烘干法检测PET瓶口饮料残留的方法分析

Analysis of PET Bottle Residue in Beverage by Drying Method

烘干法检测PET瓶口饮料残留中,主要影响因素为烘干温度和时间。该文以一款含糖含氨基酸粉的饮料(糖度6.5%,氨基酸粉含量150mg/L)为研究对象,通过载玻片试验、瓶盖耐热试验、瓶口结晶试验及瓶口滴加饮料试验,分析饮料随烘干温度变化的显色趋势并探究饮料烘干法可显色的最大稀释度,从而确定烘干法检测PET瓶口饮料残留的最适烘干温度和时间。实验结果表明:当烘干温度为100℃时,载玻片上饮料有轻微的黄色糖斑,且随着烘干温度升高,玻板上饮料糖斑颜色逐渐加深;HDPE盖烘干温度大于130℃瓶盖即会融化变形;当饮料稀释至1∶80(v/v)时,达到可显色的最大稀释度,在可显色的稀释度范围内,饮料均在30min内显色最深,在40~60min内糖斑无明显脱落。该饮料烘干法检测瓶口残留的最适烘干温度为130℃、时间为30min。

The residues on the PET beverage bottle mouth were determined by the drying method and the main influencing factors were drying temperature and time. This article takes a beverage containing sugar and amino acids（sweetness 6.5%,amino acid content 150 mg/L）as the research object. Through the glass slide test,bottle cap heat resistance test,bottle crystallization test,and bottle drop beverage test,the beverage color trend with the change of the drying temperature and the maximum dilution of the beverage discoloration were analyzed,and then the optimum drying temperature and time of residues on the PET bottle mouth using the drying method were determined. The results showed that,when the drying temperature reached to 100℃,there were some yellow sugar spots on the glass plate,as the drying temperature rose,the color of the sugar spots on the glass plate gradually deepened;when the temperature for drying the HDPE lid was higher than 130℃,the bottle cap would melt and deformed.The color development could be achieved when the diluted beverages were not below 1∶80（v/v）. Within the range of the color developable dilution,all the colors of the beverages changed in30 min,and the color did not significantly deepen in 40 ~60 min,along with no obvious loss of sugar spots. So the optimum drying temperature and time were 130℃ and 30 min,respectively,for the residues on the PET beverage bottle mouth by drying method.