Effect of cinnamaldehyde on melanosis and spoilage of Pacific white shrimp (Litopenaeus vannamei) during storage

BACKGROUND: Shrimp is a very perishable product and postmortem changes occur rapidly. Sulfiting agents were once and are still widely used as a preservative in the shrimp industry. However, the application of sulfite in shrimp may pose a risk to human health. Thus development of a natural preservative as a sulfite alternative to extend the shelf life of Pacific white shrimp is urgently needed. RESULTS: The effects of cinnamaldehyde essential oil (1 and 5 g kg^?1) on the shelf life of Pacific white shrimp stored at 4 °C were investigated. As the concentration of cinnamaldehyde increased, residual polyphenoloxidase (PPO) enzyme activity decreased. Kinetic analysis showed that cinnamaldehyde was a noncompetitive inhibitor for the oxidation of L ‐DOPA (L ‐3,4‐dihydroxyphenylalanine) by PPO of Pacific white shrimp. Based on this study, shrimp treated with 5 g kg^?1 cinnamaldehyde possessed the lowest aerobic plate count, total volatile basic nitrogen, and pH values in all treatments after 10 days of storage. According to the results of L*, cinnamaldehyde showed inhibitory activity toward the formation of melanosis. CONCLUSION: Treatment with cinnamaldehyde could improve the sensory properties and extend the shelf life of Pacific white shrimp to 8 days. Therefore, cinnamaldehyde could be used as a promising natural preservative for inhibiting melanosis and preventing the growth of microbes during the chilled storage of Pacific white shrimp. Copyright © 2012 Society of Chemical Industry     

Formula optimization for melanosis-inhibitors of Pacific white shrimp (Litopenaeus vannamei) by response surface methodology

Food Science and Biotechnology - Melanosis is major problem of crustaceans during their rigor mortis storage. This study for the first time was designed to optimize the formula of...     

Effect of low-temperature preservation on quality changes in Pacific white shrimp,Litopenaeus vannamei: a review

Shrimp has been widely accepted as an excellent resource for white meat due to its high-protein and low-fat content, especially low cholesterol. However, shrimps are highly perishable during preservation and retailing procedures due to the activities of enzymatic proteolysis, lipid oxidation, and microbial degradation. With increasing knowledge of and demands for safety, nutrition, and freshness of shrimp products, energy efficient, quality, maintained, and sustainable preservation technologies are needed. Low-temperature preservation, a practical processing method for improving the shelf life of food products, is widely used in the aquatic industry. This review focuses on the effects of low-temperature preservation on the quality changes in Litopenaeus vannamei. It considers physicochemical properties, sensory evaluation, melanosis assessment, and microbiological analysis. The perspectives of non-protein-based techniques on quality analysis of shrimps during preservation are also discussed. © 2019 Society of Chemical Industry     

Autolysis of Pacific white shrimp (Litopenaeus vannamei) meat: characterization and the effects of protein additives

ABSTRACT:  Autolytic activity of Pacific white shrimp ( Litopenaeus vannamei ) mince in the absence and in the presence of 2.5%NaCl was investigated. Pacific white shrimp mince exhibited the maximum autolytic activity at 35 and 40 °C in the absence and in the presence of 2.5%NaCl, respectively, as evidenced by the highest TCA-soluble peptide content and the greatest disappearance of myosin heavy chain (MHC). The autolysis was more pronounced in the acidic pH values, followed by alkaline pH ranges. Pepstatin A showed the highest inhibition toward autolysis in the acidic condition, revealing that aspartic proteinase was dominant in shrimp muscle. Nevertheless, soybean trypsin inhibitor effectively inhibited the autolysis at neutral and alkaline pH values, suggesting that serine proteinase was present in shrimp mince but contributed to autolysis at a lower extent in shrimp meat. Autolysis in shrimp meat could be inhibited partially by all protein additives, including bovine plasma protein (BPP), egg white (EW), and whey protein concentrate (WPC). The inhibition of autolysis increased when the level of protein additives increased with the concomitant increase in band intensity of MHC retained. WPC and BPP in the range of 2% to 3% exhibited the highest inhibition toward autolysis of shrimp mince.     

Laundry detergent-stable lipase from Pacific white shrimp (Litopenaeus vannamei) hepatopancreas: Effect of extraction media and biochemical characterization

Extraction and biochemical properties of a new lipase from the hepatopancreas of Pacific white shrimp were studied. Recovery of the hepatopancreas powder with 50 mM Tris-HCl, pH 7.0 containing 0.2% (v/v) Brij35 gave a higher recovery of lipase activity than other extractants tested (p < 0.05). The optimal pH and temperature for lipase activity were 8.5 and 60°C, respectively, when p-nitrophenyl palmitate was used as a substrate. The enzyme was stable to heat treatment up to 40°C and over a pH range of 7.0–10.0 for 30–120 min. Lipase activities continuously decreased as the sodium deoxycholate (NaDC) concentration increased, but activities increased as NaCl concentration increased up to 3.0 M. Hydrolytic activity was enhanced by NaN₃, but strongly inhibited by Hg²⁺, Cu²⁺, Al³⁺, and phenylmethanesulfonyl fluoride. The lipase was evaluated as highly stable against surfactants (Tween 20, Tween 80, Triton X-100, and gum arabic). However, the enzyme was unstable against sodium dodecyl sulphate. Stability of the lipase with commercial liquid and solid detergents (Attack^®, Bres^®, Omo^®, and Pao^®) was also investigated. The lipase exhibited substantial stability and compatibility with tested commercial liquid and solid laundry detergents for 30–60 min. The overall properties of the lipase from Pacific white shrimp hepatopancreas, thus leading us to propose that it is an excellent candidate for use as biocatalysts for better detergent formulation.     

Arginine aminopeptidase from white shrimp (Litopenaeus vannamei) muscle: purification and characterization

Aminopeptidases act on N-terminal of proteins and peptides produce free amino acids making an impact on the final flavor of foods. An arginine aminopeptidase (RAP) which preferred to hydrolyze basic amino acids from N-termini of peptides and proteins was purified to homogeneity from white shrimp (Litopenaeus vannamei) muscle. The molecular mass of RAP was estimated as 100 kDa on SDS-PAGE. Peptide mass fingerprinting analysis obtained 95 amino acid residues which was 100 and 77.9 % identical to puromycin-sensitive aminopeptidases from insect and zebrafish, respectively. Optimum pH and temperature of the RAP were 7.0 and 30 °C. RAP rapidly hydrolyzed fluorogenic substrates l-arginine 4-methylcoumaryl-7-amide (Arg-MCA) and Lys-MCA with K _m values of 2.7 and 4.9 μM, respectively. The enzyme can be strongly inhibited by puromycin, bestatin, and 1,10-phenanthroline and partially inhibited by ethylenediaminetetraacetic acid (EDTA) and ethylene glycol-bis (2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA). Moreover, the competitive inhibition of puromycin for RAP was confirmed, and K _i value was calculated as 0.07 nM. Metal ions of Zn²⁺ and Mn²⁺ significantly reactivated the inactive apoenzyme activity dialyzed by EDTA. All these results indicated that the purified enzyme is a metalloaminopeptidase which would possibly contribute to flavor development in shrimp muscle.     

Impact of pulsed electric field pretreatment on yield and quality of lipid extracted from cephalothorax of Pacific white shrimp (Litopenaeus vannamei) by ultrasound-assisted process

Pacific white shrimp cephalothorax was subjected to pulsed electric field (PEF) pretreatment at different electric field strengths (4, 8, 12 and 16 kV cm⁻¹) and pulse numbers (120, 160, 200 and 240) to enhance the extraction yield of lipids. PEF-treated samples were subsequently subjected to lipid extraction using ultrasound-assisted extraction (UAE) process at ultrasound amplitude of 80% for 25 min in continuous mode. PEF-pretreated samples subjected to UAE rendered the highest lipid yield (30.34 g 100 g⁻¹ solids). PEF pretreatment resulted in reduced lipid oxidation as evidenced by the decreases in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Lipids from PEF-pretreated samples extracted using UAE had higher content of PUFAs and carotenoids, including astaxanthin, astaxanthin monoester, astaxanthin diester, canthaxanthin and β-carotene. Overall, PEF pretreatment helped in enhancing the extraction yield of lipids and carotenoids from shrimp cephalothorax and reduce lipid oxidation to some extent.     

Effect of severing skeletal muscle at different stage of rigor on the quality of pacific white shrimp (Litopenaeus vannamei)

Effect of severing skeletal muscle (by beheading) at different stages of rigor on the quality of pacific white shrimp (Litopenaeus vannamei) during ice storage was assessed by physical, chemical, and sensory evaluation. Shrimps were divided into three lots, one lot (T₁) beheaded immediately after killing, 2nd (T₂), and 3rd (T₃) lots were beheaded after 5 h and 35 h post‐mortem corresponding to pre‐rigor, in‐rigor, and post‐rigor stages, respectively. There was an increase in the moisture content in all the treatments during the storage. PV, TVB‐N, and TMA‐N values also increased with the storage time, though the values of all these parameters were well within the acceptable limits. Total protein, Sarcoplasmic protein, NPN, and water holding capacity showed a decreasing trend in all the treatments. Hardness, springiness, cohesiveness and chewiness values did not differ significantly (p ≤ .05) between the treatments. L* value showed a decreasing trend throughout the study. Information provided in this study can serve as baseline for postharvest preservative treatments of crustacea products.

Practical applications

This work examined the effect of the time of beheading on the quality of shrimps in ice storage. No work ever looked at the possibility of whether the quality of shrimp varies if its skeletal muscle is severed (by beheading) during pre‐rigor, on‐rigor, and post‐rigor stages. The ice storage studies of three lots demonstrated similar deterioration of quality, without significant differences among the lots. This strongly suggests that the transportation of the whole shrimps to a processing factory at a distant site provides no comparative advantage in terms of quality.     

不同贮藏条件下南美白对虾中生物胺的变化

利用超声辅助固相分散萃取结合反相高效液相色谱法测定在常温(25℃)和冷藏(4℃)条件下南美白对虾中生物胺的变化,并分析生物胺与pH、总挥发性盐基氮(total volatile basic nitrogen,TVB-N)、硫代巴比妥酸(thiobarbituric acid,TBA)值和菌落总数(total viabl...     

超高压处理条件下的虾仁品质变化动力学

超高压技术是一种新型的食品非热加工技术。为掌握不同压力对凡纳滨对虾虾仁品质的影响规律,采用动力学方法建立虾仁品质变化的动力学模型,研究虾仁品质变化的动力学特性;通过动力学方程拟合,确定了虾仁品质在零级或一级模型中的动力学反应速率常数k和指数递减时间D值。研究表明:超高压处理压力和时间对虾仁的质量损失、水分含量、硬度、pH、红度a*、黄度b*值均有显著影响(p<0.05);不同压力条件下虾仁的质量损失、硬度、黄度值b*的变化遵循零级反应动力学,水分含量和pH的变化遵循零级反应动力学或一级反应动力学,红度a*值的变化遵循一级反应动力学模型。该研究结果可为预测和控制超高压加工虾仁品质提供参考。      

Effect of pyrophosphate and 4-hexylresorcinol pretreatment on quality of refrigerated white shrimp (Litopenaeus vannamei) kept under modified atmosphere packaging

ABSTRACT:  The effect of pretreatment with pyrophosphate and 4-hexylresorcinol in combination with modified atmosphere packaging (MAP) (80% CO₂, 10% O₂, 10% N₂, or 80% CO₂, 20% N₂) on the quality of white shrimp during storage at 4 °C was investigated. Shrimp pretreated with 2% pyrophosphate and 0.25% 4-hexylresorcinol and stored under MAP showed the lower microbiological and chemical deteriorations as evidenced by delayed microbial growth as well as lower trimethylamine (TMA) and total volatile base nitrogen (TVB) production ( P < 0.05). Additionally, the growth of coliforms was inhibited effectively. White shrimp pretreated with 4-hexylresorcinol had the lower melanosis throughout the storage compared with those without treatment ( P < 0.05). This was associated with the lowered polyphenol oxidase (PPO) activity in shrimp treated with 4-hexylresorcinol. Therefore, the effective retardation of microbiological and chemical deterioration of white shrimp stored under MAP with the decrease in melanosis could be achieved by pretreatment of the shrimp with pyrophosphate and 4-hexylresorcinol. Furthermore, decapitation could be another means to lower the microbial load and melanosis in white shrimp, particularly those stored under MAP.     

膨化制粒和环模制粒工艺对饲料制粒加工质量和凡纳滨对虾生长性能的影响

本次研究比较了膨化制粒和环模制粒工艺对饲料制粒加工质量和凡纳滨对虾生长性能、饲料利用、肝胰腺和肠道组织学的影响。设计鱼粉质量分数为20%的基础饲料,分别采用环模制粒和膨化制粒的方式,生产硬颗粒饲料和沉性膨化颗粒饲料,在检测饲料制粒加工质量指标后,饲喂初重为7.72 g的凡纳滨对虾6周。和硬颗粒饲料相比,沉性膨化颗粒饲料的容重、耐久性指数和淀粉糊化度显著增加（P<0.05）,硬度和含粉率显著降低（P<0.05）, 但二者在溶失率上没有显著差异（P>0.05）。经过6周养殖后,沉性膨化颗粒饲料组的饲料系数显著低于硬颗粒饲料组（P<0.05）,虾体增重率在数值上高于硬颗粒饲料组（P>0.05）;二者在摄食量、成活率、含肉率、全虾组成和肝胰腺消化酶、糖代谢相关酶活性方面均无显著差异（P>0.05）;在肝胰腺和肠道组织学方面,摄食沉性膨化颗粒饲料和硬颗粒饲料的凡纳滨对虾均表现为组织结构清晰完整,未见明显的损伤。综上,沉性膨化颗粒饲料较硬颗粒饲料具有更优的加工性能和更高的饲料利用效率（更低的饲料系数）,二者对于凡纳滨对虾肝胰腺消化酶、糖代谢相关酶活性和肝胰腺、肠道组织学方面具有基本一致的影响。     

Chitosan-based edible coatings for quality preservation of postharvest whiteleg shrimp (Litopenaeus vannamei)

Postharvest shrimp is highly susceptible to both microbiological spoilage and endogenous enzymatic browning, so it should be preserved properly using effective and appropriate methods. The effects of 1.0% and 1.5% O-carboxymethyl chitosan (CMC) and 1.0% and 1.5% chitosan (CH) coatings on the quality changes of whiteleg shrimp (Litopenaeus vannamei) during refrigerated storage (0 ± 1 °C) of 10 d were investigated. The pretreatment with CMC and CH solution (1.0% or 1.5%) retarded growth of psychrophilic bacteria throughout storage in comparison with the control (P < 0.05). The lower increases in pH and total volatile base (TVB) content were obtained in the shrimp treated with CMC and CH solution at both levels, compared with the control samples (P < 0.05). Loss in freshness and melanosis decreased after the shrimp was treated with CMC and CH. In addition, CMC and CH (1.0% or 1.5%) showed inhibitory activity toward total viable bacteria counts of white shrimp in a dose-dependent manner. Therefore, chitosan and O-carboxymethyl chitosan can be used as promising melanosis inhibitors as well as antimicrobial agents during refrigerated storage. PRACTICAL APPLICATION: The main practical application behind the development of chitosan (CH) and O-carboxymethyl chitosan (CMC) used to preserve postharvest whiteleg shrimp lies with the fact that these polysaccharides represent a renewable source of natural biodegradable polymers and meet with the emergence of more and more food safety problems. Both CMC and CH can be used as food preservatives to extend shrimp shelf life. However, CMC is more convenient due to its solubility. In the future, CMC will be used in the food processing industry because of its soluble, compatible, antimicrobial, and antioxidative characteristics.     

Albacore tuna (Thunnus alalunga) spleen trypsin partitioning in an aqueous two-phase system and its hydrolytic pattern on Pacific white shrimp (Litopenaeus vannamei) shells

Partitioning behaviors of trypsin from the spleen of albacore tuna (Thunnus alalunga) in an aqueous two-phase system (ATPS) were investigated. Partitioning behaviors of proteins were influenced by polyethylene glycol (PEG) molecular mass and concentration, types and concentration of salts, NaCl concentration, and temperature. Trypsin was preferentially partitioned into the PEG-rich top phase. The best ATPS conditions for trypsin partitioning from albacore tuna spleen were 15% PEG 4000–15% NaH₂PO₄ at 40°C without the addition of NaCl, which increased the purity by 5.54-fold with the recovered activity of 71.92%. Based on SDS-PAGE, the enzyme after ATPS separation was near homogeneity and the result of SDS-substrate gel electrophoresis revealed that the band intensity of enzyme in ATPS fraction increased, indicating the enhanced specific activity of splenic extract. The study further investigated the effect of fractionated trypsin on the hydrolysis of Pacific white shrimp (Litopenaeus vannamei) shells. Electrophoretic study revealed that trypsin after ATPS separation was a potential enzyme for extraction of carotenoprotein from Pacific white shrimp shell waste. Therefore, ATPS was an effective method for purification and recovery of trypsin from the spleen of albacore tuna and it could be used as an alternative cheap proteinase for the extraction of carotenoprotein from shrimp shells.