A review of the use of plant extracts to control melanosis in farmed shrimp

Shrimp is a highly perishable product with limited shelf life due to melanosis and biological composition. Controlling the destructive effects of melanosis is one of the major challenges for the industry. Melanosis in crustaceans is usually controlled by inhibitors such as sodium metabisulfite. However, the use of synthetic inhibitors for melanosis and antioxidants in food processing is usually limited by considerations related to safety and impact on food quality. Thus, over the last decade, the trend towards studies on the use of natural extracts to control shrimp melanosis has increased. Data from some articles published by ScienceDirect, PubMed, Scopus, SpringerLink, and Scopus databases on the occurrence of melanin black pigment in shrimp skin were used. The shrimps were dipped in extracts and stored in ice or refrigerator. In Iran, only the effects of grape seed extract to prevent melanosis have been studied. Some studies have reported higher effects of plant extracts such as Garcinia cowa Roxb, Persicaria Odorata, rosemary, green tea, avocado, Arabic coffee grounds, and chamomile than sodium bisulfite. Some researchers have described the effects of extracts such as olive, rosemary, and thyme along with metabisulfite in preventing melanosis more than metabisulfite alone. Plant extracts were effective in reducing black spots in shrimp for 2-28 days. Studies have shown that plant extracts can act as antioxidants and be an effective natural alternative to inhibit melanosis after shrimp death.