School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.
J Sci Food Agric. 2024 Aug 15;104(10):5896-5906. doi: 10.1002/jsfa.13417. Epub 2024 Mar 22.
The structural changes of starch would have a more crucial impact on oil absorption and quality changes in starch-rich fruits and vegetables during frying process with enhanced heat transfer (such as infrared frying). In the present study, the influence of integrated ultrasonic and ethanol (US + ethanol) pretreatment on oil uptake in infrared fried (IF) ginkgo seeds was evaluated regarding modifications in the physicochemical properties of starch. The pretreatment was performed with ultrasonic (40 kHz, 300 W) and ethanol osmotic (95%, v/v) treatment individually or integrated for 40 min.
The mass transfer in the pretreatment was facilitated by combined ultrasound and ethanol. The swelling power, solubility, and gelatinization degree of starch was significantly increased. Low-frequency-NMR curves and images revealed that the bound water fraction in ginkgo seeds was increased and the water distribution was homogenized. The results of Fourier transform-infrared spectrum and differential scanning calorimeter revealed that the crystalline regions of starch were reduced and the thermal enthalpy was decreased after US + ethanol pretreatment. The total, surface and structural oil content in IF ginkgo seeds with US + ethanol pretreatment was reduced by 29.10%, 34.52% and 29.73%, respectively. The US + ethanol pretreatment led to a thinner crust layer with increased porosity and smaller-sized pores in the IF ginkgo seeds as observed by stereo microscopy and scanning electron microscopy.
The changes in structural and physicochemical properties of starch by combined ultrasound and ethanol affect the crust ratio and pore characteristics in fried high-starch fruits and vegetables, thereby reducing oil absorption. © 2024 Society of Chemical Industry.
在强化传热（如红外油炸）过程中，淀粉的结构变化将对富含淀粉的水果和蔬菜在油炸过程中的吸油和品质变化产生更关键的影响。在本研究中，评估了超声和乙醇（US+乙醇）联合预处理对红外油炸（IF）银杏种子吸油的影响，研究了淀粉理化性质的变化。预处理分别采用超声（40 kHz，300 W）和乙醇渗透（95%，v/v）处理 40 min，或联合进行。
超声和乙醇的联合促进了传质。淀粉的溶胀力、溶解度和凝胶化程度显著提高。低场 NMR 曲线和图像表明，银杏种子中的结合水分数增加，水分分布均匀化。傅里叶变换红外光谱和差示扫描量热仪的结果表明，US+乙醇预处理后淀粉的结晶区减少，热焓降低。与 IF 银杏种子相比，US+乙醇预处理后的总油、表面油和结构油含量分别降低了 29.10%、34.52%和 29.73%。体视显微镜和扫描电子显微镜观察到，US+乙醇预处理使 IF 银杏种子的外壳层变薄，孔隙率增加，孔径变小。
超声和乙醇联合作用导致淀粉结构和理化性质的变化，影响油炸高淀粉水果蔬菜的外壳比例和孔隙特征，从而降低吸油率。© 2024 化学工业协会。
