Impact of high pressure treatment on the available glucose content of various starch types: A case study on wheat, tapioca, potato, corn, waxy corn and resistant starch (RS3)

In this work the impact of high pressure (HP) processing on the available glucose after enzymatic digestion of various starch types (A-, B-, C- and resistant starch) was investigated. Starch suspensions were HP treated achieving different gelatinization degrees (from 25 to 100%). Starch samples were then freeze-dried and re-suspended in water before further thermal treatment, simulating cooking conditions of ready-to-eat meals. The respective thermally-treated starches were also prepared, achieving 100% gelatinization. The available glucose content was assayed for all starch samples; HP starches that undergone the cooking simulation test released lower amounts of glucose after 2 h of enzymatic digestion in comparison to the thermally-gelatinized samples. Moreover, among the HP pre-treated starches, waxy corn starch released the lowest amount of glucose. Further, the impact of freeze-drying on the enzymatic digestion was investigated. It was noticed that dehydration causes a slight increase in the levels of the released glucose after 120 min of digestion. Industrial relevance High pressure is an established nonthermal processing technology that can be industrially used to optimize existing products or allow development of novel products of high quality. The specific study shows that HP technology favors starch gelatinization and can be used to contribute to the production of starch based ready-to-eat meals characterized by low levels of released glucose.