How Harvest Technique Affects Flesh Quality

Excessive fish activity prior to and during harvest affects the external and internal appearance of the fish or fillet. External injuries including scale loss, bruising and open injuries as well as internal injuries including fillet gaping, blood spotting, reduced translucency and yield and a reduced shelf life all lead to reducing market acceptability and a reduction in the fish value.  The AQUI-S® rested harvest technique dramatically reduces the occurrence of these injuries which results in a premium market price for the product.

Blood Spotting

Blood spotting can be significantly reduced or eliminated in fish that have been harvested in a rested state using AQUI-S®. Most blood spotting occurs in fish that have been highly active and stressed from the harvest procedure. Stress culminates in the blood vessels being weakened and rupturing during harvest leading to pooling of the blood in the tissue. During processing the blood leaks into the white muscle appearing as distinct areas of discolouration. This is an issue for value added products, particularly smoked products. Often the blood spotting is not visible until after smoking and this will result in a downgrading of the product. Removal, where possible, is time-consuming and expensive.


Fish at the point of sale are predominantly presented in the form of fillets or steaks. The customer therefore must rely on the appearance of the “meat” as the key factor to be considered in making a buying decision. The occurrence of gaping is significantly reduced or completely eliminated in fish that have been harvested in a rested state using AQUI-S®.

Shelf Life

Shelf life or spoilage is another key quality factor that will determine the value of the final product. Shelf life can be attributed to the action of autolysis (muscle breakdown) and consequent microbial growth in the muscle. Unstressed fish flesh delay autolytic activity and microbial spoilage thus extending the shelf life and maximising the period of highest quality and edibility.


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