Superchilled Storage Research Articles

Quality tracking of largemouth bass (Micropterus salmoides) fillets during superchilling storage by pretreatment with NaCl

The objective of this research was to investigate the effect of salt pretreatment (1 % and 2 %) on the physicochemical properties, sensory characteristics and safety indices of largemouth fillets during superchilling storage. During superchilling storage, the 2 % group had the lowest values of ice crystal formation temperature, thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), and total viable counts (TVC), and the deterioration of fish quality in the 2 % group was significantly slower than that in the 1 % group (P<0.05). At the later stage of storage, low-field nuclear magnetic resonance (LF NMR) results showed that moisture in the fish fillets showed a mixture of ice crystals and water, and TBA, TVB-N, and TVC values were significantly higher in the salt-treated group (P<0.05); the proteins interacted with unfrozen fractions to form relatively ordered structures, which promoted the intensity of protein bands. The pH of the fillets transferred from neutral to weakly acidic throughout the period of storage, and the L*, W and b* values of the 2 % group were significantly lower (P<0.05) than those of the other two groups. The results of shear force, microstructure and western blot (WB) indicated that salt pretreatment significantly improved fillet tenderness and odor. These indicated that the ideal salt pretreatment concentration and quality of the bass fillets for superchilled storage were 2 % and 21 d, respectively. This study provides a theoretical basis for the application of the preservation of aquatic products.

The Diversity of Bacterial Microbiota and Spoilage Characteristics of Tilapia Under Super-Chilled Storage Condition

ABSTRACT To characterize the spoilage of tilapia under super-chilled storage, the bacterial profile and odor and volatile compounds were analyzed. Results showed that the shelf life and bacterial profile of tilapia from different sources varied remarkably, with Pseudomonas being the most dominant organism in tilapia under super-chilled storage (−1.5°C). The correlation analysis showed that the volatile compounds from the spoiled samples were closely related to the bacterial profile. Therefore, no volatile compounds or the response of the electronic nose significantly correlated with sensory spoilage although some of them correlated with that of some specific samples. On the other hand, the total volatile basic nitrogen (TVB-N) was significantly correlated with the sensory spoilage of all samples. In conclusion, under super-chilled storage, the volatile compounds in tilapia, except TVB-N, are sample dependent due to the variation of bacterial profile and therefore cannot be used as a spoilage indicator.

Investigation of oxygen packaging to maintain beef color stability and microbiology safety after periods of long-term superchilled storage

This study aimed to develop an appropriate modified atmosphere packaging (MAP) system for displayed beef steaks following long-term superchilled (−1 °C) storage. After superchilled storage for 0, 2, 8, or 16 weeks, beef loins were fabricated into steaks and displayed with 20%, 50%, or 80% O2-MAP under chilled conditions. At each storage point, after display for 0, 3, 7, or 10 days, instrumental color, myoglobin redox forms percentage, lipid oxidation, total viable count (TVC), and total volatile basic nitrogen (TVB-N) were evaluated. Meat color stability decreased, with prolonged storage period and display time. When the storage period was within 8 weeks, under all the above MAP conditions, the display time for the beef steaks was up to 10 days. Considering 80% O2-MAP promoted lipid oxidation, 50% and 80% O2-MAP were not recommended for displaying steaks for more than 10 and 7 days respectively after 16 weeks of storage. However, 20%, 50%, or 80% O2-MAP could maintain 3 days of microbial shelf-life according to TVC and TVB-N results. Additionally, after long-term superchilled storage for 16 weeks, the various O2 concentrations had minimal impact on microbiota succession during the MAP display period. Furthermore, beef steaks packaged under various MAP systems exhibited similar microbial compositions, with the dominant bacteria alternating between Lactobacillus and Carnobacterium. This study provided practical guidance for improving beef color stability after long-term superchilled storage.

Active film preparation using pectin and polyphenols of watermelon peel and its applications for super-chilled storage of chilled mutton.

We investigated the effect of active packaging films prepared by pectin (WMP) and polyphenols (WME) obtained from watermelon peel on the quality of chilled mutton during super-chilled storage. The addition of WME created new chemical and hydrogen bonds in film. Furthermore, an appropriate amount of WME (≤1.5%) was evenly distributed throughout the film matrix, improving barrier properties, mechanical properties, thermal stability, and light transmittance of the film. An assessment of the meat quality showed that the pH, L*, b*, thiobarbituric acid reactive substances (TBARs), total volatile basic nitrogen (TVB-N), and total bacterial count (TCA) of super-chilled+film group were significantly lower, whereas shear force and a* value were significantly higher (P<0.05) than other groups. The WMP/WME film has dense microstructure and excellent mechanical properties after storage. Pectin and polyphenols obtained from watermelon peel have good potential as a novel packaging material for chilled mutton during super-chilled storage.

Effect of super-chilled preservation on the water-holding properties of fresh beef during storage

In this study, comparison of the effects of chilled (4 °C), super-chilled (-4 °C), and frozen (-18 °C) storage on the water-holding properties was evaluated by drip loss, surface hydrophobicity, and calpain activity of raw beef. These results indicated that storage temperature can significantly affect the water-holding properties. In contrast to chilled storage, super-chilled storage can maintain a higher thiol group content, which can maintain better myofibrillar protein hydration capacity. Furthermore, super-chilled storage effectively slowed down the increase in the rate of protein hydrophobicity compared with chilled and frozen storage. Additionally, the super-chilled sample exhibited the highest glutathione reductase activity, followed by the frozen sample. These results revealed that super-chilled storage is a good way to preserve the water-holding properties of raw beef.

Effects of kojic acid on changes in the microstructure and myofibrillar protein of duck meat during superchilled storage.

This study investigated the effect of 0.8% (m/v) kojic acid treatment on changes in the microstructure and myofibrillar protein of duck meat covered with oxygen-permeable polyvinylchloride (PVC) film (9±0.5µM) during superchilled storage (-1.65±0.5°C). The superchilled samples exhibited wider gaps between muscle fibers at 5 weeks storage compared with kojic acid-treated groups. Based on the variation of water status, the water-holding capacity decreased significantly (p<0.05), and bound water and immobilized water were gradually converted into free water during superchilled storage. For kojic acid-treated samples, however, no major changes were observed with respect to muscle structure, water status, and protein degradation at 6 weeks. The 0.8% (m/v) kojic acid treatment increased the water-holding capacity, reduced carbonyl content and protein degradation, and decreased the α-helix contents loss of myofibrillar proteins. Kojic acid treatment effectively protected myofibrillar protein structure from being destroyed during superchilled storage, suggesting that this method was a good way to reduce protein oxidation and prolonged its shelf life.

Effect of the combination of superchilling and super-chilled storage on shelf-life and bacterial community dynamics of beef during long-term storage

This study investigated the effect of superchilling (−30 °C until the core temperature achieved −3 °C, and − 1 °C until 24 h, SC) on shelf-life and bacterial community dynamics of beef loins, with a typical very fast chilling (−30 °C until the core temperature achieved 0 °C, and − 1 °C until 24 h, VFC) and conventional chilling (0– 4 °C for 24 h, CC) as controls. The super-chilled storage (−1 °C) was adopted after each chilling procedure, and physicochemical traits and microbiological quality were evaluated during a long-term storage. No remarkable adverse impact on meat color and lipid oxidation were observed in SC treatment. The bacterial composition results showed that Carnobacterium spp. were the main bacteria in SC treatment in the late storage period (63– 84 days). The loss of Lactobacillus spp., due to the “ultra-low temperature” during the superchilling, might be the reason that the SC did not result in a longer shelf-life compared with CC samples.

The effect of super-chilled preservation on shelf life and quality of beef during storage

The effect of super-chilled storage (-2 °C) on shelf life and quality of beef was investigated, compared with chilled (4 °C) and frozen (-18 °C) storage. The pH value, color, TVB-N, water-holding capacity, total viable counts (TVC) and sensory evaluation were used to evaluate the freshness, shelf life and quality of beef. These results indicated that the fresh beef stored in super-chilled condition demonstrated better pH and color stability compared to chilled storage, and exhibited better water-holding capacity and sensory score compared to frozen storage. Based on the TVB-N level and TVC, the super-chilled storage was conducive to prolong the shelf life of beef with good quality. The super-chilled storage is a good way to preserve freshness of fresh beef. In conclusion, this work provides data for the preservation of fresh beef which will benefit the meat industry.

Effects of superchilling on quality of crayfish (Procambarus clarkii): water migration, biogenic amines accumulation, and nucleotides catabolism

SummaryEffects of refrigerated (3.5 ± 0.5 °C), iced (0 ± 0.5 °C) and superchilled (−3.0 ± 1.0 °C) storage on quality of crayfish (Procambarus clarkii) were evaluated by monitoring the water migration, microbial contamination, biogenic amines accumulation, and nucleotides catabolism during 21 days. The results indicated that superchilling was effective in accelerating the rate of water migration and reducing total volatile basic nitrogen, trimethylamine, total viable bacteria, Enterobacteriaceae and psychrotrophic bacteria of crayfish. Meanwhile, significant (P &lt; 0.05) lower putrescine, cadaverine and tyramine contents were observed in superchilled sample (SS), whereas histamine concentrations were at lower levels (0.76–2.31 μmol g−1) in all treatments. In addition, the predominant nucleotides degradation pathway in crayfish was the conversion of inosine monophosphate, which was accumulated massively (3.74 µmol g−1) in SS at the end of storage. According to the dynamic changes of inosine and hypoxanthine contents, the shelf life of SS was prolonged to 15 days.

Changes in chilled beef packaged in starch film containing sea buckthorn pomace extract and quality changes in the film during super-chilled storage

This study aimed to evaluate the effects of super-chilled storage (−1.3 °C) combined with starch film packaging containing different contents of sea buckthorn pomace extract (SSF, 0, 1, 2, and 3%, w/w) on the quality of chilled beef. The release kinetics, microstructure, and mechanical properties of the film were also measured to investigate its suitability for super-chilled storage. The results of the meat quality assessment showed that the L*, a*, and sensory evaluation values of the SSF-3% samples were significantly higher (P < 0.05), and the pH, b*, thiobarbituric acid reactive substance (TBARS), total volatile basic nitrogen (TVB-N), and total viable count (TCA) were significantly lower (P < 0.05) than the SSF-0%. The release of SBP from the SSF film was controlled by diffusion. Furthermore, SSF-3% was found to have a compact microstructure and good mechanical properties at the end of the super-chilled storage. The results demonstrated that SSF is an effective packaging material for beef at super-chilling temperatures.

Quality characteristics of shucked crab meat (Eriocheir sinensis) processed by high pressure during superchilled storage.

High-pressure processing (HPP) at 300MPa for 20min at 25°C was used for shucking Chinese mitten crab. The shelf-life, quality as well as internal protein changes in HPP-shucked meat were investigated during superchilled storage at -4o C. Upon 3-week storage, the lightness and whiteness of HPP-shucked crab meat start to decline, while no significant changes were observed in the hardness, gumminess, and chewiness. Sensory and microbial evaluation suggested that HPP-shucked crab meat can be generally preserved in an acceptable manner within 3weeks, although a negative influence on drip loss was found. The loss of entrapped water in crab meat as revealed by low field nuclear magnetic resonance was responsible for the relatively high thawing drip loss. The severe deterioration of meat quality and sensory occurred at 4-week storage probably as a result of exacerbated myofibrillar protein oxidation, denaturation, and crosslinking. PRACTICAL APPLICATIONS: It has been confirmed that HPP shucking can maintain the fresh-state of the crab meat and save energy compared to the conventional treatment, which could meet consumers' demand for minimally processed seafood products. In this work, the shelf-life of HPP-shucked crab meat stored at -4o C was evaluated to be 3weeks and HPP shucking combined with superchilling can be an effective way to preserve the crab meat. These results can provide basic knowledge for the storage and distribution of HPP-shucked crab meat.

Effect of medium voltage electrical stimulation and prior ageing on beef shear force during superchilled storage

The effect of medium voltage electrical stimulation (ES), prior ageing (0–4 °C, 7 days), and their combination on the decrease of shear force in beef during superchilled storage (−4 °C) for 24 weeks was evaluated, in the context of a high shear force obtained under this storage condition. Both ES and prior ageing significantly reduced the initial Warner-Bratzler shear force, and the combination of ES and prior ageing shortened the storage time needed to reach an acceptable shear force of superchilled beef, which is mainly due to increased myofibrillar degradation as indicated by changes in desmin (P < 0.01, r = 0.35). Additionally, ES and prior ageing did not negatively affect lipid oxidation, total volatile basic nitrogen or water loss of superchilled beef. Consequently, ES combined with ageing for 7 days offered an effective approach for decreasing shear force and ensuring good quality superchilled beef.

Protein degradation and structure changes of beef muscle during superchilled storage

This study investigated the effect of superchilled storage (−4 °C) on protein degradation and structural changes of beef steaks from M. longissimus lumborum compared with traditional chilling (2 °C) and frozen storage (−18 °C). Traditional chilling induced significantly greater degradation of troponin T and desmin, and more rapid loss of calpain activity, compared to superchilled or frozen storage treatments. The proteolysis of key myofibrillar proteins resulted in a sharp decline of WBSF values during traditional chilled storage. For frozen beef samples, no major changes were observed with respect to protein degradation or muscle structure during storage. However, superchilled samples exhibited wider gaps between muscle fibers at 12 weeks storage, associated with muscle fiber shrinkage.

Microstructure and quality attributes of Saurida tumbil muscle during superchilled storage as affected by shell/ and non-shell freezing

ABSTRACT The aim of this study was to determine the influence of shell freezing and non-shell freezing methods on the location/distribution of ice crystals and quality properties (microbiological analysis and physiochemical properties (pH, total volatile bases nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA), water holding capacity (WHC)) during the superchilling storage of Greater Lizardfish Saurida tumbil. Non-shell frozen fillets resulted in form of extracellular ice crystals during superchilling. Shell frozen fillets formed both intracellular and extracellular ice crystals uniformly. From the result, it was found that using the shell freezing method had significant effect on reduced bacteria population or decreased capacity of bacteria or both. At the end of the storage, TVB-N, pH, TBARS, and FFA values of the non-shell freezing method was more than others (P < 0.05). There was significant difference (P < 0.05) in the WHC between shell-frozen samples and non-shell-frozen samples. Shell-frozen freezing had a strong influence on the characteristics of ice crystals (location/distribution) and quality of the final superchilled fillets.

Shelf-life and bacterial community dynamics of vacuum packaged beef during long-term super-chilled storage sourced from two Chinese abattoirs

This study explored the shelf-life and bacterial community dynamics of beef cuts stored at super-chilled conditions (-1±0.5°C) for 20weeks when sourced from two Chinese abattoirs, in order to determine whether domestic beef has equivalent quality as that imported from Australia. The initial total viable counts (TVC) were 4.15 and 4.87 log CFU/cm2 in beef from abattoirs A and B, respectively at the commencement of the storage period. The TVC of beef from abattoir A was above 6.0 log CFU/cm2 at 6weeks and kept below 7.0 log CFU/cm2 at 20weeks; while the counts were above 6.0 log CFU/cm2 at 3weeks and reached at 7.3~7.6 log CFU/cm2 in beef from abattoir B. The beef shelf-life was deemed less than 12 and 9weeks in abattoirs A and B, respectively, based on the total volatile basic nitrogen (TVBN) threshold, although all samples were acceptable organoleptically. High-throughput sequencing showed that the initial bacteria community and bacterial succession during storage were different between the two abattoirs. Carnobacterium spp. and Lactobacillus spp. dominated in both abattoirs throughout 3-9weeks while Serratia spp. co-dominated in abattoir B, and Lactobacillus spp. and Carnobacterium spp. were dominant for the rest of storage in abattoir A and B, respectively. Overall, the high initial TVC is a concern compared to imported beef from Australia. To achieve comparable shelf-life, domestic super-chilled stored beef would need to be sourced from abattoirs employing effective decontamination technologies or where strict hygiene procedures are adopted.

Antioxidant and antibacterial properties of coating with chitosan-citrus essential oil and effect on the quality of Pacific mackerel during chilled storage.

The goal of the study was to investigate whether chitosan–citrus essential oil composite works as an efficient preservative in Pacific mackerel (Pneumatophorus japonicus) during chilling storage. FT‐IR analysis showed that chitosan–citrus essential oil coating was successfully prepared. Our results demonstrated that chitosan–citrus essential oil coating possessed significantly higher capability of scavenging reactive oxygen species (O2- and OH−) than chitosan. Furthermore, Pacific mackerel coated with chitosan–citrus essential oil composite could significantly reduce parameters of corruption including physicochemical (drop loss, biogenic amine, and thiobarbituric acid‐reactive substances) and microbiological parameters (total viable count), as compared with untreated and chitosan groups after 12 days of storage at −3°C. These results indicated that CS‐CEOs could work as efficient preservative for Pacific mackerel storage through ameliorating redox state and inhibiting microbial growth and suggested that chitosan–citrus essential oil composite has great potential in preservation of aquatic products during superchilled storage.

Improved Microbial Safety of Direct Ozone-Depurated Shellstock Eastern Oysters (Crassostrea virginica) by Superchilled Storage.

The effect of superchilled storage at -1°C on the microbial safety of oyster depurated with 0.2, 0.4, and 0.6 mg/L ozone was studied for 14 days. Fecal coliforms (4,100–16,000 MPN/100 g), Escherichia coli (1,500–3,650 MPN/100 g), Vibrio cholerae non-O1/non-O139 (13.0–102.0 MPN/g), and Salmonella spp. (2.270–3.035 × 103 CFU/g) were initially present in raw oysters. After 6 h depuration, fecal coliform counts decreased (P < 0.05) to 300, 20 and 20 MPN/100 g for 0.2, 0.4, and 0.6 mg/L treatments, while a 0.3 log decrease in control oysters was observed. Initial E. coli counts decreased (P < 0.05) in oysters to 50, 20, and 20 MPN/100 g for 0.2, 0.4, and 0.6 mg/L treatments, respectively. A 1 log reduction in V. cholerae non-O1/non-139 levels were observed in 0.4 and 0.6 mg/L-treatments after 2 and 4 h depuration. Salmonella spp. was not detected in oyster samples after 6 h depuration in 0.4 and 0.6 mg/L-ozone treatments. Considering the bacterial loads after depuration, at the end of superchilled storage the 0.4 mg/L-ozonated oysters attained lower (P < 0.05) fecal coliform levels (280 MPN/100 g) and E. coli counts in 0.4 and 0.6 mg/L-ozonated oysters (20 and 95 MPN/100 g, respectively). A 2-log decrease in V. cholerae non-O1/non-O139 levels on day 5 in 0.4 and 0.6 mg/L-ozonated oysters (< 0.3 MPN/g) was attained. V. cholerae non-O1/non-O139 counts in control oysters decreased 1 log on day 9 of superchilled storage. Salmonella spp. was not detected in ozonated and superchilled stored oysters. Levels of fecal coliforms, E. coli, Salmonella spp., and V. cholerae non-O1/non-O139 in non-ozone depurated oyster samples were higher than in control, 0.4 and 0.6 mg/L ozonated oyster samples during superchilled storage. The cumulative mortality rates after 14 days of storage for superchilled oysters (22.2%) was higher (P < 0.05) than 0.6 mg/L O3 (7.2%) and 0.4 mg/L O3 (5.8%) treatments, and control oysters (5.6%). pH values in control oysters decreased significantly (P < 0.05) throughout the storage period but not in oysters of both ozone treatments, indicating no detrimental effects on oyster survival. The results of this study suggest that superchilled storage enables ozonated shellstock oysters (0.4 mg/L-6 h) stored for 9 days to be safe human consumption.

English

Biochemical changes of Atlantic salmon (Salmo salar) i¬llets during superchilled storage were evaluated. Due to the signii¬cant differences in ice crystal sizes observed, the biochemical changes were evaluated both at the top and centre parts of the superchilled samples. No signii¬cant differences were found in biochemical changes between top and centre parts of the superchilled samples. The amount of cell tissue fluid (CTF) increased significantly from day 1 to 3 in the top and centre parts of the superchilled samples. The amount of CTF was stable between day 3 and 14 but increased significantly from day 21 to 28. A significant increase in the activity of β-N-acetyl-glucosaminidase in the CTF at the top was observed between day 3 and 7, while at the centre at day 7 of storage. There was also a significant increase in β-N-acetyl-glucosaminidase both at the centre and the surface of the superchilled samples between day 21 and 28 of storage whereby the activity in these samples was on the same level as in the frozen samples. In the superchilled samples, the cathepsin B activity in CTF and homogenates were stable for the first one week of storage. There was significant increase in activity of cathepsin B in cell tissue fluid and homogenates between day 21 and 28 for both chilled and superchilled samples. These i¬ndings provides valuable information on the quality of food products for the food industry in relation to ice crystallisation/recrystallisation during superchilled storage. Key words: Partial freezing, biochemical changes, superchilled storage, salmon fish (Salmo salar).

Protein degradation of olive flounder (Paralichthys olivaceus) muscle after postmortem superchilled and refrigerated storage

ABSTRACTThe aim of this study was to investigate the effect of superchilling at −2°C in comparison with refrigerated storage at 4°C on the protein degradation of olive flounder (Paralichthys olivaceus) muscle. Flounder muscle softened and shear force value decreased markedly (P < 0.05) with prolonged storage time, while values of electrical conductivity, TCA-soluble peptide, free amino acids, and proteolysis index increased (P < 0.05). The changes were slowed down significantly in samples superchilled at −2°C (P < 0.05). The fracture of muscle fibre and formation of cracks were accelerated in the samples refrigerated at 4°C, and intercellular spaces were observed after 9 days of storage. Moreover, protein bands of myosin heavy chain (MHC), actin, tropomyosin, 97 kDa, 50 ~ 60 kDa and 35 ~ 36 kDa occurred in varying degrees of degradation with storage time. The results demonstrated that significant postmortem degradation of muscle proteins occurred with extending storage time, while the changes were retarded obviously in samples during superchilled storage.

Influence of lightly salting and sugaring on the quality and water distribution of grass carp (Ctenopharyngodon idellus) during super-chilled storage

Low Field Nuclear Magnetic Resonance (LF-NMR) was used to evaluate the water mobility in grass carp during super-chilled storage. Grass carps were analyzed for inosine monophosphate (IMP), total viable counts, cooking loss, drip loss, biogenic amines, and sensory. Pearson's regression analysis between LF-NMR parameters and quality indicators was done to assess the feasibility of using LF-NMR to predict fish quality. Three water populations, T2b (<10 ms), T21 (20 ms–80 ms), and T22 (>100 ms), were measured. The major component T21, immobilized water, shifted to longer relaxation time with added salt and sugar due to the swelling of myofibers (P < 0.05). T21 of cooked (85 °C) flesh was lowered, indicating that immobilized water mobility decreased during heating. Curing treatments predominately accelerated IMP formation, inhibited bacterial growth, retarded cooking loss, and improved the overall sensory quality. The study also showed that the LF-NMR was capable of monitoring unsalted fish deterioration.