Closing the loop, adding value

This article describes an innovation which uses waste blood from meat processing to create a valuable bio-based plasti

Single screw extruder performance characteristics during processing of corn protein blends

During the last decade, the global biofuels industry has experienced exponential growth. By-products such as distillers dried grains with solubles (DDGS) have grown in parallel. DDGS is primarily an animal feed, but it has also been shown to be suitable as a biopolymer. In this study, the extrusion processing behaviour of DDGS was evaluated. Prior to processing, water was added to DDGS at a level of 3 kg DDGS to 1.5 kg water (water at 50 parts per hundred (pph)). Additionally, a DDGS/water blend with 50 pph CaCO₃ was used as a tracer to determine residence time during processing. The blends were processed in a single screw autogenous extruder, which relied solely upon friction for dissipative heating. Two die plates were used: one consisted of 6 orifices equally spaced, 2 mm diameter each, with a total opening area of 18.85 mm²; the other consisted of multiple orifices (960 in total) arranged concentrically around the plate, with a diameter of 2.30 mm each, for a total opening area of 3988.45 mm². Processing began with DDGS blends without tracer; after reaching steady state, the tracer blend was introduced. Samples were collected every 5 sec during processing to determine extrudate changes over time. Extruder power consumption, mass flow rate, and temperature profile were determined during processing. Extrudates were analysed for Hunter colour (L-a-b) changes over time. Extrusion processing characteristics were highly influenced by the die opening area. Die exit temperatures ranged from room temperature (25°C) to more than 100°C, purely due to increased friction for the smaller die opening. Future work should characterize the mechanical properties of these extrudates to assess their suitability as either bioplastic feedstocks or pelletized animal feeds

Processibility of corn protein blends and resulting properties of the extrudates

During the last decade, the global biofuels industry has experienced exponential growth. By-products such as high protein corn gluten meal (CGM) and high fibre distillers dried grains with solubles (DDGS) have grown in parallel. CGM has been shown to be suitable as a biopolymer; the high fibre content of DDGS reduces its effectiveness, although it is considerably cheaper. In this study, the processing behaviour of CGM and DDGS blends were evaluated and resulting extrudate properties were determined. Prior to processing, urea was used as a denaturant. DDGS:CGM ratios of 0, 33, 50, 66 and 100% were processed in a single screw extruder, which solely used dissipative heating, with a 2 mm circular die. Resulting screw speeds ranged from 216 to 228 rpm, and die exit temperatures ranged from 96 to 150oC. Blends containing DDGS were less uniformly consolidated and resulted in more dissipative heating. Blends showed multiple glass transitions, which is characteristic of mechanically compatible blends. Transmission electron microscopy revealed phase separation on a micro-scale, although distinct CGM or DDGS phases could not be identified. On a macro-scale, optical microscopy suggested that CGM-rich blends were better consolidated, supported by visual observations of a more continuous extrudate formed during extrusion. As with all biological materials, the extruded blends exhibited sorption behaviour over time, the magnitude of which varied according to blend ratio. EMC values ranged from approximately 0% to nearly 50%, depending upon the humidity level and blend ratio. Nonlinear regression was successfully used to model the effects of relative humidity and blend ratio on the equilibrium moisture contents, with a coefficient of determination of 99%. Future work should aim to also characterize the mechanical properties of these blends to assess their suitability as either bioplastic feedstock or pelletized livestock feed

Log Skeletons: A Classification Approach to Process Discovery

To test the effectiveness of process discovery algorithms, a Process Discovery Contest (PDC) has been set up. This PDC uses a classification approach to measure this effectiveness: The better the discovered model can classify whether or not a new trace conforms to the event log, the better the discovery algorithm is supposed to be. Unfortunately, even the state-of-the-art fully-automated discovery algorithms score poorly on this classification. Even the best of these algorithms, the Inductive Miner, scored only 147 correct classified traces out of 200 traces on the PDC of 2017. This paper introduces the rule-based log skeleton model, which is closely related to the Declare constraint model, together with a way to classify traces using this model. This classification using log skeletons is shown to score better on the PDC of 2017 than state-of-the-art discovery algorithms: 194 out of 200. As a result, one can argue that the fully-automated algorithm to construct (or: discover) a log skeleton from an event log outperforms existing state-of-the-art fully-automated discovery algorithms.Comment: 16 pages with 9 figures, followed by an appendix of 14 pages with 17 figure

Blends of linear-low-density polyethylene and thermoplastic bloodmeal using maleic anhydride grafted polyethylene as compatibilizer

Linear Low-Density Polyethylene (LLDPE) was blended with Novatein Thermoplastic from bloodmeal (NTP.) The compatibilizing effect of maleic anhydride grafted polyethylene (PE-g-MAH) on mechanical, morphology thermal properties and water absorption were studied and compared with blends without compatibilizer .The amount of polyethylene added was varied between 20% to 70% with 10% of compatibilizer. An improvement in compatibility between NTP and LLDPE was evident across the entire composition range only when using compatibilizer. The tensile strength of blends decreased over that pure LLDPE, but never dropped below that of pure NTP. Results showed that blending NTP with LLDPE decreased water absorption significantly, even more so using a compatibilizer. The result is a more water stable material

Biofibre production from chicken feather

The global poultry industry generates at least 2 million tonnes of chicken feather every year. Feather fibre has potential as reinforcement for polymer composites with light-weight, thermal insulation and acoustic dampening properties. This study aimed to develop a process to produce clean fibre recovered from chicken feather. Raw feather was decontaminated by 0.15% sodium hypochlorite in 25 L water at pH 10.0 for two 30 min stages and cleaned by 0.15% hydrogen peroxide in 25 L water for three 30 min stages. Cleaned feather was comminuted in 300 L water using a centrifugal pump at 30 Hz impeller speed on full recycle for 4 h. Rachis and partially cut feather were removed using a 5 mm filter and fibre was recovered using a 1 mm filter. Wet fibre was dried in an air-forced oven at 70°C. Morphological studies revealed fibre surface remained intact after the treatment process

Development of blood meal protein thermoplastic

Polymers are blended with other polymers to combine their properties or improve physical characteristics and blending turns to be the most reliable techniques compare to synthesis of chemically new polymers. In the research of sustainable materials from non-potential food sources, bloodmeal is one of the best candidates for bioplastic manufacture. It is one of the highest non-synthetic sources of nitrogen coming from meat processing and approximately 80000 tonnes of raw blood is collected annually in New Zealand. Natural polymers often present processing difficulties as well as maintaining product quality over extended periods because of their hydrophilic nature. Blending bloodmeal with other polymers may offer a solution to this problem. However, most blends are immiscible, and the processing are challenging because of dissimilar nature of natural and synthetic polymer, thus requiring compatibilization to achieve good blends performance. The process to solve incompatibility is the compatibilizer should migrate to the interface, reducing the interfacial tension, stabilizing the blend morphology and improving the adhesion between phases in solid state, hence improving the mechanical properties. True thermodynamic term of miscibility of polymer blends is a mixture containing two or more components that form one phase system but this determination of miscibility may be rather ambiguous. In practice, polymer blend compositions is said compatible if they exhibit two phases on a microscopic level but the interactions between polymer groups might be reasonable in a manner that provides useful properties of the multicoponent system. In many instances, it is desirable to have two phases present, as long as we can control the multicomponent systems which depend on their structure, polymer interactions and phase sizes. We have identified several strategies in order to improve miscibility; 1. Addition of a small quantity of a third component that is miscible with both phases 2. Addition of a copolymer whose one part is miscible with one phase and another with another phase 3. Compounding blends in the presence of chemical reactants that lead to modification of at least one macromolecular species (reactive compatibilization), resulting in generation of an in-situ desired quantity of compatibilizer. The propose of this paper is to explore the potential of blending bloodmeal with other thermoplastic by taking account the type of polymer, type of compatibilization and processing condition in order to improve processability and mechanical properties

Toward immune intervention in MS

Towards immune intervention in MS The aim of the studies described in this thesis was to modulate the immune responses that are believed to be involved in MS. This is a disease that is characterized by inflammation of the CNS resulting in neuronal dysfunction. Local inflammatory lesions contain T cells, macrophages and monocytes and are accompanied by the production of cytokines and chemokines. In our research group, we hypothesize that the myelin-associated protein aB-crystallin plays a key role in the CNS inflammatory disease MS. This notion is based on studies that have shown that aB-crystallin is the dominant antigen in MS-affected myelin for human T cells. In both patients and healthy subjects a strong peripheral aB-crystallin reactive memory T-cell response exists qualifying it as a potential autoimmune target in MS. Also, as shown in this thesis, readily detectable antibody levels exist in human serum that are selectively directed at aB-crystallin. These results indicate that there is not an unusual peripheral immune response in MS but rather a local CNS problem causing local inflammation. Thus, our present view of the immune responses that take place in MS is that they consist of a combination of a pre-existing peripheral T-cell response to aB-crystallin together with increased expression and presentation of aB-crystallin due to local CNS inflammation. Although aB-crystallin-reactive-T cells as such are not considered as the primary cause of CNS inflammation, they are believed to aggravate such inflammation to clinically overt levels. This would be consistent with the apparent lack of differences between the T-cell and antibody repertoires of MS patients on the one hand and of healthy controls on the other. An animal model that combines a pro-inflammatory T-cell response against aB-crystallin and local CNS inflammation is still lacking. Therefore, commencing our study of immune modulatory methods, we first developed an animal model that combines both these immunological events. This combination is in line with our present views as to the relevant immune response in MS. CNS inflammation in animal models may be induced by immunization with myelin proteins, generating myelin-specific T cells. The presence of these T cells results in CNS damage in genetically susceptible mice. Despite extensive efforts, very few clinical or histological signs of CNS inflammation have been detected in rodents after immunization with aB-crystallin. This is because these rodents are fully tolerant to aB-crystallin in contrast to humans. Therefore, we used aB-crystallin-/- mice to generate aB-crystallin-specific T cells. We first showed that transfer of aB-crystallin reactive T cells obtained from aB-crystallin-/- mice into MHC-compatible wildtype mice in the absence of any CNS stress, did not induce any form of CNS inflammation. Hence these T cells are not encephalitogenic when present in the periphery even in large numbers. Yet, when recipient mice were infected with the neurotropic Semliki Forest virus followed by a transfer of aB-crystallin-reactive T cells, these mice developed mild yet clear signs of acute EAE. In this model we confirmed that aB-crystallin-reactive T cells alone are not encephalitogenic but become so when an expedient pro-inflammatory environment in the CNS promotes the influx of T cells and local functional presentation of aB- crystallin to these T cells. Mice deficient in aB-crystallin themselves also turned out to be very useful in studying immune modulation of aB-crystallin-specific immune responses. These mice developed a T-cell response against aB-crystallin together with an antibody response against this protein. Such an antibody response is also detected in humans. In this thesis, antibody levels against aB-crystallin of MS patients with and without uveitis were compared to healthy controls. The results showed that the established antibody levels are similar in MS patients and in healthy controls, meaning that they are a normal aspect of the adult human immune repertoire. Thus, both the antibody response and the T-cell response against aB-crystallin that can be induced in aB-crystallin-/- mice are representative for the human situation, making these mice very useful to test aB-crystallin-specific immune modulation. We further focused on different methods for modulating the immune response. First, various flavonoids were studied for their anti-inflammatory capacities in vitro. These studies provide new evidence for an important role of certain flavonoids as anti- inflammatory compounds in reducing T-cell proliferation and the production of inflammatory cytokines. The T cells used were obtained from mice and from humans. Mouse-derived T cells were reactive to the peptide 139-151 of the myelin protein PLP. Human-derived T cells were reactive to aB-crystallin. We found markedly reduced activation of antigen-specific T cells in vitro. The structurally related flavonoids luteolin and apigenin were especially potent inhibitors of both proliferation and IFN-? production by antigen-specific T cells. This was observed with both mouse and human antigen-specific T cells. This inhibition by flavonoids was very promising and we therefore subsequently examined whether flavonoids may also reduce a pro- inflammatory T-cell response in vivo using the model of EAE in SJL mice. Upon immunization with PLP139-151, these mice develop both acute and subsequent chronic signs of EAE, which is known to be primarily mediated by T cells. Reduction of the T-cell response in vivo would therefore be expected to lessen clinical signs. Indeed, when mice were fed with luteolin, apigenin or morin, the proliferative T-cell reactivity was reduced. Yet, to our surprise, recovery from inflammation in actively induced EAE was reduced by two out of four flavonoids tested. Curcumin, the only food component used that was not a flavonoid, had mild beneficial effects in reducing the inflammation. Reduced recovery from EAE was even more pronounced when PLP139-151-specific T cells, isolated from flavonoid-fed mice, were transferred into untreated recipient mice. These mice developed clinical signs of EAE and showed also a clearly reduced recovery from the acute inflammation. Another way to influence the immune response is by using probiotics. Probiotics are live microbial food supplements that, in contrast to most other bacteria, exert health benefits for the host in having anti-inflammatory properties not only in the gastrointestinal tract but also in the periphery. Probiotics most likely exert their immune-modulating effects by altering DC function. The effects of probiotics on DC were studied, primarily in order to find markers that can predict whether the selected probiotics species may be beneficial for use in vivo. As a first step, the expression levels of Toll-like receptors (TLR) on DC under influence of probiotics were explored. TLR shape the adaptive immune response that is mediated by DC, by direct recognition of pathogens. Also, surface markers and cytokine production by DC were monitored after probiotic stimulation. Probiotic-stimulated DC reduced the expression of TLRs 1, 2, 4 and 6 and increased the expression of TLRs 7-9, as compared to unstimulated DC. Also, DC displayed increased expression of the antigen-presenting molecule HLA-DR and the costimulatory molecules CD40, CD80 and CD86. Therefore, the strains used are indeed capable of activating the DC which will be of relevanceDijkstra, C.D. [Promotor]Noort, J.M. van [Copromotor

Processing peracetic acid treated bloodmeal into bioplastic

Renewable and biodegradable bioplastics can be produced from biopolymers such as proteins. Animal blood is a by-product from meat processing and is rich in protein. It is dried into low value bloodmeal and is used as animal feed or fertiliser. Previous work has shown that bloodmeal can be converted into a thermoplastic using water, urea, sodium dodecyl sulphate (SDS), sodium sulphite and triethylene glycol (TEG). To increase its range of applications and acceptance from consumers, the colour and odour was removed from bloodmeal using peracetic acid (PAA). The aim of this study was to investigate the bioplastic processing of 3-5% (w/w) PAA treated bloodmeal. 3-5% PAA treated bloodmeal powder was compression moulded using different combinations of water, TEG, glycerol, SDS, sodium sulphite, urea, borax, salt and sodium silicate at concentrations up to 60 parts per hundred bloodmeal (pphBM). Partially consolidated extrudates and fully consolidated compression moulded sheets were obtained using a combination of water, TEG and SDS. 4% PAA treated bloodmeal produced the best compression moulded sheets and extrudates and was chosen for investigating the effects of water, TEG and SDS concentration on consolidation, specific mechanical energy input (SME) and product colour during extrusion. Analysis of variance (ANOVA) showed SDS was the most important factor influencing its ability to be extruded because it detangled protein chains and allowed them to form new stabilising interactions required for consolidation. The best extruded sample, which was 98% consolidated and 49% white, contained 40 pphBM water, 10 pphBM TEG and 6 pphBM SDS

Rheology of the gel formed in the California Mastitis Test

The California Mastitis Test has previously been adapted for use in an inline, cow-side sensor and relies on the fact that the viscosity of the gel formed during the test is proportional to the somatic cell concentration. In this paper, the use of capillary and rotational viscometry was compared in light of the expected rheology of the gel formed during the test. It was found that the gel is non-Newtonian, but the initial phase of viscosity increase was not due to shear dependence, but rather due to the gelation reaction. The maximum apparent viscosity of the gel was shear dependent while the time it took to reach the maximum was not truly shear dependent, but was rather dependent on the degree of mixing during gelation. This was confirmed by introducing a delay time prior to viscosity measurement, in both capillary and rotational viscometry. It was found that by mixing the reagent and infected milk, then delaying viscosity measurement for 30 s, shortened the time it took to reach maximum viscosity by more than 60 s. The maximum apparent viscosity, however, was unaffected. It was found that capillary viscometry worked well to correlate relative viscosity with somatic cell count, but that it was sensitive to the reagent concentration. It can therefore be deduced that the rheology of the gel is complicated not only by it being non-Newtonian, but also by the strong dependence on test conditions. These make designing a successful sensor much more challenging