Martin Anna, Naumann Susanne, Osen Raffael, Karbstein Heike Petra, Emin M Azad
Department of Food Process Development, Fraunhofer Institute for Process Engineering and Packaging IVV, 85354 Freising, Germany.
Singapore Institute of Food and Biotechnology Innovation, Agency for Science, Technology and Research (A*STAR), Singapore 138669, Singapore.
Foods. 2021 May 21;10(6):1160. doi: 10.3390/foods10061160.
For the valorization of oilseed press cakes into food products, extrusion can be used. A common way of applying the protein- and fiber-rich press cakes in directly expanded products is the combination thereof with starch, since starch gives a favourable texture, which correlates directly to expansion. To control product properties like expansion of protein and fiber-rich extruded products, the underlying physicochemical changes of proteins, fibers and starch due to thermomechanical input need to be comprehensively described. In this study, rapeseed press cake (RPC) was extruded and treated under defined thermomechanical conditions in a closed-cavity rheometer, pure and in combination with four starches. The impact of starch type (potato PS, waxy potato WPS, maize MS, high-amylose maize HAMS) and temperature (20/25, 80, 100, 120, 140 °C) on protein solubility, starch gelatinization (D), starch hydrolysis (S) and fiber solubility of the blends was evaluated. The extrusion process conditions were significantly affected by the starch type. In the extruded blends, the starch type had a significant impact on the protein solubility which decreased with increasing barrel temperature. Increasing barrel temperatures significantly increased the amount of soluble fiber fractions in the blends. At defined thermomechanical conditions, the starch type showed no significant impact on the protein solubility of the blends. Therefore, the observed effects of starch type on the protein solubility of extruded blends could be attributed to the indistinct process conditions due to differences in the rheological properties of the starches rather than to molecular interactions of the starches with the rapeseed proteins in the blends.
为了将油籽压榨饼转化为食品，可以采用挤压工艺。将富含蛋白质和纤维的压榨饼应用于直接膨化产品的一种常见方法是将其与淀粉混合，因为淀粉能赋予良好的质地，而质地与膨化直接相关。为了控制富含蛋白质和纤维的挤压产品的性能，如膨胀率，需要全面描述蛋白质、纤维和淀粉在热机械作用下发生的物理化学变化。在本研究中，油菜籽压榨饼（RPC）在密闭腔流变仪中于规定的热机械条件下进行挤压处理，分别单独处理以及与四种淀粉混合处理。评估了淀粉类型（马铃薯淀粉PS、蜡质马铃薯淀粉WPS、玉米淀粉MS、高直链玉米淀粉HAMS）和温度（20/25、80、100、120、140℃）对混合物中蛋白质溶解度、淀粉糊化度（D）、淀粉水解度（S）和纤维溶解度的影响。挤压工艺条件受淀粉类型的影响显著。在挤压混合物中，淀粉类型对蛋白质溶解度有显著影响，蛋白质溶解度随料筒温度升高而降低。料筒温度升高显著增加了混合物中可溶性纤维组分的含量。在规定的热机械条件下，淀粉类型对混合物中蛋白质溶解度没有显著影响。因此，观察到的淀粉类型对挤压混合物中蛋白质溶解度的影响可能归因于淀粉流变学性质差异导致的工艺条件不明确，而非淀粉与混合物中油菜籽蛋白的分子相互作用。
