微波-热风耦合干燥处理对牛肉干品质的影响

Effect of combined microwave-hot air drying on quality of beef jerky

该文采用微波-热风耦合干燥技术对牛肉干进行干燥,通过与单一热风干燥及单一微波干燥对比,考察其对牛肉干的色泽、嫩度、质构特性、微观结构、水分分布和风味等品质特性的影响。结果表明,与单一热风干燥或微波干燥相比,微波-热风耦合干燥处理可以明显改善牛肉干的色泽,提高牛肉干的嫩度,降低牛肉干的硬度。热风干燥可以较好地保护牛肉干肌纤维束结构,但是微波干燥会破坏其肌纤维束结构,而微波-热风耦合干燥可以弥补微波干燥引发的结构损伤。与单一干燥相比,微波-热风耦合干燥过程在微波和热风的共同作用下,可显著提高牛肉干内部不易流动水弛豫时间(T_(2)),增强其流动性,有利于水分子分布的均一性。最后,对不同干燥方式牛肉干的挥发性成分进行鉴定,发现热风干燥或微波干燥会造成原有风味物质的大量损失,而微波-热风耦合干燥可以更好地保留风味物质,并能够促进杂环胺类物质的生成,赋予牛肉干较好的烤香味。因此,微波-热风耦合干燥对提高牛肉干整体品质具有重要意义,是一种具有发展前景的干燥方式。

The effects of microwave coupled with hot air drying processing on the color,tenderness,texture,microstructure,water distribution,and flavor of beef jerky was evaluated and compared with single hot air drying and single microwave drying.Compared with single hot air drying or microwave drying,microwave coupled with hot air drying can manifestly improve the color and tenderness of beef jerky as well as reduce its hardness.The muscle fiber bundle structure of beef jerky could be well preserved by hot air drying but was damaged by microwave drying,while combined microwave-hot air drying could greatly compensate for the structural damage generated by microwave drying.In comparison with the single drying process,combined microwave-hot air drying could significantly improve the relaxation time(T_(2))of immobile water in beef jerky and enhance its fluidity,which was beneficial to the uniform distribution of water molecules within the beef jerky.The volatile components in beef jerky by different drying processes were further identified.Single hot air drying or microwave drying caused a great loss of original flavor substances in beef jerky,while combined microwave-hot air drying could better retain the flavor substances and promote the generation of heterocyclic amines(HCAs),which endowed beef jerky with a superior roasting flavor.Therefore,combined microwave-hot air drying has broad application prospects in the production of beef jerky with good quality.