Modern ketchup began in the early 20th century. The direct cause of its emergence is the discussion of the use of sodium benzoate. Harvey Willy, the father of the US Food and Drug Administration, questions the safety of benzoic acid. Entrepreneurs, especially H. J. Heinz (founder of Heinz Foods), began looking for substances that could be used to replace benzoic acid.
Previous ketchups were very thin, due to the use of immature tomatoes with less pectin content. The vinegar contained in the ketchup was also less than today. By picking ripe tomatoes as raw materials, it is not necessary to use benzoic acid in ketchup, and its taste is not worse than that of earlier ketchup. Some experts believe that this change in raw materials not only removes the use of benzoic acid, but also changes its taste, and it is this change in taste that makes it a widely used condiment today.
Previous ketchups have two flavors: bitter and salty. But after switching to mature tomatoes and adding more tomato flesh, the ketchup also gained an umami taste. It also gets sour and spicy by adding more vinegar. Its sweetness is doubled without benzoic acid. The blend of these five flavors makes the ketchup very delicious.
In the past, ketchup was made using fresh tomatoes. After harvesting the tomatoes, they are evaporated into a very viscous tomato paste by vacuum evaporation. This tomato paste can be stored at room temperature for a long time, so that it can be used to make ketchup all year round.
In the past, ketchup was usually placed in a glass bottle, which effectively protected the ketchup from drying and oxidization, but because the ketchup was thicker, it was not easily poured out of the glass bottle. The newly introduced polyethylene bottle makes it easy to squeeze out tomato sauce. Most of today's ketchup is in polyethylene bottles.