Quantitative risk assessment model of the presence of porcine epidemic diarrhea and African swine fever viruses in spray-dried porcine plasma.

Introduction: There are no microbiological regulatory limits for viruses in animal feed and feed ingredients. Methods: A performance objective (PO) was proposed in this study to manufacture a spray-dried porcine plasma (SDPP) batch absent of any infectious viral particles. The PO levels of -7.0, -7.2, and -7.3 log TCID50/g in SDPP were estimated for three batch sizes (10, 15, and 20 tons). Results and discussion: A baseline survey on the presence of porcine epidemic diarrhea virus (PEDV) in raw porcine plasma revealed a concentration of -1.0 ± 0.6 log TCID50/mL as calculated using a TCID50-qPCR derived standard curve. The mean African swine fever virus (ASFV) concentration in raw plasma was estimated to be 0.6 log HAD50/mL (0.1-1.4, 95% CI) during a pre-clinical scenario (collected from asymptomatic and undetected viremic pigs). Different processing scenarios (baseline: spray-drying + extended storage) and baseline + ultraviolet (UV) radiation were evaluated to meet the PO levels proposed in this study. The baseline and baseline + UV processing scenarios were >95 and 100% effective in achieving the PO for PEDV by using different batch sizes. For the ASFV in SDPP during a pre-clinical scenario, the PO compliance was 100% for all processing scenarios evaluated. Further research is needed to determine the underlying mechanisms of virus inactivation in feed storage to further advance the implementation of feed safety risk management efforts globally.

Feeding Spray-Dried Porcine Plasma to Pigs Improves the Protection Afforded by the African Swine Fever Virus (ASFV) BA71∆CD2 Vaccine Prototype against Experimental Challenge with the Pandemic ASFV-Study 2.

This study aimed to evaluate the effects of feeding spray-dried porcine plasma (SDPP) on the protection afforded by the BA71∆CD2 African swine fever virus (ASFV) vaccine prototype. Two groups of pigs acclimated to diets without or with 8% SDPP were intranasally inoculated with 105 plaque-forming units (PFU) of live attenuated ASFV strain BA71∆CD2 and, three weeks later, left in direct contact with pigs infected with the pandemic Georgia 2007/01 ASFV strain. During the post-exposure (pe) period, 2/6 from the conventional diet group showed a transient peak rectal temperature >40.5 °C before day 20 pe, and some tissue samples collected at 20 d pe from 5/6 were PCR+ for ASFV, albeit showing Ct values much higher than Trojan pigs. Interestingly, the SDPP group did not show fever, neither PCR+ in blood nor rectal swab at any time pe, and none of the postmortem collected tissue samples were PCR+ for ASFV. Differential serum cytokine profiles among groups at vaccination, and a higher number of ASFV-specific IFNϒ-secreting T cells in pigs fed with SDPP soon after the Georgia 2007/01 encounter, confirmed the relevance of Th1-like responses in ASF protection. We believe that our result shows that nutritional interventions might contribute to improving future ASF vaccination strategies.

Feeding Spray-Dried Porcine Plasma to Pigs Reduces African Swine Fever Virus Load in Infected Pigs and Delays Virus Transmission-Study 1.

The objective of this study was to evaluate the potential benefits of feeding spray-dried porcine plasma (SDPP) to pigs infected with African swine fever virus (ASFV). Two groups of twelve weaned pigs each were fed with CONVENTIONAL or 8% SDPP enriched diets. Two pigs (trojans)/group) were injected intramuscularly with the pandemic ASFV (Georgia 2007/01) and comingled with the rest of the pigs (1:5 trojan:naïve ratio) to simulate a natural route of transmission. Trojans developed ASF and died within the first week after inoculation, but contact pigs did not develop ASF, viremia, or seroconversion. Therefore, three more trojans per group were introduced to optimize the ASFV transmission (1:2 trojan:naïve ratio). Blood, nasal, and rectal swabs were weekly harvested, and at end of the study ASFV-target organs collected. After the second exposure, rectal temperature of conventionally fed contact pigs increased >40.5 °C while fever was delayed in the SDPP contact pigs. Additionally, PCR Ct values in blood, secretions, and tissue samples were significantly lower (p < 0.05) for CONVENTIONAL compared to SDPP contact pigs. Under these study conditions, contact exposed pigs fed SDPP had delayed ASFV transmission and reduced virus load, likely by enhanced specific T-cell priming after the first ASFV-exposure.

Dietary supplementation with spray-dried animal plasma improves vaccine protection in aged mice.

Background: Senescence is characterized by an aggravated inflammatory state that reduces vaccine responsiveness. Dietary supplementation with spray-dried porcine plasma (SDP) exerts anti-inflammatory effects in different mucosal areas. We aimed to determine if the anti-inflammatory properties of SDP improve the efficiency of immunization in senescent animals. Methods: Experiments were performed in 2-month-old and 6-month-old male SAMP8 mice fed control or SDP (8%) feeds for 4 months. The mice received nasal doses of 2.5 µg of Staphylococcus aureus enterotoxin B (SEB) or vehicle every 15 days (i.e., 3 times). Fifteen days after the last dose, a lethal shock was induced by intraperitoneal administration of SEB and LPS. Results: Immunization increased anti-SEB IgA in intestinal and bronchoalveolar fluid (p < 0.05). After the lethal shock, all immunized aged mice that were supplemented with SDP survived, in contrast to only 66% of those fed the control feed (p < 0.05). Moreover, after the lethal challenge, aged mice showed higher expression levels of pro-inflammatory cytokines (Il-6, Tnf-α, Ifn-γ, and Il-1ß) in jejunal and (Tnf-α, and Il-1ß) in lung tissues (p < 0.05), which were reduced by SDP supplementation (p < 0.05). Furthermore, in senescent mice, SDP supplementation augmented Il-4 and Il-10 expression in both tissues (p < 0.05). Conclusion: SDP reduces the mucosal inflammation associated with aging, improving vaccine protection in senescent mice.

Spray-dried porcine plasma enhances feed efficiency, intestinal integrity, and immune response of broilers challenged with necrotic enteritis.

Re-emergence of enteric diseases in the postantibiotic era has imposed severe loss to the poultry industry leading to the urgent need for appropriate additives to maintain gut health. Recently, more attention has been paid to animal plasma due to its high concentrations of active components such as albumins and globulins. The objective of this study was to evaluate the effects of spray-dried porcine plasma (SDP) supplementation during the starter phase (d 0-10) on growth performance, intestine health, and immune response of broilers under necrotic enteritis (NE) challenge. A total of 720 day-old male broiler parental line chicks (Ross 308) were randomly assigned to a 2 (NE challenge: no, yes) × 2 (SDP: 0, 2%) factorial arrangement with 12 replications of 15 chicks each. To induce NE, birds were inoculated with live Eimeria vaccine on d 9 and Clostridium perfringens on d 14. The body weight of birds and feed consumption were measured per pen on d 8, 10, 24, and 29 to calculate performance parameters. On d 16, three birds per pen were sampled to analyse the intestinal lesion score, gut permeability, villi morphology, relative weight of organs, and immune response. Results showed that SDP improved (P < 0.001) FCR in the pre-challenge phase (d 0-8). The results indicated that supplementing SDP lowered (P < 0.01) FCR at the end of the experiment (d 29). Dietary SDP decreased (P < 0.05) the concentration of FITC-d in serum samples of challenged broilers, although it did not affect the intestinal morphology and lesion score. Birds fed with SDP had a higher (P < 0.05) relative weight of bursa (g/kg live body weight) compared to non-supplemented birds. Supplementing SDP reduced the concentration of interleukin-6 (P < 0.05) and α-1 acid glycoprotein (P = 0.051) in serum samples of broilers. In conclusion, supplementation of SDP in the starter phase enhanced feed efficiency and gut integrity in NE challenged broilers, possibly through manipulating the immune response, while further studies targeting intestinal microflora and key genes are required to explore the mode of action.

Evaluating the Functional Properties of Spray-Dried Porcine Plasma in Gilthead Seabream (Sparus aurata) Fed Low Fish Meal Diets.

Blood by-products are an untapped source of high-quality ingredients for aquafeeds, containing a broad variety of cytokines, hormones, growth factors, proteins, bioactive peptides, and amino acids. The effects of the spray-dried porcine plasma (SDPP), a type of processed animal protein on several immune parameters, were evaluated in sea bream using ex vivo and in vitro assays. In this study, fish were fed with two isoproteic, isolipidic, and isoenergetic diets: control diet (7% fish meal, FM) and SDPP diet (2% FM and 5% SDPP). At the end of the 92-days trial, those fed the SDPP diet were larger in body weight (p < 0.05) without differences in feed conversion ratio (p > 0.05). The ex vivo immune stimulation of splenocytes indicated that SDPP had a beneficial effect in promoting systemic immunity, since the surface cell marker (cd4), pro- (il-1ß), and anti-inflammatory (tgf-ß1) cytokines, and genes involved in humoral immunity (IgM) were up-regulated. The co-culture assays of skin mucus corroborated that SDPP enhanced the antibacterial capacity of mucus against V. anguillarum. In addition, main mucus biomarkers did not show significant differences, except for cortisol levels which were lower in the SDPP diet. The present study indicated that SDPP may be considered a functional ingredient in aquafeeds formulated with low FM levels.

The Neuroprotective Effects of Spray-Dried Porcine Plasma Supplementation Involve the Microbiota-Gut-Brain Axis.

Dietary supplementation with spray-dried porcine plasma (SDP) reduces the Alzheimer's disease (AD) hallmarks in SAMP8 mice. Since gut microbiota can play a critical role in the AD progression, we have studied if the neuroprotective effects of SDP involve the microbiota−gut−brain axis. Experiments were performed on two-month-old SAMP8 mice fed a standard diet and on six-month-old SAMP8 mice fed a control diet or an 8% SDP supplemented diet for four months. Senescence impaired short- and long-term memory, reduced cortical brain-derived neurotrophic factor (BDNF) abundance, increased interleukin (Il)-1ß, Il-6, and Toll-like receptor 2 (Tlr2) expression, and reduced transforming growth factor ß (Tgf-ß) expression and IL-10 concentration (all p < 0.05) and these effects were mitigated by SDP (all p < 0.05). Aging also increased pro-inflammatory cytokines in serum and colon (all p < 0.05). SDP attenuated both colonic and systemic inflammation in aged mice (all p < 0.05). SDP induced the proliferation of health-promoting bacteria, such as Lactobacillus and Pediococcus, while reducing the abundance of inflammation-associated bacteria, such as Johnsonella and Erysipelothrix (both q < 0.1). In conclusion, SDP has mucosal and systemic anti-inflammatory effects as well as neuroprotective properties in senescent mice; these effects are well correlated with SDP promotion of the abundance of probiotic species, which indicates that the gut−brain axis could be involved in the peripheral effects of SDP supplementation.

Purification and identification of a novel hypotensive and antioxidant peptide from porcine plasma.

BACKGROUND: Pig plasma contains a large amount of protein. Porcine plasma polypeptide can be prepared by the enzymatic hydrolysis of porcine plasma protein. The present study investigated the function, structure, and mechanisms of porcine plasma peptides. RESULTS: The results showed that WVRQAPGKGL had a major ability to scavenge hydroxyl radical scavenging activity (HRSA) (35.25%), 2,2'-azino-bis (3-ethylbenzothiazo line-6-sulfonic acid) diammonium salt radical scavenging activity (ABTS RSA) (93.09%) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH RSA) (25.72%), as well as in angiotensin converting enzyme (ACE) inhibition (91.64%). WVRQAPGKGL could inactivate ACE by binding to Zn2+ because of the presence of carboxyl in WVRQAPGKGL. The ACE inhibition, HRSA, and DPPH of synthetic WVRQAPGKGL were improved by 12.70%, 16.06%, and 117.11% respectively after in vitro digestion. It (0.1 mg mL-1 ) also increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) by 59.78%, 69.05%, and 59.06%, and decreased reactive oxygen species (ROS) and malondialdehyde (MDA) by 22.08% and 50.59%, respectively, to protect HepG2 cells induced by H2 O2 . Furthermore, in a spontaneously hypertensive rat (SHR) model, the systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the peptide group (30 mg kg-1 ) both decreased by about 33.33% in comparison with captopril. CONCLUSION: A new difunctional (antioxidant and hypotensive) peptide, WVRQAPGKGL, derived from porcine plasma hydrolyzate was isolated by gel filtration and reverse phase chromatography, and identified by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-1 . The difunctional peptide WVRQAPGKGL from porcine plasma could therefore be used in formulating functional foods or pharmaceuticals. © 2022 Society of Chemical Industry.

Identification of novel antioxidant peptide from porcine plasma hydrolysate and its effect in in vitro digestion/HepG2 cells model.

A novel antioxidant peptide EDEQKFWGK from porcine plasma hydrolysate (PPH) was separated by chromatography, HPLC, and identified by LC-MS/MS. Results showed that EDEQKFWGK had better antioxidant ability (Hydroxyl RAS 32.19%, ABTS RAS 92.93% and DPPH RAS 26.76%) compared with glutathione (30.11%, 82.01%, 26.44%) due to the presence of hydrophobic, aromatic acids (F, W) and acidic amino acids (E, D), decreasing ROS by providing hydrogen atom and chelating metal ions. Furthermore, the antioxidant properties of synthetic EDEQKFWGK still significant despite in vitro digestion because of the production of smaller active peptide. Additionally, it could increase SOD, CAT, GSH-Px to resist oxidative damage in HepG2 cells by inhibiting ROS (O2- , OH·), forming complexes to prevent OH· from destroying DNA and binding to ARE to promote antioxidase expression. Thereby, the novel peptide EDEQKFWGK from porcine plasma had much stable antioxidant properties and hade great potential in formulating functional foods. PRACTICAL APPLICATIONS: This research isolated a novel antioxidant peptide. Moreover, the antioxidant effects of peptide were confirmed under the in vitro digestion model and oxidative damage HepG2 cells model. The results showed the antioxidant peptide could play better effect after digestion and protect the cells from oxidative damage. These data could expand the sequence data of antioxidant peptides and promote the high-value utilization of PPH.

Effect of spray-dried porcine plasma in peripartum sow feed on subsequent litter size.

BACKGROUND: Nutritional strategies for sows designed to reduce peripartum stress are suggested to support postpartum recovery and productivity. Spray-dried plasma (SDP) in sow feed has been reported to benefit sow and litter performance. Stressed animals fed diets with SDP have a more efficient immune response supporting animal recovery and health. The objectives of the present study using 452 sows (147 parity 1 sows, 148 parity 2 sows) were to determine if 0, 0.5 or 2.5% spray-dried porcine plasma (SDPP) in peripartum feed provided from entry in maternity through day 5 of lactation affects sow productivity and serological immune and oxidation status markers around parturition. Post-weaning sow productivity parameters including litter size at the next parturition was evaluated, but peripartum diets were only provided during the first parturition. RESULTS: In the first parturition, total born litter size was lower (P <  0.05) especially for sows allotted to the peripartum diet with 2.5% SDPP. Percentage of stillborn pigs decreased quadratically (P <  0.05) for sows fed 0.5% or 2.5% SDPP compared to 0% SDPP in peripartum feed and this result was not affected by total born litter size. Serum glutathione peroxidase activity linearly increased (P <  0.01) with increased dietary SDPP for both prepartum and postpartum sampling periods. In the next parturition, total born pigs from combined data of parity 1 and 2 sows linearly increased (P <  0.05) and live born pigs tended (P = 0.09) to linearly increase as level of SDPP increased and this result was not affected by total born litter size in the first parturition. The change in total and live born pigs from the first to the next parturition linearly (P <  0.01) increased as dietary SDPP increased for parity 1 and 2 sows. CONCLUSIONS: The reduced percentage of stillborn pigs and increased litter size of parity 1 and 2 sows in the next parturition was independent of total born litter size in the first parturition suggesting SDPP in peripartum sow feed may have merit for reducing stillborn pigs and benefit litter size in the next parturition for parity 1 and parity 2 sows.

Effect of porcine plasma hydrolysate on physicochemical, antioxidant, and antimicrobial properties of emulsion-type pork sausage during cold storage.

This study evaluated the effect of porcine plasma hydrolysates (PPH) on the physicochemical, antioxidant, and antimicrobial properties of emulsion-type pork sausages. Five levels of PPH were added to sausages (CON, 0 g/kg; T1, 5 g/kg; T2, 10 g/kg; T3, 15 g/kg; and T4, 20 g/kg) and their chemical composition, purge loss, lipid oxidation, microbial count, pH, color, texture, and sensory properties were compared on day 1 and after 4 weeks of cold storage. At 4 weeks of storage, hardness, cohesiveness, and gumminess were highest in T3 (P < 0.05). The peroxide value increased in all treatments during the 4-weeks of storage (P < 0.05); however, it was not significantly different between CON, T2, and T3 (P > 0.05). The total aerobic plate count was the lowest in T4 at week 4 (P < 0.05). Therefore, PPH addition could improve the texture of the emulsion-type pork sausages, and an antimicrobial effect was expected following exposure to at least 20 g/kg PPH.

The Canadian 2014 porcine epidemic diarrhoea virus outbreak: Important risk factors that were not considered in the epidemiological investigation could change the conclusions.

The introduction and spread of porcine epidemic diarrhoea virus (PEDV) in North America resulted in significant death loss in the swine industry. As the industry learned how to manage this disease, many new risks were identified, including the potential for feed and feed ingredients to become contaminated and spread PEDV. In addition, biosecurity practices were reevaluated and strengthened throughout the industry. At the time of the outbreak epidemiologists did not understand, as well as they are understood today, all the risk factors that contribute to the spread of PEDV. As a result, the epidemiological investigations into the 2014 PEDV outbreak in eastern Canada may not have investigated all risk factors as thoroughly as they would be investigated today. In retrospect, many of the Bradford Hill criteria used to determine causation were not fulfilled. This review identifies risk factors that were not included in the 2014 epidemiology. If these risk factors were included in the epidemiology, the conclusions and determination of causation may have been different.

UV-C irradiation is able to inactivate pathogens found in commercially collected porcine plasma as demonstrated by swine bioassay.

Liquid porcine plasma is an animal origin raw material for the manufacturing process of spray-dried porcine plasma that is used in pig nutrition worldwide. In previous studies we found that the application of ultraviolet light C (UV-C) in liquid plasma that was inoculated with a variety of bacteria or viruses of importance in the swine industry can be considered as redundant safety steps because in general achieve around 4 logs reduction for most of these pathogens. However, the final validation of the UV-C light as safety feature should be conducted with commercial liquid plasma and using the pig bioassay model. As a first objective, the potential infectivity of a raw liquid plasma product collected from an abattoir was tested by means of a swine bioassay. We used Porcine circovirus 2 (PCV-2), a ubiquitous virus that has been systematically detected by PCR in porcine plasma at abattoirs as selection criteria for commercial liquid plasma lot. As a second aim of the study, the effects of different doses of UV-C irradiation on the selected raw liquid plasma were assayed in the animal bioassay. Moreover, other swine infecting agents, including Porcine reproductive and respiratory syndrome virus (PRRSV), were also determined in the original plasma and monitored in the inoculated animals. Pigs negative for PCV-2 and PRRSV genome and antibodies were allotted to one of five groups (6 to 8 pigs/ group) and injected intra-peritoneally with 10 mL of their assigned inoculum at 50 d of age. Negative control pigs (group 1) were injected with PBS. Positive control pigs (group 5) were injected with a PCV-2 inoculum. Groups 2, 3 and 4 were injected with liquid porcine plasma that had been subjected to 0 (raw plasma), 3000 or 9000 J/L UV-C irradiation, respectively. Group 2 pigs (0 J/L UV-C) got infection by PRRSV but no PCV-2 infection or seroconversion. However, one pig from group 2 seroconverted to Rotavirus A (RVA) and Hepatitis E virus (HEV) and three group 2 pigs seroconverted to Porcine parvovirus (PPV). Groups 1, 3 and 4 pigs showed no evidence of infection or seroconversion associated with the tested viruses or any other pathogens found in the liquid plasma before UV-C irradiation. Group 5 pigs developed PCV-2 infectivity as expected. UV-C irradiation of liquid plasma at 3000 and 9000 J/L was effective in preventing PRRSV and other pathogens transmission. Moreover, raw liquid plasma was non-infectious for PCV-2 in naïve pigs.

Development and validation of an ultra-high performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of iohexol, p-aminohippuric acid and creatinine in porcine and broiler chicken plasma.

In order to study the renal function, in terms of glomerular filtration and effective renal plasma flow, in broiler chickens and pigs, an ultra-high performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of iohexol, p-aminohippuric acid (PAH) and exogenously administered creatinine in plasma was developed and validated. Sample preparation consisted of a deproteinization step using methanol for porcine plasma and an Ostro™ Protein Precipitation & Phospholipid Removal Plate was used for broiler chicken plasma. Chromatographic separation was achieved on a Hypersil Gold aQ column using 0.1% formic acid in water and 0.1% formic acid in methanol as mobile phases. The total run time was limited to 10 min. Matrix-matched calibration curves for iohexol and PAH were prepared and good linearity (r ≥ 0.9973; gof ≤ 6.17%) was achieved over the concentration range tested (0.25-90 µg/mL). Limits of quantification were 0.25 µg/mL for iohexol and PAH. Water was used as surrogate matrix for analysis of creatinine in plasma. This surrogate calibration curve showed good linearity over the concentration range tested (0.25-90 µg/mL) (r ≥ 0.9979; gof ≤ 5.66%). For creatinine, the relative lower limit of quantification was 201.03 ±â€¯49.20% and 60.14 ±â€¯7.64% for chicken and porcine plasma, respectively. The results for within-day and between-day precision and accuracy fell within the specified ranges. This straightforward, cost-effective and rapid method, determining iohexol, PAH and creatinine within one single chromatographic run, has been successfully used for the analysis in porcine and broiler chicken plasma samples in order to determine the renal function of these species.

Study on inactivation of porcine epidemic diarrhoea virus, porcine sapelovirus 1 and adenovirus in the production and storage of laboratory spray-dried porcine plasma.

AIM: Evaluation of the thermal and physical conditions for inactivation of adenovirus (AdV), porcine sapelovirus 1 (PSV1) and the economically important viruses porcine epidemic diarrhoea virus (PEDV) and porcine circovirus 2 (PCV2) in the production of spray-dried porcine plasma (SDPP). METHODS AND RESULTS: Citrate-treated porcine plasma of pH 7·5, 9·8 and 10·2 (8·5% dry-matter) was spiked with PEDV, PSV1, PCV2 and AdV and incubated at 3°C for maximum 24 h, and at 44 or 48°C for maximum 10 min (Experiment 1). Spiked citrate-treated concentrated plasma of pH 7·5 and 9·8 (24% dry-matter) was spray dried in a laboratory scale apparatus (Experiment 2). Aliquots of SDPP were stored over a period of 0-10 weeks at 11 and 20°C (Experiment 3). Reverse transcription(RT)-quantitative PCR detected no notable reduction in viral genomes in treated plasma and SDPP samples. No infectious PSV1 was re-isolated from plasma and SDPP samples in cell culture. At pH 10·2 and 3°C, infectivity of PEDV in plasma was reduced with a reduction factor of 4·2 log 10 (LRF) at 10 h contact time, whereas heating to 44°C for at least 1 min at alkali pH was needed to achieve a LRF of 4·2 for AdV. Spray drying at an outlet temperature of 80°C reduced AdV infectivity effectively (LRF = 5·2) and PEDV infectivity for 95% (LRF = 1·4). After storage at 20°C for 2 weeks no infectious PEDV was re-isolated from SDPP anymore (LRF ≥4·0). Due to growth of antibiotic-resistant bacteria from plasma in cell cultures used for PCV2 isolation, no data regarding inactivation of PCV2 were obtained. CONCLUSIONS: Five percent of PEDV stayed infectious after our spray drying conditions. Spray drying in combination with storage for ≥2 weeks at 20°C eliminated infectivity of PEDV effectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The conditions for inactivation of virus in plasma and SDPP determined are important for producers to inactivate PEDV during production of SDPP.

In vitro protein digestion kinetics of protein sources for pigs.

In current feed evaluation systems, the nutritional value of protein sources in diets for pigs is based on the ileal digestibility of protein and amino acids, which does not account for the kinetics of protein digestion along the gastrointestinal tract. The objective of the present study was to determine the in vitro protein digestion kinetics of different protein sources (soya bean meal (SBM), wheat gluten (WG), rapeseed meal (RSM), whey powder (WP), dried porcine plasma protein, yellow meal worm larvae and black soldier fly larvae (BSF)). Protein sources were incubated with pepsin at pH 3.5 for 0 to 90 min and subsequently with pancreatin at pH 6.8 for 0 to 210 min at 39°C. The in vitro protein digestion kinetics were described as the kinetics of nitrogen (N) solubilisation and the release of low molecular weight peptides (LMW) (<500 Da). The N solubilisation rate ranged from 0.025 min-1 for BSF to 0.685 min-1 for WP during the incubation with pepsin, and from 0.027 min-1 for RSM to 0.343 min-1 for WP during the incubation with pancreatin. The release rate of LMW peptides ranged from 0.027 min-1 for WG to 0.093 min-1 for WP during the incubation with pepsin, and from 0.029 min-1 for SBM to 0.385 min-1 for WP. Black soldier fly larvae showed a similar release rate of LMW peptides as WP during the incubation with pancreatin. At the end of the sequential incubation with pepsin (90 min) and pancreatin (210 min), WG and WP showed the highest percentage of N present in LMW peptides relative to total N (78% and 79%, respectively), whereas SBM showed the lowest (35%). In conclusion, protein sources for pig diets show substantial differences in in vitro protein digestion kinetics as measured by the kinetics of N solubilisation and the release of LMW peptides. The rate of release of LMW peptides was not correlated to the rate of N solubilisation for each of the protein sources evaluated.

Evaluation of ultraviolet-C and spray-drying processes as two independent inactivation steps on enterotoxigenic Escherichia coli K88 and K99 strains inoculated in fresh unconcentrated porcine plasma.

The objectives of this study were to assess the effectiveness of an ultraviolet (UV-C, 254 nm) irradiation system and the spray-drying method as two independent safety steps on inactivation of Escherichia coli K88 and K99 spiked in porcine plasma at 6·46 ± 0·04 log10  ml-1 and 6·78 ± 0·67 log10  ml-1 respectively for UV-C method, and at 7·31 ± 0·39 log10  ml-1 and 7·66 ± 0·11 log10  ml-1 , respectively for the spray-drying method. The UV-C method was performed at different UV light doses (from 750 to 9000 J l-1 ) using a pilot plant UV-C device working under turbulent flow. Spray-drying treatment was done at inlet temperature 220 ± 1°C and two different outlet temperatures, 80 ± 1°C or 70 ± 1°C. Results indicated that UV-C treatment induced a 4 log10 viability reduction for both E. coli at 3000 J l-1 . Full inactivation of both E. coli strains was achieved in all spray-dried samples dehydrated at both outlet temperatures. The special UV-C system design for turbid liquid porcine plasma is a novel treatment that can provide an additional redundant biosafety feature that can be incorporated into the manufacturing process for spray-dried animal plasma. SIGNIFICANCE AND IMPACT OF THE STUDY: The safety of raw materials from animal origin such as spray-dried porcine plasma (SDPP) may be a concern for the swine industry. Ultraviolet treatment at 254 nm (UV-C) of liquid plasma has been proposed as an additional biosafety feature in the manufacturing process of SDPP. We found that UV-C exposure in the liquid plasma at 3000 J l-1 reduces about 4 log10 ml-1 for E. coli K88 and K99. Full inactivation of both E. coli strains was achieved in all spray-dried samples. The incorporation of UV-C treatment to liquid plasma improves the robustness of the SDPP manufacturing process.

Sensitivity of African swine fever virus (ASFV) to heat, alkalinity and peroxide treatment in presence or absence of porcine plasma.

African swine fever virus (ASFV) is a highly resistant viraemic virus with devastating socio-economic impact. Its present epidemiology in Eastern Europe and Russia warrants increased biosecurity measures in Western Europe. This includes proactive precautions on traffic of pork products within and between areas that are officially free from ASF. Namely, delayed notification of clinical signs or introduction of a low-virulent strain in ASF-free areas could result in presence of ASFV in veterinary inspected pork and pork by-products. The present study evaluated sensitivity of ASFV to physical and chemical processing conditions that can be applied on abattoir collected blood for production of spray dried porcine plasma (SDPP). Standard endpoint dilution assays were used to determine the sensitivity of Vero-cell adapted Lisbon/60 strain ASFV to heat treatment (H) at alkaline conditions (A) with or without peroxide (P). Time (T) dependent inactivation was evaluated in presence or absence of porcine plasma. HAPT-treatment at H = 48 °C, A = pH 10.2 and P = 20.6 or 102.9 mM H2O2 during 10 min (T) inactivated (95LCL) 3.35, respectively, 4.17 log10 TCID50 ASFV/ml plasma. In absence of plasma, 6.99 log-inactivation was reached within 5 min. Implementation of HAPT-treatment on plasma from ASFV-free areas provides an additional safety hurdle for derived blood products in the unlikely event that blood from few undetected infected pigs would contaminate pooled veterinary inspected blood. Such an additional processing step in the production of SDPP is thus a valuable precautionary measure to overcome a potential biosecurity-break that may arise during the high-risk phase between transboundary introduction of ASFV and first notification of the disease.

Short-term retrogradation behaviour of corn starch is inhibited by the addition of porcine plasma protein hydrolysates.

The potential inhibition of porcine plasma protein hydrolysates (PPPH) on the short-term retrogradation of corn starch (CS) was investigated. Compared with native CS, PPPH significantly enhanced breakdown and decreased the total setback in a rapid visco analyser (RVA) measurement (P < 0.05). Dynamic time sweep analysis of pre-prepared gelatinized samples showed a decrease in the storage modulus (G') and increase in the loss tangent (tan δ) in the presence of PPPH. Differential scanning calorimetry results showed that PPPH significantly reduced the gelatinization enthalpies (ΔHg) and retrogradation enthalpies (ΔHr) of CS (P < 0.05). Fourier transform infrared spectroscopy analysis indicated that the addition of PPPH decreased the amount of hydrogen bonds within starch. Low field nuclear magnetic resonance results showed that the addition of PPPH has an important role in increasing the mobility of water molecules and blocking the short-term retrogradation of CS. X-ray diffraction results showed that the peaks at 2θ close to 17-18° were progressively decreased to smaller angles with increasing PPPH concentrations. This phenomenon indicated that PPPH could interact with amylose and cause lattice distortion, which reduced the starch retrogradation. The results demonstrate that the addition of PPPH plays a crucial role in interfering with short-term retrogradation of CS.

Structural characteristics of low bitter and high umami protein hydrolysates prepared from bovine muscle and porcine plasma.

The aim of this study was to use different enzyme mixtures to investigate the influence of peptide characteristics and taste of protein hydrolysates from bovine muscle and porcine plasma. Minced beef and porcine plasma were hydrolysed using 10 food-grade enzymes, including Protease A, Protease P, ProteAX, Flavourzyme, Alcalase, Papain, Bromelain, Protamex, Neutrase and Sumizyme BNP-L. The relationship between degree of hydrolysis (DH), molecular weight (MW) distribution, enzyme specificity, and sensory characteristics of hydrolysates were investigated. The results demonstrated that Protease A, a mixture of endo- and exo-peptidases, was the optimal protease to generate hydrolysates with low bitterness. Endopeptidases (Papain and Bromelain) elicited bitter taste of protein hydrolysates. A positive correlation was suggested between umami taste and MW distribution (<0.5 kDa), while bitterness was positively correlated with MW distribution (0.5-1 kDa). Overall, hydrolysis with enzyme preparations containing endo- and exo-peptidases was effective to reduce bitterness of hydrolysates.