Red raspberries, which contain a variety of nutrients and phytochemicals that are beneficial for human health, can be utilized as a raw material in the creation of several supplements. This research suggests micronized powder of raspberry pomace production. The molecular characteristics (FTIR), sugar, and biological potential (phenolic compounds and antioxidant activity) of micronized raspberry powders were investigated. FTIR spectroscopy results revealed spectral changes in the ranges with maxima at ~1720, 1635, and 1326, as well as intensity changes in practically the entire spectral range analyzed. The discrepancies clearly indicate that the micronization of the raspberry byproduct samples cleaved the intramolecular hydrogen bonds in the polysaccharides present in the samples, thus increasing the respective content of simple saccharides. In comparison to the control powders, more glucose and fructose were recovered from the micronized samples of the raspberry powders. The study’s micronized powders were found to contain nine different types of phenolic compounds, including rutin, elagic acid derivatives, cyanidin-3-sophoroside, cyanidin-3-(2-glucosylrutinoside), cyanidin-3-rutinoside, pelargonidin-3-rutinoside, and elagic acid derivatives. Significantly higher concentrations of ellagic acid and ellagic acid derivatives and rutin were found in the micronized samples than in the control sample. The antioxidant potential assessed by ABTS and FRAP significantly increased following the micronization procedure.
Anaerobic digestion (AD) is widely used for the sustainable treatment of biological wastes and the production of biogas. Its byproduct, digestate, is a valuable organic waste and needs appropriate management, which is one of the major concerns with a negative impact on the efficiency of biogas installations. One approach to extend the utilization of digestate as well as improve its handling and storage characteristics is compaction into pellets. This study aimed to evaluate the behavior of digestate during cyclic loading and unloading in a closed matrix. The findings presented here may provide insights into the mechanisms of pellet formation for optimizing the production of pellets and improving their sustainable management. The study can be considered novel as it applied cyclic loading, for the first time, in view of densification modeling and pelleting prediction. A Zwick universal machine was used in the experiments. The moisture content of digestate was found to be 10–22%. Samples were loaded with a constant amplitude of 20 kN for 10 cycles. The distribution of energy inputs, including the total energy, energy of permanent deformations, and energy lost to elastic ones, was thoroughly evaluated. A decrease in the total loading energy was observed in the first cycle, in cycles 2–10, and after all 10 applied cycles due to the rise in the moisture content of digestate. Similar relations were also found for the nonrecoverable energy part. In subsequent cycles of loading/unloading, the values of total energy and permanent deformation energy fell asymptotically. One of the most noteworthy findings of the study was that the absolute values of elastic deformation energy were consistent across all the cycles and moisture levels. However, it was noted that the percentage of energy dissipated to elastic deformation in all cycles significantly increased as the moisture content increased. Loading, which contributed to elastic deformations, was identified as the key factor causing an increase in cumulative energy inputs, and the majority of the energy expended was dissipated. Dissipated energy was the only component that permanently altered the total energy required for compaction. Another important finding, which resulted from the analysis of successive courses of loading and unloading curves, was that the shape of the areas enclosed between the loading/unloading curves was significantly influenced by the moisture content of the digestate.
The aim of this work was to study the particle size distribution of micronized oat bran. An impact classified mill was used to pulverizing. Before the pulverizing raw material was sterilized using overheated steam at 150°C during 3.5 min. The moisture of bran after sterilization decreased from 7.2 to about 3.9%. Five speeds of the rotor disc were used: 2600, 2970, 3340, and 3710 rpm. For each speed of the rotor disc the following speeds of classifier wheel were applied: 480, 965, 1450, 1930, 2410 and 2890 rpm. The particle size distribution of oat bran layer was measured by laser light scattering. Moreover, the sense of touch of coarse particles of micronized oat bran on a tongue was assessed according to five point scale. The largest fragmentation of the oat bran was obtained at a disc speed of 3710 rpm and at a classifier rotation speed of 1930 rpm, whereas the most coarse particles were obtained when these parameters were 3340 rpm and 480 rpm, respectively. On the other hand, the highest uniformity in size of particles in size was observed when the lowest speed of disc and classifier were used. Moreover, for the most samples the pulverized particles of oat bran were almost not discernible on tongue.
The study concerns an evaluation of the effect of selected parameters on the course of horizontal pneumatic separation of unsorted husked soybean and the process efficiency. The efficiency of the process of isolating endosperm fraction from husks and other impurities was evaluated by determining the separation efficiency indicator η. It was shown that increased moisture content of the mixture results in a significant decrease in the η indicator. For example, with the 2.2% increase of moisture content (from W1 = 10.1% to W2 = 12.3%), the separation efficiency indicator decreased, on average, by 6.8%. The value of the η indicator rose with the increased velocity of the airstream, but the amount of valuable fraction that is picked up by the airstream is higher as well. It was found that, when the air velocity increased from V1 = 7.8 m·s−1 to V2 = 10.5 m·s−1 (for the moisture content W1 = 10.1% and W4 = 15.7%), the increment in the efficiency was the highest and reached 14.9–34.3%. A parametric model of the separation process of fragmented mixtures of biological origin was developed based on the analysis of the obtained results observation undertaken. This model can be used in designing and carrying out operations of separation into particular size fractions and cleaning of various feed mixtures, or in determining parameters of the movement of specific mixture components within pneumatic channels.
The aim of the study was to examine the Peleg and Normand model to characterize the overall stress relaxation behavior of wheat kernel at varying load conditions. The relaxation experiments were made with the help of the universal testing machine, Zwick Z020, by subjecting the samples to compression at four distinct initial load levels, i.e., 20 N, 30 N, 40 N, and 50 N. The measurements were made for four wheat varieties (two soft and two hard-type endosperms) and seven levels of moisture content. Relaxation characteristics were approximated with the help of the Peleg and Normand equation. An interactive influence of the load level, moisture, and wheat hardness on the Peleg and Normand constants has been confirmed. For moist kernels, a higher amount of absorbed compression energy was released, since less energy was required to keep the deformation at a constant level. The constants differed depending on wheat hardness. Higher values of k1 revealed that the initial force decay was slower for hard varieties. This is more characteristic of elastic behavior. Similarly, higher values of k2 pointed to a larger amount of elastic (recoverable) energy at the end of the relaxation. The initial loading level had no or only a slight effect on the model coefficients (Y(t), k1, and k2). The parameters of the Peleg and Normand model decreased with an increase in the water content in the kernels.
A comprehensive understanding of the mechanisms associated with the pelletization of an anaerobic digestate is necessary to optimize the pellet production process and achieve better and more sustainable management of the digestate. This work evaluated the digestate behavior during cyclic loading and unloading in a closed matrix. The results presented here are a continuation of those observed in previous work that evaluated the effect of moisture content on the behavior of the digestate under cyclic loading/unloading conditions in a closed matrix. The effect of moisture content on the distribution of permanent and elastic strain energy demonstrated in the previous study was verified in the present work under different loading conditions. A Zwick universal machine was used for the experiments. The samples were loaded with amplitudes of 8, 11, 14, 17, and 20 kN for 10 cycles. Two distinct moisture levels of the digestate—10% and 22%—were analyzed. The results of the present study confirmed that the elastic energy dissipated was independent of the moisture content of the digestate and remained relatively constant for a wide range of the applied loads. Higher values of elastic strain energy were observed for the digestate with higher moisture content only when higher loads were applied. In the range of the studied loads, characteristic differences were noted in loading/unloading curves regardless of the load magnitude. The increase in the applied load led to an increase in pellet strength, but only when the moisture content of the digestate was 10%. The results of the pellet strength reflect well the results of irreversible energy and the conclusions about the area enclosed between loading and unloading curves.