Today, when you go shopping, most of the food are kept in plastic or paper containers (or tin can).
What types of containers were used to sell, transport and keep the food before plastic ? and before industrial era in the everyday life ?
Pottery (amphora), barrels, and wineskins mostly - which is why archaeologists know so much about pottery, as it is the only one of the three relatively imperishable.
Paper was relatively expensive by todays standards until the early 20th century (and glass more so as only hand-blown glass was known) thus would have been used only to store relatively pricey items such as spices and medicines.
Metal tins (not tin cans!) were useful because a very tight seal could be obtained rom metal-on-metal contact, but this really only becomes common in Europe after the development of improved sheet-rolling technology in the early 19th century. (Think tobacco containers, and their almost air-tight seal.)
Tin cans followed a few decades later, in time for the Arctic and Antarctic expeditions of the late 19th century.
As an example of the sometimes dramatic price changes that have ensued from cheap electric power, consider the cutlery at Louis Napoleon's coronation. The most favoured guests were provide with the even-more-expensive-than-platinum cutlery, manufactured from aluminum. Only the hoi-polloi were provided with silver cutlery!
Before plastic, most of liquids were sold in paper containers or glass bottles (paper packs for liquids appeared in 20th century though). Solid food was sold in paper envelopes or boxes, metal boxes, foil or in natural envelopes (guts, leafs).
Sometimes people were required to come with their own volumes to buy a liquid or a semi-liquid, with large quantities stored in wood/metal barrels.
Modern food packaging came much later than the "industrial era". The food like fruits and vegetables was sold without any packaging. Meat, butter, cheese, sausage etc. was wrapped in paper by the seller at the time you bought it, liquids were sold in glass bottles. This was the usual practice, for example, in Soviet Union until it collapsed. Tin cans and conservation were invented in XIX century. Large quantities of liquids were preserved in wood barrels.