Optimization of cocoa alkalization process and its use in chocolate as a model food

In this study, the effects of different alkali types and different process conditions on cocoa alkalization were examined. In the first stage of the study, NaOH, KOH and K2CO3 were selected as alkaline agents and in the second stage of study temperature, time and alkali concentration selected as process conditions in different combinations. In all samples, the important alkalization indicators (a*/b*, pH, and TroMP/TMP) were considered as responses and optimization was carried out. In the first phase of the study, where the effect of different alkali types on alkalization was examined, significant models have been determined for pH, a*/b*, TrMP/TMP, color properties (L*, a*, b*), Sauter mean (D3:2), bulk density and tapped density (P<0.05). In the second stage of alkalization study, where the effects of different process conditions on alkalization are examined significant models have been obtained for pH, color properties (L*, a*, b*), antioxidant capacity (DPPH and ABTS), total phenolic content (TPC), particle size (D90) and wettability properties (P<0.05). Alkalized cocoa powders which are obtained from in the first and the second stage of alkalization study were used in milk chocolate as a model food. The effects of the alkalized cocoa powders used on the physicochemical, rheological and sensory properties of the prepared milk chocolate were examined. It has been determined that the a*/b* and TrMP/TMP values determined as alkalization indicators vary depending on the use of different alkali salts and process conditions in the prepared milk chocolates, and different alkalization processes can be designed depending on the desired cocoa powder properties.