高静压处理对预制绿芦笋品质的影响
Effect of high hydrostatic pressure on qualities of prepared green asparagus spears
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摘要: 绿芦笋嫩茎含水量高,呼吸作用较强,采收后不耐贮藏。高静压技术(High hydrostatic pressure,HHP)是一种新兴的最少加工技术,为解决绿芦笋采后损失问题提供了有效途径。本文研究了高静压处理对预制绿芦笋(Asparagus officinalis L)杀菌效果与品质的影响。分别在300、400、500、600 MPa压力和室温(25℃)下,研究了HHP处理绿芦笋1、3、5、10、15、20 min对微生物的杀灭效果。在保证杀菌效果的基础上,筛选出3组HHP处理参数,研究了高静压处理后预制绿芦笋贮藏品质的变化。结果表明:随着压力升高及保压时间延长,HHP的杀菌效果逐渐增强;霉菌和酵母对压力比较敏感,300 MPa处理3 min就能全部杀灭;300 MPa处理15 min、400 MPa处理10 min、500 MPa处理5 min、600 MPa处理3 min后,绿芦笋菌落总数含量均低于100 cfu/g。Weibull模型在压力300~600 MPa范围内拟合度较高(相关系数R~2>0.970)。贮藏期间,与传统热处理相比,3组高静压处理较好的保留了绿芦笋的色泽、质构、维生素含量等品质。综上所述,500 MPa处理5 min的预制绿芦笋贮藏期可达21 d,品质优于其它两组高静压处理。Abstract: Green asparagus( Asparagus officinalis L.) spears is one of tender shoot vegetables with high water content and strong respiration metabolism during storage. High hydrostatic pressure( HPP) is an immerging minimal processing technology which might be used as a potential approach for extending the storage time of raw asparagus spears.Effect of HHP on inactivation of aerobic bacteria,mould and yeast at various pressure levels( 300~600 MPa) for 1~20 min treatments were studied.In addition,three treatment conditions were selected to study the effect of HHP on the quality of prepared green asparagus during storage. The results showed that the effects of microorganism inactivation were improved with increasing of pressure and / or the holding time.The mold and yeast were more sensitive to HHP than the aerobic bacteria,which were inactivated completely at treatment of 300 MPa for 3 min.The aerobic bacteria of the 400 MPa processing 10 min,500 MPa treatment 5 min,600 MPa 3 min were less than 100 cfu / g.The Weibull model was used to analyze the survival curves. The coefficients of determination( R2) were all higher than 0.97,indicating that the Weibull model fitted the microbial inactivation kinetics curve well.During the storage,the asparagus treated at 500 MPa for 5 minutes can be stored for 21 days and obtained better qualities,such as color and texture,than that of the products treated at 400 and 600 MPa.
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