Biogenic Amino Acids and their Metal Salts as Catalysts of Caramelization

Abstract

~~Basic amino acids and one neutral aminohydroxy acidserine -,all at the concentration of 5%(w/w), are the most suitable as catalysts of caramelization. Among basic amino acids asparagine is the superior catalyst. Although caramels obtained with serine as the catalyst showed higher tinctorial strength they do not fully dissolve in alcohol, beer, hydrochloric acid and aq. citric acid. The application of lithium, sodium, and potassium salts of amino acids under study sometimes give an increase of tinctorial strength of caramels which, however, form precipitate in the citric acid test. The choice between particular salts as catalysts can be dependent on requested aroma of the caramel. Biogene Aminosauren und ihre Metallsalze als Katalysatoren fur die Karamelisierung. Basische Aminosauren und eine neutrale Aminohydroxysaure -Serin -, alle in der Konzentration von S%(w/w), sind die am besten geeigneten Katalysatoren fur die Karamelisierung. Unter den basischen Aminosauren ist Asparagin der uberlegene Katalysator. Obwohl das mit Serin als Katalysator erhaltene Karamel hohere Farbekraft zeigte, loste es sich nicht vollstandig in Alkohol, Bier, Salzsaure und waRriger Citronensaure. Die Anwendung der Lithium-, Natrium-und Kaliumsalze der untersuchten Aminosauren zeigten manchmal eine Erhohung der Farbekraft des Karamels, welche jedoch in dem Citronensaureversuch einen Niederschlag bildet. Die Auswahl unter den verschiedenen Salzen als Katalysatoren kann von dem gewunschten Aroma des Karamels abhangig gemacht werden.

Geometrically frustrated magnetic structures of the heavy-fermion compound CePdAl studied by powder neutron diffraction

“…Within experimental uncertainty all ordered Tb moments are determined to be parallel or antiparallel to the hexagonal c-axis, which suggests a similar magnetic anisotropy for the two compounds, TbNiAl and CePdAl. Table 6 contains the possible magnetic modes calculated by the program MODY [10] for the case of TbNiAl (space group P 62m, magnetic Tb atoms on site 3f and a propagation vector k 1 = [1/2, 0, 1/2]). The commensurate antiferromagnetic propagation vector k 1 belongs to a star of three arms:…”

“…We now proceed to explain the determination of the magnetic structure of CePdAl (results of table 3) in more detail. Group theoretical calculations known as the symmetry analysis method allow us to find all models of magnetic structures that are compatible with the symmetry of the paramagnetic phase [10]. The magnetic representation S(r) is an axial vector function which can be presented as a direct sum of irreducible representations ψ νn λ of the paramagnetic symmetry group G:…”

“…τ ] and k 6 = −k 5 . A calculation by the program MODY [10] performed for k 1 and k 2 gives the possible magnetic modes listed in table 4. The magnetic Ce atoms on site 3f are split into two independent types, called orbits in [10], with positions (0.58, 0, 0) and (0.42, 0.42, 0) belonging to type 1 and position (0, 0.…”

“…With respect to the two generators of the group G k , {1} (identity) and {m(0, y, z)} (mirror plane (0, y, z)), the representations τ 1 and τ 2 have characters (+, +) and (+, −), respectively. [10] for the case of space group P 62m, site 3f and incommensurate propagation vectors…”

“…The other neutron diffraction study was done partly at reactor Saphir of the Paul Scherrer Institute (PSI) at Villigen, Switzerland, and partly at the Institute Laue-Langevin (ILL) at Grenoble, France. The results of the two experiments are presented in this paper together with group theoretical symmetry analysis considerations, calculated by the program MODY [10]. Experiment and theory both support the view that in CePdAl a geometrically frustrated magnetic structure with coexisting magnetically ordered Ce moments and disordered Ce moments is stable in a certain temperature range below T N = 2.7 K. Magnetic structures of CePdAl are compared with those of the isostructural compound TbNiAl [3], where a non-zero ordered moment for the geometrically frustrated Tb atoms is allowed by symmetry.…”