北京油鸡肉4 ℃贮藏过程中的品质及风味变化

北京油鸡是我国珍贵地方品种,为了解其鸡胸肉在4 ℃真空包装冷藏过程中的风味及品质变化规律,测定 其在贮藏过程中的挥发性盐基氮含量、菌落总数、感官评分、硫代巴比妥酸反应物值、总脂肪酸、肌苷酸及其他三 磷酸腺苷代谢物含量的变化,并利用电子鼻技术测定其在贮藏过程中的挥发性风味整体变化,与感官评分建立回归 方程。结果表明：综合各项理化、微生物及感官指标,真空包装北京油鸡鸡胸肉在4 ℃冷藏过程中的贮藏期为6 d; 脂肪氧化、不饱和脂肪酸和鲜味核苷酸的含量影响其贮藏过程中风味的劣变,并且利用电子鼻检测技术可以有效预 测其品质变化。     

电子鼻检测不同贮藏温度下猪肉新鲜度变化

采用电子鼻研究冷却猪肉在不同贮藏温度(－ 18、0、4、10、20℃)条件下新鲜度变化规律。选用优化后的进样体积(1500μL)进样,对实验数据进行主成分分析(PCA)、货架期模拟及拟合感官评分的偏最小二乘回归分析(PLS)。结果表明：5 种温度条件下贮藏不同时间肉样挥发性气味差异显著,贮藏温度越高肉样新鲜度发生显著下降时刻越早,预测时间分别为336、180、72、48、18h。对4、20℃条件下电子鼻检测数据与感官评分拟合后进行PLS 分析,相关系数分别高达0.9982和0.9998,表明电子鼻能代替感官评定。逐一选取每一根传感器进行PLS 拟合后发现,TA/2、T40/1、T40/2、P30/2、P40/1、P10/2、P10/1 是对不同新鲜度肉样挥发性气味具有良好特异性响应的传感器。     

基于电子鼻技术判定冷鲜罗非鱼片品质劣变进程

应用电子鼻采集贮藏过程冷鲜罗非鱼片顶空挥发性气味,同步进行感官评价、微生物和理化分析。结果表明：传感器响应信号随着鱼片气味浓度增大而增大,且对不同新鲜度气味有良好响应。线性判别(LDA)比主成分分析(PCA)更能有效区分鱼片的不同新鲜度、微生物及挥发性盐基氮含量,表明电子鼻可快速检测鱼片的品质劣变进程。通过负荷加载分析和相关分析表明,W2W、W1W、W1S、W2S对区分冷鲜罗非鱼片不同新鲜度的贡献较大,并与感官可接受性、菌落总数和挥发性盐基氮的相关性良好,可作为今后研制鱼用电子鼻系统精选传感器的理论参考。     

Post-slaughter changes in ATP metabolites,reducing and phosphorylated sugars in chicken meat

The formation of ATP breakdown products in chicken M. pectoralis major post-slaughter is reported. The concentrations of metabolites were followed in chicken breast throughout the carcass processing post-slaughter and during chilled storage. The concentration of glucose remains similar throughout the period whilst that of glucose-6-phosphate decreases linearly. Glucose and glucose-6-phosphate concentrations were inversely related to the pHu of the breast meat throughout chilled storage. Rapid post-mortem glycolysis and high pHu values suggest the occurrence of stress at and pre-slaughter. Whilst ATP, ADP and AMP were rapidly broken down, the concentration of IMP rose rapidly and remained high. Concentrations of inosine, ribose and hypoxanthine increased gradually post-slaughter but an initial increase in ribose phosphate was not sustained. Most of the potential ribose present in chicken meat, believed to be important for flavor formation, remains bound in the form of inosine and IMP. There is evidence that additional breakdown pathways for ribose and ribose-5-phosphate may deplete the concentrations of these precursors.     

Nondestructive Prediction of Tilapia Fillet Freshness During Storage at Different Temperatures by Integrating an Electronic Nose and Tongue with Radial Basis Function Neural Networks

This study developed principal component analysis and radial basis function neural networks (PCA-RBFNNs) for predicting freshness in tilapia fillets stored at different temperatures by integrating an electronic nose and electronic tongue. Total volatile basic nitrogen (TVB-N), total aerobic counts (TAC), and K value increased at 0, 4, 7, and 10 °C, while sensory scores decreased significantly. The electronic nose and tongue acquired the volatiles and dissolved chemical compounds in the stored samples. Gas chromatography-mass spectrometry (GC-MS) verified the changes in gas species and contents in fillets stored for different periods of time at different temperatures. PCA-RBFNNs based on data fusion were developed and presented good performance for prediction of TVB-N, TAC, K value, and sensory score in tilapia fillets. The established PCA-RBFNNs based on feature variables of the electronic nose and tongue is a promising method to predict changes in the freshness of fillets stored from 0 to 10 °C in the cold chain.     

冬凌草甲素/壳聚糖复合膜对冰鲜鸡胸肉的保鲜效果

制备了冬凌草甲素/壳聚糖(OR-CS)复合膜,考察了其对冰鲜鸡胸肉的保鲜效果。将复合膜覆盖于鸡胸肉表面,复合膜外再包被一层保鲜膜,4℃贮藏,检测贮藏过程中鸡胸肉的pH、色度、保水性、挥发性盐基氮(TVB-N值)、菌落总数、感官质量的变化。试验结果表明,通过OR-CS复合膜处理的冰鲜鸡胸肉能显著延缓贮藏期间的pH值、菌落总数、TVB-N含量和汁液损失率的上升。OR-CS复合膜包装组使冰鲜鸡胸肉的货架期由4 d(对照组)延长至9 d;此外,通过色差测定和感官评定,OR-CS包装组可以更好地保持冰鲜鸡胸肉的品质和色泽,在贮藏期间能有效延缓肉表面亮度的减弱,显著改善了肉的颜色、气味、黏度和弹性。     

Removal of Rancid-Acid Odor of Expeller-Pressed Virgin Coconut Oil by Gamma Irradiation: Evaluation by Sensory and Electronic Nose Technology

Expeller-pressed virgin coconut oil, known to have disagreeable rancid-acid odor due to the presence of octanoic acid, was subjected to gamma (γ) irradiation for removal of the same. Sensory evaluation in tandem with electronic nose (Heracles and ENOVISION) analyses established that the oil irradiated at 4.2 kGy had no rancid-acid odor (absence of octanoic acid) at the end of 28 days of storage at 23 ± 2 °C. Therefore, 4.2 kGy was established as the “appropriate irradiation dose” for removal of rancid-acid odor of virgin coconut oil. A “deodorization index” with respect to rancid-acid odor was also developed using electronic nose for confirmation of this “appropriate dose” and thereby provided possible means of preventing detrimental effects of high dose of γ-irradiation in oils. GC–MS analysis of hydrocarbons extracted from oil irradiated at 4.2 kGy by supercritical carbon dioxide extraction revealed radiolysis of octanoic acid resulting in elimination of rancid-acid odor. Further, γ-irradiation at 4.2 kGy did not affect the antioxidant potency of coconut oil rendering it a safe and healthy alternative to conventional deodorization techniques for oils. Development of methodology for assessment of rancid-acid odor of coconut oil using electronic nose has been reported for the first time in this work.     

冰鲜鸡肉品质及其货架期的研究进展与展望

相对于热鲜鸡肉和冷冻鸡肉,冰鲜鸡肉在口感、风味、新鲜度以及营养等方面具有很大优势,具有很好的市场发展前景。但冰鲜鸡肉的品质在生产加工和流通过程中容易发生腐败变质。随着消费者食品安全意识的日益提高,冰鲜鸡肉的品质及其货架期受到越来越多的关注。本文总结了冰鲜鸡肉的品质表征指标;阐述了微生物因素、物理因素以及化学因素对冰鲜鸡肉品质的影响;比较了化学、超高压和辐照等6种保鲜技术对冰鲜鸡肉保鲜的效果及特点;结合食品货架期预测模型,梳理了已有预测冰鲜鸡肉货架期的相关研究;最后分析了冰鲜鸡肉品质及其货架期的研究现状,并对其未来的研究趋势进行了展望,指出随着研究技术、手段和保鲜技术的不断发展,冰鲜鸡肉货架期的研究也将不断向实用和智能化的方向发展。     

不同冷链贮运条件下冷鲜鸭肉品质变化

为研究不同冷链贮运条件对冷鲜鸭肉品质变化的影响,通过模拟产品冷链贮运过程中的环境,以感官评定、菌落总数和挥发性盐基氮(total volatile base-nitrogen,TVB-N)值为评定标准,研究了不同包装方式、运输时长、运输温度及运输途中的振动强度对冷鲜鸭肉品质的影响。结果显示,气调包装(53%O2+47%CO2)在贮运末期的TVB-N值仅为12.78 mg/100 g,仍处于二级鲜度,比真空包装和气调包装更能维持冷鲜鸭肉原有品质;运输1 h组在整个实验过程中感官评分值下降较慢,在实验末期其感官评分仍在8分以上;运输温度对产品贮运后期的菌落总数有显著影响(p<0.05),低温(4℃)运输能够有效地保持产品品质,比高温运输延长1~2 d贮藏期;振动强度对产品菌落总数有显著影响(p<0.05),3 Hz振幅对鸭肉品质影响较小,在贮藏末期菌落总数为5.04 lg CFU/g,TVB-N值为11.01 mg/100 g。本研究为冷鲜鸭肉冷链运输条件的选择提供了参考。     

Extractive components of boiled–dried scallop adductor muscle and effect on the taste of soup after mixing with chicken leg meat

The extractive components of raw and boiled–dried scallop adductor muscle were examined. On a dry weight basis the levels of total free amino acids, total adenosine triphosphate (ATP) and related compounds, and betaines in the boiled–dried sample were lower than those in the raw muscle, which may have been due to the outflow of these compounds during boiling. Soup prepared from the boiled–dried scallop and chicken leg meat was assessed by sensory evaluation. This soup cooked with the scallop and chicken was stronger in sweetness, umami and body and rated higher in overall preference than the soup containing these ingredients after cooking separately. The inosine monophosphate (IMP) level in the former soup was 4.4 times higher than that in the latter. The adenosine monophosphate (AMP) deaminase (EC 3.5.4.6) activity in the crude extract from the chicken meat was 9.16 units l^?1, whereas no activity could be detected in the crude extract from the boiled–dried scallop. It is concluded that AMP, which was mainly derived from the boiled–dried scallop, was converted to IMP by AMP deaminase from the chicken meat during the preparation of the soup, resulting in an improvement in the taste. Copyright © 2004 Society of Chemical Industry     

不同冷冻温度对鲅鱼理化指标及新鲜度的影响

以pH、挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量、硫代巴比妥酸值(thiobarbituric acid,TBA)和肌原纤维蛋白含量等理化指标,结合感官评价,分析了-50、-30和-18℃ 3种冻结温度下鲅鱼新鲜度差异。采用电子鼻技术,获取了不同冻结温度处理后鲅鱼的气味信息,利用主成分分析(principal component analysis,PCA)法处理了电子鼻气味信息数据,建立一种快速区分鲅鱼新鲜度的方法。结果表明,不同冻结温度处理后鲅鱼的新鲜度存在显著差异(p<0.05),-50℃冻结组综合新鲜度显著优于另两组,其中TVB-N和TBA值显著低于另外两组(p<0.05),而pH和肌原纤维蛋白含量显著高于另外两组(p<0.05),同时,-50℃冻结组感官评分也优于其他两组。电子鼻结果显示,电子鼻对各个温度下冻结的鲅鱼肉响应灵敏,区分结果同理化和感官评价结果相一致,能有效区分出不同冻结温度下鲅鱼肉气味差异,表明电子鼻技术可以作为一种区分冻结鲅鱼新鲜度的快速检测手段。     

不同温度养殖的雌体三疣梭子蟹性腺和蟹肉风味品质比较

研究常温养殖与加温养殖对雌体三疣梭子蟹性腺和蟹肉的风味影响,测定2 组蟹性腺和肉中的主要滋味物质,并进行电子舌、电子鼻和感官评价的分析。结果表明：电子舌和电子鼻均可对不同水温养殖三疣梭子蟹的性腺以及蟹肉进行有效区分;加温养殖会提高鸟苷酸（guanosine monophosphate,GMP）和腺苷酸（adenosinemonophosphate,AMP）对性腺滋味的贡献,使总游离氨基酸含量有所减少,呈味氨基酸和必需氨基酸百分比有所上升。对蟹肉而言,加温组GMP、肌苷酸、AMP相比常温组增加了0.40、0.66 倍和3.46 倍,呈味氨基酸、必需氨基酸和总游离氨基酸的含量显著升高（P＜0.05）,味精当量值与常温组相比增加0.59 倍。感官评价表明,加温养殖组性腺的肥满度和气味评分有一定的提高,蟹肉的整体感官品质明显高于常温组。     

Discrimination of Chicken Seasonings and Beef Seasonings Using Electronic Nose and Sensory Evaluation

This study examines the feasibility of electronic nose as a method to discriminate chicken and beef seasonings and to predict sensory attributes. Sensory evaluation showed that 8 chicken seasonings and 4 beef seasonings could be well discriminated and classified based on 8 sensory attributes. The sensory attributes including chicken/beef, gamey, garlic, spicy, onion, soy sauce, retention, and overall aroma intensity were generated by a trained evaluation panel. Principal component analysis (PCA), discriminant factor analysis (DFA), and cluster analysis (CA) combined with electronic nose were used to discriminate seasoning samples based on the difference of the sensor response signals of chicken and beef seasonings. The correlation between sensory attributes and electronic nose sensors signal was established using partial least squares regression (PLSR) method. The results showed that the seasoning samples were all correctly classified by the electronic nose combined with PCA, DFA, and CA. The electronic nose gave good prediction results for all the sensory attributes with correlation coefficient (r) higher than 0.8. The work indicated that electronic nose is an effective method for discriminating different seasonings and predicting sensory attributes.     

草鱼冷藏期间ATP关联物含量及新鲜度变化

目的：分析草鱼冷藏期间腺嘌呤核苷三磷酸关联物含量的变化,研究草鱼肉中各核苷酸的含量与其新鲜度的相关性。方法：利用强碱将不稳定的核苷酸关联物反应生成其钠盐形式,通过高效液相色谱法检测核苷酸含量,并通过总挥发性盐基氮含量和感官性状的变化进行鲜度评价。结果：生成钠盐形式的腺嘌呤核苷三磷酸关联物能通过色谱很好地分离。新鲜鱼肉中含有高含量的肌苷酸,达504.34 mg/kg。冷藏2 d内草鱼腺嘌呤核苷三磷酸、肌苷酸含量快速下降,次黄嘌呤含量则迅速增加。冷藏后腺嘌呤核苷三磷酸未检出,肌苷酸下降幅度达92.77%,次黄嘌呤增加幅度达89.82%。冷藏期间挥发性盐基氮含量一直上升,冷藏6 d后超出最大值限度,冷藏草鱼的贮藏期限为6 d。     

鸡肉冷藏成熟过程中新鲜度和嫩度与肽含量关系

为研究冷藏成熟过程中鸡肉新鲜度和嫩度与肽含量的关系,以刚屠宰的鸡胸肉为研究对象,探究宰后鸡肉常规冷却与快速冷却过程中的肽含量与其感官评分、新鲜度和嫩度的相关性。结果表明：鸡肉中肽含量随冷藏时间的延长先下降后上升,在冷藏0.5 d时达到最低值,冷藏3 d后逐渐上升,且常规冷却组鸡肉肽含量极显著高于快速冷却组（P＜0.01）;鸡肉中总游离氨基酸含量与肽含量变化趋势相反;冷藏0.5 d后,随着冷藏时间的延长,鸡肉中肽含量与pH值、菌落总数及挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量同步上升,而剪切力及感官评分逐渐降低。快速冷却能够延长成熟的时间,有利于鸡肉贮藏保鲜。冷藏期间,2 组鸡肉中的肽含量与菌落总数、pH值和TVB-N含量呈显著或极显著正相关（P＜0.05、P＜0.01）,肽含量可用于评价鸡肉的新鲜度。     

Determination of the Freshness of Beef Strip Loins (M. longissimus lumborum) Using Electronic Nose

A beef strip loins (Musculus longissimus lumborum) freshness determination method utilizing electronic nose (e-nose) was investigated in this paper. Fresh beef strip loins samples were stored at 4°C continuously for 10 days. Total viable count (TVC) index, total volatile basic nitrogen (TVB-N) index, and e-nose responses to beef strip loins samples were measured every day. TVC and TVB-N index rose with the increase of storage time. Principal component analysis (PCA) only partially discriminated beef samples under different storage days. Stochastic resonance (SR) signal-to-noise ratio (SNR) spectrum discriminated all beef samples successfully. Beef strip loins freshness discrimination model was developed using SR SNR maximums (SNRmax) linear fitting regression. The proposed method forecasted beef freshness with high accuracy. It is holds promise in meat freshness determination applications.     

Ridgetail White Prawns,Exopalaemon carinicauda,Storage Time Rapid Determination Using Electronic Nose

Ridgetail white prawns, Exopalaemon carinicauda, storage time rapid determination method based on electronic nose was investigated in this paper. Prawns were stored at 4 °C for 9 days. Each day, electronic nose responses, and total volatile basic nitrogen index were measured during the storage period. Total volatile basic nitrogen index provided a freshness standard according to China standard protocols. Signal-to-noise ratio spectrum calculated by stochastic resonance discriminates prawn samples under different storage days successfully. Prawns' storage time determination model was developed based on signal-to-noise ratio eigenvalues. Validating experiments demonstrated that this model predicted prawn storage time with an accuracy of 90 %. Prawn freshness critical value ?82.77066 was also obtained by referring to total volatile basic nitrogen index and the developed model. This method is promising in seafood freshness evaluation.     

基于电子鼻技术的鲈鱼新鲜度评价

采用电子鼻获取不同保藏时间鲈鱼(Lateolabrax japonicus)鱼鳃和鱼肉的气味信息,通过对数据进行主成分分析(PCA)、线性判别分析(LDA)和负荷加载分析,并结合感官评价、挥发性盐基氮(TVB-N)和菌落总数进行分析,建立一种基于电子鼻技术判别鲈鱼新鲜度的方法。结果表明,随着保藏时间的延长,电子鼻传感器的响应强度逐渐增大,鲈鱼鱼鳃和鱼肉的气味随之发生变化,且鱼鳃的气味响应强度大于鱼肉,其中2号传感器对第1主成分的贡献率最大;电子鼻分析结果与感官、TVB-N值和菌落总数结果基本一致。因此电子鼻可以用来区分不同新鲜度的鲈鱼,鱼鳃的区分效果优于鱼肉。     

Chinese Quince (Cydonia oblonga Miller) Freshness Rapid Determination Method Using Surface Acoustic Wave Resonator Combined with Electronic Nose

In this article, Chinese quince (Cydonia oblonga Miller) freshness determination method was investigated using surface acoustic wave resonator, electronic nose, and surface acoustic wave resonator combined with electronic nose. Human sensory evaluation and weight loss index were examined as freshness reference. Results indicated that quince freshness decreased during storage procedure. Surface acoustic wave resonator output frequency and electronic nose measurement data stochastic resonance signal-to-noise ratio Eigen values characterized quince quality under different storage time. Freshness predictive models were developed using surface acoustic wave resonator frequency, electronic nose signal-to-noise ratio spectrum Eigen values, and their hybrid model. Validating experiments results demonstrated that the hybrid predictive model presented higher predicting accuracy (R² = 0.987) than other two models. The proposed method is promising in fruit quality rapid analysis.     

基于智能感官与人工感官评价的中国三大干腌火腿风味特性分析

以我国三大干腌火腿金华火腿、宣威火腿和如皋火腿三个不同年份或等级的火腿为研究对象,分别采用人工感官评价和电子鼻、电子舌智能感官技术分别对香气与滋味进行研究。人工感官评价结果显示,肉香味、腌制味和油脂香是三大火腿的特征香气,如皋和金华火腿中2年/优级和3年陈/特级的干腌火腿较于1级/1年陈具有更加浓郁的肉香,而1年陈/1级火腿的酸味更为明显。电子鼻和电子舌数据的主成分分析(Principal component analysis,PCA)结果表明,不同干腌火腿样品均能实现良好区分。1年陈/1级与2年/优级、3年陈/特级干腌火腿气味轮廓相差较远,金华火腿与宣威2、3年陈的火腿香气和滋味轮廓均比较接近。采用软独立建模分类法(Soft independent modeling class analogy,SIMCA)构建了干腌火腿的判别模型,以三个产地最优干腌火腿为标准样品的等级鉴别模型能够实现对其他年份干腌火腿的有效判别。说明不同年份的火腿风味变化呈现一定规律,可利用智能感官技术对火腿进行快速有效的等级鉴别。