In Japan there are documentary references to the seafood known as surimi going back to 1115. Surimi, which means “ground meat” in Japanese, refers to a paste made from fish meat.
White fish such as Alaska pollock and threadfin bream are gutted, filleted, deboned, refined and mixed with cryoprotectants before freezing to produce this paste.
In 2016 the global surimi market volume exceeded 1.5 million tons a year, with China, Vietnam and USA each contributing 20% to global production. Surimi and its products are a familiar part of Asian cuisine; Japan leads consumption, with around 500,000 tons per year. While Asian markets remain the main drivers of consumption, surimi is becoming increasingly popular in other regions too. This development is accompanied by demands for higher quality, standardization and additional health benefits like mineral fortification and sodium reduction. Jungbunzlauer, a producer of ingredients obtained by fermentation, has been exploring how innovative applications could provide tastier, healthier options for the surimi industry.
Health: Sodium reduction
Consumers are increasingly moving towards healthier lifestyles, with a focus on wellness and wellbeing. Conversely they want to spend less time preparing meals and more time doing things they value. Busy lifestyles, woman in the workforce and the aging population all influence consumer demand for processed food. However, processed food usually contains high levels of sodium. A diet high in sodium and low in potassium adversely affects blood pressure and increases the risk of heart disease and stroke. According to the World Health Organisation, 2.5 million deaths could be prevented each year if global sodium consumption could be reduced to the recommended < 2 g of sodium per day (corresponding to 5 g of salt). Yet global average consumption is currently 9–12 g of salt per day, and therefore twice the general
In surimi, salt has a fundamental function. It not only imparts flavour, it also give the paste its desirable smooth texture and gelling properties. Salt ions selectively bind to the negatively charged groups on protein surfaces and break the intermolecular ionic bonds, thus increasing the affinity of the proteins to water. This helps to disperse proteins and increases water-holding capacity. Added salt contributes up to 80–90% of the total sodium in surimi. Thus raw surimi contains around 150 mg of sodium per 100 g, but adding the extra 1.5–3% of salt needed to produce processed surimi seafood products can take their levels up to 800–1,200 mg sodium per 100 g. Reducing the amount of salt in surimi reduces saltiness but it also affects extraction and stability, which in turn affects its cooked texture. Jungbunzlauer offers a range of salt substitutes under the brand name sub4salt®. This is a mixture of sodium chloride and potassium salts designed to reduce sodium content by up to 43% (table 2) without compromising the taste and texture of products. sub4salt® can be used to replace salt on a 1:1 basis, keeping the same saltiness and functionalities. Replacing salt with sub4salt® N1000 or sub4salt® plus 50 in a basic surimi sausage formulation leads to a 15–33% increase in hardness (expressed as breaking strength), and 5–13% increase in cohesiveness (expressed as distance to rupture). This can be attributed to the potassium ions present in sub4salt®, which enhance protein solubility and gelation better than sodium ions (Hofmeister series). Using a product like sub4salt® not only has an impact on the healthiness of surimi products but also improves their texture without compromising on taste.