摘要
以感官特性、细菌总数、理化参数(基本营养组成、质构、色差、pH、TBA、TMA-N、TVB-N、K值、Ca2+-ATPase活性、SDS-PAGE)为指标,考察了真空包装的青石斑鱼片在0℃贮藏过程中的品质变化情况。结果表明,青石斑鱼片是一类高蛋白低脂肪的食品;气味和口感与贮藏时间均有显著正相关性(r=0.94和0.98),且口感评分比气味评分增加得快,但未达到阈值3分;细菌总数随贮藏时间呈显著递增(r=0.97),在第12天仍没有超过4LogCFU/g,保持着一级鲜度,在第15天达到4.34LogCFU/g,处于二级鲜度;硬度(r=-0.89)、胶黏性(r=-0.73)、咀嚼性(r=-0.87)与时间显著负相关;随着肌肉的老化,L*值和Cab值随贮藏时间显著下降(r=-0.91和-0.95),而b*值与贮藏时间呈显著正相关性(r=0.99),肌肉逐渐呈灰色调、变暗、彩度明显下降;pH、TBA值在贮藏期变化不大,与贮藏时间弱相关,因此,不适合用于作为反映青石斑鱼片品质变化的指标;在贮藏期末,TVB-N与TMA-N与贮藏时间呈显著线性相关(r=0.86和0.99),其含量分别达到12.94mgN/100g和0.75mgN/100g,均低于腐败水平阈值;SDS-PAGE显示肌动蛋白球重链和肌动蛋白呈连续性的水解;Ca2+-ATPase活性下降速度较快,且与贮藏时间显著相关(r=-0.96);K值随贮藏时间延长而显著增加(r=0.98),贮藏末期达到54.91%,呈中等新鲜水平。因此,0℃真空包装下,其细菌总数增长缓慢,保持较好的感官品质及延缓TVB-N等理化指标的变化及和蛋白质的水解。感官指标、细菌总数、质构(硬度、粘附性和咀嚼性)、色度(L*、b*和Cab值)、TVB-N、TMA-N、Ca2+-ATPase活性和K值在贮藏期内变化显著,且与贮藏时间显著相关,可考虑作为反映青石斑鱼片腐败的合适指标,但货架期的评定,需综合上述参数而定。
Sensory attributes,total number of bacteria,physical and chemical parameters （ proximate composition,texture analysis,color measurements,pH,TBA,TMA-N,TVB-N,K-value,Ca2 ＋-ATPase activity, SDS-PAGE） changes of yellow grouper （ Epinephelus awoara） stored under vacuum packaging at 0 ℃ were investigated.The results showed that yellow grouper was a fish with low level of fat but high level of protein.During the storage,sensory attributes（ odor and taste） exhibited significant variations and correlations in storage time（ r=0.94 and 0.98,respectively） .Taste score increased faster than the odor score,however,neither of them reached the reject limit of 3 scores.There were significant linear increases in total viable counts（ TVC） in the storage（ r=0.97） .TVC on the 12th day was lower than 4 Log CFU/g,indicating the fillets kept at first grade of freshness,and was 4.34 Log CFU/g at the end of 15 days storage,kept at second grade of freshness.With regards to the texture profile,hardness（ r =-0.89） ,gumminess（ r =-0.73） ,chewiness（ r =-0.87） showed a significant and negative correlation with storage time.L and the chroma values decreased,and b values increased,reflecting the colour changes experienced by the fillets over time.No significant differences were found in pH and TBA concentrations during the storage and they displayed a weak correlation with time, so they may not be the suitable indicators for reflecting the quality changes of yellow grouper fillets during the storage.The amount of TVB-N and TMA-N significantly increased with time,at the final of storage,TVB-N and TMA-N reached 12.94 mg N/100 g and 0.75 mg N/100 g respectively,and both of them were lower than limit.The proteolytic degradation of muscle protein was observed by SDS-PAGE,the results showed that MHC and Actin were hydrolyzed continuously throughout storage.Ca2 ＋-ATPase activity declined fast from the initial value of 0.25 μg Pi/（ min·mg） to the final value of 0.07 μg Pi/（ min·mg） .K value increased fast with time （ r =0.98） and reached 54.91% at the end of storage,keeping the middle level of freshness.The results suggested that total viable counts（ TVC） increased slowly under vacuum packaging at 0 ℃,and it kept good sensory characters,inhibited the changes of the paraments（ TVB-N value,etc.） and hydrolysis of protein.The sensory attributes,microbiological counts,texture（ hardness,cohesiveness and chewiness） ,colour（ L ,b ,and Cab） ,TVB-N,TMA-N,Ca2 ＋-APTase activity and K value exhibited strong correlations with storage time and were sensitive.Therefore,they may be considered as good indicators for evaluating yellow grouper spoilage during the storage under vacuum packaging at 0 ℃ for 15 days,but the consideration of shelf-life should be combined with all those indicators.
出处
《水产学报》
CAS
CSCD
北大核心
2010年第8期1285-1293,共9页
Journal of Fisheries of China
基金
国家"八六三"高技术研究发展计划(2007AA091806)
关键词
青石斑鱼
鱼片
冷藏
真空包装
品质变化
yellow grouper（ Epinephelus awoara）
fillets
storage
vacuum packaging
quality changes
