Rheological properties and structural changes in steamed and boiled abalone meat

ABSTRACT: Changes in tissue structures, rheological properties, and water content of abalone meat were studied in relation to boiling and steaming time. The adductor muscle of abalone Haliotis discus, which was removed directly from the shell, was boiled or steamed for 1 h, 2 h, and 3 h. When observed under a light microscope and by scanning electron microscopy, structural changes in the myofibrils were greatest in the boiled abalone meat compared with the steamed meat. When heating time was increased from 1 h to 3 h, the instantaneous modulus E ₀ of boiled abalone meat decreased gradually with increased heating time, whereas the E ₀ of steamed abalone meat was reduced when heated for 2 h. When heated for 1 h, the relaxation time of steamed abalone meat was much longer than that of boiled meat. There were no significant changes in the relaxation time of abalone meat among the different boiling times, but the relaxation time of steamed abalone meat was reduced gradually with increasing heating times. The study's results confirmed that the difference in rheological properties between the boiled and steamed meats was due mainly to the denaturation level of myofibrils when heated for 1 h, as well as due to the changes in water and solid content and the manner in which the inner water was exchanged after heating time was increased from 1 h to 3 h.     

The Rheological Properties and Structural Changes of Abalone Meat with Different Drying Methods

Changes in tissue structure and rheological properties of abalone meat with cold air drying and natural drying were studied. Natural drying took 168 h, while cold air drying took 120 h, which was 71% of natural drying. Nutrition loss of cold air drying abalone meat was less than that of natural drying samples. Muscle fibers in heated samples reassembled, and voids in muscular tissue extended. With drying time increasing, muscle fibers in abalone meat shrank, and the size of aperture among myofibrils decreased. While drying finished, myofibrils in cold air drying abalone meat had a homogeneous network structure, which was fit for water restoration. Rheological properties (elasticity modulus E, viscosity modulus η, and rupture strength) in heated samples were smaller than those in raw samples, while the relaxation time τ was greater. During the drying process, E, η, and rupture strength tended to increase, and the relaxation time τ had no significant regularity changes. Compared with natural drying, the cold air drying had more advantages in actual production as the drying time was shorter, and the drying process and sanitary conditions were easy to control.     

不同加热温度下刺参肌肉组织与胶原纤维结构的变化

为研究鲜活和不同加热温度下刺参体壁组织构造及其胶原纤维结构的变化,采用VanGieson染色法观察组织构造、采用细胞分裂扫描电镜法(cell-maceration/SEM)观察胶原纤维结构,同时利用示差扫描量热仪(DSC)测定刺参肌肉蛋白质的热收缩温度。结果发现,在不同加热温度条件下,刺参体壁组织构造及其胶原纤维结构均发生显著变化。随着加热温度的升高,刺参肌肉组织中纤维逐渐聚集交联,形成多孔网状结构;蛋白质发生热变性、胶原纤维结构收缩,导致纤维排列紧密,纤维间孔隙度呈减小趋势。与刺参整体组织构造的变化相比,胶原纤维结构的变化尤其明显。鲜活刺参体壁肌肉蛋白质的热收缩温度为68.92℃,加热过程中蛋白质的热变性是引起其构造变化的主要原因。     

Quality and Sensory Characteristics of Volutharpa ampullacea perryi (False Abalone) Meat during the Boiling Cooking

Volutharpa ampullacea perryi (false abalone) meats were water cooked at 75–100°C for 5–60 min, and the changes in weight loss, pH, color, in vitro digestibility, texture, microstructure, and sensory characteristics were investigated. The weight rapidly decreased in the initial cooking and decreased slightly with the extension of both heating temperature and time. Obvious differences in color were found compared between the raw and cooked meats with respect to ΔL*, Δa*, and Δb* values. Digestibility was significantly improved with the thermal treatments. Textual properties, such as hardness, springiness, chewiness, and resilience, improved with the increasing of thermal intensity, but reduced with overcooking, and the variations were further confirmed by the scanning electron microscopy analysis. The samples boiled at 90–95°C for 10–15 min and 100°C for 5–10 min acquired better acceptance in the sensory evaluation. The complex relationship among cooking conditions and physicochemical and histological characteristics of meat as well as the consumer perceptions was illuminated by the principal components regression analysis. These results could provide useful information for quality control in V. a. perryi meat cooking.     

Chemical, physical and sensory changes of small abalone meat during cooking

ABSTRACT:   Small abalone meats were heated at 80°C and 98°C for 0–120 min and the differences in chemical, physical and sensory changes of the cooked meats were investigated. The decrease in moisture and weight and the increase in browning and Hunter's b -value were relatively higher for cooking at 98°C than at 80°C. After cooking for 20–120 min, the total amount of adenosine triphosphate and its related compounds on a dry weight basis decreased by 17–27% at 80°C and by 30–39% at 98°C; the total amount of free amino acids on a dry weight basis changed insignificantly at 80°C but decreased by 22–35% after cooking at 98°C. The meats cooked at 80°C were higher in cutting force whereas the levels in the samples cooked at 98°C did not decrease until samples had been cooked for 60 min. The hydroxyproline content showed little change during cooking except for in samples cooked at 98°C for 120 min, in which the content was found to be low. The extended cooking at 80°C improved the acceptability of small abalone meat, whereas only the acceptability score of aroma increased significantly for cooking at 98°C.     

Comparison of taste components in cooked meats of small abalone fed different diets

ABSTRACT: Differences in taste preference and the levels of extractive components and glycogen were compared between cooked meats of small abalone Haliotis diversicolor fed either gracilar (G-small abalone) or an artificial diet (A-small abalone). Using sensory tests, taste preference of cooked meats was significantly higher for A-small abalone than for G-small abalone. Results of clustering analysis and principal component analysis of chemical data also revealed that the two cooked meats differed from each other in terms of their measured constituent compositions irrespective of sampling periods. Compared with G-small abalone, A-small abalone meats were lower in taurine and arginine, but higher in glycine (Gly), glutamic acid (Glu), alanine, serine, proline, adenosine monophosphate (AMP), and glycogen. It is concluded that the discrepancy in the levels of taste-active components of abalone, such as Gly, Glu, and AMP, is likely to be responsible for the differences in taste preference between G- and A-small abalone cooked meats.     

熟制与贮藏对凡纳滨对虾挥发性成分的影响

为研究熟制与贮藏对凡纳滨对虾挥发性成分的影响,采用电子鼻及固相微萃取—气相色谱—质谱联用技术分析虾肉的挥发性成分,并采用相对气味活度值和感官评定法评价虾肉风味的变化。结果显示,熟制与贮藏对虾肉中的挥发性成分影响显著。凡纳滨对虾生虾、熟虾、熟虾冷却、熟虾冷却过夜及二次熟制虾分别被检出50、68、63、49和41种挥发性成分。二次熟制后,虾肉中的挥发性成分有所减少,感官上虾的特征鲜香气也略微减弱;一次熟制对虾肉的风味影响不大。生虾肉中检测出的挥发性成分如壬醛和癸醛等对风味有显著性影响;熟虾肉中检测出壬醛、癸醛和十四醛等;二次熟制的虾肉中检测出对风味影响较大的挥发性成分主要是十八醛、二丁基羟基甲苯等。熟虾经过夜(4°C)放置后,其中检测出的挥发性成分种类和总量均减少,但总量差异不显著。研究表明,熟制可显著增加挥发性风味成分种类和总量,二次熟制与一次熟制相比,凡纳滨对虾的关键风味物质种类和含量显著降低;熟虾冷却后4°C贮藏12 h风味差异不显著。     

Nutrient Composition of Raw and Cooked Meat of Male Southern King Crab (Lithodes santolla Molina, 1782)

This study provides information about nutrient composition of adult males of southern king crab (Lithodes santolla). Proximate composition of raw and cooked meat (g/100 g meat) averaged: moisture?=?80.9 and 78.6, protein?=?14.6 and 16.3, fat?=?0.70 and 0.76, and ash?=?2.03 and 2.10, respectively. Arginine, glutamic acid, leucine, and aspartic acid (20.4, 9.4, 8.0, and 7.9 g aa/100 g protein, respectively) were the major amino acids. The predominant fatty acid was 18:1n-9c (21.8 and 22.1%), followed by 20:5n-3 (17.1 and 21.8%), 16:0 (15.8 and 15.3%), and 22:6n-3 (11.0 and 13.5%). Cooked meat contained more cholesterol (51.0 mg/100 g meat) and phospholipids (60.1 mg/100 g meat) than raw meat (37.3 and 13.9 mg/100 g meat, respectively), with phosphatidylcholine representing over 80% of the total phospholipid content. The main tocopherol was α-tocopherol (raw meat?=?1.30 mg/100 g meat, cooked meat?=?1.14 mg/100 g meat). Major mineral contents of raw and cooked meat (mg/100 g meat) were: Na?=?509 and 594, K?=?179 and 203, Ca?=?114 and 197, P?=?126 and 143, Mg?=?34 and 41, Fe?=?1.26 and 1.86, and Zn?=?1.88 and 2.64, respectively. Thus, the nutritional quality of the cooked meat of the southern king crab makes it especially adequate for cholesterol-restricted, balanced low-fat meat diets.     

不同加热条件下海螺足部质构的变化

研究了鲜活和不同加热条件下(5、20、60 min)海螺足部的组织构造及其流变学特性的变化,并进行了质地剖面分析(TPA)和感官评定试验,为海螺深加工制品的开发及加工工艺的优化提供理论基础和科学依据.组织构造变化采用Van Gieson染色法观察,流变学特性参数和TPA通过质构仪测定,同时比较了TPA和感官评定间的相关性.结果表明:不同的加热处理对海螺足部的组织结构和流变学特征参数有明显影响.流变学特性与组织结构的变化之间具有一定的关联性.流变学特征参数表明鲜活海螺足部的肌肉具有硬度大、弹力和粘着性小的质地特点,而加热样品则是硬度小、弹力和粘着性大.海螺足部的热加工应以加热20 min为宜,时间太短或过长都无法给人以最佳的口感.TPA和感官评定在硬度(R=0.969 2)、弹性(R=0.927 2)和咀嚼性(R=0.854 2)方面呈显著相关性,在粘着性(R:0.794 5)方面也有较好的相关性.