This study was conducted to produce water-soluble polysaccharide extracts (WSP) from perilla seed meal (PSM), a by-product of perilla seed oil extraction, using enzymatic hydrolysis. The aim was to confirm the potential of this method to obtain functional materials from PSM. The cellulose and hemicellulose fractions from PSM were hydrolyzed using Celluclast 1.5 L and Viscozyme L, respectively. The yield of WSP from both fractions increased with an increase in hydrolysis time. Physical properties of WSP, including solubility, oil-holding capacity, and emulsification properties, were increased by enzymatic hydrolysis. WSP produced by hydrolysis had greater antioxidant activity than WSP obtained without hydrolysis; the highest activity was observed after a hydrolysis reaction of 24 h. WSP retarded glucose and bile acid absorption. The data indicate that WSP from PSM have potentially valuable functional and biological activities.

The Agua Negra drainage system (30 12'S, 69 50' W), in the Argentine Andes holds several ice- and rock-glaciers, which are distributed from 4200 up to 6300 m a.s.l. The geochemical study of meltwaters reveals that ice-glaciers deliver a HCO₃⁻----Ca²⁺ solution and rock-glaciers a SO₄²⁻----HCO₃⁻----Ca²⁺ solution. The site is presumably strongly influenced by sublimation and dry deposition. The main processes supplying solutes to meltwater are sulphide oxidation (i.e. abundant hydrothermal manifestations), and hydrolysis and dissolution of carbonates and silicates. Marine aerosols are the main source of NaCl. The fine-grained products of glacial comminution play a significant role in the control of dissolved minor and trace elements: transition metals (e.g. Mn, Zr, Cu, and Co) appear to be selectively removed from solution, whereas some LIL (large ion lithophile) elements, such as Sr, Cs, and major cations, are more concentrated in the lowermost reach. Daily concentration variation of dissolved rare earth elements (REE) tends to increase with discharge. Through PHREEQC inverse modelling, it is shown that gypsum dissolution (i.e. sulphide oxidation) is the most important geochemical mechanism delivering solutes to the Agua Negra drainage system, particularly in rock-glaciers. At the lowermost reach, the chemical signature appears to change depending on the relative significance of different meltwater sources: silicate weathering seems to be more important when meltwater has a longer residence time, and calcite and gypsum dissolution is more conspicuous in recently melted waters. A comparison with a non-glacierized semiarid drainage of comparable size shows that the glacierized basin has a higher specific denudation, but it is mostly accounted for by relatively soluble phases (i.e. gypsum and calcite). Meltwater chemistry in glacierized arid areas appears strongly influenced by sublimation/evaporation, in contrast with its humid counterparts.

The fractured volcanic aquifer of the Abaya Chamo basin in the southern Ethiopian Rift represents an important source for water supply. This study investigates the geochemical evolution of groundwater and the groundwater flow system in this volcanic aquifer system using hydrochemistry and environmental tracers. Water types of groundwater were found to transform from Ca-Mg-HCO₃ (western part of Lake Abaya area) to Na-HCO₃ (northwestern part), from the highland down to the Rift Valley. Silicate hydrolysis and Ca/Na ion exchange are the major geochemical processes that control groundwater chemistry along the flow path. Groundwaters are of meteoric origin. The δ¹⁸O and δD content of groundwater ranges from −4.9 to −1.1‰ and –27 to 5‰, respectively. The δ¹⁸O and δD values that lie on the summer local meteoric water line indicate that the groundwater was recharged mainly by summer rainfall. δ¹³CDIC values of cold groundwater range from −12 to −2.7‰, whereas δ¹³CDIC of thermal groundwater ranges from −8.3 to +1.6‰. The calculated δ¹³CCO₂₍g₎ using δ¹³CDIC and DIC species indicates the uptake of soil CO₂ for cold groundwater and the influx of magmatic CO₂ through deep-seated faults for thermal groundwater. In the western part of Lake Abaya area, the shallow and deep groundwater are hydraulically connected, and the uniform water type is consistent with a fast flow of large gradient. In contrast, in the northern part of Lake Abaya area, water underwent deep circulation and slow flow, so the water types—e.g. high F⁻ (up to 5.6 mg/L) and Na⁺—varied laterally and vertically.