The low‐field NMR studies the change in cellular water in tilapia fillet tissue during different drying conditions

Abstract

Tilapia has the advantages of hypoxia tolerance, disease resistance capacity, rapid growth, and reproduction, and its nutritional value is high (Wang et al., 2019). In recent years, China became the top producers in the world to cultivate tilapia (FAO, 2017). In addition, in global fish farming, tilapia is the most popular farmed fish (Duan et al., 2011). But tilapia has high water content, and tilapia is apt to be highly spoilage when it is affected by enzymes and microorganisms (Kituu et al., 2010;Li et al., 2017), which can potentially result in substantial economic losses. In order to increase tilapia shelf life and maintain the quality of the tilapia products, it is of great necessary to dry for tilapia. At present, the methods of drying tilapia mainly include hot air-drying (HAD), microwave drying (MD), hot air-microwave combined drying (HAMCD), heat pump drying (HPD), vacuum microwave drying (VMD), and vacuum freeze-drying (VFD). Among these methods, the vacuum freeze-drying (VFD) is the best method of water removal for all kinds of foods, but its operation cost is high (Duan et al., 2010). Therefore, it is limited to use. Vacuum freeze-drying (VFD) is only used when it provides a reasonable added value to the products or the costly materials are dried (Ratti, 2001).In order to improve the quality of the products and reduce the drying time, it is necessary to pretreat the samples and combine two drying techniques to dry tilapia fillets. The previous research found that the quality of tilapia fillets by ultrasound-assisted polydextrose osmotic vacuum freezing-heat pump combined drying (UAPOVFHPCD) is close to the quality of that by vacuum freeze-drying; moreover, compared with vacuum freeze-drying, it took less time. In addition,

Effects of maternal vitamin D3 status on quality characteristics of pork batters in offspring pigs during cold storage

“…Moreover, compared with bound water and non-flowing water, free water has the highest content. This is consistent with the findings of Luo et al (2021), which are attributed to cell membrane rupture. These results suggested that maternal high-dose vitamin D 3 addition could inhabit water mobility, increase juiciness, and improve the quality of pork batters in offspring pigs during cold storage period.…”

Effects of partial replacement of unwashed Antarctic krill surimi by Litopenaeus vannamei surimi on the heat‐induced gelling and three‐dimensional‐printing properties

“…Three peaks, T 21 (0.01–10 ms), T 22 (10–200 ms), and T 23 (>200 ms) were observed in Figure 2b and Table 2, corresponding to strongly bound water, partially immobilized water, and free water in the gel, respectively. The relative content of each water was represented by the graph's peak area (Luo, Li, Zhang, Zheng, & Ming Ling, 2021). T 2 reflects the combination degree of each water, and lower T 2 indicates a higher water‐binding degree (Li et al, 2012; Luo et al, 2020).…”

Effects of different phosphorus‐free water‐retaining agents on the quality of frozen tilapia fillets

“…These three forms represent: water closely bound with macromolecules, that is, binding water T 2b (0.1–1.0 ms); water inside the myofibril, that is, water that cannot easily flow T 21 (30–200 ms); and water outside the myofibril network, that is, free water T 22 (300–800 ms) (Bertram et al., 2002 ). The area of each peak, enclosed by the abscissa, is the water content of each part (Luo et al., 2021 ). Thus, the corresponding water content can be obtained by integrating each peak.…”

“…Figure 4 outside the myofibril network, that is, free water T 22 (300-800 ms) (Bertram et al, 2002). The area of each peak, enclosed by the abscissa, is the water content of each part (Luo et al, 2021). Thus, the corresponding water content can be obtained by integrating each peak.…”