Treatt, which makes ingredients for the flavour, fragrance and cosmetic industries, has lifted half year pre-tax profit by 6% and revenue by nearly a third despite the recession.Profit before tax for the six months ended 31 March 2009 rose to £1.39m from £1.32m a year ago on revenue 31% higher at £28.3m, in line with expectations.UK unit R.C. Treatt enjoyed "a particularly good" six months, benefiting from the strong dollar. Three quarters of its order book is dollar-based. Group order books were up over 13% year on year. Treatt USA maintained sales and margins.Earthoil, bought last year, has continued to show "marked improvement", with like-for-like sales up 82% year on year, and with "much improved" margins."Following a modest improvement in cash flow during the period, the board expects to see cash flows improve significantly in the second half of the year and was able to renew all existing bank facilities without difficulty," it said. Treatt sees margins returning to lower levels during the second half of the year as the impact of the strong dollar levels off. "Whilst current economic conditions create uncertainty and necessitate a strong degree of caution, the board believes that the full year results will now exceed its current expectations, although it is too early to quantify the extent to which this may be the case," the firm added.The interim dividend rises to 3.7p a share from 3.6p last year.