Protein changes in shrimp (<i>Metapenaeus ensis</i>) frozen stored at different temperatures and the relation to water‐holding capacity

Shi

Food Processing Preservation

2022

To explore an effective quality evaluation system based on microstructure changes, tilapia samples were preserved at the temperature of −20, −40, and −80°C up to a storage period of 270 days. The porous structure of fish muscle was quantified using the cross‐section area (CA) and fractal dimension (FD) of ice crystals, and the effectiveness of the two was compared. The relationships between microstructure changes and traditional quality parameters, including water‐holding capacity, texture properties, K value, and total volatile basic nitrogen (TVB‐N), were also explored. The results showed that FD dropped by 8.79, 4.53, and 3.03% of fillets at −20, −40, and −80°C after 270 days of storage, respectively. The better fitting on the basis of FD for evaluating quality of tilapia compared with CA. Traditional quality indicators were correlated well with the FD (R2 > 0.94), except for relaxation time (T2). The first‐order kinetic equation FD = exp (0.0895 t exp[−7240.26/RT])/1.8903 was developed, and FD relative errors between predicted and observed values were all less than 3%, which demonstrated that the feasibleness and accuracy of quality evaluation based on FD during frozen storage. Practical applications Frozen storage inevitably has a negative impact on the tissue, water‐holding capacity, and protein properties of fish. Thus, it is of great urgency to put forward an effective quality evaluation system of frozen fish. Here, tilapia samples were studied over a period of 270 days by measuring their microstructure of muscle fibers and traditional quality parameters. Correlation analysis of each index was also conducted and kinetic model based on FD was established and validated finally. In addition to establishing an effective quality evaluation system based on microstructure changes for tilapia, these results will provide new insights into the quality evaluation and laid a foundation for the application of fractal dimension in tilapia processing and transportation.

Section: Resultsmentioning

confidence: 99%

Establishment of quality evaluation method for frozen tilapia ( Oreochromis niloticus ) fillets stored at different temperatures based on fractal dimension

Shi

Food Processing Preservation

2022

“…The water‐holding capacity (WHC) of prolamin from distiller's grains was evaluated using the method of Ji with minor modification (Ji et al ., 2021). Briefly, an aliquot of 1.0 g prolamin and 10 mL water were put into a centrifuge tube, mixed thoroughly, and subsequently heated in a water bath at 30, 40, 50, 60, and 70 °C, respectively, for 30 min.…”

Section: Methodsmentioning

confidence: 99%

Physicochemical properties and application in film preparation of prolamin from distiller's grains

Liang

et al. 2022

Int J of Food Sci Tech

Prolamin of sorghum-based distiller's grains was extracted and its physicochemical properties were further determined. The prolamin was found to be rich in acidic amino acids, resulting in an isoelectric point of pH 4.0. High content of α-helix structure endowed the protein good thermostability with a denaturation of 123.47 °C. The prolamin was resistant to pepsin but susceptible to trypsin in vitro digestion. The nutritional evaluation score was low and the protein does not belong to a good source of food protein due to the low digestion and lack of essential amino acids. The prolamin exhibited low water-holding capacity, oil-holding capacity, foam properties, and emulsifying properties. Moreover, the protein possessed good film-forming properties, and the characteristics of high temperature resistance, low water-holding capacity and oil-holding capacity of prolamin can endow the protein film with excellent properties of water blocking, oil blocking, and high thermal stability.

Comp Rev Food Sci Food Safe

“…Frozen temperatures from −20 • C to −30 • C are generally satisfactory in maintaining quality of muscle foods. The marginal gain in quality of storage at −60 • C may be small, but can be critical for demanding consumers (Ji et al, 2021). During freezing (and thawing), if heat removal (supply) is slow, muscle foods will remain at temperatures around −1 • C for quite long time.…”

Section: Decrease In Temperaturementioning

confidence: 99%

Freezing of meat and aquatic food: Underlying mechanisms and implications on protein oxidation

Bao

Ertbjerg

Estévez

et al. 2021

Self Cite

Over the recent decades,protein oxidation in muscle foods has gained increasing research interests as it is known that protein oxidation can affect eating quality and nutritional value of meat and aquatic products. Protein oxidation occurs during freezing/thawing and frozen storage of muscle foods, leading to irreversible physicochemical changes and impaired quality traits. Controlling oxidative damage to muscle foods during such technological processes requires a deeper understanding of the mechanisms of freezing-induced protein oxidation. This review focus on key physicochemical factors in freezing/thawing and frozen storage of muscle foods, such as formation of ice crystals, freeze concentrating and macromolecular crowding effect, instability of proteins at the icewater interface, freezer burn, lipid oxidation, and so on. Possible relationships between these physicochemical factors and protein oxidation are thoroughly discussed. In addition, the occurrence of protein oxidation, the impact on eating quality and nutrition, and controlling methods are also briefly reviewed. This review will shed light on the complicated mechanism of protein oxidation in frozen muscle foods.