超声辅助腌制处理对牛肉干干燥及理化特性的影响

Effect of Ultrasound-Assisted Curing on Drying Rate and Physicochemical Characteristics of Beef Jerky

超声具有多种物理和化学效应,可导致食品理化特性发生改变。本研究通过水分损失率、可溶性物质及肌红蛋白浓度、干燥速率、脂质氧化程度、嫩度的测定和微观结构的观察,评估腌制过程中应用超声处理对牛肉干加工过程的影响。结果表明:腌制环节应用超声处理会导致牛肉片水分损失率显著升高(P<0.05),且与超声功率和作用时间呈正相关,在0.60 W/cm^2、60 min处理条件下牛肉片水分损失率最高,为6.93%,而静置腌制则吸收质量分数6.14%的水分;超声对蛋白溶出具有促进作用,但功率过大会导致蛋白溶出量下降;超声处理促进了肌红蛋白溶出和脂质氧化,且与超声功率和作用时间呈正相关;在0.30 W/cm^2和0.60 W/cm^2条件下超声处理60 min均显著降低了牛肉干的剪切力(P<0.05),但其余条件下差异不显著(P>0.05);苏木精-伊红染色切片观察结果证实,在0.60 W/cm^2条件下超声处理30 min和60 min对牛肉肌纤维造成不同程度的破坏。综上,牛肉干加工过程中应用超声可降低产品硬度、缩短干燥时间,且没有明显的不利影响。

Ultrasound has a variety of physical and sonochemical effects, which can lead to physicochemical changes in foods. This study evaluated the effects of ultrasound-assisted curing on water loss, the concentrations of soluble substances and myoglobin in NaCl solution, drying rate, lipid oxidation, tenderness and microstructure of beef jerky. The results showed that the application of ultrasound during the curing process increased water loss significantly(P<0.05), which had a positive correlation with ultrasound power and processing time. The water loss of beef slices treated at 0.60 W/cm^2 ultrasound intensity for 60 min was the highest(6.93%), while the control without ultrasound treatment absorbed 6.14% water. Ultrasound processing promoted protein dissolution from beef significantly(P<0.05), but excessively high ultrasound intensity could lead to a decrease in protein dissolution. Ultrasound treatment significantly promoted myoglobin dissolution and lipid oxidation(P<0.05), and the effect was positively correlated with ultrasonic power and processing time. Additionally, the shear force of beef slices decreased significantly(P<0.05) after ultrasound treatment at 0.30 or 0.60 W/cm^2 for 60 min, but there was no significant difference under the other conditions investigated. Histological observation with hematoxylin-eosin staining confirmed that ultrasound treatments for 30 and 60 min at 0.60 W/cm^2 could cause different degrees of damage to beef muscle fibers. In conclusion, the application of ultrasound in beef jerky processing can reduce the product hardness and shorten the drying time without any significant adverse effects.