Food
As the UK moved in to space and with an increasing population the technology of improving food production became a priority. Although traditional foods including fresh vegetables, fruits, and meats were still the staple diet it was more expensive, limited, and considered a luxury in many cases.
It was many years before the UK released its food processing technologies to the rest of the world. Long after many countries had lost millions to famine and disease.
Algae
Algae are simple, single celled organisms that can thrive in many places that would kill normal crops such as salt and polluted water. Although algae has been eaten around the world for years it wasn't considered a staple food in Great Britain and was used as an animal feed, a fertiliser, and for algae oil production, a type of bio-ethanol.
As algae farming increased the crop could be made in to a variety of sustaining foods capable of providing all of the nutrients a person needed.
Artificial Meat
Stem cell research has finally created the artificial structure to form meat. the artificial muscle structures use false blood flow, electrical contraction and stimulation techniques, and false feeding to create a vat grown meat product. Early examples were tasteless and relied on artificial flavourings to gain any taste. The latest ones have better flavour but are still no match or the real thing.
Super Green Rice
This was originally created by Zhikang Li before the UK isolation began. it is a non-GM crop that is far more productive than the usual rice plants. Capable of surviving salty, drought, flood, insects and disease. It is readily grown in large or small quantities and will even grow in zero-g and has been know to survive in vacuum conditions.
Desert Greening
Another technology that was pre-isolation. Charlie Paton envisaged vast seawater greenhouses capable of transforming deserts in to arable farmland. Hot desert air is first cooled and then humidified by seawater. This humidified air is used to nourish crops and then is forced to condense again when it meets seawater cooled radiators. the now fresh water is used to irrigate the crops and the excess is used for nearby farmland.