The effect of different melanosis-inhibiting blends on the quality of frozen deep-water rose shrimp (Parapenaeus longirostris)

Evaluating shelf life and anti-browning of shrimp by chitosan-coated nanoliposome loaded with licorice root extract

Chitosan coating containing nanoliposomes loaded with licorice root extract was prepared to investigate shrimp's shelf life and anti-browning function during 20 days of ice storage. 1% licorice root hydroethanolic extract (LHE) was encapsulated in nanoliposomes or coated with chitosan, and then the shrimp were immersed in coating solutions. LHE treatment had the lowest browning indices (5 and 1.02), TBA (0.32 mg MDA/kg), and FFA (0.01%). Chitosan-coated LHE treatment (Ch-LHE) showed the best performance for TVN, microbial counts, and discoloration. PV, WHC, and cook loss in the treatment with LHE nanoliposome coated with chitosan (Ch-N-LHE) were measured at acceptable levels of 0.53 meq/kg, 86.12%, and 15.06%, respectively. Experiments showed that pure or encapsulated LHE is an effective method for increasing the quality and preventing the browning of shrimp. Additionally, due to its cost-effectiveness and health benefits, it can be an effective natural substitute for sodium metabisulfite at the global export level.

Effect of modified atmosphere packaging with different gas mixtures on the texture and muscle proteins of Pacific white shrimp (Litopenaeus vannamei) during cold storage

In this study, the effect of modified atmosphere packaging with different gas mixtures on texture and muscle properties of Pacific white shrimp (Litopenaeus vannamei) during refrigerated storage was studied via texture profile, water holding capacity (WHC), protein properties (Ca2+-ATPase, TCA-soluble peptides, myofibrillar/sarcoplasmic protein content), and microbial counts. The results showed that the antibacterial effect of Modified atmosphere packaging (MAP) was correlated with the increase of CO2 with the presence of low level of O2. Though MAP without O2 had a higher whiteness value but also had higher bacterial counts and total volatile basic nitrogen (TVB-N) values compared with other MAP-groups. In general, a gas composition of 80% CO2 + 5%O2 + 15% N2 treatment had lowest microbial counts and reduced TVB-N values by 22.85% in comparison with the control on day 10. However, MAP was found to have a complicated impact on muscle protein and texture of shrimp. 60% CO2 + 5% O2 + 35% N2 and 40% CO2 + 5% O2 + 55% N2 had an advantage in maintaining springiness and the content of myofibrillar/sarcoplasmic proteins. The correlation analysis showed that WHC had stronger relationship with springiness, resilience, myofibrillar protein content. Therefore, regarding the texture and protein properties, the concentration of CO2 in MAP for Pacific white shrimp should not be higher than 60%.

Effects of Non-Enzymatic Browning and Lipid Oxidation on Color of Ready-to-Eat Abalone during Accelerated Storage and Its Control

The deepening of color of ready-to-eat (RTE) abalone during storage leads to sensory quality degradation, which seriously affects the shelf life of products and consumers’ purchasing desire. The goal of this study is to look into the causes of non-enzymatic browning and lipid oxidation, as well as how to control them, and their effect on the color of RTE abalone during storage. The control, bloodletting and antioxidants groups (lactic acid, citric acid and 4-hexylresorcinol) of RTE abalone were stored for 0, 20 and 40 days at 40 °C, respectively, to explore the rule and mechanism of the color change in RTE abalone. This research shows that RTE abalone undergoes browning during storage. Meanwhile, the content of reducing sugar, phenols and unsaturated fatty acids decreases, while the formation of lipid hydroperoxides and aldehydes increases during storage. In addition, the color change in RTE abalone during storage is mainly related to the Maillard reaction, while the lipid oxidation mainly forms pyrrole and participates in the Strecker degradation process as part of the Maillard reaction. The quality of RTE abalone can be maintained by controlling browning effectively as well as lipid oxidation through bloodletting and the addition of antioxidants to ensure that RTE abalone has high storage stability. According to our research, bloodletting and the addition of antioxidants to RTE abalone have a good application prospect and popularizing value in the storage of RTE abalone.

Effect of different packaging methods on the free amino acid profiles of the deep-water rose shrimp (Parapenaeus longirostris) during frozen storage

The composition of free amino acids (FAAs) in seafood products contributes to characterizing their flavor, as well as freshness and quality during storage. Deep-water rose shrimps (Parapenaues longirostris, Lucas, 1846) (DWRS) are being increasingly harvested in the Mediterranean Sea, and the captured specimens are quickly frozen onboard fishing trawlers to preserve freshness and post-harvest quality. Here, we quantified the FAA profiles of DWRS packaged using five methods: (1) 100% N₂; (2) vacuum; (3) 50% N₂ + 50% CO₂; (4) commercial anhydrous sodium sulfite; and (5) air (control). All samples were quickly frozen at -35°C and stored for 12 months at -18°C. Arginine (661 mg/100 g), proline (538 mg/100 g), and glycine (424 mg/100 g) were the most abundant FAAs, whereas the least abundant were tyrosine (67 mg/100 g), histidine (58 mg/100 g), and aspartic acid (34 mg/100 g). FAAs in all samples gradually (and significantly) increased in the first 6 to 8 months of storage, and then significantly decreased. The sodium sulfite treatment (Method 4) kept the initial FAA contents lower than the other treatments, due to the strong antioxidant action of sulfite agents. Interestingly, similar results were obtained for vacuum packaging (Method 2). Thus, combining frozen storage with vacuum packaging represents an alternative approach to chemical additives in shrimp/prawn processing to meet the increasing demand for high-quality seafood products with long shelf-life.

Quality Evaluation of Shrimp (Parapenaeus longirostris) Treated with Phenolic Extract from Olive Vegetation Water during Shelf-Life, before and after Cooking

The focus of this study was to assess the quality traits and sensory profile of cooked rose shrimps (Parapenaeus longirostris) treated with a phenolic extract, derived from olive vegetation water (PEOVW). To achieve the aim, four different groups of shrimps were analysed, specifically the control (CTRL) group, where the shrimps were soaked in tap water; sulphites (S) group with shrimps soaked in 0.5% sodium metabisulfite tap water solution, phenolic extract (PE) group where a tap water solution containing 2 g/L of phenols was used; and PE+S group where the shrimps were dipped in 0.25% sodium metabisulfite tap water solution containing 1 g/L of phenols. The groups were then stored at 2 °C and analysed on the day of packaging (D0), after 3 (D3), 6 (D6), and 8 (D8) days. On each group, microbiological parameters such as Enterobacteriaceae, mesophilic and psychrotrophic bacteria, and colorimetric indices were investigated on six (n = 6) shrimps before cooking, while the evolution of the phenolic content, antioxidant activity, and sensory analysis during the storage period were evaluated on cooked shrimps. Regarding colour coordinates, there were no noteworthy variations overtime nor between groups, while it is important to note that the microbiological results for the PE group showed at each time interval and for all the considered parameters, significantly lower values than the other groups (p < 0.05). This result is very interesting when considered further in correlation with the sensory analysis, where shrimps mainly in PE and secondarily in PE+S groups were shown to retain the freshness characteristics better than the other groups (α = 0.01), without giving the shrimps any particularly bitter and pungent sensations typical of the olive phenolic compounds. In conclusion, the results obtained in this study give PEOVW the potential to be valorised in the food sector and, above all, it could represent a sustainable solution to reduce the use of synthetic additives.

Variation in the terminology and methodologies applied to the analysis of water holding capacity in meat research

Studies examining meat quality variation, possibly resulting from animal physiology, processing, or ingredient additions, are likely to include at least one measure of water holding capacity (WHC). Methods for evaluating WHC can be classified as direct or indirect. Direct methods either gauge natural release of fluids from muscle or require the application of force to express water. The indirect methods do not actually measure WHC. They attempt to separate meat into two or three categories based on predictions of direct method results: the extreme of high and low WHC and an optional 'normal' group. Considerable statistical analyses are required to generate these predictive models. Presently, there are inconsistent terms (e.g., water holding, WHC, water binding, water binding potential/capacity) used to describe WHC and no standardized techniques recommended to evaluate it. To ensure that results can be compared across different laboratories, a better consensus must be reached in how these terms are employed and how this critical parameter is determined.

Comparing the inhibitory abilities of epigallocatechin-3-gallate and gallocatechin gallate against tyrosinase and their combined effects with kojic acid

Inhibition of tyrosinase activity contributes to the control of food browning and skin pigmentation diseases. Herein, the inhibitory mechanism of epigallocatechin-3-gallate (EGCG) and gallocatechin gallate (GCG) on tyrosinase were investigated. Both EGCG and GCG inhibited tyrosinase in a mixed manner with the IC₅₀ values of 39.4 ± 0.54 μM and 36.8 ± 0.21 μM, and showed a synergism with their combination, while EGCG and GCG combined with kojic acid (IC₅₀ = 19.2 ± 0.26 μM) exhibited antagonism and additive effect, respectively. EGCG and GCG interacted with tyrosinase mainly by hydrogen bonding and hydrophobic interactions and induced a looser conformation of tyrosinase. Molecular docking indicated that EGCG and GCG bound to the active center of tyrosinase and interacted with copper ions and key amino acid residues. Molecular dynamics simulation further characterized the structure and property of EGCG/GCG-tyrosinase complex. This study provides novel insights into the mechanism of catechins as tyrosinase inhibitors.

Kappa-carrageenan and its oligosaccharides maintain the physicochemical properties of myofibrillar proteins in shrimp mud (Xia-Hua) during frozen storage

As a popular hot-pot ingredient, Chinese-style shrimp mud (Xia-Hua) is usually transported and stored frozen. However, frozen storage leads to decreased quality of Xia-Hua products caused by the variations in physicochemical and functional properties of myofibrillar proteins (MPs). Κ-carrageenan and its oligosaccharides are reported as antioxidants and antifreeze and can stabilize proteins in whole shrimp, but their effects on MPs in Xia-Hua remain poorly understood. Compared to the control and Na₄ P₂ O₇ treatments, the physicochemical properties of MPs in κ-carrageenan and its oligosaccharides-incorporated Xia-Hua were evaluated during 120 days of frozen storage. The results showed that cold stress increased the susceptibility of MPs to denaturation and oxidation during frozen storage. Carrageenan oligosaccharides maintained the turbidity, emulsifying activity, stability, and foaming capacity of MPs. Oxidation analysis showed that the incorporation of carrageenan oligosaccharides significantly retarded the rapid decrease of Ca²⁺ -ATPase activity, total sulphydryl and active sulphydryl contents, and also effectively inhibited the increases of carbonyl content and surface hydrophobicity of MPs. Thermal stability results confirmed that the oligosaccharides improved the denaturation temperature and enthalpy of MPs compared to the control, Na₄ P₂ O₇ , and carrageenan treatments. This study suggests that κ-carrageenan and its oligosaccharides maintain the properties of MPs in Xia-Hua during frozen storage. PRACTICAL APPLICATION: The cryoprotection and antioxidant effects of carrageenan oligosaccharides on the stability of MPs in frozen shrimp mud can be used to extend the shelf-life and maintain the quality of frozen Xia-Hua products. Furthermore, it can drive the development of aquatic product health industry, improve the quality and safety of aquatic products, reduce the occurrence of public food safety incidents, and maintain social stability.