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随着人们生活结构的变化,罐装食品越来越受人们青睐。但选购时应注意几点: 一、外观质量 好的罐装食品底部和盖稍有内陷,不是平的:敲罐可听到清脆的响声,因为马口铁的罐装食品在制造时,须经高温处理,封罐后、罐内蒸气冷凝成水、罐内空气变稀薄,外部气压大、便使罐头的底部和盖向内凹一些。如果罐头的底和盖凸起、轻敲罐头发出混浊的声音、则说明罐头已变质。因罐内食品会腐败变质而产生气体,导致罐头膨胀。
With the change of people’s living structure, canned food is more and more favored by people. However, when buying should pay attention to several points: First, the appearance of good quality canned food Bottom and cover slightly indented, not flat: Knocking can hear the crisp sound, because the tin canned food at the time of manufacture, After high-temperature treatment, sealing cans, the steam condensate into the tank, thinning the air inside the tank, the external pressure is large, will make the bottom of the can and the lid concave inward. If the bottom of the can and the lid are raised, tapping the can produces a cloudy sound, then the can has deteriorated. Due to the deterioration of the food inside the tank will produce gas, resulting in canned expansion.