山西省马铃薯主产区土壤重金属含量状况评价与膳食暴露评估

【目的】探明山西马铃薯种植区域土壤重金属污染状况,并对马铃薯进行重金属摄入健康风险评价。【方法】选取山西省境内马铃薯优势产业基地县(区)作为调查研究对象,用电感耦合等离子体质谱仪分析了马铃薯产地土壤及产品中铅、镉、砷、铬、镍、铜、锌等七种重金属元素含量状况,并采用单因子指数法、内梅罗综合指数法和潜在生态危害指数法对土壤中重金属进行生态风险评价,采用目标危险系数法对马铃薯进行重金属摄入健康风险评价。【结果】山西省马铃薯主产区土壤中7种重金属单项污染指数均小于1,综合污染指数小于0.5,潜在生态危害为轻微,土壤环境质量总体属于非污染水平,成人和儿童因食用马铃薯而摄入重金属的健康风险指数均小于1。【结论】山西省马铃薯主产区土壤中重金属污染程度较低,而马铃薯中重金属的残留对人体健康存在隐患,建议制定预防性手段,加强对马铃薯及其他蔬菜等土壤中重金属的跟踪与监测,确保农产品产地环境质量,从而确保农产品质量安全。     

Study of ultrasonic treatment on the structural characteristics of gluten protein and the quality of steamed bread with potato pulp

Physicochemical properties and microstructure of gluten protein, and the structural characteristics of steamed bread with 30 % potato pulp (SBPP) were investigated by ultrasonic treatments. Results showed that 400 W ultrasonic treatment significantly (P < 0.05) increased the combination of water and substrate in the dough with 30 % potato pulp (DPP). The contents of wet gluten, free sulfhydryl (SH), and disulfide bond (SS) were influenced by ultrasonic treatment. Moreover, UV-visible and fluorescence spectroscopy demonstrated that the conformation of gluten protein was changed by ultrasonic treatment (400 W). Fourier transform infrared (FT-IR) illustrated that the β-sheet content was significantly (P < 0.05) increased (42 %) after 400 W ultrasonic treatment, and the surface hydrophobicity of gluten protein in SBPP increased from 1225.37 (0 W ultrasonic treatment) to 4588.74 (400 W ultrasonic treatment). Ultrasonic treatment facilitated the generation of a continuous gluten network and stabilized crumb structure, further increased the specific volume and springiness of SBPP to 18.9 % and 6.9 %, respectively. Those findings suggested that ultrasonic treatment would be an efficient method to modify gluten protein and improve the quality of SBPP.