Marzocchi Silvia, Caboni Maria Fiorenza, Greco Miani Marcello, Pasini Federica
Department of Agricultural and Food Sciences and Technologies, University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy.
Casillo Next Gen Food S.r.l., Via Sant'Elia Z.I., 70033 Corato, Italy.
Foods. 2022 Apr 1;11(7):1032. doi: 10.3390/foods11071032.
Wheat germ (WG)'s shelf life after the milling process is incredibly short because of the presence of enzymes that aggravate the oxidation process; thus, stabilization is required in order to exploit the nutrients and bioactive compounds within WG. The critical point for the oxidation process is the mechanical treatment used to separate WG from the kernel, which exposes the lipid fraction to the air. Showing the connection between the quality of durum wheat, considering its storage management, and wheat germ oil (WGO), extracted with a cold press, solvent and supercritical CO, is the aim of the study. The acidity and peroxide values were analyzed to evaluate lipid oxidation, while fatty acids, tocols, sterols and policosanols were evaluated for WGO characterization. The first fundamental step to control lipid oxidation is raw material management. Subsequently, the tempering phase of durum wheat, which is applied before the degermination process, is the most critical point for oxidation to develop because of the increase in moisture in the caryopsis and the activation of lipase and lipoxygenase. This represents a paradox: in order to stabilize the germ with degermination, first it seems inevitable to carry out a process that destabilizes it. To retains its highest quality, this will lead to a better use of the whole grain by reducing WG and by-product waste.
由于存在加速氧化过程的酶，小麦胚芽（WG）在研磨后的保质期极短；因此，为了利用WG中的营养成分和生物活性化合物，需要进行稳定化处理。氧化过程的关键点是用于将WG与谷粒分离的机械处理，这会使脂质部分暴露于空气中。本研究的目的是展示硬粒小麦的品质（考虑其储存管理）与通过冷榨、溶剂萃取和超临界CO₂萃取的小麦胚芽油（WGO）之间的联系。分析了酸度和过氧化值以评估脂质氧化，同时对WGO的脂肪酸、生育酚、甾醇和多廿醇进行了评估以进行表征。控制脂质氧化的首要基本步骤是原料管理。随后，在脱胚过程之前应用的硬粒小麦调湿阶段是氧化发展的最关键点，因为颖果中的水分增加以及脂肪酶和脂氧合酶的激活。这体现了一个悖论：为了通过脱胚使胚芽稳定，首先似乎不可避免地要进行一个使其不稳定的过程。为了保持其最高品质，这将通过减少WG和副产品浪费来更好地利用整粒谷物。
