PIGMENT CONTENT IN PHYTOPLANKTON, EPIPHYTON AND BOTTOM SEDIMENTS OF LAKE NERO

This article presents new data of spectrophotometric determination of pigment concentrations in phytoplankton, epiphyton and bottom sediments of the shallow highly productive Lake Nero based on survey materials in summer 2017. The average concentrations of chlorophyll a were 73.5±6.1 μg/L in phytoplankton and 40.7±21.4 mg/m2 of substrate in epiphyton, the sum of chlorophyll a with pheopigments in bottom sediments was 313±20.6 μg/g dry sediment. These values are comparable to those in the previous observation years. The parameters of pigment degradation were characterized by low values in the functioning communities of phytoplankton and epiphyton and reached the highest values in bottom sediments. The spatial distribution of algal pigments depended on the presence of macrophyte thickets. Overgrowing of the territory with macrophytes affected the content of pigments in phytoplankton negatively but the pigment accumulation in bottom sediments positively. The trophic state of the lake remains hypertrophic, as in previous years of observation.

Application of Raman Spectroscopy to Ancient Materials: Models and Results from Archaeometric Analyses

Numerous experimental techniques of analysis find applications in many branches of the archaeometry. Among them, Raman spectroscopy carved out a niche in the field of diagnostic and conservation of cultural heritage. The exceptional ability to predict and discover the structural properties of materials set for Raman spectroscopy, an exclusive role among the analytic techniques, is further boosted when it is coupled with mathematical or statistical models able to deepen the studied phenomena. In this work, we present a review of recent studies where pairing Raman spectroscopy and mathematical models allowed achieving important results in the case of potteries, porcelains, ancient and modern paper, ancient jewelry, and pigment degradation. The potentialities of this approach are evidenced and analyzed in detail.

Fixings Agent Effect to β-carotene Stabilityof Crude Extract from Dunaliella salina Microalga at Different Temperature Condition

Abstract<br />Dunaliella salina is a microalga rich pigment carotenoids that can be used asnatural dyes. The problem<br />faced for temporative β-carotene stability which is unstable and easily degraded is unstable and easily<br />degraded. The purpose ofthis researchwas to determine content and stability of β-carotene pigment in<br />D.salina with fixings addition of MgCO3 and NaHCO3 with temperature treatment as factor that influence<br />β-carotene pigment degradation during storage condition. The research method used β-carotene pigment<br />which was obtainedbymaceration and adding fixing agent (NaHCO3 0,5% and without fixings addition),<br />and was heated at temperature of (50°, 70° and 90°C), be measured the content of β-carotene pigment<br />during storage (observation hour 0, 24, 48, 72, 96, 120 and 144). Data analyzed by ANOVA and Honestly<br />Significant Different (HSD). The result showed that content of β-carotene pigment at 50°C temperature<br />showed that stability and pH value performed slowest degradation after144 hours. While stability and pH<br />value at 90°C temperature performed fastest degradation after 96 hours. Based on this study the addition of<br />NaHCO3 gave more effective in retaining β-carotene degradation compared to that of MgCO3 which showed<br />by high stability in sample NaHCO3 0,5%, temperature 50°C in 144 hours storage length.<br /><br />

Fixings Agent Effect to β-caroteneStabilityof Crude Extract from Dunaliella salinaMicroalgaat Different Temperature Condition

faced for temporative β-carotene stability which is unstable and easily degraded is unstable and easily<br />degraded. The purpose ofthis researchwas to determine content and stability of β-carotene pigment in<br />D.salina with fixings addition of MgCO3 and NaHCO3 with temperature treatment as factor that influence<br />β-carotene pigment degradation during storage condition. The research method used β-carotene pigment<br />which was obtainedbymaceration and adding fixing agent (NaHCO3 0,5% and without fixings addition),<br />and was heated at temperature of (50°, 70° and 90°C), be measured the content of β-carotene pigment<br />during storage (observation hour 0, 24, 48, 72, 96, 120 and 144). Data were analyzed by analysis of variance<br />(ANOVA) and Honestly Significant Different (HSD). The result showed that content of β-carotene pigment<br />at 50°C temperature showed that stability and pH value performed slowest degradation after144 hours.<br />While stability and pH value at 90°C temperature performed fastest degradation after 96 hours. Based on<br />this study the addition of NaHCO3 gave more effective in retaining β-carotene degradation compared to that<br />of MgCO3 which showed by high stability in sample NaHCO3 0,5%, temperature 50°C in 144 hours storage<br />length.<br /><br />