Heron Foods has notched up another year of sparkling results.

The frozen food discounter, which has 170 stores across the north of England and the Midlands, saw its profits rise 15% to £8.1m on sales up 11.3% to £164.9m in the year to 31 December 2011, according to accounts filed at Companies House.

Its performance is a big improvement on the year before when profits dropped 9% after the company chose to pay down debts.

Heron will be hoping to continue the upward trend in the months ahead, after The Grocer revealed two weeks ago that it had acquired 54 of Cooltrader’s 58 stores from owner Iceland for an undisclosed sum.

Writing in the accounts, the directors said Heron now planned to “expand its current operations into new sites and is actively managing its property portfolio to drive footfall and turnover forward still further and to release cash for the repayment of debt”.

It’s in a great sector to do this. According to The Grocer’s Top 100 ranking of the UK’s biggest grocery retailers, frozen food retailing is a cool place to be right now. Even though the frozen sector has struggled in recent years, no-frills freezer centres haven’t. The five frozen discounters on the rankings collectively increased sales by 8% and profits by 7% in the past 12 months, leaving them with an enviable profit margin of 6.1%.

This is way ahead of grocery retailers as a whole. Collectively, sales and profits for the 100 grocers on the rankings increased by 5% on the year before, with profit margins static at 4.8%.

You can digest all these findings and more in the Top 100 here.