不同干燥条件对风干牛肉品质影响

Effects of Different Drying Conditions on Beef Quality

为提高风干牛肉的干燥效率,明确干燥条件对风干牛肉品质的影响,以牛肉为研究对象,通过常规方式和高温短时干燥处理方式[对照组(15℃,7 d)、A组(50℃,30 h)、B组(55℃,27 h)、C组(60℃,24 h)、D组(65℃,21 h)]对其进行风干,分析不同处理对牛肉水分含量、水分活度、剪切力、蛋白质氧化、硫代巴比妥酸反应物(thiobarbituric acid reactive substances,TBARS)值、游离氨基酸含量、风味成分变化及感官评分的影响。结果表明,高温短时干燥对风干牛肉水分含量和水分活度影响不显著(p>0.05),对牛肉剪切力影响显著(p<0.05)。风干牛肉脂肪氧化和蛋白质的氧化、水解随着风干温度升高而增加。风干结束后,5组样品中TBARS值最高为1.18 mg MDA/kg,羰基含量为4.66 mmol/mg蛋白;风干牛肉游离氨基酸总量B组最高,为628.88 mg/100 g。气相色谱-离子迁移谱(gas chromatography ion mobility spectrometry,GC-IMS)结果显示,B组样品主要的挥发性风味物质最为丰富,且与其他4组差异最大,主要的特征风味物质为丁酸丙酯、丙二酸二乙酯、辛酸乙酯、丙酸异丁酯、乙酸甲酯、乙酸正己酯、乙酸辛酯等;适当提高干燥温度可以明显改善风干牛肉的色泽、风味和组织状态的评分。综合各项指标,风干温度55℃、风干时间27 h处理的风干牛肉品质最佳。

The beef samples were dried at different conditions[control(15℃for 7 d),group A(50℃for 30 h),group B(55℃for 27 h),group C(60℃for 24 h),group D(65℃for 21 h)]and the effects of different drying conditions on beef quality were studied.The beef quality indicators included moisture content,water activity(aw),Warner-Bratzler shear force(WBSF),protein oxidation,thiobarbituric acid reactive substances(TBARS),free amino acids(FAAs),and sensory attributes.The results showed that drying at high temperature for short time had no significant effect on the moisture or aw(p>0.05),while it changed the WBSF of the beef(p<0.05).Fat oxidation,protein oxidation,and protein hydrolysis of beef increased with the increase in drying temperature.After air drying,the highest TBARS and carbonyl content in the five samples were 1.18 mg MDA/kg and 4.66 mmol/mg protein,respectively,below the national standards,and the total FAAs was the highest in group B(628.88 mg/100 g).The gas chromatography-ion mobility spectrometry(GC-IMS)showed that the main volatile flavor substances in group B were the most abundant and had the largest differences from those in the other four groups.The main characteristic flavor substances were propyl butyrate,diethyl malonate,ethyl octanoate,isobutyl propionate,methyl acetate,hexyl acetate,and octyl acetate.Therefore,elevating drying temperature within a certain range is an effective way to accelerate the dry process and improve the sensory attributes such as color,flavor,and texture of dried beef.With full consideration to all the quality indicators,drying at 55℃for 27 h was the optimal scheme.