A new crystalline form of αβ-D-lactose prepared by oven drying a concentrated aqueous solution of D-lactose

A new crystalline form of αβ-D-lactose (C12H22O11, Z' = 2) has been prepared by rapid drying of an approximately 40 % w/v syrup of D-lactose. Initially identified from its novel powder X-ray diffraction pattern, the monoclinic crystal structure was solved from a microcrystal recovered from the generally polycrystalline, mixed-phase residue obtained at the end of the drying step. This is the second crystalline form of αβ-D-lactose to be identified and it has a high degree of structural 3D similarity to the previously identified triclinic form

Rietveld-based quantitative phase analysis of sugars in confectionery

Sugars are a near-ubiquitous ingredient in food products, yet rising rates of obesity and related illnesses have prompted a drive to reduce their content. The use of amorphous sugars in confectionery may be one way of achieving this by providing a similarly sweet sensation due to increased dissolution rate. However, accurate amorphous and crystalline form characterisation and quantification of complex foodstuffs can be difficult. In this study, a method for the quantification of crystalline and amorphous sugars in chocolate precursors, using powder X ray powder diffraction, is presented. The method was first validated by the use of known compositions of mixtures of amorphous and crystalline sugars, then employed in assessing two chocolate crumb samples. The results show that the method can reliably determine the absolute quantity of amorphous and crystalline components in a confectionery sample, whilst maintaining sample integrity, apart from the addition of an inert internal standard. As such, it is a valuable addition to other techniques currently used

Colloidal particles for Pickering emulsion stabilization prepared via antisolvent precipitation of lignin-rich cocoa shell extract

This study concerns the preparation and functionality testing of a new class of Pickering particles for food emulsion stabilization: colloidal lignin-rich particles (CLRPs) derived from ethanol-soluble extract of cocoa shell. A further goal was to achieve Pickering functionality without the need to add co-emulsifying surfactants during emulsion processing. Cocoa shell is a co-product of the food manufacturing industry. As such it is anticipated that the particles would be accepted as a natural food ingredient, provided no harmful solvents are used in any step of their processing. The cocoa shell particles were milled, dispersed in water and exposed to 250 °C for 1 h in a stainless-steel tubular reactor followed by ethanol extraction to obtain a lignin-rich extract (46% (w/w) lignin with the remainder predominantly lipids). CLRPs were then fabricated by the precipitation of ethanol-dissolved extract into water (antisolvent). By employing an agitated process and droplet dosing into a non-agitated process, four particle suspensions of a range of submicron diameters were obtained. All particle suspensions contained the same mass fraction of extract and were surface active, with surface tension decreasing with increasing particle size. The smallest particles were obtained when lipids were removed from the extract prior to particle processing. In contrast to the other four particle suspensions, this one failed to stabilize a 10% (w/w) sunflower oil-in-water emulsion. We hypothesize that the phospholipids indigenously present in these CLRP formulations are a critical component for Pickering functionality. It can be concluded that we have successfully introduced a new class of Pickering particles, fabricated from an industry co-product and anticipated to be food grade

Stability of Sugar Solutions:A Novel Study of the Epimerization Kinetics of Lactose in Water

This article reports on the stereo chemical aspects of the chemical stability of lactose solutions stored between 25 and 60 degrees C. The lactose used for the preparation of the aqueous solutions was a-lactose monohydrate with an anomer purity of 96% alpha and 4% beta based on the supplied certificate of analysis (using a GC analytical protocol), which was further confirmed here by nuclear magnetic resonance (NMR) analysis. Aliquots of lactose solutions were collected at different time points after the solutions were prepared and freeze-dried to remove water and halt epimerization for subsequent analysis by NMR. Epimerization was also monitored by polarimetry and infrared spectroscopy using a specially adapted Fourier transform infrared attenuated total reflectance (FTIR-ATR) method. Hydrolysis was analyzed by ion chromatography. The three different analytical approaches unambiguously showed that the epimerization of lactose in aqueous solution follows first order reversible kinetics between 25 to 60 degrees C. The overall rate constant was 4.4 X 10(-4) s(-1) +/- 0.9 (+/- standard deviation (SD)) at 25 degrees C. The forward rate constant was 1.6 times greater than the reverse rate constant, leading to an equilibrium constant of 1.6 +/- 0.1 (+/- SD) at 25 degrees C. The rate of epimerization for lactose increased with temperature and an Arrhenius plot yielded an activation energy of +52.3 kJ/mol supporting the hypothesis that the mechanism of lactose epimerization involves the formation of extremely short-lived intermediate structures. The main mechanism affecting lactose stability is epimerization, as no permanent hydrolysis or chemical degradation was observed. When preparing aqueous solutions of lactose, immediate storage in an ice bath at 0 degrees C will allow approximately 3 min (180 s) of analysis time before the anomeric ratio alters significantly (greater than 196) from the solid state composition of the starting material. In contrast a controlled anomeric composition (similar to 38% a and similar to 62% beta) will be achieved if an aqueous solution is left to equilibrate for over 4 h at 25 degrees C, while increasing the temperature up to 60 degrees C rapidly reduces the required equilibration time.</p