Exponent Private Equity and Intermediate Capital Group bought the meat-free division, after six companies considered making offers.
The future of the brands has been the subject of months of speculation with the short list of parties interest in the business narrowed down to two in the last few months.
Premier, which produces Hovis bread and Mr Kipling cakes, has been looking to offload some brands to pay down its £1.4bn debt pile.
The debt was amassed after Premier bought Hovis-owner RHM and Campbell’s Soup in the UK and Ireland.
Quorn was purchased for £172m from Marlow Foods in 2005.
The first Quorn product was launched in 1985 and the brand has since become a popular meat substitute for vegetarians.
Cauldron offers a range of tofu products and vegetarian sausages.
Premier said in the year ending 31 December, the meat-free division made revenues of £128.8m and a trading profit of £16.2m.
Premier chief executive Robert Schofield said: “We are pleased to have concluded this sale agreement. It makes a significant contribution to reducing our debt.
“It will also enable the business to focus further on building our current portfolio of great British brands.”
The brands are produced at three sites in the UK with 595 staff.