Penetration of Sodium Tripolyphosphate into Fresh and Prefrozen Peeled and Deveined Shrimp

The distribution of sodium tripolyphosphate (STP) in peeled and deveined shrimp tails after treatment was investigated using P³² labeled STP. Fresh and frozen brown (Penaeus aztecus) and fresh and frozen white (Penaeus setiferus) shrimp were used in the study. Shrimp were treated in solutions of either 0.5%, 1%, 5%, or 10% STP that had been prepared using P³² labeled STP diluted with “cold” STP. The duration of treatment was either 20 sec, 1 min, 5 min, or 20 min. When shrimp were treated in 0.5% and 1% STP solutions, a phosphate concentration gradient was evident in the shrimp muscle. After such treatments, STP was shown to accumulate on the surface of the muscle preventing further STP uptake. At higher STP concentrations (5% and 10% solutions) prolonged time treatments overcame the concentration gradient as STP became equally distributed through the shrimp muscle (4.8 mm). No difference in the STP penetration mechanism between fresh and prefrozen treated shrimo was evident.     

青岛市售冻虾及冻虾仁中磷酸盐残留量的调查分析

通过对青岛市售冻虾及冻虾仁中磷酸盐残留量的调查分析,为水产品的质量安全及风险监测提供一定的科学依据。本文采用离子色谱法,先后对水产样品中正磷酸盐、焦磷酸盐、三聚磷酸盐、三偏磷酸盐含量进行测定。采集水产样品共计265份,其中冻虾64份、冻虾仁201份。结果表明,少数数水产样品中正磷酸盐含量较高,多聚磷酸盐中焦磷酸盐和三聚磷酸盐含量较高;冻虾及冻虾仁中正磷酸盐含量不存在显著性差异(P>0.05),多聚磷酸盐含量均存在一定的显著性差异(P<0.05),冻虾仁中多聚磷酸盐含量明显高于冻虾。     

Protein Hydrolysis and Quality Deterioration of Refrigerated and Frozen Seafood Due to Obligately Psychrophilic Bacteria

Two obligately pychrophilic marine Vibrios, MV-3 and MV-6, hydrolyzed proteins and deteriorated refrigerated and frozen seafoods (fresh and cooked shrimp, fish, and scallops). Protein hydrolysis was determined after storage at 4°C and -20°C, and reported as the percent increase over uninoculated controls stored under the same conditions. When fresh shrimp was inoculated with isolate MV-3, increases in protein hydrolysis were 19.2% after 2 wk refrigeration and 14.2% after 12 wk frozen storage. Thus, the isolates were capable of hydrolyzing protein and deteriorating quality of fish and shellfish under refrigeration or frozen storage.     

Effect of Cryoprotectants on Frozen Whitefish Fillets

Whitefish fillets (Coregonus cupleaformis) were treated with sodium tripolyphosphate (STP), monosodium glutamate (MSG) or a high-pH buffer by high pressure injection, then frozen and stored at ?12°C. Control samples included untreated fillets stored at ?12°C and ?60°C, and STP-dipped fillets (?12°C). Samples treated with STP or high-pH buffer showed better textural properties (reduced centrifugal drip, cooked drip and firmness) than untreated control samples. High pressure injection of STP was not significantly better and sometimes less effective than surface application. Sensory analysis at 18 wk revealed that STP-treated samples (?12°C) were significantly preferred over untreated control samples (?12°C) but not over ?60°C control samples.     

Effect of Cryoprotectants on Frozen Burbot Fillets and a Comparison with Whitefish Fillets

Burbot fillets (Lota lota) were injected with sodium tripolyphosphate (STP), sodium glutamate (MSG), a high pH buffer or an antioxidant mixture (BHA, propyl gallate and citric acid) under high pressure, then frozen and stored at ?12°C. Control samples included untreated fillets stored at ?12°C and ?60°C, and STP dipped fillets. Samples treated with STP or the high-pH buffer had better textural properties than untreated control samples. Samples injected with STP exhibited no improvement as compared to the dipped STP samples and in some respects were worse. Burbot and whitefish have very different textural properties; however, the patterns of change during frozen storage are quite similar.     

卡拉胶寡糖对冷冻南美白对虾的抗冻保水作用

目的:研发冷冻南美白对虾虾仁的抗冻保水剂并探索其应用效果。方法:以冷冻虾仁解冻损失率、明度、p H值、肌原纤维蛋白含量、Ca~(2+)-ATPase活性、弹性和咀嚼性为评价指标,以焦磷酸钠为阳性对照,研究卡拉胶寡糖对冷冻虾仁的抗冻保水效果及微观组织结构的影响情况。结果:卡拉胶寡糖和焦磷酸钠浸泡处理能有效抑制冷冻虾仁解冻损失率的增加,减少肌原纤维蛋白含量和Ca~(2+)-ATPase活性的下降,对虾仁pH值、明度和质构特性的保护效果显著,且3g/100 m L处理组的保护效果整体高于1 g/100 m L处理组;同时,3 g/100 m L卡拉胶寡糖处理对虾仁肌原纤维蛋白的保护效果显著高于3 g/100 m L焦磷酸钠处理(P0.05);微观结构观察发现,冻藏6周后,3 g/100 m L卡拉胶寡糖处理组虾仁肌纤维排列紧密,完整性较好,与新鲜冷冻虾仁组织结构较为相近。结论:3 g/100 m L卡拉胶寡糖浸泡处理有利于冷冻虾仁品质的保持。研究结果可为开发一种低甜味、低热量的虾仁抗冻剂提供参考。     

海藻糖、海藻胶及寡糖对蒸煮南美白对虾的抗冻保水作用

为探索海藻糖类在冷冻熟制水产品中的应用效果,以蒸煮南美白对虾为研究对象,以焦磷酸钠为阳性对照,研究海藻糖、海藻胶及寡糖对蒸煮虾仁的抗冻、保水作用。结果表明：－18 ℃冻藏6 周后,1.0 g/100 mL海藻糖、海藻胶寡糖浸泡处理,显著降低了冷冻蒸煮虾仁解冻和蒸煮损失率（P＜0.05）,其与焦磷酸钠保水效果无显著性差异（P＞0.05）。在整个冻藏期内,0.5、1.0 g/100 mL海藻糖和海藻胶寡糖处理,虾仁肌肉a*值保持效果显著优于其他处理组（P＜0.05）,表明该2 种糖类对蒸煮虾仁色泽具有较好的保护。随着冻藏时间延长,不同处理组虾仁水分含量、水分活度和质构特性均呈逐渐下降趋势,其中以海藻糖、海藻胶寡糖处理对虾仁水分、质构特性保持效果较好,且显著优于蒸馏水和焦磷酸钠组（P＜0.05）。经组织结构观察发现,1.0 g/100 mL海藻胶寡糖处理虾仁,肌纤维排列致密、无扭曲变形,且肌肉中无较大间隙或孔洞产生,表明海藻胶寡糖具有抑制肌肉间隙冰晶生长、保护肌肉组织完整性的作用。结果可为开发一种安全、高效、适用于冷冻蒸煮虾仁的无磷保水剂提供参考。     

Comparison of the Cryoprotective Effects of Trehalose,Alginate, and Its Oligosaccharides on Peeled Shrimp (Litopenaeus Vannamei) During Frozen Storage

The cryoprotective effects of trehalose, alginate, and its oligosaccharides on peeled shrimp (Litopenaeus vannamei) during frozen storage was investigated by monitoring thawing loss, color, texture, myofibrillar protein content, Ca²⁺‐ATPase activity, and performing microscopic structural analysis. Data revealed significant (p < 0.05) inhibitory effects on thawing loss and textural variables (springiness and chewiness) in trehalose‐, alginate oligosaccharides‐, and sodium pyrophosphate‐treated shrimp compared with the control and alginate‐treated batches. L* values revealed that these saccharides had a positive effect on color stability during frozen storage. In addition, the results of chemical analyses showed that trehalose and alginate oligosaccharide treatments effectively maintained an increased myofibrillar protein content and Ca²⁺‐ATPase activity in frozen shrimp. In addition, hematoxylin & eosin staining and SDS‐PAGE confirmed that these cryoprotective saccharides slowed the degradation of muscle proteins and the damage to muscle tissue structures. Overall, the application of trehalose and alginate oligosaccharides to peeled frozen shrimp might maintain better quality and extend the commercialization of these refrigerated products.     

几种添加剂对南美白对虾保水性的研究

为了提高南美白对虾冻藏过程中的保水性,本实验以盐溶蛋白热诱导凝胶保水性（WHC）、硬度、浸泡增重率、解冻增重率、蒸煮损失率为指标,在单因素的基础上,通过L9（34）正交实验,分析了氯化钠、焦磷酸钠和三聚磷酸钠对南美白对虾虾仁保水性的影响,得到了复合保水剂配方,即氯化钠浸泡液质量浓度为0.8%,三聚磷酸钠为2.2%,焦磷酸钠为1.2%。与未处理组相比,解冻增重率从-2.17%升高至9.96%,蒸煮损失率从16.79%降至4.04%,WHC从31.18%升高至47.45%,硬度从21.5 N降至14.0 N。该复合保水剂中3种成分对虾仁保水性影响的主次顺序为氯化钠>三聚磷酸钠>焦磷酸钠。实验得到的复合保水剂配方能够有效的提高对虾的保水性,可以作为低磷保水剂投入生产使用。      

Effect of Treatment, Ice Storage and Freezing on Residual Sulfite in Shrimp

When fresh shell-on tails of penaeid shrimp were treated with sodium bisulfite according to current good manufacturing practices, residual sulfite (SO₂) on the edible portion varied from a high of 92.7 to a low of 60.9 ppm with an average of 80.2 ppm. During freezing and a short period of frozen storage, there was an average loss of 17% in residual sulfite. For shrimp held on ice storage, on the other hand, there was a rapid decrease in residual sulfite to below 10 ppm after six days of storage. The residual levels found on treated shrimp were consistent with action levels set by USFDA for shrimp treated according to good manufacturing practices.     

Quality of Whole Lobster (Homarus americanus) Treated with Sodium Tripolyphosphate Before Cooking and Frozen Storage

ABSTRACT: The objective of this study was to determine the effects of pre-rigor treatment of lobster muscle with sodium tripolyphosphate (STP) before cooking, cryogenic freezing, and frozen storage. STP concentrations of 0.1% and 0.3% were prepared in 0.9% saline solution and injected into lobster before processing. Controls were injected with 0.9% saline solution. Lobsters were then steam-cooked, cryogenically frozen, and stored at −15 °C. Chemical and textural analyses were conducted on reheated samples at storage months 0, 2, 4, and 6, and sensory analyses were conducted at months 2 and 6. Cook loss results showed the 0.3% STP-treated lobsters had a 5% significantly ( P 0.05) lower cook loss than the 0.1% STP and control samples. Yield results revealed that STP-treated tails had a 0.7% to 0.8% significantly ( P 0.05) higher meat yield than control samples. Total moisture results showed that STP-treated lobster tail and claw meat had higher total moisture levels compared with control samples at month 6. Sensory results revealed that panelists rated both 0.1% and 0.3% STP-treated lobster tails significantly ( P 0.01) higher for flavor and texture, and significantly ( P 0.001) higher for overall acceptability than control samples at month 6. The results indicated that STP added at low concentrations may extend the shelf life of whole cooked cryogenically frozen lobster, decrease lipid oxidation over frozen storage time, maintain texture, color, and flavor attributes, increase yield, and decrease drip loss.     

Effects of Various Phosphates on the Palatability, Appearance and Storage Traits of Flaked and Formed Restructured Beef Steaks

Seven blends (9.1 kg raw meat) were formulated with 0.75% NaCl and 0.25% or 0.5% sodium tripolyphosphate (STP), sodium hexa-metaphosphate (SHMP) or sodium acid pyrophosphate (SAPP). Steaks from all blends were “slightly” to “moderately” desirable in flavor and overall satisfaction scores. Steaks made with STP had higher shear force values and work required to shear values than all other restructured steaks indicating an increase in binding occurred with added STP. Restructured steaks formulated with 0.5% STP or SHMP had more desirable raw color scores than the control or steaks made with SAPP. Storage life of all phosphate added restructured steaks was past 90 days frozen storage, and steaks containing STP had thiobarbituric acid values below 1.0 at 120 days storage.     

低聚木糖和卡拉胶寡糖新型保水剂对单冻熟凡纳滨对虾(Litopenaeus vannamei)品质的影响

以单冻熟凡纳滨对虾(Litopenaeus vannamei)虾仁为研究对象,评价低聚木糖和卡拉胶寡糖对蒸煮虾仁的保水效果及冻藏品质的影响情况。结果表明,低聚木糖和卡拉胶寡糖浸泡处理显著降低了虾仁的蒸煮和解冻损失(p<0.05)。其中卡拉胶寡糖处理组的蒸煮损失率为15.7%,与焦磷酸钠处理组无显著性差异(p>0.05)。低聚木糖处理的解冻损失率为7.10%,显著低于焦磷酸钠处理组(p<0.05)。在冻藏过程中,低聚木糖和卡拉胶寡糖处理虾仁肌肉的a*值为8.7和11.29,显著高于焦磷酸钠组的6.12(p<0.05)。随冻藏时间延长,不同处理组虾仁水分含量、水分活度和质构特性均呈逐渐下降趋势,其中以低聚木糖和卡拉胶寡糖处理虾仁的水分、质构特性保持作用最好,且显著优于焦磷酸组(p<0.05)。微观结构观察发现,冻藏7周后,低聚木糖和卡拉胶寡糖处理组虾仁肌纤维排列紧密、无严重扭曲变形,且肌肉中无较大间隙或孔洞产生,与新鲜蒸煮虾仁组织结构较为相近。结论:研究可为开发一种低甜味、低热量且适用于单冻熟虾仁的抗冻保护剂提供参考。      

Effect of Sodium Salts and Added Water on Color of Dark Meat Turkey Patties Subjected to Long-term Storage

Patties from a Control (all meat), Treatment I (meat, 1.1% water, 1.0% NaCl and 0.5% STP) and Treatment II (meat, 11.1% water, 1.0% NaCl and 0.5% STP) were frozen for 0 to 24 wk, broiled, and analyzed for color attributes. Treated patties had lighter exterior surfaces with reduced redness and increased yellowness. The opposite effects were observed for the interior of patties. Treatment II had elevated values for internal yellowness as compared to Treatment I. Storage caused an increase in both external and internal color values. Sensory scores indicated that internal redness of treated patties was greater than that of the Control but gradually decreased during storage.     

Inhibition of melanosis formation in Pacific white shrimp by the extract of lead (Leucaena leucocephala) seed

Lead (Leucaena leucocephala) seed extract was prepared using distilled water as a medium. An extraction yield of 26.16 g/100 g of seed was obtained after extraction at room temperature for 12 h. Total phenolic and mimosine contents in the lead seed extract powder (LSEP) were 17.4 g GAE/100 g and 8.8 g/100 g, respectively. LSEP at different concentrations (0.05%, 0.1%, 0.25%, 0.5%, and 1%, w/v) showed inhibitory activity towards polyphenoloxidase (PPO) of Pacific white shrimp in a dose dependent manner. When the whole Pacific white shrimp were treated with 0.25% and 0.5% (w/v) LSEP, the shrimp treated with 0.5% LSEP had the lower melanosis score throughout the storage of 12 days and showed a higher score for colour and odour, as well as overall likeness, compared with the control (without treatment) and 1.25% sodium metabisulphite treated samples at day 12 (P < 0.05). Meat of shrimps treated with LSEP at both levels had the increase in mimosine content up to 8 days, suggesting the migration of mimosine into shrimp muscle during extended storage. Therefore, 0.5% LSEP can be used as a novel melanosis inhibitor for Pacific white shrimp.     

Indole in Shrimp: Effect of Fresh Storage Temperature, Freezing and Boiling

The development of indole, total volatile nitrogen, trimethylamine and total aerobic plate count (APC) in shrimp stored in ice, at 4°C, 12°C and 22° C were investigated. At low temperature storage, final indole levels in severely decomposed shrimp (APC >10⁸/g) were much lower than the 25 μg indole/100g shrimp which has been suggested as the defect action level for shrimp decomposition by the Food & Drug Administration. At higher storage temperatures, (12° and 22°C), indole formation was greatly accelerated resulting in very high indole levels. The net result is that while indole levels indicate decomposition, decomposed shrimp may not necessarily contain indole. Frozen storage and cooking had little effect on indole levels in acceptable quality shrimp. Indole is of value in assessing the history of shrimp if high temperature abuse is suspected.     

海藻糖类抗冻保水剂对冻藏南美白对虾(Litopenaeus vannamei)品质的影响

以冻藏南美白对虾(Litopenaeus vannamei)虾仁为研究对象,0.5%和1.0%(w/v)海藻糖、海藻酸钠、海藻酸钠寡糖溶液作为抗冻保水剂,蒸馏水、0.5%和1.0%(w/v)焦磷酸钠分别为阴性对照组和阳性对照组,于-18 ℃下贮藏6周,通过对冻藏南美白对虾仁的解冻损失、颜色、肌原纤维蛋白含量、Ca2+-ATPase活性以及微观结构等指标进行分析,评价海藻糖类等对冻藏虾仁品质的影响。结果表明,与对照组相比,海藻糖、海藻酸钠寡糖、焦磷酸钠处理组虾仁的解冻损失显著降低(p<0.05)。海藻糖类提高了南美白对虾冻藏期间颜色的稳定性。海藻糖和海藻酸钠寡糖处理有效地保持了冻藏虾仁中肌原纤维蛋白含量和Ca2+-ATP酶活性,其中肌原纤维含量分别为104.2、103.2 mg/g,Ca2+-ATP酶活性分别为0.141、0.142 μmol Pi/mg·min。染色实验和电泳实验结果表明,海藻糖类对冻藏后肌肉蛋白质的降解和肌肉组织结构的损伤具有减缓作用,虾仁肌肉肌纤维结构完整,肌肉间无较大空隙形成,较好地保持了冻藏虾仁组织完整性,副肌球蛋白和肌动蛋白条带的强度都没有明显的降低。研究表明:在南美白对虾的冻藏过程中,海藻糖和海藻酸钠寡糖抗冻剂起到了良好的抗冻效果,能够更好地保证冻藏虾仁的质量和品质,得到一种冻藏水产品复合磷酸盐保水剂的较好替代品。     

虾蛄肌原纤维蛋白磷酸化工艺及其在虾蛄肉制品中的应用

研究多聚磷酸盐磷酸化虾蛄肌原纤维蛋白的最佳工艺条件,并探究复合磷酸盐在虾蛄肉制品中的应用。采用三聚磷酸钠(STP)、焦磷酸钠(SPP)、三偏磷酸钠(STMP)分别对虾蛄肌原纤维蛋白进行磷酸化改性,在单因素实验的基础上,利用响应面法优化虾蛄肌原纤维蛋白磷酸化条件,结果表明:STP最佳工艺条件为:反应pH8.0、STP添加量4%、反应时间2.0 h,所得磷酸化程度为102.87 mg/g;SPP最佳磷酸化条件为:反应pH7.5、SPP添加量2%、反应时间2.0 h,所得磷酸化程度为96.41 mg/g;STMP最佳磷酸化条件为:反应pH8.0、STMP添加量4%、反应时间2.5 h,所得磷酸化程度为76.53 mg/g。在此基础上,探究4组不同比例复合磷酸盐对新型果蔬虾饼品质的影响,结果表明:复合磷酸盐可显著降低虾饼的蒸煮损失和在加工过程中抗坏血酸含量的损失(p<0.05),并提高其质构特性;当STP:SPP:STMP比例为2:1:2时,能显著改善虾蛄肉制品的品质(p<0.05),证实了磷酸化改性的可行性。     

不同糖类对反复冻融下 冻藏南美白对虾虾仁品质特性的影响

为探讨不同糖类对反复冻融下冻藏南美白对虾品质特性的影响,以3%低聚木糖、3%卡拉胶寡糖、3%海藻糖、3%海藻胶寡糖和3%焦磷酸钠(阳性对照)浸泡处理南美白对虾虾仁后,在-55~4 ℃循环冷冻-解冻过程中,分析冻藏虾仁肌肉解冻损失率、L^*值、质构特性、肌原纤维蛋白含量、总巯基含量及肌原纤维蛋白Ca²⁺-ATPase活性等变化情况。结果表明,经反复冻融6次后,蒸馏水组虾仁解冻损失率和L^*值分别显著增加46.2%和11.7%,而其咀嚼性、硬度、肌原纤维蛋白含量、Ca²⁺-ATPase活性和总巯基含量则分别显著下降了57.5%、43.8%、14.0%、29.7%和23.4%(P<0.05)。相比于蒸馏水组,几种糖类浸泡处理,均对冻藏虾仁表现出一定的保水及蛋白质冷冻变性抑制效果。其中,卡拉胶寡糖处理虾仁,经6次冻融后其肌肉解冻损失率和L^*值增加至5.65%和47.35,而其咀嚼性、硬度、肌原纤维蛋白含量、Ca²⁺-ATPase活性和总巯基含量则维持在5.43 mJ、1.28 mm、95.24 mg/g、0.093 U/mg和7.31 mmol/L,相比于其它几种糖类,卡拉胶寡糖对虾仁品质特性的保护作用较好。综上,糖类处理对温度波动下的冻藏南美白对虾有重要的冷冻保护效果,其可为冻藏虾仁的品质保障技术提供一定的理论依据。     

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.