Li Ting, Kuang Shiyao, Xiao Ting, Hu Lihui, Nie Pengcheng, Ramaswamy Hosahalli S, Yu Yong
College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, Ministry of Agriculture, 866 Yuhangtang Road, Hangzhou 310058, China.
Foods. 2022 Jun 22;11(13):1842. doi: 10.3390/foods11131842.
In this study, a self-cooling laboratory system was used for pressure−shift freezing (PSF), and the effects of pressure−shift freezing (PSF) at 150 MPa on the quality of largemouth bass (Micropterus salmoides) during frozen storage at −30 °C were evaluated and compared with those of conventional air freezing (CAF) and liquid immersion freezing (LIF). The evaluated thawing loss and cooking loss of PSF were significantly lower than those of CAF and LIF during the whole frozen storage period. The thawing loss, L* value, b* value and TBARS of the frozen fish increased during the storage. After 28 days storage, the TBARS values of LIF and CAF were 0.54 and 0.65, respectively, significantly higher (p < 0.05) than the 0.25 observed for PSF. The pH of the samples showed a decreasing trend at first but then increased during the storage, and the CAF had the fastest increasing trend. Based on Raman spectra, the secondary structure of the protein in the PSF-treated samples was considered more stable. The α-helix content of the protein in the unfrozen sample was 59.3 ± 7.22, which decreased after 28 days of frozen storage for PSF, LIF and CAF to 48.5 ± 3.43, 39.1 ± 2.35 and 33.4 ± 4.21, respectively. The results showed that the quality of largemouth bass treated with PSF was better than LIT and CAF during the frozen storage.
在本研究中，使用了一种自冷式实验室系统进行变压冷冻（PSF），并评估了150MPa变压冷冻（PSF）对−30°C冻藏期间大口黑鲈（Micropterus salmoides）品质的影响，并与传统空气冷冻（CAF）和液浸冷冻（LIF）进行了比较。在整个冻藏期间，PSF的解冻损失和蒸煮损失显著低于CAF和LIF。冻鱼的解冻损失、L值、b值和硫代巴比妥酸反应物（TBARS）在储存期间增加。储存28天后，LIF和CAF的TBARS值分别为0.54和0.65，显著高于（p<0.05）PSF的0.25。样品的pH值起初呈下降趋势，但在储存期间随后升高，且CAF的升高趋势最快。基于拉曼光谱，PSF处理样品中蛋白质的二级结构被认为更稳定。未冷冻样品中蛋白质的α-螺旋含量为59.3±7.22，PSF、LIF和CAF冷冻储存28天后分别降至48.5±3.43、39.1±2.35和33.4±4.21。结果表明，在冻藏期间，PSF处理的大口黑鲈品质优于LIT和CAF。
