Pellet Hardness Research Articles

Physical and chemical characteristics of rabbit complete pellet feed containing different level of leucaena leaf meal

This research aimed to evaluate physical and chemical quality of rabbit feed complete pellet with different level of leucaena leaf meal (LLM) replacing the soybean meal. Four formulas of complete pellet with different level of LLM were tested (0%, 5%, 10% and 15%). The crude proteins of the diets were 17.7-18.1% and energy of the diets was 2,277-2,542 kcal/kg. The feed ingredients of the pellets consisted of corn, pollard, Pennisetum purpureum cv. Mott, molasses, soybean meal, LLM, copra cake, tapioca flour, and premix. The data measured were physical quality (hardness and durability), and chemical quality (dry matter, crude protein, crude fiber, extract ether, and ash). Data were analyzed based on a completely randomized design. The results showed that crude fiber and hardness of pellet were significant (P<0.01) between the treatments. The pellets with 15% LLM results highest of crude fiber and highest of pellet hardness. It is concluded that LLM can partially replace soyabean meal even at 15% without reducing the physical and chemical quality of the pellets.

Refused derived fuel pellets from municipal solid waste and rice husk

The objective of this study was to optimize the parameters for the development of refused derived fuel (RDF) pellets from municipal solid waste (MSW) and rice husk by using Response Surface Methodology (RSM). In this a systematic study was conducted, where three parameters were varied according to RSM factorial design. The binder concentration (5-10%) pressure (700-1200 psi) and retention time (3-7 minutes) were used for RDF pellet development under hydraulic press, measured hardness bulk density (BD) and durability (DU). The T3 treatment results revealed the highest pellet hardness, bulk density, and durability 25 kg, 805 kg/m3, 99% respectively by application binder concentration (5%), pressure (1200 psi) and retention time (5 minutes). The experimental data on response variables were fitted into quadratic polynomial model using the multiple regression analysis and found that it was statistically significant quadratic model. The RDF physical chemical and mechanical characteristics were also evaluated and found their relationship between HHV, carbon, ash, DU, BD and energy density. The ash contents were inversely proportional to DU and HHV whereas DU was directly related to BD.&#x0D; Bangladesh J. Sci. Ind. Res.54(4), 329-338, 2019

Effect of Conditioning Temperature on Pellet Quality, Diet Digestibility, and Broiler Performance

SUMMARY Pelleting is the most common heat processing method used in the poultry feed industry and the quality of feed processing directly impacts the efficiency of the utilization of feedstuffs by broilers, and consequently, their performance. The objective of this experiment was to evaluate the influence of conditioning temperature on pellet physical quality, and on the apparent ileal digestibility coefficients of dry matter (CIADDM), crude protein (CIADCP) and starch (CIADstarch), coefficient of apparent metabolizability of dry matter (CAMDM), and the apparent metabolizable energy content (AME) of the diets. The live performance of broilers (feed intake, FI; weight gain, WG; and feed conversion ratio, FCR) was evaluated. Treatments consisted of a mash diet and pelleted/crumbled corn-soybean meal based diets submitted to different conditioning temperatures (no conditioning or conditioned at 60, 70, 80, and 90°C). Feed was steam-conditioned for 15 s at a 1.5 kgf/cm2 for all pelleted treatments. Pellet quality was determined as a function of Pellet Durability Index (PDI), percentage of fines, and pellet hardness. Conditioning temperature linearly increased (P

Nutritional quality of different starches in feed fed to juvenile yellow perch, Perca flavescens

This study determined whether accumulated liver and visceral lipid in yellow perch can be alleviated by feeding an appropriate starch source. We compared the growth performance, nutritional composition and health of yellow perch fed a control diet (no added starch) and three diets with corn, potato or wheat starch (200 g/kg diet) to replace an equal proportion of fishmeal in the control diet. Dietary starch led to increased bulk density, hardness and gelatinization levels of feed pellets compared with the control diet. At the end of an 8‐week feeding, all fish fed the test diets had similar growth rates (p > .05). However, the wheat starch diet resulted in significantly enlarged livers and increased accumulation of lipid in the liver, viscera and whole body (p < .05). This diet also caused significantly higher levels of fasting glucose, aspartate aminotransferase and alkaline phosphatase activities in serum than the control diet. Liver cell diameters were larger, and Kupffer cell numbers were lower in the fish fed the wheat starch than those fed the control diet. Potato or corn starch had less impact on fish health and is considered to be an appropriate carbohydrate sources for yellow perch under the current testing conditions.

Effect of different types and levels of fat addition and pellet binders on physical pellet quality of broiler feeds

ABSTRACTTwo experiments were conducted to evaluate the effects of different types and levels of mixer-added fat (soybean oil: SO and calcium fat powder: CFP) and pellet binders (PBs: calcium lignosulfonate (CaLS) and bentonite (Ben)) on physical pellet quality (PPQ) parameters. PPQ included pellet durability index (PDI), pellet hardness, and pellet length of broiler diets processed under short-term conditioning. The first experiment had 4 treatments arranged as a 2 × 2 factorial with 2 types (SO and CFP) and 2 levels (1.5 and 3%) of mixer-added fat. In the second experiment, 22 treatments, combinations of 2 types of mixer-added fat (SO and CFP) at 3 levels (0, 1.5 and 3%) and 2 types of PB (CaLS = 0, 0.5, and 1% and Ben = 0, 1, and 2%), were arranged by a completely randomized design. PDI was measured by 2 devices: Pfost Tumbling box (PDIT) and Holmen NHP tester (PDIH). The results showed that the diets containing 1.5% CFP without PB had significant differences in all PPQ parameters. The results revealed that adding 0.5% CaLS to the 3% SO diets significantly enhanced PDIH, pellet hardness, and pellet length compared to other treatments. Moreover, 1.5% CFP diets with 2% Ben had significantly higher PDIT, PDIH, and pellet hardness among the treatments. Based on contour plots, different levels of Ben in the diets containing SO failed to create optimum PDIT values (>96%). However, 1.5 to 2.50% CFP diets without Ben had the optimum PDIT values. The optimum PDIT value was achieved by the diets containing 3% SO in the range of 0.21 to 0.56% CaLS. Furthermore, adding 0.5% CaLS to the diets containing less than 2.86% SO resulted in suboptimal PDIT values (<96%). The diets containing 1.5 to 2.50% CFP without CaLS had the optimum PDIT values. However, increasing CaLS levels more than 0.38% led to suboptimal PDIT values. Overall, these results indicated that the selection of appropriate PBs should be based on type and level of mixer-added fat.

Development and Optimization of a Floating Multiparticulate Drug Delivery System for Norfloxacin.

Norfloxacin is a synthetic broad-spectrum antibacterial drug having poor bioavailability and pH-dependent solubility. The purpose of the present study was to develop a gastroretentive floating multiparticulate drug delivery system for norfloxacin. Norfloxacin core pellets were prepared using microcrystalline cellulose (MCC) and polyvinylpyrrolidone K30 (PVP K30) by extrusion and spheronization. A 3-level, 3-factor, 17-run experimental Box-Behnken design was adopted to optimize levels of variables in the pellets' formulations. The selected independent variables were amounts of MCC and PVP K30 and spheronizing speed and the dependent variables were aspect ratio and hardness of pellets. Sodium bicarbonate and hydroxypropyl methylcellulose K15M in the ratios of 1:1, 1:2, and 2:1 (w/w) on a dry solid basis were incorporated into the norfloxacin pellets and they were further coated with Eudragit RL 100 using a fluidized bed processor to obtain weight gain of 5%, 10%, and 15% w/w. The fourier transform infrared spectrum, scanning electron microscopy, physical characterization, particle size distribution analysis, floating studies, and in vitro drug release studies of the pellets were evaluated. Among the floating multiparticulate pellets batches, batch B-22 was found to be optimized based on the criteria of attaining the minimum floating lag time (<10 min) and the maximum value of drug released 82.11% in 8 h. The percentage drug release for batches B-21 and B-23 was 91.12% in 5 h and 60.67% in 8 h, respectively. The drug release studies indicated that as the Eudragit RL 100 polymer coat increases the drug release decreases, producing sustained release of norfloxacin. The floating studies revealed that 70%-90% of pellets remained floating for up to 8 h. All the batches have excellent flow properties with angle of repose in the range of 25.5±0.49° to 28.02±0.30°, and Carr's index and Hausner's ratio in the range of 5% to 15% and 1.05±0.3 to 1.14±0.3, respectively. The significant outcome obtained in the study is that such an approach can be effectively employed for improvement of the bioavailability of drugs having poor absorption in the lower part of the gastrointestinal tract with enhanced therapeutic efficacy.

Effect of binder additive on mechanical properties of straw pellet

Research was carried out into the impact of the content of wheat flour in a mixture with chopped wheat straw and the humidity of this material on the hardness of the pellet obtained from this raw material. The maximum content of wheat flour was 9.6% of the dry matter of the raw material, and the humidity of the raw material was 11.6, 25.7 and 36.0%. An increase of wheat flour content in the whole range examined considerably increased the pellet hardness, while an increase of humidity content in the raw material had an impact on increased hardness up to 25.7% only.

Impact of fish protein concentrate on apparent viscosity and physical properties of soy protein concentrate subjected to thermomechanical treatment

The aim of this research was to investigate the plasticizing and binding effect of fish protein concentrate (FPC) on soy protein concentrate (SPC) with the use of a capillary rheometer with pre-shearing capabilities. A 3-component mixture design was used to study the effect of the variables SPC, FPC and water. Mixture models with R2 in the range of 0.703–0.998 (P < 0.01) were established for apparent viscosity, extrudate hardness and expansion parameters of the plasticized materials. Extrudate microstructure as porosity, pore size distribution, cell wall thickness and distribution, were measured with the use of X-ray microtomography and models established with R2 in the range of 0.582–0.941 (P < 0.02). The mixture components affected apparent viscosity with the highest value observed for the blend with maximum SPC concentration (1381.6 Pa s) followed by maximum FPC concentration (858.6 Pa s), and lowest for the blend with maximum water concentration (398.0 Pa s). Lowest pellet hardness (136.2 N), density (904.3 kg/m3) and highest expansion (1.44) were found for the blend with maximum SPC concentration and can be attributed to incomplete thermomechanical transformation. Extrudate physical properties and expansion were explained by the extrudate microstructure. FPC added at a concentration of 65–70 g/kg gave values of hardness, extrudate density and microstructure similar to SPC added 100 g/kg of water, confirming the potential for the use of FPC as plasticizer and binder in the fish feed extrusion process.

DETERMINATION OF PHYSICOCHEMICAL PROPERTIES OF FORMULATED FISH FEED SUPPLEMENTED WITH MICROALGAE FROM BIOREMEDIATION PROCESS

This study was conducted to determine the potential of Scenedesmus sp. from phycoremediation as fishmeal replacer in formulated fish feed targeted for Oreochromis niloticus. Formulated fish feeds were designated with Formulation 1 being the control; in Formulation 2 and 3, 2 % of fishmeal was substituted with Scenedesmus sp. cultivated in Bold’s Basal Medium, and in artificial wastewater, respectively. It was found that supplementation with Scenedesmus sp. did not alter the hardness of the feed pellets (p&gt;0.5), but the water stability of Formulation 2 and 3 was significantly lower than Formulation 1 (p&lt;0.05). Zero correlation was established based on the fishmeal content with water stability (p&gt;0.05). Negative correlation was determined between moisture content and water stability of Formulation 2 and 3 (p&lt;0.05). This study showed the phycoremediation ability of Scenedesmus sp. in artificial wastewater with removal efficiency of 12.42 % and 49.25 % for Zn and Fe, respectively. It also found that biomass productivity of microalgae was lower in artificial wastewater compared to that in Bold’s Basal Medium. Overall, the results of the study suggested the sustainability of wastewater-treated microalgae as fishmeal replacer had little effect on physicochemical properties of fish feed.

Investigation of Wood Sawdust Effect on Production and Final Quality of Composite Pellets Based on Sunflower Husks

The pressure to diversify the raw material base of solid biofuels is steadily rising worldwide. The waste from agricultural production and its post-processing represents a huge but still little used energy potential. The use of such plant waste brings many technical problems. The paper is focused on research of increasing physical, mechanical and thermal quality indicators of composite pellets based on a mixture of sunflower husks and spruce sawdust. Tested mixtures varied by increasing the weight proportion of wood sawdust from 0% up to 40% in sunflower husks. The quality of this fuel pellets was evaluated using standardized parameters - particular density, bulk density, pellet moisture, mechanical durability, pellet hardness, calorific value, ash content etc.. Realized experiments have shown that it is not only possible to successfully transform this homogenized mixture into fuel pellets (pure sunflower husks represent a considerable problem with densification regard to their composition), but the qualitative parameters of the fuel also increase by increasing the weight proportion of wood in sunflower husks. The research results showed that the optimum ratio of wood component in the composite fuel is 30% based on the resulting mechanical quality parameters and economy of its production.

Effects of feed form and particle size, and pellet binder on performance, digestive tract parameters, intestinal morphology, and cecal microflora populations in broilers

This study was conducted to assess the effects of feed form (FF), particle size (PS), and pellet binder (PB) on performance, digestive tract parameters, intestinal morphology, and cecal microflora populations in broiler chicks. Two FF (mash and pellet), two feed PS (fine and coarse), and two levels of PB (0 and 3%) were evaluated in a completely randomized design with a 2 × 2 × 2 factorial arrangement of treatments. A total of 256 one-day-old male Ross 308 chicks were allocated into 8 treatments consisting of 8 replicates (4 birds/cage) with equal weight from 25 to 42 d of age. The results showed a three-way interaction among FF, PS, and PB for growth performance in broilers. The growth performance parameters were significantly improved by feeding the pellet-coarse PS-3% PB diet in comparison to the other treatments (P < 0.05). Birds fed pelleted diets had lower relative weight of the gizzard and pancreas, goblet cell (GC) number of the duodenum, crypt depth (CD) of the jejunum, higher villus height (VH) of the duodenum, and cecal spore-forming bacteria population (P < 0.05). Coarse PS resulted in lower jejunum CD and higher cecal count of lactic acid bacteria (LAB) and spore-forming bacteria (P < 0.05). Adding PB significantly improved pellet durability index (PDI) (P < 0.05). In addition, coarse PS-3% PB diets had higher pellet hardness. Also, adding PB to diets significantly (P < 0.05) decreased cecal spore-forming bacteria population. Pellet-coarse PS-3% PB diets fed broilers had a lower (P < 0.05) cecal Clostridium spp. bacterial population. The main factors had no significant effect (P > 0.05) on cecal Coliform spp. levels. Birds fed pellet-3% PB diets had higher VH:CD ratio both in the duodenum and jejunum, and those fed mash-3% PB diets had significantly (P < 0.05) lower VH in the jejunum than other treatments. Overall, pellet-coarse PS-3% PB diets improved growth performance through the positive changes on intestinal morphology of broilers under short-term conditioning (STC).

Influence of feed ingredients with pellet-binding properties on physical pellet quality, growth performance, carcass characteristics and nutrient retention in broiler chickens

The influence of inclusion of pellet binder on physical pellet quality, growth performance, carcass characteristics and total tract apparent retention of nutrients was examined. Broiler starter (Days 1–21, pellet diameter: 2.5 mm) and finisher (Days 22–42, pellet diameter: 4 mm) diets were formulated and then allocated to one of the seven treatments including control diet, and diets including sodium bentonite (10 and 20 g/kg), wheat gluten (10 and 20 g/kg) and wheat (100 and 200 g/kg). All ingredients used as a pellet binder significantly (P &amp;lt; 0.05) increased the pellet-durability index compared with control diet. Wheat gluten and wheat at both inclusion rates were significantly (P &amp;lt; 0.05) more efficient than was sodium bentonite in improving pellet hardness. From Day 1 to Day 42, chickens fed 10 g/kg wheat gluten and 100 and 200 g/kg wheat gained significantly (P &amp;lt; 0.05) more weight than did control. During starters, birds fed 200 g/kg wheat showed the highest feed intake (P &amp;lt; 0.05). On Day 42, all the pellet binders resulted in a heavier heart weight than in the control (P &amp;lt; 0.05). At Day 21, the length of ileum was significantly (P &amp;lt; 0.05) higher in birds fed 10 and 20 g/kg sodium bentonite, 10 g/kg wheat gluten and 200 g/kg wheat, but at Day 42, it was greater in birds fed 20 g/kg wheat gluten and 200 g/kg wheat than in those fed the control diet. Inclusion of wheat gluten (10 and 20 g/kg) and wheat (100 and 200 g/kg) increased (P &amp;lt; 0.05) fat apparent retention. Birds fed 20 g/kg wheat gluten had a significantly (P &amp;lt; 0.05) higher total tract apparent retention of crude fibre, also calcium apparent retention improved by wheat gluten inclusion at concentrations of 10 and 20 g/kg compared with control (P &amp;lt; 0.05). Overall, inclusion of 10 g/kg wheat gluten, and 100 and 200 g/kg of wheat improved physical pellet quality and weight gain in broilers.

Processing diets containing corn distillers’ dried grains with solubles in growing broiler chickens: effects on performance, pellet quality, ileal amino acids digestibility, and intestinal microbiota

The present study investigated the effects of feed form and distillers' dried grains with solubles (DDGS) on growth performance, nutrient digestibility, and intestine microbiota in broilers. A total of 720 broilers (Ross 308; average BW 541 ± 6g) was randomly allotted to 6 treatments on the basis of BW. There were 6 replicates in each treatment with 20 birds per replicate. Birds were fed 3 different feed forms (mash, simple pellet, and expanded pellet) and DDGS (0 or 20% of diet) in a 3 × 2 factorial arrangement. Simple pellet (SP) and expanded pellet (EP) fed birds showed an increase in BW gain (P < 0.05). The interaction between feed processing and DDGS level was observed on pellet hardness (P < 0.01). The lowest (P < 0.01) pellet durability index (PDI) and hardness were observed in the diet with DDGS. Values for PDI and hardness were higher for EP compared with SP (P < 0.01). Simple pellet decreased ileal digestibility of CP compared to mash feed. The inclusion of DDGS decreased the digestibility of CP, and tended to decrease digestibility of DM (P = 0.056) and gross energy (P = 0.069). Expanded pellet feeding decreased (P < 0.05) the ileal digestibility of isoleucine, lysine, methionine, phenylalanine, threonine, cysteine, and glutamine compared with mash diet. Processed feed increased (P < 0.01) pH in the gizzard and duodenum; however, processing decreased pH in ileum. The addition of DDGS to the diet reduced pH in the duodenum. The population of Lactobacillus spp. was lower in the duodenum of birds fed the EP diet compared to the mash diet. Processed feed increased the colonization of Clostridium spp. in the gizzard. These results indicated that SP and EP in broiler diet had a potential to improve BW gain, but EP compromised amino acid digestibility. In addition, DDGS supplementation (20%) decreased pellet quality and CP digestibility in broiler chickens; however, the growth performance and feed intake were not affected.

Influence of feed form and conditioning time on pellet quality, performance and ileal nutrient digestibility in broilers

An experiment was conducted to investigate the effects of the feed form and conditioning time of pelleted diets on pellet quality, broiler performance and nutrient digestibility during the starter phase. A total of 480 male Cobb broilers were distributed according to a completely randomized experimental design into six treatments with eight replicates each. Treatments consisted of a mash diet and five crumbled diets submitted to different conditioning times (zero, 60, 80, 100, or 120 seconds). The broilers fed pelleted diets submitted to steam conditioning presented higher feed intake and BW gain (P ≤ 0.05), higher coefficient of ileal apparent digestibility (CIAD) of DM and CP, as well as higher ileal digestible energy (IDE) (P ≤ 0.05) than those fed the mash diet. However, treatments did not influence FCR or starch digestibility (P > 0.05). Feed intake increased linearly (P ≤ 0.05) with conditioning time while a quadratic response (P ≤ 0.05) was noted for IDE. Conditioning time did not affect the amount of intact pellets or protein solubility (P > 0.05), but increased pellet durability index (P ≤ 0.01), pellet hardness (P ≤ 0.05), and water activity (P ≤ 0.05). It was concluded that feed physical form and conditioning time influence the performance and nutrient digestibility in starter broilers. and that increasing conditioning times promote better pellet quality.

Selected properties of the potato snacks expanded in the microwave radiation

The results of measurements of the selected properties of the extruded potato pellets and snacks expanded in the microwave field are presented in the paper. The potato pellets with the addition of the baking soda were prepared with a single screw extruder TS-45. The snacks were obtained by pellets expansion in a conventional microwave oven. The expansion index and the hardness of the pellets and the snacks, as well as, the texture properties of the snacks were evaluated during this study. The results showed that baking soda addition reduced the potato pellet expansion during their extrusion. This was an effect of a smaller thickness of the obtained pellets. The addition of baking soda had positive influence on potato snacks expansion in microwave radiation. The higher content of the soda additive resulted in lower hardness of pellets during cutting tests. The opposite effect was observed during texture measurements of the snacks. The addition of baking soda increased hardness of the expanded snacks. Soda addition lowers crispness and fragilityof the potato snacks expanded in the microwave radiation.

Acrylamide Production in Autoclaved Rodent Feed.

Sterilization of rodent feed by steam autoclaving is a common practice in many research institutions. Often we only consider the beneficial effects of this process-the reduction of microbial contamination-and forget that the high temperatures and pressures can have negative effects on diet quality. The purpose of our study was to assess both the physical and chemical changes to a standard rodent feed autoclaved at multiple sterilization temperatures and the effects of the treated diets on mice. Pelleted NIH31 rodent feed was autoclaved at 4 sterilization temperatures (230, 250, 260, and 270 °F). Feed pellet hardness and the acrylamide concentrations of the diets were tested and compared with irradiated NIH31 feed. Study diets were fed to mice for 28 d, after which tissue samples were collected for analysis of acrylamide, glycidamide (the active metabolite of acrylamide), and genotoxicity. Both feed pellet hardness and acrylamide concentration increased with increasing sterilization temperatures; however, neither affected feed intake or body weight gain. Plasma acrylamide and glycidamide were significantly elevated only in mice fed NIH31 diet autoclaved at 270 °F compared with the irradiated feed, whereas urine acrylamide and glycidamide metabolites were significantly elevated in most autoclaved diets. Liver DNA adducts, which correlate with genotoxicity, were significantly elevated in all autoclaved diets compared with the irradiated diet. Institutions that autoclave their animal diets should carefully consider the temperatures necessary to achieve feed sterilization and the type of studies in which these autoclaved diets are used.

Pelletizing Pure Biomass Substances to Investigate the Mechanical Properties and Bonding Mechanisms

Solid fuel for heating is an important product, and for sustainability reasons, it is important to replace nonrenewable fuels with renewable resources. This entails that the raw material base for pellet production has to increase. A broader spectrum of materials for pelleting involves variation in biomass substances. This variation, due to lack of knowledge, limits the possibilities to increase the pellet production using new raw materials. In this study, pellets were produced with a single pellet press from 16 different pure biomass substances representing cellulose, hemicellulose, other polysaccharides, protein, lignin, and extractives, and five different wood species, representing softwoods and hardwoods. All pellets were analyzed for the work required for compression and friction, maximum force needed to overcome the backpressure, pellet hardness, solid density, and moisture uptake. The results showed that the hardest pellets were produced from the group of celluloses, followed by rice xylan and larch arbinogalactan. The weakest pellets were from the group of mannans. Conclusions are that the flexible polysaccharides have a greater impact on the pelletizing process than previously known, and that the differences between xylan and glucomannan may explain the difference in the behavior of pelletizing softwoods and hardwoods.

High lipid microalgae (Schizochytrium sp.) inclusion as a sustainable source of n-3 long-chain PUFA in fish feed—Effects on the extrusion process and physical pellet quality

The aim of this research was to investigate effects on the extrusion process and physical pellet quality of high lipid microalgae (HL-microalgae) inclusion level as a source of n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) in fish feed. The experiment was based on a 3-component mixture design on commercially relevant feed blends by varying the content of dried HL-microalgae Schizochytrium sp. meal, vital wheat gluten (WG), and soy protein concentrate (SPC). Mixture models with R2 in the range of 0.881–0.998 (P<0.01) were established for specific mechanical energy (SME), feed melt viscosity and temperature behind die, expansion parameters, and pellet hardness and durability. The mixture components affected SME, melt viscosity and viscous heat dissipation with the highest values observed for SPC followed by WG, and lowest for HL-microalgae rich blends. Increase in viscous heat dissipation and feed melt temperature increased the steam flashing rate and consequently pellet expansion and fat adsorption capacity. Lowest pellet hardness and durability were found for blends high in HL-microalgae or SPC level due to incomplete cooking. HL-microalgae addition up to 132g/kg DM in SPC rich blends gave favourable processing effects with respect to improved plasticisation and physical pellet quality. This study documents that HL-microalgae has a potential to be used as an alternative and sustainable source of n-3 LC-PUFA in aquaculture feeds without compromising physical pellet attributes.

Influence of apple pomace inclusion on the process of animal feed pelleting

ABSTRACTApple pomace (AP) is the main by-product of apple juice production. Large amounts of this material disposed into landfills can cause serious environmental problems. One of the solutions is to utilise AP as animal feed. The aim of this study was to investigate the impact of dried AP inclusion into model mixtures made from conventional feedstuffs on pellet quality and pellet press performance. Three model mixtures, with different ratios of maize, sunflower meal and AP, were pelleted. Response surface methodology (RSM) was applied when designing the experiment. The simultaneous and interactive effects of apple pomace share (APS) in the mixtures, die thickness (DT) of the pellet press and initial moisture content of the mixtures (M), on pellet quality and production parameters were investigated. Principal component analysis (PCA) and standard score (SS) analysis were applied for comprehensive analysis of the experimental data. The increase in APS led to an improvement of pellet quality parameters: pellet durability index (PDI), hardness (H) and proportion of fines in pellets. The increase in DT and M resulted in pellet quality improvement. The increase in DT and APS resulted in higher energy consumption of the pellet press. APS was the most influential variable for PDI and H calculation, while APS and DT were the most influential variables in the calculation of pellet press energy consumption. PCA showed that the first two principal components could be considered sufficient for data representation. In conclusion, addition of dried AP to feed model mixtures significantly improved the quality of the pellets.

β-pyrophosphate: A potential biomaterial for dental applications

Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of β-pyrophosphate pellets (sintered at 1000°C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the β-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of β-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped β-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped β-pyrophosphate may be a promising material for restoring acid eroded and worn enamel.