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.

Food Processing Preservation

“…The juiciness, tenderness, and flavor of aquatic products have a great influence on WHC (Zhang et al, 2021). WHC is evaluated by cooking loss, centrifugation loss, drip loss, compression loss, thawing loss, and evaporative loss (Ji et al, 2021).…”

Section: Whcmentioning

confidence: 99%

Recent advances in emerging techniques for freezing and thawing on aquatic products' quality

Yang

Bian

et al. 2022

Aquatic products are favored by the majority of consumers because of their low fat, high protein, particularly low cholesterol. In recent years, consumers are demanding the high nutrition, freshness, and safety of aquatic products. Therefore, efficient preservation technologies are all important. Freezing can extend the shelf life and inhibit the seasonal fluctuations in different species. Thawing is an important step for aquatic products. Repeated freezing-thawing usually occurs because of the imperfection of cold chain technology and temperature fluctuations in warehousing, transportation, and retail. These can affect the quality of aquatic products, including water holding capacity, texture, total volatile basic nitrogen, k value, protein oxidation, and lipid oxidation. Emerging freezing and thawing technologies can improve the quality of aquatic products. This review introduces the influences of freezing, thawing, and repeated freezing-thawing on the quality of aquatic products and the development of freezing and thawing technologies for aquatic products. Practical applicationsFreezing, thawing, and repeated freezing-thawing affect the quality of aquatic products, including water holding capacity, texture profile analysis, lipid oxidation, and protein oxidation. In recent years, emerging freezing and thawing technologies have been found by more and more researchers. These technologies can improve the quality of aquatic products.