Stability and quality of strawberry jam low-sucrose

Abstract

Quality of a product includes nutritional value, sensory quality and safety of. Currently, consumers prefer products with a high content of biologically active substances, similar to the natural taste. In this paper it is argued by experimental data and the scientific importance of a new process for obtaining strawberry jam low-sucrose and high content of biologically active substances. Jam with low-quality sucrose was assessed over time (3, 6 and 10 months), by: changing spectral optical density of the products tested (χ 210 – 750 nm), color change (Hunter method) and reducing oxidationstate change. By means of spectrum analysis we concluded that the brown color of gem is a result of oxidative degradation of polyphenolis and anthocyans. After 10 months of storage, the strawberry gem with 40 ... 45% saccharose has a better stability of antioxidants (polyphenols and anthocyans) with a lower content of brown substances. By analyzing the spectral composition of strawberries has been shown that evolution (depreciation) appearance of finished products, look brown color is due to degradation of anthocyanins, polyphenols and formation of brown compounds identified in UV spectral range, λ = 220 ... 270 nm. Prevent the formation of brown compounds can be achieved by lowering water activity (aw) or free water in the finished products. The survey reveals that although low-sugar jam occurred oxidative degradation of antioxidants, however even at 10 months storage product state was reduced.