversion, is strain-dependent and probably related to the ability of the producer strain to tolerate the toxic effects of LA and LNA. Since natural concentrations of CLA and CLNA in ruminal food products are relatively low to exert their health benefits, food-grade bacteria with linoleate isomerase activity could be used as starter or adjunct cultures to develop functional fermented dairy and meat products with increased levels of CLA and CLNA or included in fermented products as probiotic cultures. However, results obtained so far are below expectations due to technological bottlenecks. More research is needed to assess if bacterial production kinetics can be increased and can match food processing requirements.

Effect of carnosic acid, quercetin and α-tocopherol on lipid and protein oxidation in an in vitro simulated gastric digestion model.

Carnosic acid, quercetin and α-tocopherol are well-known antioxidants in many biological systems. However, their antioxidative effect during food digestion against lipid and protein oxidation is not well known. Therefore, in this study, an in vitro simulated gastric digestion model was used to investigate their stability during gastrointestinal conditions and their antioxidative properties during low pH digestion. In general, the stability of the antioxidants in the different steps of digestion was in the order of α-tocopherol > quercetin > carnosic acid. Salivary components, as well as the acidity of the gastric juice, were responsible for the reduction in antioxidants. Both α-tocopherol and quercetin were able to lower lipid oxidation during digestion, while the effect on protein oxidation was not clear. In contrast, carnosic acid did not have any effect on lipid oxidation and tended to stimulate protein oxidation. This study clearly demonstrated that the environmental conditions are of major importance to the properties of antioxidant compounds.