The effect of chicken blood and its components on wastewater characteristics and sewage surcharges

Local wastewater treatment authorities levy surcharges from their non-residential customers that are based, in part, on the concentration of various pollutants in the customer's wastewater. Blood has long been recognized as the most potent contributor to pollutant loads in chicken processing plant wastewater. Quantification of the impact of blood on wastewater characteristics and sewage surcharges is hindered by lack of information on specific characteristics of chicken blood, and by the highly variable methods used by local authorities for calculating surcharges. In this study, the most commonly used wastewater characteristics are determined for whole chicken blood as well as its individual components. The characteristics measured include biochemical oxygen demand, chemical oxygen demand, total suspended solids, fats oil and grease, total Kjeldahl nitrogen, ammonia, and total phosphorus. Sewage surcharge calculation methods were collected from 71 local wastewater authorities. The results show all components of the blood to be extremely high-strength pollutants. The impact of blood on sewage surcharges is shown to be highly variable depending on the rates applied by the local authority.

Using alternative flours as partial replacement of barbari bread formulation (traditional Iranian bread)

Wheat flour is used in most of breads because of its nutrient components and high availability, but different problems are associated with this flour, such as allergies and loss of nutrient components due to milling and refining. In this study, five flours were used (20 %) in combination with wheat flour (80 %).to produce traditional Iranian Barbari bread. These included amaranth, barley, DDGS, rye and oat. Compositional measurements of moisture, fat, fiber, protein and ash content were taken. Physical tests were done to understand the changes in color, thickness, and texture. Results showed that the gluten content of each flour had a significant effect on the texture and thickness of the bread. Bread made with rye flour had the highest L* and that made with oat flour had the highest a*. As for b*, the highest was for the bread made with DDGS. It was also determined that bread made with 20 % DDGS and 80 % wheat flour had the highest fiber and moisture content, while that made with amaranth had the highest ash content, and that with rye had the highest fat. Adding different flours to wheat changed the physical and chemical attributes of final producst significantly.

Effect of co-products of enzyme-assisted aqueous extraction of soybeans on ethanol production in dry-grind corn fermentation

Enzyme-assisted aqueous extraction processing (EAEP) is an environmentally-friendly alternative to solvent and mechanical oil extraction methods, and can achieve ∼ 97% oil recovery from soybeans. The present study utilized soy skim (protein rich) and insoluble fiber (IF; carbohydrate rich), both co-products of EAEP, in dry-grind corn fermentation. The effects of adding soy skim and untreated IF (UIF), either separately or together, and adding pretreated IF (TIF), on ethanol production were investigated. Maximum ethanol production was achieved when UIF and skim were slurried together (corn-to-UIF ratio 1:0.16; skim-to-UIF ratio 6.5:1) and when fiber-hydrolyzing enzymes were added to corn fermentation. This modification to corn fermentation increased ethanol yield by 20%, ethanol production rate by 3%, and decreased fermentation time by 38 h compared to corn-only fermentation. An attempt was also made to utilize pentoses (from soy skim and IF) in integrated corn-soy fermentation slurry by an additional Escherichia coli KO11 fermentation step.

Changes in chemical and physical properties of Latin American wheat flour based tortillas substituted with different levels of distillers dried grains with solubles (DDGS)

Tortilla is the most popular type of bread both in South and Central America. Since the demand for this bread among different classes of society is significant, improving its nutrient content could be important. Distillers dried grains with solubles is good source of fiber and protein, and can be used in the fortification of tortilla. In this study, three levels of DDGS (0, 10 and 20 %) were substituted for wheat flour and the physical and chemical properties of the resulting products were evaluated. Results showed that for the 20 % DDGS level, minimum force was required to rupture the tortilla. The color of the tortillas substituted with 10 and 20 % DDGS were darker, being 64.11 and 59.99, respectively (P < 0.05). As for chemical properties, the samples fortified with 10 and 20 % DDGS had higher protein (9.35 and 10.78 % dried basis), fiber (2.21 and 2.33 % dried basis) and fat (23.60 and 24.65 % dried basis) values at P < 0.05. Thus, it appeared that using DDGS in wheat tortillas can improve some of the nutritional values such as protein and fiber as well as the textural properties of these breads. Further work should examine consumer acceptability of these products.

Preliminary Evaluation of Rainbow Trout Diets Containing PepSoyGen, a Fermented Soybean Meal Product, and Additional Amino Acids

Juvenile rainbow trout Oncorhynchus mykiss diets containing PepSoyGen, a commercially-available fermented soybean meal product, were supplemented with methionine and other amino acids. A fish meal-based control and four experimental diets were used in a 36-day feeding trial; two diets contained 40% PepSoyGen and 10% fish meal, and two diets contained 50% PepSoyGen and no fish meal. Each of these diets was supplemented with either methionine, or methionine and additional amino acids. One mortality was observed during the trial. Overall weight gain, percent gain, and feed conversion ratio were significantly greater for the fish meal control than for any of the PepSoyGen diets, although feed conversion ratios from all of the diets were still below 1. Apparent protein digestibility was significantly less in the fish receiving the control diet compared to any of the experimental diets, and significantly increased with increasing Pep- SoyGen concentrations. There was no significant difference in length, weight, condition factor, hepatosomatic index, viscerosomatic index, or any fish health responses among dietary treatments. Fillet composition, as determined by crude protein, crude lipid, water, and ash, was also not significantly different among fish reared on any of the diets. The supplementation of other amino acids in addition to methionine had no noticeable effect. The results from this study indicate that PepSoyGen with amino acid supplementation can completely replace fish meal in juvenile rainbow trout grower diets over a relatively short time-frame, albeit with some decrease in rearing performance.

Aerobic stability of distillers wet grains as influenced by temperature

BACKGROUND

The storability of distillers wet grains (DWG) influences the economic, energetic, and carbon balances of fuel ethanol production, yet there are limited published data on the deterioration of DWG following its production. We used biogenic CO(2) production to assess the aerobic stability of DWG incubated at three temperatures (12 °C, 22 °C, 32 °C) and compared CO(2) production over time to the appearance of mold and changes in DWG color parameters.

RESULTS

CO(2) production and mold colonization indicate that at temperatures near 12 °C, the aerobic stability of DWG was high and that it can be stored for at least a 10-day period. At temperatures close to 22 °C, the onset of increased microbial activity and visible mold colonization occurred between 4 and 7 days and both activity and mold ratings were very high by the ninth day in all three experiments. At 32 °C, 2 days may be a more appropriate limit for storage.

CONCLUSION

Temperature and time interact in a nonlinear fashion that permits the prediction of DWG stability boundaries. The simple visual appearance of mold appears to be a reasonable indicator that correlates well (r = 0.694) with CO(2) production, a measure of the aerobic stability of DWG.

Extruded aquafeeds containing distillers dried grains with solubles: effects on extrudate properties and processing behaviour

BACKGROUND

The tremendous supply and low cost of distillers dried grains with solubles (DDGS) make it an attractive feedstuff for aquaculture diets. Also, several studies have shown that DDGS can be successfully fed to various finfish. The objective of this study was to evaluate the effects of inclusion rate of DDGS (0, 250, 500 g kg(-1) ), feed moisture content (350, 450 g kg(-1) ) and die opening area (die A = 18.85 mm(2) , die B = 3988.45 mm(2) ) on the properties of the extrudates and on processing behaviour using a single-screw extruder.

RESULTS

Increasing the inclusion rate of DDGS resulted in extrudates with lower unit density, bulk density, expansion ratio, water solubility index and brightness (Hunter L) but higher redness (Hunter a) and yellowness (Hunter b). The increase in moisture content affected the extrudate properties in different ways: it increased bulk density, Hunter L, Hunter b and mass flow rate, whereas specific mechanical energy decreased at high moisture content. Increasing the die opening area primarily decreased expansion ratio of extrudates, power consumption and barrel temperatures but increased mass flow rate.

CONCLUSION

Extrudates from all treatments exhibited high durability and floatability, and less energy was required to produce extrudates when DDGS was used compared with soybean meal-based diets. The aquaculture industry can use this information to develop high-quality feeds at low cost.