Effects of temperature fluctuation on quality changes of large yellow croaker ( Pseudosciaena crocea ) with ice storage during logistics process

Abstract

Effects of temperature fluctuation on quality changes of large yellow croaker with ice storage during logistics process were evaluated. Samples of cold chain group (T1) were stored at 4 °C with ice all the time and the other samples in logistic group (T2) were stored in 20 °C for the simulation process of moving, transportation, distribution and sale. Microbiological, physicochemical, protein functional properties parameters were used to assess the quality of large yellow croaker in different temperature environments. Moreover, low‐field nuclear magnetic resonance was applied to investigated the water mobility in muscle of samples. The results indicated that microbiological and physicochemical index of T1 groups can maintain lower values than T2 one during storage. Furthermore, protein functional properties in samples of T1 can be kept well. It revealed that the shelf‐life of T2 samples was shortened by 72 hr when compared with T1 samples. Practical applications The microbiological, physicochemical, and protein functional properties indexes combined with low‐field nuclear magnetic resonance were measured so as to investigate the influence of temperature fluctuation on quality changes of large yellow croaker with ice storage during logistics process. The results demonstrate that the shelf‐life of large yellow croaker was shortened by 72 hr when stored in fluctuant temperature condition and LF‐NMR T2 transverse relaxation time is sensitive to different temperature condition.

Low-Field NMR and MRI to Analyze the Effect of Edible Coating Incorporated with MAP on Qualities of Half-Smooth Tongue Sole (Cynoglossus Semilaevis Günther) Fillets during Refrigerated Storage

“…The activity of Ca 2+ -ATPase is broadly used to assess the actomyosin integrity, reflecting the degradation of myofibrillar protein [14]. In the current study, a decreasing trend was detected no matter what kind of treatment was carried out during refrigerated storage (Figure 1g), which was concordance with the results with Pavap [22].…”

“…The multiexponential fitting of transverse relaxation T 2 distribution was carried out by Origin software and the protons associated with three types of water were identified. These results were consistent with some researches [14,16]. As shown in Table 1, the shortest relaxation time T 21 in the range of 1.32-6.14 ms was detected, representing the bound water entrapped within tertiary and quaternary protein structures.…”

“…Furthermore, the samples treated with bioactive edible coating combined with MAP had lower content of free water than the control and edible coating group alone. Above all, we could conclude that the synergetic effects of the edible coating combined with MAP could effectively retard water located within the myofibrillar macromolecules to release or translate to free water based on the destruction of the muscle fiber and keep excellent quality attributes of the HTS fillets [14]. …”

“…The extraction of actomyosin was performed as described by Sun et al [14], with slight modifications. Briefly, fillet samples of 1 g were mixed and homogenized with 10 mL precooled KCl solution (0.6 mol/L, pH 7.0) and then the homogenate was centrifuged at 10,000 r/min for 20 min in 4 • C, then the supernatant was added to three fold volume cooled distilled water and centrifuged at 10,000 r/min for 20 min.…”

“…However, low-field NMR (LF-NMR) and magnetic resonance imaging (MRI) techniques have more advantages in decreasing cost, saving time, and reducing damage to samples compared with the above instruments [4,10,11]. In addition, LF-NMR and MRI are able to assess the quality changes by providing the distribution as well as structural information of protons from water and lipid [12][13][14].…”