Investigación y docencia en el Instituto Nacional de Ciencias de la JAE

By Royal Decree, on 27 May 1910 the Junta para Ampliación de Estudios joined at the Instituto Nacional de Ciencias Físico-Naturales several Museums and Laboratories previously existing that were devoted to those sciences by means of laboratory research, courses, printed books and articles, fieldwork, etc. Renamed Instituto Nacional de Ciencias by Royal Decree on 23 December 1916, two new institutions will arise from it: the Instituto Nacional de Física y Química (in September 1931) and the Instituto Nacional de Ciencias Naturales (in September 1936, once the civil war han broken). Along those nearly three decades the Instituto Nacional de Ciencias constituted a significant progress both in the scientific research and the teaching developed in every one of its dependencies, as it is meant to be shown through this paper

Capillary liquid chromatographic determination of neutral phenolic compounds in apple juices

Capillary liquid chromatography (CLC) is evaluated as an alternative to conventional HPLC to analyse complex phenolics. Several neutral phenolic compounds were separated on a packed-reversed phase fused-silica capillary column, and determined with UV detection. A conventional liquid chromatographic equipment was adapted for such purposes. Application of the proposed method to the quantification of neutral phenols in apple juices is reported. Phenolics are extracted and fractionated into neutral and acidic compounds by means of a C18 solid-phase cartridge. Typical recoveries ranging from 90 to 105% are obtained and reproducibility between extractions is <7% in all cases. Mass detection limits are at the sub-nanogram level

Fatty acid composition of cider obtained either by traditional or controlled fermentation

A pilot-scale model for controlled fermentation in cider-making is described. This technology is compared with the conventional induction of alcoholic fermentation and spontaneous malolactic conversion on the basis of the cider’s fatty acid profile. Controlled cider fermentations were carried out by means of sequential inoculation of Saccharomyces cerevisiae and Leuconostoc oenos. It was observed that there are significant differences in fatty acid composition depending on the fermentation process employed. The contents in fatty acids of ciders elaborated by a conventional process were higher than those of ciders obtained by controlled fermentation. The use of principal component analysis (PCA), linear discriminant analysis (LDA), soft independent modeling of class analogy (SIMCA) and partial least squares (PLS) in conjunction with the fatty acid composition allowed the authors to typify fermented apple products on the basis of the fermented technology. The most relevant variables for classification purposes were lauric and palmitic acids

Volatiles in Distillates of Cider Aged in American Oak Wood

kinds of cider aged in oak wood. During aging, a significant increase was detected in the concentration of diethyl butanedioate, ethyl 3-methylbutanoate, esters of long-chain fatty acids, and 1-hexanol; in contrast, the acetate esters and long-chain fatty acids decreased. When cider made with traditional technology was used as raw material, spirits with higher concentrations of decanoic and dodecanoic ethyl esters and long-chain fatty acids were obtained. When cluster and factor analyses were employed, “natural” groupings among the spirits studied were obtained on the basis of the raw material used and aging time

Determination of monosaccharides in cider by reversed-phase liquid chromatography

A reversed-phase high-performance liquid chromatographic (HPLC) method is described for the simultaneous determination of aldoses and uronic acids in cider, previously derivatized with p-aminobenzoic ethyl ester (ABEE). Narrow-bore C8 columns are recommended as this alternative provides good separation efficiency, along with greater economy and sensitivity. Detection limits for aldoses (glucose, galactose, xylose, arabinose, ribose, fucose, and rhamnose) and uronic acids (d-glucuronic acid and d-galacturonic acid) range between 82 and 182 ng ml−1. The ABEE derivatives are separated in 29 min. Recovery studies showed good results for all solutes (90–102%). The method is linear for all compounds over the concentration range tested, and precision was found to be satisfactory (R.S.D. < 5%)

Changes in the Major Volatile Compounds of Cider Distillates During Maturation

Principal aroma components in cider distillates were determined by gas chromatography with direct sample injection; the method described was found to be reliable. Acetaldehyde decreased during aging, which could be a consequence of the interaction of this molecule with ethanol, since an increase of acetal level was detected. A higher concentration of methanol was observed in spirits obtained from cider made from apple juice concentrate; this fact could be due to the intense enzymatic treatment (liquefaction) employed in manufacturing of apple juice concentrate. The system for concentrating apple juice might foster a higher level of furfural in the distillates manufactured from cider obtained from apple juice concentrate than the spirits made from traditional cider; the level of this carbonyl component increased during aging. The higher alcohol level rose throughout maturation; this fact could probably be explained by the acid-catalysed transesterification reaction. When cluster and factor analyses were employed, ‘natural’ groupings among the spirits under study were obtained on the basis of the raw material and aging time

Determination of organic acids in apple juice by capillary liquid chromatography

The organic acids quinic, malic, shikimic and citric were separated on a packed reverse phase fused-silica capillary column using 0.01 M K2HPO4/H3PO4 at pH 2.7 as eluent at a flow rate of 2 μL/min, and determined with UV detection. Conventional liquid chromatographicequipment was adapted for such purposes. The organic acids were able to be separated with detection limits of 2.4, 2.1, 0.04 and 2.9 ng, respectively. Application of the proposed method to the quantification of organic acids in apple juice is reported

Characterization of cider by its hydrophobicproteinprofile and foamparameters

This paper describes the characterization of ciders (both “natural” and sparkling cider) from the Principality of Asturias (northwest region of Spain) through the analysis of their protein content, based on their hydrophobic properties, and their foam characteristics. A reversed-phase high performance liquid chromatography (RP-HPLC) was applied to the protein analysis, and the foamparameters were measured with Bikerman’s method. Multivariate techniques allowed the authors to differentiate ciders on the basis of the press and foam taking technologies, and foam sensory quality. Feasible and robust models were constructed for classifying purposes. Higher than 95% correct classifications were obtained for differentiating ciders on the basis of the factors studied (cider making technology and foam sensory quality). The multivariate regression model computed allowed the authors to predict (correlation coefficients higher than 0.8) the foamparameters related to foam stability and bubble average lifetime in “natural” cider