Research on chlorophyll a from Spirulina (Spirulina sp.) powder has been done in order to determine chlorophyll a content, to compare degradation pattern and kinetics degradation of chlorophyll a and crude extract as well as to investigate the difference of antioxidant activity of chlorophyll a with or without irradiation. Chlorophyll a content in spirulina powder was calculated by using Porra's equation. Irradiation and recovery ability of chlorophyll a were measured by using volpi light (Intralux 6100) equipped with daylight filter. The antioxidant activity of chlorophyll a was determined by using DPPH method. The results showed that chlorophyll a content was 2.886 μg/g dry weight. Chlorophyll a has the higher stability than crude extract against 60 minutes irradiation at room temperature. Kinetics degradation of chlorophyll a was based on second order while crude extract based on first order. Chlorophyll a and crude extract have recovery ability. The results also showed that antioxidant activity of chlorophyll a was increased after 60 minutes of irradiation.   Keywords: antioxidant activity, chlorophyll a, photodegradation, spirulina powder

Two new polyamine ligands, L1 and L2, incorporating pyridyl and aliphatic amine donor sites have been prepared and their reaction with copper(ii) yields the mono- and binuclear complexes [Cu(L1)](ClO4)2 (1) and [Cl2Cu(L2)CuCl(H2O)]ClO4 (2), respectively. The X-ray structure of 1 confirms that the five nitrogen donors of L1 are bound to the central copper ion to give a distorted square pyramidal coordination sphere. In 2, L2 acts as a bridging ligand with its N3-donor coordination domains separated by a m-xylylene spacer group. An unusual feature of this latter complex is that symmetrical L2 gives rise to non-equivalent coordination behaviour at the individual copper sites; while both sites display five-coordination with distorted square pyramidal arrangements, they differ in having N3Cl2- and N3ClO-donor atom sets, respectively. The electron paramagnetic resonance (EPR) spectra of both complexes are discussed. Variable temperature magnetic susceptibility data confirmed the absence of magnetic interactions in 1 while a weak antiferromagnetic interaction between copper(ii) centres occurs in 2.

This study aims to identify consumers’ most liked formulation and evaluate the effect of thickening agents of potato starch (PS) and xanthan gum (XG) on the overall acceptability of cilantro sauces, viscosity, and pH. There are five formulas to be tested: F1 (1% PS), F2 (0.75% PS: 0.25% XG), F3 (0.50% PS: 0.50% XG), F4 (1% XG), and F5 (control). The results show significant differences based on taste and texture in the acceptance test, but no significant differences were discovered based on color and aroma. While no significant changes were identified in pH, there was a substantial difference in the viscosity test for each formulation. Based on the results, the ideal formulation for cilantro sauce consists of 0.75% PS and 0.25% XG (F2).

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