Impact of Hydro-Alcoholic Solvents on the Oil and Phenolics Extraction from Walnut (Juglans regia L.) Press-Cake and the Self-Emulsification of Extracts

The objective was to evaluate the performance of four hydro-alcoholic solvents to simultaneously extract oil and more polar molecules as phenolics, among others, to produce complex extracts that eventually could self-emulsify after solvent removal. Walnut press-cake was selected as the sourcing material. Extractions were performed as a semi-continuous operation up to a solvent-to-solid ratio of 28, with a fractional collection of the effluent. Among the solvents, labelled by their alcohol content EtOH 58, EtOH 86, iPro 60 and iPro 90 for ethanol (EtOH) and isopropanol (iPro), iPro 90 allowed to reach an oil extraction efficiency of 97% while the recovery for the other solvents was in the range of 30–40%. For both alcohols, the increase of the solvent hydration negatively influenced the oil extraction but positively increased the recovery of phenolics that reached 17.6 mg GAE/gcake when EtOH 58 was used. Several fractions contained enough surface-active material and oil to self-assemble as emulsions. IPro 90 and EtOH 86 showed better performances in the sense that most extracts were able to emulsify, though extraction kinetics pointed out differences. The most hydrated solvents behaved equally, with extraction yields in the same range and a similar but limited emulsifying capacity of only few fractions.

Bio-Crude Production from Protein-Extracted Grass Residue through Hydrothermal Liquefaction

In the present study, the protein-extracted grass residue (press cake) was processed through hydrothermal liquefaction under sub and supercritical temperatures (300, 350 and 400 °C) with and without using a potassium carbonate catalyst. The results revealed that bio-crude yield was influenced by both temperature and the catalyst. The catalyst was found to be effective at 350 °C (350 Cat) for enhancing the bio-crude yield, whereas supercritical state in both catalytic and non-catalytic conditions improved the quality of bio-crude with reasonable HHVs (33 to 36 MJ/kg). The thermal behaviour of bio-crude was analysed and higher volatile contents (more than 50% under the range of 350 °C) were found at supercritical conditions. The overall TOC values in the residual aqueous phase varied from 22 to 38 g/L. Higher carbon loss was noticed in the aqueous phase in supercritical conditions. Furthermore, GCMS analysis showed ketones, acids and ester, aromatics and hydrocarbon with negligible nitrogen-containing compounds in bio-crude. In conclusion, the catalytic conversion of grass residue under subcritical conditions (350 Cat) is favourable in terms of high bio-crude yield, however, supercritical conditions promote the deoxygenation of oxygen-containing compounds in biomass and thus improve HHVs of bio-crude.

Influence of Temperature and Screw Pressing on the Quality of Cassava Leaf Fractions

In this study, the development of a mild processing method for cassava leaves to remove cyanogenic compounds with minimum nutritional loss is evaluated. Fresh leaves were reduced in size using a mixer at temperatures of 25 (room temperature), 55, 80, and 100 °C for 1 min before screw pressing to separate the juice and press cake fractions. Cyanide content in the fresh leaves was reduced by 60% at 100 °C and by 57% in the juice sample processed at 25 °C. The press cake cyanide content was low (210 ppm) in both the control and the sample that was processed at 55 °C. An increase in the temperature for processing cassava leaves to 100 °C resulted in a loss of 5–13% of the CP and 7–18% of the vitamin C content. The press-cake fraction had high beta-carotene, lutein, and chlorophyll a and b content, and low values were registered for the juice fraction. Processing fresh cassava leaves at 25 and 55 °C resulted in fractions with high beta-carotene and lutein content. The protein quality of press cake was better than that of juice for feed. Short thermal shredding with pressing resulted in minimal loss of nutrients and a significant reduction of cyanide in the leaves.

Integrating Camelina Into Organic Pig Production—Impact on Growth Performance of Pigs, Costs, and Returns

The sustainability of organic production and cover crops depends on production costs and the economic value of products. Feed cost, contributing 65–75% of the total production cost, has a significant impact on profitability of organic pig farming. Utilizing grains harvested from cover crops as a feed ingredient for organic pigs can potentially protect the environment and increase the economic value of cover crops. This study was the first to evaluate the viability of integrating winter cover crop, camelina, into organic pig production. Winter camelina was grown organically in single or relay with soybeans to increase the total yield per hectare. Camelina yields in monocrop and in relay-crop fields were 1,394 and 684 kg ha−1, respectively. Although the total yield of camelina and soybean (1,894 kg ha−1) in the relay-crop field was higher than camelina yield in the monocrop field, monocropping camelina is more economical than relay-planting with soybeans due to the difference in production costs. Camelina press-cake was supplemented in diets fed to pigs raised under near-organic standards. Supplementing 10% camelina press-cake in diets reduced feed intake, weight gain, final weight at market, carcass weight, and dressing percent of pigs, but did not affect feed efficiency, belly firmness or pork quality. The viability of integrating camelina into organic pig production depends on marketing organic pigs for $2.4 kg−1 of live weight and marketing camelina oil for $3.59 kg−1 or more if monocropping.

BLOOD BIOCHEMICAL INDICES OF SEED BULLS WHEN USING MINERAL SUPPLEMENT BASED ON MARAL ANTLER PRESS-CAKE

The seed bulls used for artificial insemination should be in good health, have outstanding genetic characteristics, have high sexual activity, and the biological products ob-tained from them should have high quality indices. One of the possible methods of increasing semen production is the introduction of dietary supplements into the diet. The intro-duction of new feed and biologically active supplements into the diet may cause both positive and negative changes in metabolic processes. Monitoring the biochemical status of blood allows detecting not only metabolic disorders in highly productive animals but also a lack of vitamins, mac-ro-and microelements. The research goal was to study the effect of a natural biostimulant (mineral supplement) made from maral antler press-cake on the blood biochemical indices ofBlack Pied seed bulls in the breeding company AO “Plempredpriyatiye Barnaulskoye”. Along with the basic diet, the seed bulls of the trial group received the natural biostimulant (mineral supplement) based on maral antler press-cake; the daily dose -15.0 g per head, for 30 days with 10 days’ interval after each application. The supple-ment was thoroughly mixed with compound feed before feeding. The mineral supplement is of powder form and contains a complex of vitamins, minerals, amino acids and other biologically active substances. The use of a mineral supplement increased the amount of total protein and al-bumin by 7.15% and 18.3%, respectively. The blood glu-cose level in the seed bulls of the trial group was higher by 12% and cholesterol by 17.1% than in the blood of the con-trol group animals. Cholesterol of the seed bulls may be used as a structural material or a precursor in the synthesis of sex steroid hormones. The level of total calcium, alkaline reserve at the end of the experiment increased in the seed bulls when using the mineral supplement made from maral antler press-cake in the diet by 4.8% and 8.1%, respective-ly, as compared to the control group.

Combined Butyric Acid and Methane Production from Grass Silage in a Novel Green Biorefinery Concept

In a Green Biorefinery, grass silage can be a source for lactic acid, proteins, amino acids and fibres. Processing residues can be used for anaerobic digestion and methane production. But by changing the ensiling conditions, butyric acid fermentation can be achieved. That makes grass silage also a potential substrate for a combined butyric acid and methane production. The objective of this study was to determine the potential of butyric acid production at different ensiling conditions applied to grass and measuring the methane yield potential of solid residues after a separation step. The highest butyric acid concentration in the produced press juice was 20.1 ± 4.5 g kg−1 and was achieved by carbonated lime addition and a reduced dry matter content after 90 days at mesophilic storage conditions. This resulted in a theoretical butyric acid yield of 332 kg ha−1 a−1. For the fibrous leftover press cake, a theoretical methane production potential of 2778 m3CH4 ha−1 a−1 was reached. The results show that theoretically a combined production of butyric acid and methane can be realised in a Green Biorefinery concept. Graphic Abstract