engleski

Thermal behaviour of rose hip (Rosa canina L.) fruits and some rose hip products

The aim of the study was to investigate the thermal behaviour of rose hip fruit (seeds, S and pulp, P), lyophilised puree (LP) and low-calorie jam (J). DSC scans were used to determine thermal behaviour in a temperature range from - 100 °C to 400 °C i.e., as a base for determining onset and midpoint glass transition temperatures (Tgo and Tgm), change of specific heat capacity (Δcp), melting temperatures (Tmo-onset, Tmp-peak and Tme- endset) and enthalpy of melting (ΔHm). In seeds, the main thermal effect occurred at 107.2 °C (Tmp) with enthalpy of melting of 306.3 Jg-1 (ΔHm). The exothermic events above 260 °C related probably to the degradation of fibre components in seeds. In pulp, endotherm detected at 116.8 (Tmp) with ΔHm of 819.6 Jg-1 can be attributed to water evaporation and melting of some sugars. The main thermal events detected in rose hip products at low temperatures related to glass transition phenomenon and melting transition of ice, and at high temperatures mainly corresponding to degradation of pectins and sugars. From the viewpoint of the thermal stability, rose hip seeds showed high thermal stability (with decomposition temperature of 360.2 °C) and potential for other possible applications (for example, as a biomass feedstock).

rose hip ; products ; DSC

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