【摘要】 为降低香菇采后腐烂变质导致的经济损失，基于瞬时压差膨化技术，开发了一种非油炸香菇脆。研究了渗透脱水（osmotic dehydration, OD）预处理工艺顺序、渗透剂种类及质量分数（质量分数0、10%、20%、30%、40%麦芽糊精、10%乳清分离蛋白、20%麦芽糊精+10%乳清分离蛋白复合渗透剂）对香菇脆平均干燥速率、总色差、膨化度、复水比、硬度和脆度的影响。采用低场核磁共振技术，探究了OD预处理对香菇水分组成及状态分布的影响。OD工艺顺序研究表明：相比于热泵干燥前OD预处理，热泵干燥后OD预处理可显著提高香菇脆膨化度、复水比、脆度，降低总色差（P<0.05）。渗透剂种类及质量分数研究表明：相比于对照组，OD预处理可显著提高香菇脆膨化度、复水比（P<0.05）,但对平均干燥速率、总色差、硬度和脆度的影响则取决于OD溶液组成。香菇热泵干燥至湿基含水率70%后，先采用20%麦芽糊精+10%乳清分离蛋白渗透预处理，再继续热泵干燥至湿基含水率35%±2%,预干燥后的香菇均湿后进行瞬时压差膨化得到的香菇脆品质较好。低场核磁共振技术研究表明：香菇OD预处理后，横向弛豫时间T₂向左偏移，而且随着OD溶液溶质质量分数增加偏移幅度增大；然而自由水占比降低，结合水与不易流动水占比增加，热泵干燥后，除了30%、40%麦芽糊精预处理外，香菇主要以弱结合水和不易流动水状态存在，而自由水所占比例很低（0.41%～4.67%）。与对照组相比，热泵干燥后，香菇自由水（除了10%乳清分离蛋白预处理外）和不易流动水所占比例显著降低，但弱结合水比例显著增加（P<0.05）。Pearson相关性分析表明：相比于热泵干燥，OD预处理对瞬时压差膨化香菇脆品质影响更大，而且与低场核磁共振弛豫参数密切相关。香菇脆膨化动力的产生主要取决于不易流动水和结合水尤其是弱结合水，而与自由水无关。研究旨在为非油炸香菇脆瞬时压差膨化技术提供理论依据和技术参考。更多还原

【Abstract】 In order to reduce the economic loss caused by postharvest deterioration of Lentinus edodes, based on instant controlled pressure drop puffing（Franch for Détente Instantanée Contr8lée,DIC） technology, L. edodes was applied to develop non-fried L. edodes crisps. The effects of procedure sequence of osmotic dehydration（OD）, osmotic agent types and mass fractions of OD solution, including 0, 10%, 20%, 30%, 40% maltodextrin（MD）, 10% whey protein isolate（WPI）, and composite osmotic agents of 20% MD+10% WPI, on the average drying rate, total color difference, puffing degree, rehydration ratio, hardness and crispness of DIC dried L. edodes crisps were investigated. Low field nuclear magnetic resonance（LF-NMR） was used to investigate the effects of OD pretreatment on the water composition and status distribution of L. edodes. The results of procedure sequence of OD research showed that compared with the OD pretreatment before heat pump drying（HPD）, OD pretreatment after HPD could significantly improve the puffing degree, rehydration ratio, crispness, and decrease the total color difference of L. edodes crisps（P<0.05）. The results of osmotic agent types and concentration research showed that compared with the control group, OD pretreatment could significantly improve the puffing degree and rehydration ratio of L. edodes crisps（P<0.05）, but the effects of OD pretreatment on the average drying rate, total color difference, hardness and crispness were dependent on the composition of osmotic solution. The optimal procedure was that L. edodes was firstly heat pump dried to moisture content of 70% in wet basis, and then OD pretreatment was performed with 20% MD+10% WPI. The OD treated L. edodes were subsequently pre-dried by HPD to moisture content of 35%±2%, and finally the equilibrated samples were performed by DIC. The quality characteristics of L. edodes crisps under aforementioned optimal procedure were superior. LF-NMR results revealed that after OD pretreatment, the transverse relaxation time（T₂） was shifted to the left and the amplitude increased with the increase of mass fraction of solute in the osmotic solution. Whereas the proportion of the free water was decreased but the bound water and immobilized increased. After HPD, except for 30% and 40% MD pretreatment, water in L. edodes was mainly comprised of loosely bound water and immobilized water, but the proportion of free water was very low（0.41%-4.67%）. Compared with the control group, after HPD the proportion of free water（with the exception of 10% WPI pretreatment） and immobilized water in L. edodes was significantly decreased, but the proportion of loosely bound water was significantly increased（P<0.05）. Pearson correlation analysis indicated that the OD pretreatment had greater influence on the quality of L. edodes crisps than HPD process, and the quality characteristics were closely related to LF-NMR relaxation parameters. The puffing driving force of L. edodes depended mainly on the immobilized and bound water especially loosely bound water, but it had nothing to do with the free water. This study aimed to provide theoretical basis and technical reference for the DIC technology of non-fried L. edodes crisps.更多还原