Op—Ca保鲜剂对鹰爪糙对虾的保鲜效果

报告了常温下Op-Ca保鲜剂对鹰爪糙对虾（Trachypenaeus curvirostirs)的保鲜效果。鹰爪糙对虾营养价值、味道鲜美。用0．1％浓度的Op-Ca保鲜剂溶液浸泡鹰爪糙对虾30min后常温（18℃）下贮藏,通过感官评价,细菌总数和T－VBN值等指标的发现,Op-Ca保鲜剂在常温下（18℃）下对鹰糙对虾有较好的保鲜效果,常温下可延长保鲜期2d。     

冰温下复合保鲜剂和焦亚硫酸钠对南美白对虾防黑变保鲜效果比较

为有效防止对虾黑变,超量使用亚硫酸盐的现象屡禁不止,造成虾类产品中二氧化硫严重超标,危害人体健康。使用复配防黑保鲜剂(植酸0.1%、柠檬酸0.8%、壳聚糖0.1%)处理南美白对虾,然后与1%焦亚硫酸钠处理组进行比较,总结两者的防黑保鲜效果,为进一步推广使用安全的化学、生物复配防黑保鲜剂提供参考资料。结果表明:在冰温贮藏条件下,复配保鲜剂处理的对虾的感官评分、p H值、TVB-N、质构、酚氧化酶活性、色差、细菌总数在贮藏期间的变化与1%焦亚硫酸钠处理组非常相近,两者防黑保鲜效果基本一致。从食品安全角度来说,复合保鲜剂更安全,可以替代亚硫酸盐。     

亚硫酸钠浸泡预处理对脱水蒜片主要品质指标的影响

蒜片在干制过程中,会发生褐变反应导致产品品质下降,考察亚硫酸钠溶液处理质量浓度、处理时间及温度对脱水蒜片色泽、硫代亚磺酸酯含量、SO2残留量、体外抗氧化活性等品质指标的影响。结果表明：亚硫酸钠溶液浸泡处理可有效地保持脱水蒜片品质,浸泡时间及浸泡温度对蒜片品质总体影响较小。500?mg/L亚硫酸钠溶液浸泡30?min时,蒜片色泽较优;不同条件浸泡所得蒜片,SO2残留量随处理质量浓度的增大及处理时间的延长而增大;亚硫酸钠溶液浸泡处理后,蒜中主要功能性成分硫代亚磺酸酯含量最高可达0.115?mmol/g,显著高于对照组0.077?1?mmol/g。     

茶多酚复合保鲜剂对冷藏南美白对虾品质的影响

南美白对虾在冷藏期间极易腐败,为改善对虾的贮藏品质,用茶多酚、柠檬酸和L-半胱氨酸浸泡南美白对 虾,测定各组贮藏期间感官评价、pH值、挥发性盐基氮含量、白度值及细菌总数的变化,研究茶多酚及其复配生 物保鲜剂对冷藏条件下南美白对虾的保鲜效果,延长贮藏期。结果表明：4 ℃冷藏条件下,茶多酚及其复配生物保 鲜剂处理组能有效提高对虾贮藏期间肉质、外观和气味品质,抑制微生物生长和挥发性盐基氮产生,在一定程度上 抑制黑变反应,处理组中8 g/L茶多酚、5 g/L柠檬酸、2 g/L L-半胱氨酸复配效果最好。     

SO2熏蒸处理对维多利亚葡萄保鲜效果研究

以维多利亚葡萄为试材,研究1000、500、100μL/L三种不同浓度SO2熏蒸处理1h对0℃贮藏条件下葡萄主要品质和相关生理指标的影响.结果表明,储藏60d与对照相比,三种浓度的SO2处理均能在不同程度上降低贮藏过程中葡萄果实的腐烂率、脱粒率、果梗褐变和果穗失重率.延缓葡萄果实中可溶性固形物和维生素C的下降.使呼吸强度维持在较低水平.500μL/L和100μL/L的SO2熏蒸处理能减缓贮藏后期果实可滴定酸的下降,1000μL/L浓度SO2熏蒸处理使果实可滴定酸升高.500μL/L和100μL/L浓度SO2熏蒸处理贮藏的葡萄60d后,果肉中SO2残留量分别为8.31mg/kg和6.52mg/kg.均低于FDA安全标准(10mg/kg),而1000μL/L浓度SO2熏蒸处理使果肉中SO2残留量达到23.17mg/kg,超出FDA安全标准.     

流化冰结合防黑剂、抑菌剂对南美白对虾的保鲜效果

为探索南美白对虾的鲜度保持和黑变现象抑制方法,采用流化冰结合防黑变剂（4-己基间苯二酚（4-hexylresorcinol,4-HR）、植酸钠）、抑菌剂（稳定态二氧化氯,ClO2）处理方式,检测贮藏过程中南美白对虾感官、挥发性盐基氮（total volatile basic nitrogen,TVB-N）值、菌落总数、质构及多酚氧化酶（PPO）活性变化情况。结果表明,贮藏12 d后,流化冰保鲜对虾头部褐变较严重、肌肉尚有弹性;流化冰结合4-HR或植酸钠、ClO2保鲜对虾,头部仅轻微褐变,肌肉紧密有弹性,感官品质明显优于单纯流化冰组;其中以流化冰结合0.030 g/L4-HR、0.05 g/L ClO2保鲜对虾的感官品质（L*、b*值）保持作用最佳。贮藏16 d后,流化冰保鲜对虾TVB-N值、菌落总数、弹性、咀嚼性和PPO活性,依次为9.43 mg/100 g、6.21（lg（CFU/g））、0.56 mm、7.43 mJ和10.83 U/g;流化冰结合0.030 g/L 4-HR、0.05 g/L ClO2保鲜对虾,以上各指标分别为15.87 mg/100 g、4.90（lg（CFU/g））、0.80 mm、8.55 mJ和7.67 U/g,该处理保鲜效果显著优于单纯流化冰组（P＜0.05）。研究表明,流化冰结合4-HR、ClO2处理,可满足南美白对虾捕后保鲜、远途运输及市场销售要求。     

山楂片中二氧化硫脱除方法的研究

该试验以含硫山楂片为对象,研究了碱液浸泡、过氧化氢溶液浸泡、热水浸泡以及超声波处理对试样中二氧化硫脱除效果的影响。试验结果显示四种方法的脱硫效果均优于对照。频率40kHz,声强0.48w/cm^2的超声波处理的效果尤为显著,处理1h可使试样中二氧化硫残留量降至国家标准限量要求以下,并且对感官品质无不良影响;热水浸泡也可以显著加快脱硫速度,并与温度呈正相关,80℃浸泡2h或60℃浸泡4h,二氧化硫残留量符合国标要求,无明显煮熟味;过氧化氢溶液浸泡脱硫效果显著,但对其可能带来的潜在危害本实验未能做进一步的评估。     

采后壳聚糖处理对薄膜包装枸杞鲜果低温贮藏品质的影响

以＂宁杞1号＂鲜果为试材,采用2.5g/L和5.0g/L壳聚糖浸泡处理3min,观察果实在聚乙烯薄膜包装条件下低温（0±1）℃贮藏期间的保鲜效果。结果表明：壳聚糖处理可有效降低果实的腐烂率,贮藏24d时,2.5g/L和5.0g/L处理的腐烂率分别较同期对照低32.0%和76.2%。壳聚糖还可明显延缓贮藏期间可溶性固形物含量的降低,并在一定程度上维持可滴定酸含量,但对果实的失重率无影响。经5.0g/L壳聚糖处理的果实在贮藏30d时仍具有新鲜枸杞固有的风味,且较好地保持了果柄的新鲜度。由此表明,壳聚糖处理可作为一项措施应用于枸杞鲜果保鲜。     

熏蒸过的竹笋中二氧化硫的检测和卫生标准的探讨

目的对用硫磺熏蒸过的竹笋样品SO2残留量进行测定和研究,为国家或地方重新制定竹笋的二氧化硫标准提出了数据和依据。方法竹笋分成散装干笋、散装水发竹笋和袋装浸泡竹笋。散装干笋与水按照1∶10和1∶20作浸泡试验,每12h更换一次浸泡液,测定每次竹笋样品和浸泡液中的SO2残留量;散装水发竹笋直接测定;袋装浸泡竹笋分别直接测定和按包装袋上的食用方法处理后测定。结果散装干笋的SO2残留量都大于0.05g/kg,但经浸泡48h后,样品中的SO2残留量都低于0.05g/kg;39.3%的水发竹笋和83.5%的袋装浸泡竹笋SO2残留量超过0.05g/kg。袋装浸泡竹笋经过按包装袋上食用方法处理后,仍有60.0%竹笋的SO2残留量超过0.05g/kg。结论建议散装水发竹笋和袋装浸泡竹笋的SO2直接测定,标准定为0.15g/kg为宜。     

抗坏血酸联合乳酸链球菌素复合涂膜保鲜采后双孢蘑菇研究

为明确抗坏血酸结合乳酸链球菌素涂膜处理对采后双孢蘑菇子实体贮藏保鲜的效果,以采后双孢蘑菇为试材,采用0.8 g/L抗坏血酸+0.4 g/L乳酸链球菌素+5.4 g/L卡拉胶的复合保鲜剂浸泡30 s处理。结果表明,复合保鲜剂能够有效地减少贮藏期间双孢蘑菇子实体的腐烂率和失重率,延缓组织褐变,维持较高的硬度水平;同时,能够延缓类黄酮、内源V_C、可溶性糖和可溶性蛋白质的降解,进一步研究表明其能够维持双孢蘑菇组织较强的ABTS+、DPPH自由基清除能力。该复合保鲜剂较好维持了采后双孢蘑菇的贮藏品质,为新型食用菌保鲜剂的开发提供了一定的理论指导。     

可食性涂膜对南美白对虾微冻冷藏的影响

为改善南美白对虾易于黑变及货架期短的问题,采用M1(4-己基间苯二酚(4-HR)0.05g/L＋壳聚糖1.5g/L+乳酸链球菌素(Nisin)0.2g/L)和M2(4-己基间苯二酚(4-HR)0.05g/L＋酪蛋白酸钠1.5g/L＋聚丙烯酸钠0.5g/L＋乳酸链球菌素(Nisin)0.2g/L)两种保鲜剂配方对南美白对虾涂膜保鲜,(－3±1)℃条件贮藏。结果表明：相对于对照组,南美白对虾经M1和M2两种保鲜剂处理后,在(－3±1)℃贮藏过程中菌落总数、挥发性盐基氮(TVB-N)和丙二醛(MAD)增加缓慢,黑变被有效抑制。M1组有最佳抑菌效果,M2组有最佳的感官评分,M1和M2两种保鲜剂均可将货架期延长1倍多。     

Lactic Acid/Melanosis Inhibitors to Improve Shelf Life of Brown Shrimp (Penaeus aztecus)

l-Lactic acid, sodium bisulfite, and 4-hexylresorcinol were evaluated, alone and in combination, as melanosis and microbial spoilage inhibitors on brown shrimp (Penaeus aztecus). No effect on the microbiological shelf life of treated shrimp was observed. 4-Hexylresorcinol functioned exceptionally well as a melanosis inhibitor, alone and in combination with. l-lactic acid. However, extensive bacterial growth was demonstrated in the 4-hexylresorcinol dip solution during normal storage on deck, creating the potential for a heavy bacterial inoculation of shrimp during a typical dipping process. Addition of l-lactic acid to the 4-hexylresorcinol dip solution prevented bacterial growth in the dip solution and did not diminish melanosis inhibition.     

Role of sulfites and 4-hexylresorcinol in microbial growth and melanosis prevention of deepwater pink shrimp (Parapenaeus longirostris) using a controlled atmosphere

A controlled atmosphere containing 48% CO2 and 7% O2 was used in association with refrigeration for storage of deepwater pink shrimp (Parapenaeus longirostris). Shrimp were treated with two different concentrations of sodium metabisulfite or 4-hexylresorcinol and subjected to the controlled atmosphere immediately after capture onboard ship or on arrival in port. Total volatile basic nitrogen, total viable counts, enterobacteria, lactic acid bacteria, and luminescent bacteria were determined, and black spot progression was evaluated. The combined effect of controlled atmosphere and melanosis inhibitors was used to delay black spot development as compared to the shrimp stored in ice alone. Storage under the controlled atmosphere without ice limited microbiological quality, namely, total viable counts, but enterobacterial growth was lower.     

偏重亚硫酸钠对微生物法测定维生素B12含量的影响

摘 要: 目的 探究偏重亚硫酸钠对微生物法测定婴幼儿食品和乳品中维生素B12(VB12)含量的影响。方法 通过在标准工作液和样品待测液中添加质量浓度梯度为0、0.0025、0.005、0.02、0.08和0.16 mg/mL偏重亚硫酸钠, 测定不同处理组实验样品中VB12含量值并对质控样品进行质控结果分析, 研究偏重亚硫酸钠对莱士曼氏乳杆菌生长的促进作用及其对原生VB12提取的影响。结果 在标准溶液中添加质量浓度为0~0.16 mg/mL的偏重亚硫酸钠都可以促进莱士曼氏乳杆菌的生长。偏重亚硫酸钠能促进样品中原生VB12的提取。偏重亚硫酸钠终浓度在0~0.16 mg/mL的范围内都不会抑制莱士曼氏乳杆菌的生长, 同时在0~0.05 mg/mL的范围内, 随偏重亚硫酸钠质量浓度增加, 原生VB12的提取会成比例增加。结论 偏重亚硫酸钠在0~0.16 mg/mL浓度范围内可以促进莱士曼氏乳杆菌的生长, 提高食品原生VB12的提取率, 进而增加检测结果的稳定性和准确度。     

模糊综合评价结合响应面法优化鹰爪虾滑加工工艺

以鹰爪虾和南美白对虾为原料,研究不同漂洗工艺对虾滑凝胶性能的影响,并对虾滑配方进行优化.以凝胶强度、弹性和胶黏性为指标,得出虾肉较优的漂洗参数为水料质量比11:1,漂洗时间7 min.以虾滑感官评分为指标,利用模糊综合评价法和响应面法得出虾滑最优配方为:马铃薯淀粉添加量5.6％、白虾-鹰爪虾的粒糜比0.25:1、食盐添...     

SO2处理对新疆3种葡萄香气成分的影响

采后SO2处理对新疆“无核白”、“木纳格”和“红提”3 种葡萄果实香气成分的影响。选4-壬醇做内标,采用顶空固相微萃取-气相色谱-质谱联用技术对SO2处理前3 种葡萄成熟果实的香气成分进行定性和定量分析,同时考察了添加焦亚硫酸钠对“无核白”葡萄香气成分的影响及采后不同贮藏时间SO2处理对3 种葡萄果实香气成分的影响。结果表明,3 种葡萄中分别鉴定出40、38、37 种香气成分,其中C6醛（即己醛和E-2-己烯醛）在3 种葡萄中的含量相对较高;添加焦亚硫酸钠对“无核白”葡萄中的C6醛含量影响较大,其他成分含量变化不大;采后SO2处理3 种葡萄果实香气成分中的C6醛的含量均随着贮藏时间的延长而逐渐降低。     

Edible mushroom (Flammulina velutipes) extract inhibits melanosis in Kuruma shrimp (Marsupenaeus japonicus)

This study compared the potential of an aqueous extract of an edible mushroom (Flammulina velutipes) to prevent melanosis in cultured Kuruma shrimp (Marsupenaeus japonicus) with other antimelanosic compounds in vivo. The mushroom extract contained 9.1 mg/mL ergothioneine (ESH). Immersion of live full-grown shrimp in a 0.5% w/v solution of mushroom extract significantly reduced PPO activity in shrimp hemolymph. In addition, expression of the prophenoloxidase (proPO) gene decreased in hemocytes, suggesting that the extract blocked the activation of the proPO cascade. Consequently, the development of melanosis in the treated shrimp was significantly suppressed during ice storage. Treatment with a 0.05% w/v solution of sodium ascorbate and 4-hexyl-1,3-benzenediol had the same effect. In vitro experiments showed that ESH effectively inhibited PPO activity and activation of the proPO cascade in hemocyte lysate supernatant. This study suggests that in vivo application of F. velutipes mushroom extract is an effective natural alternative to synthetic antimelanosic agents to inhibit postmortem melanosis in shrimp. Practical Application: The extract of an edible mushroom (F. velutipes) containing ergothioneine can be a promising natural alternative to synthetic antimelanosic agents used to prevent postharvest melanosis in shrimp and other crustaceans. Furthermore, utilization of the mushroom trimmings could also help address the growing concerns on the disposal of such agricultural wastes and instead use it into a novel purpose as a source of antimelanosic and antioxidants for food and industrial application.     

Effects of Plant Extract-Sulphide Combinations on Melanosis Inhibition and Quality in Shrimp (Aristeus Antennatus)

In this study, shrimp (Aristeus antennatus) immediately after trawling was treated with plant extracts (rosemary and green tea), sodium metabisulphite solution, and their combinations. After dipping into the solutions, melanosis and selected quality changes of shrimp were investigated during the storage at 4°C. Plant extracts were found effective in delaying melanosis in shrimp. Combinations of sodium metabisulphite and plant extracts were found more effective than those groups separately treated with plant extracts. Plant extracts, sodium metabisulphite, and combinations showed lower trimethylamine and total volatile nitrogen values as compared to the control group. It is concluded that use of plant extracts decreased the need for sodium metabisulphite.     

焦亚硫酸钠对酵母细胞的毒性作用

为探讨焦亚硫酸钠的保鲜防腐机制,采用毒理学方法研究保鲜剂对酵母细胞的毒性效应。结果表明：在100～1 000 μmol/L浓度范围内,焦亚硫酸钠可抑制酵母细胞生长分裂,诱发细胞死亡;随着焦亚硫酸钠浓度升高和作用时间延长,其对酵母细胞的毒性效应也逐渐增强。经100 μmol/L焦亚硫酸钠作用2 h后,酵母细胞生长曲线与对照组产生差异;300 μmol/L焦亚硫酸钠处理6 h后,酵母细胞死亡率显著高于对照组,用抗坏血酸或LaCl3预处理可阻止焦亚硫酸钠诱发的酵母细胞死亡,表明焦亚硫酸钠通过诱导酵母细胞内活性氧和Ca2＋水平升高来引发细胞死亡。研究还发现,相同浓度的焦亚硫酸钠作用后,pH 4.0组酵母细胞的死亡率明显高于pH 7.0组,即酸性环境能增强焦亚硫酸钠对酵母细胞的毒性作用,有助于保鲜剂的抑菌防腐。     

Inactivation of Listeria monocytogenes during drying and storage of peach slices treated with acidic or sodium metabisulfite solutions

This study evaluated whether treating inoculated peach slices with metabisulfite or acidic solutions enhanced inactivation of Listeria monocytogenes during dehydration and storage. Inoculated (five strain mixture of L. monocytogenes, 7.9 log cfu/g) peach slices were treated, dried for 6 h at 60°C and stored aerobically at 25°C for 14 d. Predrying treatments of inoculated peach slices included: (1) no treatment (control); or 10 min immersion in: (2) sterile water, (3) 4.18% sodium metabisulfite, (4) 3.40% ascorbic acid, or (5) 0.21% citric acid solutions. Samples were plated on tryptic soy agar with 0.1% pyruvate (TSAP) and PALCAM agar for enumeration of surviving bacteria. Immersion in sterile water reduced bacterial populations on peach slices by 0.7 log cfu/g (TSAP and PALCAM). Immersion in the sodium metabisulfite solution reduced populations by 1.5–2.0 log cfu/g, while acidic pretreatments reduced populations by 0.5–0.8 log cfu/g. After 6 h of dehydration, populations on control or water immersed slices were reduced by 3.2–3.4 log cfu/g, whereas populations on slices treated with sodium metabisulfite or acidic solutions were reduced by 4.3–5.1 log cfu/g (TSAP) and 5.3–6.2 log cfu/g (PALCAM), respectively. Bacteria were detectable by direct plating at 14 d of storage, except on acid treated slices. Immersion in acidic or metabisulfite solutions, before dehydration, should enhance inactivation of L. monocytogenes contamination on peach slices during dehydration and storage.