海鲈鱼肉蒸制过程中品质及风味特性的变化

以海鲈鱼背部肌肉为原料,对不同蒸制时间鱼肉的质量损失率、色泽、水分分布状态和质构特性变化进行分析,并通过游离氨基酸分析、电子舌和电子鼻评价鱼肉的滋味和气味差异。结果表明,随着蒸制时间的延长,海鲈鱼肉的质量损失率显著上升（P＜0.05）,鱼肉中的不易流动水逐渐向自由水转化并流失,而结合水含量变化不明显;鱼肉的硬度和咀嚼度先下降后又显著增大,而弹性先升高后降低;蒸制后鱼肉的L*值和b*值显著升高（P＜0.05）,a*值显著降低（P＜0.05）。经蒸制后鱼肉中游离氨基酸的总量先增大后降低,在蒸制10 min达到最高值,组氨酸、甘氨酸、丙氨酸、赖氨酸和谷氨酸是海鲈鱼肉中主要的呈味氨基酸;电子舌和电子鼻均能有效区分不同蒸制时间鱼肉的滋味和气味特征。综上,限定规格的海鲈鱼块在蒸制8～10 min的品质及风味较好。     

羟自由基氧化对海鲈鱼肌原纤维蛋白生化特性及其乳化性能的影响

采用羟自由基氧化体系对海鲈鱼肌原纤维蛋白进行体外模拟氧化,研究羟自由基氧化氧化对肌原纤维蛋白生化特性和乳化性能影响。结果显示:随氧化时间的延长,羰基含量、表面疏水性和肌原纤维蛋白(MPI)平均粒径增加,总巯基和活性巯基含量下降,生色氨基酸含量减少,二聚酪氨酸含量在4 h达到最大值。H2O2浓度在1 mmol/L时上述指标变化显著,H2O2浓度在5 mmol/L和10 mmol/L条件下,前4 h乳化活性和乳化稳定性显著下降,活性巯基含量较对照组分别下降了51.93%和65.88%,MPI平均粒径较对照组分别增加了47.87%和72.38%,4 h后变化不明显,且不同氧化剂浓度之间差异性显著。SDS-PAGE电泳图谱表明经羟自由基氧化后蛋白质发生交联,形成大量高分子凝集体,在200 ku上方区域堆积,肌球蛋白重链含量减少。结果表明,羟自由基氧化体系能使海鲈鱼肌原纤维蛋白结构发生改变,导致其乳化性能下降。     

热处理方式对鲈鱼游离氨基酸及品质影响

海鲈鱼因其味道鲜美、肉质细嫩深受消费青睐.不同的热处理方式对于鱼肉的品质影响较大.通过结合烹饪损失、感官评定、色泽、质构和游离氨基酸含量等多项指标,评估传统沸煮和低温真空烹饪对鲈鱼品质的影响,结果表明低温真空烹饪的鲈鱼无论是在烹饪损失、质构,还是在游离氨基酸含量方面均具有较好的优势,在感官评定上可接受度较高.该研究结果...     

不同超声辅助解冻方式对海鲈鱼品质的影响

将五种解冻处理的海鲈鱼(超声微波解冻、超声远红外解冻、超声欧姆解冻、超声真空解冻和超声解冻)与新鲜鱼肉进行比较,研究了不同解冻方式对海鲈鱼品质的影响。本文主要分析了解冻后鱼肉的持水性、新鲜度、脂肪氧化程度、蛋白质热稳定性、凝胶特性、水分分布和微观结构的变化。结果显示,不同处理的解冻损失率和蒸煮损失率差异显著(P<0.05),超声微波解冻鱼肉的解冻损失率和蒸煮损失率最低,分别为1.52%和13.13%。低场核磁的结果显示超声微波解冻的样品中,细胞内水分向游离水迁移较少,说明超声微波解冻的鱼肉持水性较高。所有解冻样品的pH均与新鲜样品没有显著性差异(P>0.05),TVB-N值均低于15 mg/100 g,保持了较高的新鲜度。但超声远红外解冻、超声欧姆解冻、超声真空解冻和超声解冻的鱼肉TBARS值显著升高(P<0.05),脂肪氧化程度较高。超声微波解冻和超声远红外解冻的海鲈鱼具有较高的热稳定性和粘弹性,并且拥有更紧密光滑的微观结构。超声真空解冻的肌原纤维束发生轻微卷曲,超声欧姆解冻和超声解冻的纤维表面粗糙、结构疏松。其中,超声微波解冻是最优的解冻方式。     

超声-咖啡酸联合处理对海鲈鱼冷藏期间品质变化的影响

为研究超声-咖啡酸联合处理对冷藏海鲈鱼品质变化影响,将新鲜鲈鱼片随机分为5 组,分别为20 kHz、600 W超声处理10 min（US组）,2.0 g/L咖啡酸浸渍10 min（CA组）,超声联合咖啡酸处理10 min（20 kHz、600 W超声处理5 min后,咖啡酸浸渍5 min）（US＋CA组）,无菌水（空白,CK组）与体积分数1%乙酸（对照,AA组）分别浸渍10 min。将5 组样品处理后沥干,装于聚乙烯保鲜袋中,置于4 ℃冷藏。每2 d测定样品的微生物指标（菌落总数）、理化指标（pH值、总挥发性盐基氮（total volatile base nitrogen,TVB-N）含量、硫代巴比妥酸（thiobarbituric acid,TBA）值、质构特性、持水力）等,结合内源荧光强度与感官评价,综合评价超声-咖啡酸联合处理对冷藏鲈鱼的保鲜效果。结果表明：US与CA处理能明显抑制样品贮藏期间菌落总数的增长,在第10天,CA组与US组样品的菌落总数比CK组分别低18.49%与15.53%,其pH值与TVB-N含量上升速度明显缓于CK组样品。贮藏第10天时,CK组样品的TVB-N含量已超过腐败限值,达（33.88±0.56）mg/100 g,而此时US＋CA组样品的TVB-N含量为（16.71±0.41）mg/100 g,明显低于CK组。US处理使鱼肉的保水性明显改善,CA处理对抑制鱼肉的脂肪氧化有较好效果,其还能使样品的持水力得到较高提升;其中以US＋CA联合处理组样品总体品质最佳。与CK组相比,US＋CA处理对鱼肉品质保持效果较好,联合处理可使海鲈鱼的冷藏货架期至少延长4 d。     

Original article: Effect of modified atmosphere packaging using different CO2 and N2 combinations on physical,chemical, microbiological and sensory changes of fresh sea bass (Dicentrarchus labrax) fillets

The effect of different modified atmosphere packaging (MAPs) on physical, chemical, microbiological and sensory changes of sea bass fillets when stored at 4 °C and standard light conditions was investigated for up to 21 days and compared to a control batch stored in overwrap. Sea bass fillets were packed using different CO₂ and N₂ combinations (40% CO₂–60% N₂; 50% CO₂–50% N₂; 60% CO₂–40% N₂), and quality assessment was based on instrumental, chemical, microbiological and sensory analysis. The results showed that MAP extended shelf‐life of sea bass fillets from 7 days (overwrap packaging) to 14 days. Drip loss, pH values and thiobarbituric acid reactive substances (TBARS) measurements were higher in overwrap samples but no differences (P ≤ 0.05) were found between MAP samples. Bacteria grew most quickly and showed higher counts in overwrap samples followed by 40% CO₂–60% N₂; 50% CO₂–50% N₂ and finally 60% CO₂–40% N₂. Sensory analyses were in good relation with chemical and microbiological results establishing best scores and an extended shelf‐life for MAP samples especially in MAPs with high CO₂ levels.     

鲈鱼风干成熟工艺及对蛋白质水解和感官品质影响

以鲈鱼(Japanese Sea Bass)为原料进行风干成熟工艺正交试验,研究风干成熟温湿度、时间、用盐量工艺因素对产品品质及蛋白质水解规律的影响。结果表明：蛋白质水解指数(PI)随着温度提高持续增加,而游离氨基酸总量(ΣFAA)表现出先升后降的趋势;风干成熟温度对PI 和ΣFAA 有极显著影响(P ＜ 0.01);以ΣFAA 为响应的回归优化结果为：风干成熟温度15～29℃、相对湿度70%～82%,工艺时间72h,加盐量4.5%,风干成熟产品的盐分含量为2.84%、水分含量为64.33%,与感官品质评定结果有良好的一致性。     

Differentiation in the Lipid Quality of Wild and Farmed Seabass (Dicentrarchus labrax) and Gilthead Sea Bream (Sparus aurata)

ABSTRACT: The elements of differentiation that characterize the quality of the lipid fraction of wild and farmed sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) were investigated. Reared fish of either species had a total lipid content significantly higher than the wild counterparts. Liquid chromatography of unsaponifiable lipids showed, on a lipid gram basis, higher cholesterol levels in wild fish and comparable amounts of squalene, all‐trans retinol, and α‐tocopherol. Gas chromatography of total lipids revealed differences between the fatty acid profiles of wild and reared fish.     

Effects of differences in diet and seasonal changes on the fatty acid composition in fillets from farmed and wild sea bream (Sparus aurata L.) and sea bass (Dicentrarchus labrax L.)

The effects of dietary fatty acids and seasonal variation on the fatty acid profiles of farmed and wild sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) were determined by analysis of their fillets. Farmed sea bream and sea bass were fed on the same commercial feeds all year. Fatty acid profiles in the fillets reflected the fatty acid profiles of the commercial feeds. The predominant fatty acids in the trial feeds, fillets of farmed and wild sea bream and sea bass were 16:0, 18:1n‐9, 18:2n‐6, 20:5n‐3 and 22:6n‐3. The fatty acid profiles in the fillets of farmed sea bream and sea bass did not differ (P > 0.05) except in the winter season compared with those of their wild counterparts. However, the content of eicosapentaenoic acid (20:5n‐3), docosahexaenoic acid (22:6n‐3) in the fillets of the farmed and wild sea bass were significantly (P < 0.05) higher than the farmed and wild sea bream. The wild sea bream had significantly (P < 0.05) higher total saturated fatty acid and monounsaturated fatty acid (MUFA) levels, and lower total n‐6 and n‐3 polyunsaturated fatty acid (PUFA) levels in winter than in the summer and spring seasons. Similarly, in the fillets of wild sea bass, total n‐3 PUFA levels were significantly (P < 0.05) lower, and the MUFA levels were higher in winter than in the other seasons. These results indicate that the farmed fish fillets were good sources of n‐3 PUFA in each of the three seasons. However, wild fish were good sources of n‐3 PUFA in the spring and summer.     

鲈鱼干加工过程中热处理及内源酶对风味形成的影响

分别制备内源酶转化作用＋轻度热处理（S1）、内源酶转化作用＋高强度热处理（S2）、轻度热处理（S3）和高强度热处理（S4）的鲈鱼干,采用感官评价、固相微萃取结合气相色谱-质谱联用仪（gas chromatography-mass spectrometry,GC-MS）进行风味分析,运用偏最小二乘回归（partial least squares regression,PLSR）分析成分与感官属性间的相关性。感官分析结果表明,S1、S2、S3和S4风味轮廓存在显著差异。GC-MS检测结果表明正己醛、壬醛、正辛醛、丁子香酚、1-辛烯-3-醇、2,3-辛二酮、石竹烯和2,6-二叔丁基对甲酚等为鲈鱼干样品中主要挥发性成分;S1、S2、S3和S4挥发性成分差异明显,其中S1和S2挥发性成分含量显著高于S3和S4。PLSR相关性分析表明苯甲醛、癸烯醛、正辛醛、苯乙酮、庚醇和2-乙基己醇与鲈鱼干样品感官属性存在相关性。这几种物质含量在S1、S2、S3和S4中显著不同,对比发现S1和S2中己醛、苯乙酮和苯甲醛等物质由脂肪和氨基酸在内源酶作用下反应生成,提高了青草香和甜香;S3和S4中热处理促进了甘油三酯热氧化降解生成正辛醛、2-乙基己醇、癸烯醛、反-2-辛烯醛等物质,提高了橘香和脂香。此外,组织蛋白酶B在S1和S2中的酶活性远高于S3和S4。研究揭示了鲈鱼干制备过程中内源酶和不同强度热处理对风味的影响,为鲈鱼干制备工艺优化及深入了解水产食品风味形成机制提供了理论参考。     

Chemical, Physical and Sensory Characteristics of Peanut Milk as Affected by Processing Conditions

The influence of processing conditions on chemical, physical and sensory characteristics of aqueous extracts of peanuts (peanut milk) prepared for lactic bacterial fermentation was investigated. Soaking peanuts in 1.0% NaHCO₃ before extraction resulted in a lighter colored milk, and homogenization enhanced lightness. Cooking peanuts before grinding reduced total solids and protein contents of milk. Hexanal concentration was greatly reduced by cooking peanuts for 10 min. The most satisfactory conditions for preparing peanut milk consisted of soaking peanuts in 0.5% NaHCO₃, cooking for 10 min and homogenizing the extract at 4000 psi.     

Effect of salt and MTGase on the production of high quality gels from farmed sea bass

In order to obtain low salt fish products, the effects of the addition of 0.5% (w/w based on whole product, wp) MTGase and different levels (0.25%, 0.50%, 1.00% and 2.50%, w/w wp) of sodium chloride salt to heat-induced gels from farmed sea bass (Dicentrarchus labrax) trimmings were tested and compared with gels without salt and/or without MTGase.MTGase and salt addition, both, had a favourable effect on texture. However, only salt incorporation augmented water holding capacity (WHC).A synergistic effect was detected between MTGase and salt for several important textural properties, particularly, gel strength, which reached 64.3 ± 8.1 N mm, a value comparable to those of best quality surimi. Moreover, MTGase required addition of salt to the product for its effect to be felt, however only a minimal amount (0.25%, w/w wp) sufficed. In fact, the addition of MTGase enabled reduction in salt content to 1.0% (w/w wp), without significant loss of textural and overall quality.     

发芽对小麦粉营养品质及面团特性影响的研究进展

发芽能够提高小麦的营养价值,使γ-氨基丁酸、多酚类物质、以及阿拉伯木聚糖等生理活性成分含量增加,同时也会对小麦粉的加工特性产生影响.本文综述了发芽对小麦粉主要营养成分、面团流变特性、发酵特性以及面制品品质的影响.比较了发芽前后蛋白质、淀粉及膳食纤维、多酚、维生素和矿物质等营养组分的变化,分析了发芽使面团流变特性变差、发...     

Sensory, Microbiological and Chemical Quality of Mini-Peeled Carrots as Affected by Edible Coating Treatment

The effect of three application rates of an edible cellulose-based coating on sensory, microbiological and chemical quality of mini-peeled carrots was studied during storage at 2°C. Carrots treated with edible coating had reduced levels of white surface discoloration, and higher sensory scores for orange color intensity, fresh carrot aroma, fresh carrot flavor, and overall acceptability than non-coated carrots. Edible coating treatment did not affect levels of total aerobic microorganisms, yeast, mold or lactobacilli. Oxygen, carbon dioxide and ethanol levels in packages, and sugar and soluble phenolic content of mini-peeled carrots were not affected by coating treatment. An edible coating application rate of 0.23–0.49 L/min protected against surface discoloration and retained quality during storage at 2°C.     

融安金桔不同生长期果实品质特性比较

以广西融安特产油皮金桔和脆皮金桔果实为对象,研究金桔果实在不同生长时期的理化性状及其活性成分的动态变化规律。结果表明,从9月到12月,金桔的单果重、出汁率、pH值、可溶性固形物和糖酸比等理化指标均上升,果籽率和可滴定酸含量下降;主要糖含量分别从39.04和32.38 mg/g上升至111.23和137.11 mg/g;主要有机酸为抗坏血酸、苹果酸和草酸,其中抗坏血酸含量先上升后下降,10月份为金桔抗坏血酸含量高峰期(分别为48.23和23.20mg/g),而苹果酸和草酸含量一直下降;与9月份相比,12月份的油皮和滑皮金桔总黄酮含量分别从3.45和2.14 mg RE/g下降至1.21和0.76 mg RE/g,其中特征性黄酮金柑苷含量显著上升;总酚含量和抗氧化活性均显著下降。两个品种之间,成熟单果重、可滴定酸、总黄酮和橙皮苷含量无显著差异,油皮金桔的果籽率、抗坏血酸、金桔苷和总酚含量以及总抗氧化能力均显著高于脆皮金桔,而其出汁率、p H值、可溶性固形物、糖酸比、果糖、葡萄糖、蔗糖、苹果酸、草酸和芦丁含量均显著低于后者。本研究明确了两种金桔不同生长期的果实品质特性,为金桔果实的开发和利用提供了理论依据。