Another thickener you might not think you run into everyday but is as ubiquitous as, well, fruit, is the hydrocolloid pectin. Pectin is the naturally-occurring structure-giving hydrocolloid found in many fruits. It is what gives jams and jellies their thickness. More importantly, though, anytime you blend fruit in a smoothie, it is the pectin that helps to make the smoothie creamy rather than lumpy and watery. You can purchase different types of pectin to amplify the thickening power of fruits.