Instrumental Texture Profile of Traditional Varieties of Tomato (Solanum lycopersicum L.) and its Relationship to Consumer Textural Preferences.

Among components of the consumer's perception of tomato fruit quality, texture is one of the most critical, being formed of a number of attributes that are difficult to evaluate and which change during fruit ripening and storage. The present work relates different textural parameters measured in a collection of traditional tomatoes from Madrid with the appreciation collected from consumer opinions. Texture traits were highly variable in studied tomatoes; they had strong environmental influence and they differed among genotypes.

Effect of the lactose source on the ultrasound-assisted enzymatic production of galactooligosaccharides and gluconic acid.

It is well known that one of the main problems in galactooligosaccharide production (GOS) via tranglycosylation of lactose is the presence of monosaccharides that contribute to increasing the glycaemic index, as is the case of glucose. In this work, as well as studying the effect of ultrasound (US) on glucose oxidase (Gox) activation during gluconic acid (GA) production, we have carried out an investigation into the selective oxidation of glucose to gluconic acid in multienzymatic reactions (β-galactosidase (β-gal) and Gox) assisted by power US using different sources of lactose as substrate (lactose solution, whey permeate, cheese whey). In terms of the influence of matrix on GOS and GA production, lactose solution gave the best results, followed by cheese whey and whey permeate, salt composition being the most influential factor.

Enzymatic Synthesis and Structural Characterization of Theanderose through Transfructosylation Reaction Catalyzed by Levansucrase from Bacillus subtilis CECT 39.

This work addresses the high-yield and fast enzymatic production of theanderose, a naturally occurring carbohydrate, also known as isomaltosucrose, whose chemical structure determined by NMR is α-d-glucopyranosyl-(1 → 6)-α-d-glucopyranosyl-(1 → 2)-β-d-fructofuranose. The ability of isomaltose to act as an acceptor in the Bacillus subtilis CECT 39 levansucrase-catalyzed transfructosylation reaction to efficiently produce theanderose in the presence of sucrose as a donor is described by using four different sucrose:isomaltose concentration ratios. The maximum theanderose concentration ranged from 122.

Characterization of cyclitol glycosides by gas chromatography coupled to mass spectrometry.

Several cyclitol glycosides have been characterised as trimethylsilyl derivatives by their gas chromatographic (GC) retention data (linear retention indices) and electron impact mass spectrometric (MS) profiles. Both GC-MS results have been related to cyclitol glycosides structural features. Abundance ratios of characteristic m/z ions 133/129 and 260/265 have been proposed to distinguish glycosyl-inositols from glycosyl-methyl-inositols.