Treatment of Tomato-Processing Waste

The byproduct of any variation of canned tomatoes and sauces in the food-canning industry is a red sludge, filled with skins and seeds that is very difficult to break down due to high particulate and colloidal fractions. This chapter looks into various ways to process tomato-processing wastewater as well as other uses for the substance. One method is an upflow anaerobic sludge blanket (UASB) used as treatment, where various hydraulic retention times were tested and ranked based on removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), and ammonia-nitrogen (NH 4 -N). Some methods include lycopene pigment extraction through ultrasound pretreatment along with enzymatic treatment using response surface methodology (RSM). Tomato peel extracts were investigated to determine their carotenoid content, phenolic composition, and antioxidant and antimicrobial activities, suggesting alternative uses as natural bioactive molecules. This chapter only discusses some of the many technologies proposed to successfully treat tomato-processing wastewater.