Stabilization of Dry Sucrose Glasses by Four LEA_4 Proteins from Arabidopsis thaliana

Cells of many organisms and organs can withstand an (almost) total water loss (anhydrobiosis). Sugars play an essential role in desiccation tolerance due to their glass formation ability during dehydration. In addition, intrinsically disordered LEA proteins contribute to cellular survival under such conditions. One possible mechanism of LEA protein function is the stabilization of sugar glasses. However, little is known about the underlying mechanisms. Here we used FTIR spectroscopy to investigate sucrose (Suc) glass stability dried from water or from two buffer components in the presence of four recombinant LEA and globular reference proteins. Buffer ions influenced the strength of the Suc glass in the order Suc < Suc/Tris < Suc/NaP. LEA proteins strengthened the sugar H-bonded network and the molecular structure in the glassy state. The position of νOH peak and the wavenumber–temperature coefficient (WTCg) provided similar information about the H-bonded network. Protein aggregation of LEA proteins was reduced in the desiccation-induced Suc glassy state. Detailed knowledge about the role of LEA proteins in the stabilization of dry sugar glasses yields information about their role in anhydrobiosis. This may open the possibility to use such proteins in biotechnical applications requiring dry storage of biologicals such as proteins, cells or tissues.

Syrups in Sugar Confectionery Products of High Nutritional Value

Confectionery products of high nutritional value are affordable and rich in vitamins and minerals. Their development requires new raw materials with a high physiological value, which would be available on the local consumer market. Vegetable syrups can be used in sugar confectionery products, especially if they are fortified with vitamins and minerals. The present research proves the expediency of using fortified syrups in the production of sugar glasses. This type of caramel has a high energy value but no biologically valuable substances in the composition. Therefore, fortified syrups increase the biological value of the product. The study featured samples of sugar glasses with syrups fortified with rosehip, sea buckthorn, lemongrass, and cranberries. The paper describes their nutritional value, as well as the therapeutic and prophylactic properties of the syrups. It also contains data on the sensory quality, physic-chemical parameters, and the nutritional value.