The hydrolysis of sodium triphosphate in cod and beef muscle

Abstract

Polyphosphates can be used in meat and fish products to reduce liquor loss during processing. However, there have been indications that triphosphate and pyrophosphate are hydrolysed in muscle. This effect has been studied in cod and beef using P32 labelled triphosphate and it is found that the kinetics conform to a typical 'consecutivey reaction of the type For cod, k, 21 k2 and only orthophosphate remains after 30-40 hr at 0°C.In beef k, 4 k,, and also k, (beef) < k , (cod). This results in higher levels of pyrophosphate being formed in beef muscle from the triphosphate and the hydrolysis takes place over a much longer time period than in cod. S nce triphosphate is generally more effective than orthophosphate for reducing liquor loss, it is concluded that its effect on the muscle is an irreversible one.

Effects of Phosphates and Salt in Ground Raw and Cooked Farmed Cod (Gadus morhua) Muscle Studied by the Water Holding Capacity (WHC), and Supported by 31P‐NMR Measurements

“…pH is very important for WHC as it affects protein conformation (Bertram and others 2004b; Martinez‐Alvarez and Gomez‐Guillen 2006). Furthermore, it may affect enzyme (phosphatase) activity (Sutton 1973). The pH values of the brines used ranged from 5.83 (hexametaphosphate with salt) to 10.22 (basic diphosphate).…”

“…Hence, the prime objective was economical and increased quality (that is, texture and flavor improvement) was a positive side effect. Studies have indicated that phosphates can be decomposed prior to freezing of cod (Sutton 1973). This study complements available findings indicating that the positive effect of triphosphate was maintained during processing.…”

“…Decomposition of brine components in muscle samples with storage time has been described (Douglass and others 1979; Belton and others 1987; Li and others 1993; Li and others 2001). The rate of hydrolysis is very rapid in fish compared to meat (Sutton 1973), and hydrolysis as well as water‐immobilization capability in white meat (poultry) is also faster than in red meat (Sutton 1973; Belton and others 1987; Xiong 2005). Some researchers claim that these species‐specific differences are due to differences in ATP levels and depletion, and the rate of post mortem autolysis (Tanikawa and others 1963; Belton and others 1987).…”

Tripolyphosphate hydrolysis by bovine fast and slow myosin subfragment 1 isoforms

“…Studies on TPP hydrolysis in meat systems show a wide range of time for complete hydrolysis being anywhere from 15 min for ground beef (Hamm & Neraal, 1977a) and salted ground chicken (Belton, Packer, & Southon, 1987), less than 50 min. in salted chicken breast (Li et al, 2001) and up to 16 h for beef (Sutton, 1973). At the extreme case, myosin easily has the capacity to be the major TPPase in meat, while in the most rapid case, other enzymes may be involved and/or the TPPase of myosin may be activated by actin and/or other factors in the meat system.…”

“…The likely reaction scheme for TPP metabolism in meat is (adapted from Sutton, 1973; Weilmeier & Regenstein, 2004): where k 1 involves TPP hydrolysis by tripolyphosphatase (TPPase) and k 2 involves hydrolysis by pyrophosphatase. The enzymes and the kinetics involved in TPP and PPi hydrolysis in meat systems are partially understood.…”