One of my "homework assignments" for my students is to take a five senses walk with their families. I send home a brief letter and a recording sheet. They use almost all five of their senses. I do not ask them to taste anything on the walk (that could be dangerous). Instead, I have them list a seasonal food that they can taste (apples, cider, pumpkin pie, etc.).
Although you may not live in an area with the seasonal changes that we have here in New York, I am sure your students can still enjoy this activity.