Oral Presentation: Impact of amorphous sugars ratio and fiber addition in crystallization, in model food systems as affected by different water activities, Session of Engineering Properties of Food and Packaging.
Authors: Nikolaou, N. E., Nikolidaki, E., Karathanos, V. T.
Corinthian currants are dried vine products rich in simple sugars, where fructose and glucose are found in an almost equal ratio 1:1. During prolonged storage currants become susceptible to crystallization, a complex phenomenon responsible for their significant quality degradation that requires the fundamental understanding of the principles that control the formation or inhibition of the crystalline sugar phase in a solution. Controlling the phenomena involved in sugar crystal formation and growth is of practical importance for designing the optimal conditions and process for the development of sugar-rich products. The main objective of this study is the investigation of the impact of currant’s dominant sugar’s and fiber content in their standard mixtures, simulating natural dried fruit systems, in crystallization as affected by different water activities. For this purpose different ratios of sugars were selected, specifically 1:1, 1:1.2, 1:1.5 & 1:2 for glucose and fructose concentration respectively, followed by the addition of 5%, 7% and 9% of pectin and cellulose. The increase in glucose concentration contributed in the significant increase in the Melting Enthalpy values of the mixture, possibly favoring crystallization phenomena. On the contrary, a decrease in crystal growth was observed with the increase in fructose concentration. Samples with 7% of pectin addition demonstrated reduced crystal formation capacity, reflected by their lower melting enthalpy values in comparison with cellulose samples at every level of addition.
