AAAL 100% Pure Citric acid is often added to packaged food and drinks. It helps keep canned and jarred foods fresh over long periods of time. It can prevent some kinds of fresh-cut produce, like sliced apples, from turning brown. Citric acid can also help thicken foods or give them a slightly sour flavor. That's why you might see citric acid listed as an ingredient in some ice creams, sorbets, or sodas. Because Citric acid can eat away at hard water buildup, you'll often see it in dishwasher detergent. Other household cleaners also include it as an ingredient since it can help remove stains and odors. Since citric acid kills some types of bacteria and viruses, you'll find it in insect sprays, products that kill fungus or algae, hand sanitizer, and even some tissues you use to blow your nose.