Look for an "industry profile"--a short market research report with history, statistics, markets, forecasts, and more for the industries involved in the food production you're researching.  Below, I list two sources to search for industry profiles as well as articles from trade magazines. 

Articles from trade magazines cover industries in an in-depth way that you just won't find in any other publications.  Be alert to biases in the coverage, but you'll learn news not mentioned elsewhere.

Look for historical and current statistics from the government agency that oversees your particular food or collects data on your food's market.

Many trade association publications cost money, but you can often get a sampling of statistics and data for free (hint: find the page or tab for "resources" "statistics" "data" "bibliography" or "links" on most sites).