Konvektivno sušenje parčića ploda batata (Ipomoea batatas (L.) Lam), zavisnost od predtretmana

The dried of pieces of sweet potatoes (Ipomoea batatas (L.) Lam) was carried in experimental convective cabinet drier with loess. This vegetable was rich in beta carotene and was not sufficiently in our countries. The dried process was carried at 55oC, and weight changes were measured every 15 minutes. Were performed three pretreatments: dried with pretreatment, blanched with the 1% vitamin C and 5% NaCl and without pretreatment. Blanched was carried in water at 60oC, for 3 minutes. The moisture content of raw sweet potato was 76.40%, but in dried material value from 16.90 to 19.59%, respectively. Rehydration values were measure of the quality of the dried process. The best results were obtained to dried small pieces of sweet potato without pretreatment, than rehydration was 83.37%.Sušenje parčića ploda batata (Ipomoea batatas (L.) Lam) ili slatkog krompira vršeno je u eksperimentalnoj konvektivnoj sušari sa lesama. Ova povrtarska biljka bogata je beta karotenom, a nedovoljno se koristi u našoj zemlji. Proces sušenja odvijao se na 55oC, a merena je promena mase na svakih 15 minuta. Rađena su tri predtretmana blanširanjem: bez dodataka (predtretman I), sa dodatkom 1% vitamina C (predtretman II), sa dodatkom 5% NaCl (predtretman III) i sušenje bez predtretmana (kontrola). Blanširanje je vršeno u destilovanoj vodi temperature 60oC za 3 minuta, sa i bez dodataka. Sadržaj vlage u sirovom plodu batatu bio je 76,40%, a u osušenom materijalu kretao se od 16,90 do 19,59 %. Stepen rehidratacije korišćen je kao mera kvaliteta procesa sušenja. Najbolji rezultati dobijeni su kod sušenja parčića ploda batata bez predtretmana, čiji je stepen rehidratacije bio 83,37%

Geochemistry of Fe3+ in the hydrothermal dickite from Jedlina Zdroj (Lower Silesia, Poland)

Geochemical analysis for Fe was made on a representative sample of dickite-rich hydrothermal clay from Jedlina Zdroj. The mineralogy of the sample is comparatively simple, dickite being the principal component (>95 wt. % of the total sample), with lesser amounts of goethite and barite. Geochemical fractionation and inductively coupled plasma-optical emission spectrometry indicated that most of the Fe (ca. 97 wt. % of the total metal) resides in the dickite. Electron spin resonance showed that some of the Fe in the dickite structure is in the form of Fe3+. A substantial proportion of these ions (as well as Fe) in the dickite matrix were probably contained in the original hydrothermal dickite-forming solution. From the geochemistry of Fe3+, it was deduced that the oxidation potential (Eh) and pH of the solution during the formation of dickite from the Jedlina Zdroj were approximately 0.45-0.95 V (highly oxygenated) and 0-4 (highly acidic), respectivel

Geochemistry of Ni in the Cretaceous-Tertiary succession Fiskeler (Fish Clay) at Stevns Klint (Denmark): cheto-smectite of the black marl

The Cretaceus-Tertiary (KT) boundary at Stevns Klint (the Højerup succession), Fiskeler, consists of a thin red clay layer overlain by a thick one of black marl. These two layers are made up mainly from cheto-smectite and biogenic calcite. The black marl shows an enhanced concentration of Ni (655 ppm) within its smectite fraction. Additionally, its carbonate fraction also shows an enhanced concentration of Ni (245 ppm). It is reasoned that these enrichments represent a sudden and rapid input of high amounts of Ni into the late Cretaceus seawater at Stevns Klint. The ultimate source of Ni in both the carbonate and smectite fractions of the black marl was probably impact fallout, produced by the KT asteroidal impact, deposited on the nearby soil and leached by the (acid) surface waters. The geochemistry of the Ni supports the hypothesis that the smectite of this marl most likely has a local (marine or terrestrial) provenance and was probably redeposited, after its formation, from the original site to its present location at the KT boundary