Chromatographic determination of cyanoglycosides prunasin and amygdalin in plant extracts using a porous graphitic carbon column.

The determination of cyanogenic compounds in plants is often performed by HPLC. However, in this analysis, interferences due to compounds in the matrix, such as tannins and other pigments, are encountered, especially in roots and leaves. A new method is proposed for determining the cyanogenic glycosides amygdalin (D-mandelonitrile beta-D-gentiobioside) and prunasin (D-mandelonitrile beta-D-glucoside) in almond tree tissues, using poly(vinylpyrrolidone) or active carbon as scavengers for extracting cyanogenic compounds from roots or leaves, respectively. A new chromatographic approach for conducting the analysis is also discussed herein. The advantages of a Hypercarb column for the analysis of prunasin in roots are shown. The correlation coefficient with a reference method is high (>0.99), and statistical tests prove that the two methods are equivalent. In addition, the results provide evidence that prunasin is the only cyanoglycoside present in almond tree roots.

Discriminating significance of the free amino acid profile in almond seeds.

Known statistical techniques have been applied to the free amino acid composition of 107 samples from 10 different almond cultivars (Marcona, Desmayo-Largueta, Guara, Tuono, Ferragnes, Masbovera, Non Pareil, Titan, Texas, and Primorskyi) cultivated in seven different locations and growing conditions. It is concluded that free amino acid composition can constitute a basis for classifying and typifying these cultivars into five groups: (1) Marcona and Texas, (2) Ferragnes and Masbovera (and probably Primorskyi), (3) Tuono and Guara, (4) Non Pareil (and probably Titan), and (5) an isolated cultivar (Desmayo Largueta). As a result, an easy decision tree is proposed to discriminate the cultivar of an almond flour, as used in confectionery, if it consists of a single cultivar.

Comparative study on the triglyceride composition of almond kernel oil. A new basis for cultivar chemometric characterization.

Nine triglycerides (LLL, OLL, PLL, OLO, PLO, PLP, OOO, POO, and SOO; triglycerides are abbreviated using L, O, P, and S for linoleoyl, oleoyl, palmitoyl, and stearoyl fat acid radicals, respectively) in the almond kernel of 19 different cultivars have been determined by high-performance liquid chromatography. Multivariate techniques have been applied to the data from 114 chromatographic determinations. Principal component analysis efficiently reduces the number of variables so that the first two principal components explain 84.4% of the total variance. The classification obtained by the application of cluster analysis to triglyceride composition differentiates the American cultivar Texas from the rest of the cultivars. The Italian cultivars are grouped. The cultivars Achaak, Del Cid, Malagueña, Desmayo Largueta, and Chellaston form another group, and the largest group includes most of the Spanish cultivars. Discriminant analysis provides convenient functions to describe the four groups previously established by cluster analysis. The calculated classification functions correctly assign samples from the testing set to their respective groups.