How This Buyer Searches
If there is one overall deficiency from photographers it is definitely keywords.
I am primarily looking for images of different soups. The first thing I do is to define the basic soup from its appearance. As an example, let's assume I want a picture of a pumpkin soup that has white cream and parsley as a garnish.
I do not search for the word "white" and I do not search for the word "herb".
In my opinion no one looking for a food picture would ever search for the word "organic". Visually you cannot tell if a food product is or is not organic.
I find many soup pictures with the keyword "vegetarian" that have cheeses and/or cream and/or egg in the image. True vegetarians do not consume any of those products. It is very frustrating when I have to search through pictures with wrong keywords.
Every ingredient that is visible in the bowl of soup should appear as a keyword. Beans are a big problem in my searches. If a bean is visible in the soup, I need to know what kind of bean it is. I search for a specific bean if it is visible in the soup recipe.
Think about the buyer before you add your keywords. Pumpkin soups should always have the keyword "squash" and visa versa. A pumpkin is a type of squash and when pureed looks like a variety of different squashes.
Placing keywords that are incorrect infuriates me to a point where I will not buy from that photographer.
Remember that most buyers do not have hours to search through hundreds of images. They narrow down the selection using the keywords. If you don't identify what is visible you could easily lose out on a sale.
Photo credits: Rozmarina.