Granular Activated Carbons from Agricultural By-products: Preparation, Properties, and Application in Cane Sugar Refining (Bulletin #869)

The objectives of this investigation were to convert select Louisiana agricultural by-products to GAC and to characterize these carbons in terms of those physical (surface area, pore structure) and chemical (surface charge, functional groups) properties directly related to adsorption of raw sugar colorants.https://digitalcommons.lsu.edu/agcenter_bulletins/1038/thumbnail.jp

Lipase and Lipoxygenase Activity, Functionality, and Nutrient Losses in Rice Bran During Storage (Bulletin #870)

This bulletin includes information on the feasibility of using microwave heat to inactivate lipase and LOX, determine the optimum storage and packaging conditions with the fewest adverse effects on functionality, and to determine changes in functionality of rice bran as a result of heat treatment.https://digitalcommons.lsu.edu/agcenter_bulletins/1031/thumbnail.jp

Biochars impact on soil moisture storage in an Ultisol and two Aridisols

Excessive copper concentrations in water systems can negatively impact biological systems. Because copper can form strong associations with organic functional groups, we examined the ability of biochar (a carbon-enriched organic bioenergy by-product) to sorb copper from solution. In a batch experiment, potassium hydroxide-steam activated pecan shell biochar was shaken for 24 hours in pH 6, 7, 8, or 9 buffered solutions containing various copper concentrations to identify effect of pH on biochar copper sorption. Afterwards, all biochar solids from the 24 hours shaking period were air-dried and then analyzed using X-ray absorption fine structure spectroscopy to determine solid-phase copper speciation. In a separate batch experiment, biochar was shaken for 30 days in pH 6 buffered solution containing increasing copper concentrations; the copper sorption maximum was calculated based on the exponential rise to a maximum equation. Biochar sorbed increasing amounts of copper as the solution pH decreased from 9 to 6. The X-ray absorption fine structure results revealed that copper was predominantly sorbed onto a biochar organic phase at pH 6 in a molecular structure similar to copper adsorbed on humic acid. The X-ray absorption fine structure spectra at pH 7, 8, and 9 suggested that copper was associated with the biochar as three phases: 1) a complex adsorbed on organic ligands similar to copper on humic acid; 2) carbonate phases similar to azurite; and 3) a copper oxide phase like tenorite. The exponential rise equation fit to the incubated samples predicted a copper sorption maximum of 42,300 mg/kg copper. The results showed that potassium hydroxide-steam activated pecan shell biochar could be utilized as a material for sorbing excess copper from water systems, potentially reducing the negative effects of copper in the environment

Switchgrass Biochar Effects Two Aridisols

The use of biochar has received growing attention with regards to improving the physico-chemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on effects in Aridisols. The objective of this study was to investigate the effect of either low or high temperature (250 or 500C) pyrolyzed switchgrass biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to either a Declo loam (Xeric Haplocalcids) or a Warden very fine sandy loam (Xeric Haplocambids) and then incubated at 15% moisture content (by weight) for 127 days; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized water on days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO3-N, NO2-N, and NH4-N concentrations were quantified. After the incubation experiment had terminated, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO3-N, and NH4-N, total C, inorganic C, organic C, and pH. As compared to the 250C, the 500C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250C switchgrass biochar likely due to binding by biochar’s functional group sites. Both biochars caused an increase in leachate K, while the 500C biochar increased leachate P. The 500C biochar reduced leachate NO3-N concentrations as compared to the control; however, the 250C biochar reduced NO3-N concentrations to the greatest extent. Easily degradable C, associated with the 250C biochar’s structural make-up, likely stimulated microbial growth which caused NO3-N immobilization. Soil extractable K, P, and NO3-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250C could improve environmental quality in calcareous soil systems by reducing nutrient leaching potential

Biochars impact on soil moisture storage in an Ultisol and two Aridisols

Droughts associated with low or erratic rainfall distribution can cause detrimental crop moisture stress. This problem is exacerbated in the USA’s arid western and southeastern Coastal Plain due to poor rainfall distribution, poor soil water storage, or poorly-aggregated, subsurface hard layers that limit root penetration. We hypothesized that soil physical deficiencies may be improved by biochar applications. Research indicates a single biochar will not serve as a universal supplement to all soils; consequently, biochars may need to be designed with physico-chemical properties that can ameliorate specific soil physical deficiencies. We conducted a laboratory study that examined the effect of biochar on soil moisture retention and aggregate formation. Eight biochars were made from four feedstocks at two different pyrolysis temperature classes (500°C; 932°C) and were characterized for their physical and chemical properties. In addition, we included a biochar made using fast pyrolysis of hardwood wastes. All biochars were mixed at 2% w/w with either a Norfolk loamy sand (Fine-loamy, kaolinitic, thermic Typic Kandiudults), a Declo silt loam (Coarse-loamy, mixed, superactive, mesic xeric Haplocalcids), or a Warden silt loam (Coarse-silty, mixed, superactive, mesic xeric Haplocambids). Amended soils were laboratory incubated in pots for up to 127 days. About every 30 days, bulk density was measured and then each pot was leached with 1.2 to 1.3 pore volumes of deionized water. Gravimetric and volumetric soil moisture contents were determined after free drainage had ceased and again 2 and 6 days after leaching. The Norfolk-treated soils were later dry-sieved, and the sum by weight of their 0.5- to 1.0-mm aggregates was determined. In general, the biochar surface area and surface tension increased when produced under higher pyrolytic temperatures (>500°C). After leaching, Norfolk soils treated with switchgrass biochars had the most significant increase in soil moisture capacities. Similar increases were found in the Declo and Warden soils. Formation of 0.5- to 1.0-mm aggregates in the Norfolk loamy sand varied with biochar. Biochars enhanced the moisture storage capacity of the Ultisol and Aridisols thereby potentially reducing the on-set of crop moisture stress; however, the effect varied considerably with biochar feedstock and pyrolysis temperature

Bioactive compounds of plum mango (Bouea macrophylla Griffith)

The fruit of Bouea macrophylla referred as Plum mango or Gandaria is a popular seasonal fruit, which is widely consumed in the Malay subcontinent. There is ample of traditional knowledge available among the locals on the use of leaves, bark, fruits and seeds of this plant. However, very limited research information and scientific report is available on their composition, phytochemicals or on the bioactive compounds. In the present chapter, we have aimed towards comprehensively providing information on nutritional value, functional qualities, health promoting bioactive compounds and volatile constituents of this underutilized fruit

Evaluation of Physicochemical and Antioxidant Properties of Peanut Protein Hydrolysate

Peanut protein and its hydrolysate were compared with a view to their use as food additives. The effects of pH, temperature and protein concentration on some of their key physicochemical properties were investigated. Compared with peanut protein, peanut peptides exhibited a significantly higher solubility and significantly lower turbidity at pH values 2–12 and temperature between 30 and 80°C. Peanut peptide showed better emulsifying capacity, foam capacity and foam stability, but had lower water holding and fat adsorption capacities over a wide range of protein concentrations (2–5 g/100 ml) than peanut protein isolate. In addition, peanut peptide exhibited in vitro antioxidant properties measured in terms of reducing power, scavenging of hydroxyl radical, and scavenging of DPPH radical. These results suggest that peanut peptide appeared to have better functional and antioxidant properties and hence has a good potential as a food additive