2013 horse meat scandal negative for horse DNA. products were tested but were negative for all foreign DNA. Of the 37% of beef products tested positive for horse DNA, Tesco's inexpensive Everyday Value Beef Burgers tested at 29.1%. All other reported brands had less than 0.3% horse DNA. These products originated from Liffey Meats and Silvercrest Foods in Ireland and Dalepak Hambleton food processing plant in the United Kingdom. Trace amounts of horse DNA were also found in raw ingredients imported from Spain and the Netherlands. Laboratory DNA investigations were requested by the authorities into possible donkey meat adulteration of minced meat products labelled
Tesco biofuels, offering petrol-bioethanol and diesel-biodiesel blends instead of pure petrol and diesel at their petrol stations, and now offering Greenergy 100% biodiesel at many shops in the southeast of the United Kingdom. In 1998, Tesco and Esso (part of Exxonmobil) formed a business alliance that included several petrol filling stations on lease from Esso, with Tesco operating the attached shops under their Express format. In turn, Esso operates the forecourts and sells their fuel via the Tesco shop. As of 2013, there were 200 joint Tesco Express/Esso sites in the UK. In 2018, Tesco launched a separate budget chain, Jack's,