Lactose is a disaccharide of importance in humans dietary, food products, and the pharmaceutical industry. From the existing isomeric forms, -lactose is rarely found in nature. Thus, in this work, a simple methodology to obtain anhydrous -lactose ( L) from -lactose monohydrate ( L⋅H 2 O) is presented. The L⋅H 2 O powder was dispersed into a basic alcoholic solution (72 hours), at controlled conditions of temperature (27, 29, 31, and 32 ∘ C), without stirring. The slurry was dried at room temperature and characterized. Fourier transform infrared spectroscopy showed the formation of L for the samples prepared at 29 and 32 ∘ C. Raman spectroscopy confirmed this result and suggested the occurrence of crystalline L. Rietveld refinement of the X-ray diffraction patterns was employed to identify and quantify the composition of the isomers. The samples prepared at 29 and 31 ∘ C showed the formation of pure L, while those at 27 and 32 ∘ C showed the presence of L⋅H 2 O and a mixture of the two isomers, respectively. The morphology of the powders was studied by scanning electron microscopy, observing the formation of irregular shape L⋅H 2 O particles and axe-like L particles. Clearly, with this methodology, it was possible to obtain pure, crystalline, and anhydrous L at mild temperature.

In this work was studied the effect of the degree of polymerization (DP) in two systems based on inulin. Understanding the relation between the chemical and physical properties, allows establishing the potential application for inulin according to its DP. Amorphous inulin powders were characterized by mass spectrometry to determine the DP. Inulin from chicory root and dahlia tubers showed a DP of 2–15 and 2–12, respectively. The systems were exposed to different water activities, finding sigmoidal curves type II. Thermal analysis showed two melting events, suggesting the presence of crystals differing in size. The glass transition temperature range widened and lowered in the high DP inulin. By X‐ray diffraction low DP inulin presented a moderate transition behavior while in high DP inulin was conducted abruptly. State diagrams for stability showed that high DP inulin must be stored at more rigorous conditions of temperature and humidity for avoiding unwanted crystallization effects. Practical Applications The results presented in this work are useful for: (i) relating the physical and thermal properties (Tm, Td and Tg) with the degree of polymerization of sugar‐rich systems such as inulin powders, (ii) set the optimal processing conditions in an industrial application such as spray drying process while avoiding product damage, and (iii) predicting the product stability based on the physical properties plotted in the form of a state diagram.

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Urizar (2018) Obtaining orange juice-maltodextrin powders without structure collapse based on the glass transition temperature and degree of polymerization, CyTA -Journal of Food, 16:1, 61-69, DOI: 10.1080/19476337.2017 To link to this article: https://doi.org/10. 1080/19476337.2017 A set of four maltodextrins (MXs) with different degree of polymerization were employed as carrying agents for the spray drying of liquid orange juice (OJ) without collapse in the microstructure; this was visually observed as fine powders non-agglomerated were obtained with a characteristic color. The powders were subjected to water adsorption and characterized. The effect of the MX added was the increase in the adsorption of water and the subsequent depression in the glass transition temperature (T g ). The microstructure did not crystalize at any water activity, but the phase changed from an amorphous solid to a solid covered by saturated liquid. Additionally, a simple mathematical model based on the molar fractions and the T g of the individual components was proposed for predicting the overall T g of the ternary system water-OJ-MX. The results presented herein may contribute to the processing of sugar-rich systems and in the stability of food products.Obtención de polvos de jugo de naranja-maltodextrina sin colapso estructural basado en la temperatura de transición vítrea y grado de polimerización RESUMEN Se emplearon cuatro maltodextrinas (MX) con diferente grado de polimerización (GP) como agente acarreador para el secado por aspersión sin colapso de la microestructura de jugo de naranja líquido (OJ); esto fue observado visualmente como un polvo de color blanco y apariencia fina sin aglomeración. Los polvos fueron sometidos a un proceso de adsorción de agua y caracterizados. El efecto de la adición de la MX fue el incremento en la adsorción de agua y la subsecuente depresión en el valor de la temperatura de transición vítrea (T g ). Para todas las actividades de agua evaluadas la microestructura no cristalizó, pero la fase cambió de un sólido amorfo a un sólido cubierto por líquido saturado. Adicionalmente se propuso para la predicción del valor de T g del sistema ternario agua-OJ-MX, el uso de un modelo matemático simple basado en las fracciones molares y los valores de T g de los componentes individuales. Los resultados obtenidos pueden contribuir para el procesamiento de sistemas ricos en azúcares y en la estabilidad de productos alimenticios. ARTICLE HISTORY