PUB chain JD Wetherspoon has stepped up DNA testing of its products in a sign that even those companies untainted by the horsemeat scandal are increasing their vigilance.

Food is an increasingly important part of Wetherspoon's income, supporting strong like-for-like sales growth of 6.9% for the 26 weeks to January 27, the company revealed yesterday.

However, under the pressure of rising tax and utilities costs, first-half pre-tax profit at the 871-strong chain fell by £1 mil-lion to £34.8m on an underlying basis.

Chief executive John Hutson said tests of its entire menu had thrown up no evidence of contamination.

However, he added: "There have been some very good companies drawn into this.

"We have upgraded our systems accordingly."

This means more frequent testing by its suppliers and a new system of independent testing by Wetherspoon itself.

Horsemeat was found in beef lasagne and burgers supplied to Brewers Fayre pubs owner Whitbread and beefburgers supplied to catering company Compass while a number of retailers and food producers have reported problems.

Food made up just 23.2% of Wetherspoon's sales in 2003. In the most recent period it comprised 32.5% of income.

The company estimates that, in all, spending related to meals now accounts for around two- thirds of its revenue.

"People do not go out to drink as much as they used to but they go out to eat and drink more than they used to," Mr Hutson said.

The chain, which claims to attract more well-heeled customers than upmarket rivals, targeted the growing breakfast dining market three years ago.

One-third of its pubs now open as early as 7am, while the remainder start serving at 8am. However, Mr Hutson said the recession had been of little benefit to Wetherspoon, because while it had brought into its pubs some who previously dined in restaurants, many previous customers no longer have the cash to eat out.

The increased focus on dining added to costs as Wetherspoon's gas bill rose due to increased activity in kitchen as well as rising energy prices.

The company also had a larger wage bill, in part because food is far more labour-intensive than bar sales.

Meanwhile its total tax bill was £273.5m, an increase of £23.4m and representing 43.7% of its sales.

Chairman and founder Tim Martin said: "If we were taxed on the same basis as super-markets, we would have paid £40.7m less, since supermarkets pay virtually no VAT in respect of food sales."

In the six weeks to March 10, like-for-like sales growth accelerated to 7.3%, although it said taxation and other costs were continuing to rise.