It hasn't been the easiest of years for food-processing giant Archer Daniels Midland (NYSE:ADM). Challenged by volatile end-user pricing and high energy costs, the company was likely happy to escape the year with only a 1% decline in sales. The question before us now, of course, is whether better things may lie ahead.

Fourth-quarter results were something of a mixed bag. Revenue was down about 3% from the year-ago level, but segment operating profits were up by nearly one-third. While a straight comparison of net income is confounded by a $400 million charge taken for litigation expense last year, it would appear that net income grew by a like amount to segment operating profits -- about 31%.

ADM also saw a pronounced improvement in cash flow generation for the recently completed year. Free cash flow totaled about $1.5 billion -- well above the negative result last year and the $661 million and $1.2 billion generated in the two years prior to that.

While quarterly results were solid and above estimates, we are still talking about a processing business here. That means low-to-mid-single digit margins and revenue growth aren't likely to move about the high single digits.

Sure, there is an ongoing demand for oilseed processing, sweeteners, and starches around the world, but we're not talking major year-over-year growth here. What's more, companies like Cargill, Bunge (NYSE:BG), ConAgra (NYSE:CAG), and Corn Products (NYSE:CPO) are still all in the game, too, with their own processing capacity.

One aspect of ADM that could hold promise for the future is the non-food business -- specifically ethanol. The current energy bill targets a near doubling of U.S. ethanol usage over the next seven years and includes tax credits for ethanol plants. Although it's generally more sensible to produce ethanol from sugar instead of corn, the U.S. grows a heckuva lot more corn than sugar, so corn it is and corn it will continue to be.

Time will tell, though, whether this boost for ethanol fuels a sustainable boost in ADM's earnings. For now at least, it's an agricultural processing business with some opportunities in ethanol and plastics. As such, it's important to buy this stock correctly -- investors really shouldn't rely on unexpectedly high growth to bail them out of a poor initial purchase price.

In other words, heed the mantra of "margin of safety" and make sure you really like the price before plunking down your cash.

For more calorie-packed Foolishness on ADM, check out these past takes:

Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).