【作者】 张路遥；

【导师】 夏文水；

【作者基本信息】 江南大学 ， 食品科学， 2013， 博士

【摘要】 淡水鱼罐头具有安全性好、食用方便、易保藏等优点。但由于淡水鱼肉质细嫩，易造成杀菌后质构软烂、品质严重破坏，使淡水鱼罐头的消费量受到很大限制。本文研究预处理和杀菌工艺对淡水鱼罐头产品品质的影响，构建预处理后鱼肉热物性预测模型，建立基于品质保持的淡水鱼罐头加工的低热强度杀菌技术，开发高品质淡水鱼罐头制品。本研究对革新罐头食品热杀菌技术、提升罐头食品品质、促进我国淡水鱼罐头工业的发展具有重要现实意义，同时对丰富罐头食品热杀菌理论具有一定学术价值。首先研究了不同特性的淡水鱼罐头的杀菌要求。通过分析淡水鱼罐头酸化制品、固液混合制品、固态制品的杀菌过程及不同制品达到商业无菌的杀菌条件的差别，探讨产品特性对杀菌条件及热加工强度的影响。结果表明：通过温和热杀菌工艺制备的淡水鱼罐头酸化制品极大降低了热处理强度；固液混合制品传热特性好，与固态制品相比，大幅缩短杀菌时间，热加工强度大幅降低；固态制品热强度最高，需要进行降低热强度的杀菌技术研究。研究预处理对热杀菌过程中鱼肉的传热特性及罐头制品品质的影响。通过分析不同腌制、油炸工艺参数对鳙鱼肉传质、热物理性质及对罐头产品品质的影响，建立了预处理过程中的传质模型和鱼肉预处理后的热物性预测模型，优化确定最适预处理工艺参数。结果显示：建立的传质动力学参数与预处理参数的关系模型拟合度较高，利用传质模型可准确控制预处理后鱼肉各成分含量；构建的鱼肉热物性模型可准确预测预处理对鱼肉热物理性质的影响（热扩散系数R2=0.97）；在传质模型基础上，结合感官品质评价确定了以体重2.5kg鳙鱼制备的鱼头制品的最适预处理工艺为，10-15g NaCl/g的腌制液浓度腌制108-150min，170-190℃的温度油炸180-250s。应用最适预处理工艺提高了杀菌后制品品质，热物性预测模型可为杀菌工艺的优化提供计算依据。研究恒温杀菌对淡水鱼罐头品质的影响，建立低热加工强度恒温杀菌技术。通过对恒温杀菌工艺进行数值优化，探讨热致死力（F值）与制品尺寸和最优恒温杀菌工艺间的关系，并分析和验证了不同杀菌条件及冷却速率对制品品质的影响。结果显示：最优恒温杀菌工艺的表面品质率（REGS）随F值及尺寸增大而减小，温度时间规律分别随着F值的增大以及尺寸的减小由低温长时向高温短时趋势变化；应用最优恒温杀菌条件制备的制品，与其他杀菌条件的制品相比，REGS最高，质构特性明显改善，肌纤维结构最紧实致密，渗出液、感官特性、风味分析均表明最优恒温杀菌工艺能有效保持淡水鱼罐头产品品质；杀菌后的冷却方式对大尺寸淡水鱼罐头产品品质有较大影响，杀菌后采用冰水淋水式反压冷却工艺可显著提高大尺寸淡水鱼罐头产品品质。本研究基于最优恒温杀菌工艺及冰水快速冷却建立的低热加工强度的恒温杀菌技术，对提高淡水鱼罐头的品质具有重要的应用价值。为了进一步提升淡水鱼罐头产品品质，研究了新型变温杀菌技术。采用指数-台阶联合式新型变温杀菌程序对变温杀菌工艺进行数值优化，分析了F值、制品尺寸、杀菌时间与最优变温杀菌工艺间的关系，并通过质构、风味等品质分析验证了最优变温杀菌工艺对制品品质的影响。结果表明：新型变温杀菌程序与最优恒温杀菌工艺相比，REGS在不同影响因素下都显示出不同程度的提高，提高程度随着制品尺寸、F值和杀菌时间的增加而增大；新型变温杀菌程序可很好的拟合杀菌锅的温度变化(R2=0.978)，在普通杀菌设备中有很好的适用性；应用鳙鱼变温工艺制备的制品质构特性明显改善，肌纤维结构更紧实致密，感官、风味品质更好；本研究建立的新型变温杀菌程序比最优杀菌工艺具有更低的热加工强度，适用于一般杀菌设备，对于实现淡水鱼罐头品质最大化具有意义。本文确定了不同特性的淡水鱼罐头的杀菌要求，明确了不同预处理工艺对鱼肉热物理性质、杀菌效果和产品品质特性的影响，建立了基于品质保持的低热加工强度的恒温杀菌技术和变温杀菌技术，有效改善了淡水鱼罐头制品的品质，对解决淡水鱼杀菌后产品品质保持问题具有重要现实意义。更多还原

【Abstract】 Canned freshwater fishes have good virtues in security, convenience and storagestability. However, under sterilization, the undesired softening of texture and severe damagein quality due to the tender and loose texture greatly limit the consumption of cannedfreshwater fishes, and impede its industrialization progress. In this research, with emphasis oneffects of pretreatment and sterilization technology on product quality, predictive model forthermophysical properties for canned freshwater fishes is established and sterilizationtechnology based on quality maintaining of canned freshwater fishes with minimum cookvalue is investigated to produce high-quality canned freshwater fish products. This research isof academic significance in enriching the theory of sterilization technology for canned food,and of great practical significance in creating innovation of sterilization technology forcanned food, promoting quality of canned food and facilitating the development of freshwaterfishes canning industry.In order to clarify the sterilization requirements of different canned fish products anddevelop different products as acidified canned fish product, solid-liquid mixing product andsolid product, the effect of product characteristics on sterilization condition and cook valuewere discussed by the analysis of the condition differences for achieving commercial sterilitysterilization. The results showed that acidified canned fish product could be treated withpasteurization or moderate temperature to sterilize, whose heat intensity was greatlydecreased. The solid-liquid mixing product exhibited quick heat transfer and its sterilizationtime as well as cook value was greatly shortened compared with solid products. Solid productshowed the highest heat intensity. Thus, the sterilization technologies are needed to reduce thecook value of solid product.In order to investigate the effect of pretreatment on the quality of fish, understand thechange in heat transfer characteristics, the pretreatment parameters was optimized byanalyzing the effect of curing and frying process parameters on mass transfer process,thermophysical properties and qualities of bighead carp, besides, the mass transfer model wasestablished by the analysis of the change in fish components under pretreatments withdifferent process parameters, and predictive model for thermophysical properties of fish afterpretreatment was also established. The results showed that the established model betweenmass transfer kinetic parameters and pretreatment parameters was well fitted, and the modelcan accurately control the content of each component after pretreatment and predict the effectof pretreatments on thermophysical properties of fish (thermal diffusivity, R2=0.97_) Theoptimal pretreatment process for sterilization and sensory quality of bighead carp weighing2.5kg was at NaCl concentration10-15g/g, curing time108-150min, frying temperature170-190oC, frying time180-250s. The optimum pretreatment process and thermal propertiesprediction model were beneficial in maintaining product quality and helpful in providing dataof heat transfer characteristics for the subsequent optimization of sterilization process.In order to explore sterilization technology of constant retort temperature (CRT) withlow cook value, the influence mechanism of thermal death force (F value) and product size on the optimal CRT process were studied. Besides, the influence mechanism of the cooling rateon the quality of the products were discussed and validated. The results showed that thesurface quality ratio (REGS) of product under optimal CRT process decreased with increasingF value and product size, and the optimal parameters varied from short time at hightemperature to long time at low temperature as the F value increased or the product sizedecreased. Compared with other sterilization conditions, the product under optimal CRTsterilization showed highest REGS, significantly improved textural properties and morecompact muscle fiber structure. Besides, the advantage of optimal CRT sterilization in qualityretention was also proved by the data of exudates properties, sensory attribute and flavorcomponents. The quality of large-size products could be improved by accelerating the coolingrate, and after sterilization, the product showed some increase in quality when applying icewater cooling under back-pressure condition. This treatment of optimal CRT sterilizationprocess and water ice cooling was one kind of low cook technology, which was of greatpractical significance in improving the quality of canned fish.A novel type of variable retort temperature (VRT) procedures with lower cook thanoptimal CRT sterilization was established. The VRT technology was optimized by numericalmethod. The effect of F value, product size, and sterilization time on optimal VRTsterilization technology was studied.By analyzing texture and flavor of product, the effect ofthe optimal VRT sterilization on product quality was investigated. The results show that,compared with optimum CRT sterilization, product of optimal VRT sterilization showedincreased REGS under different influencing factors and the increase rate of REGS of productfrom optimum VRT sterilization increased with increasing product size, F value andsterilization time. The novel VRT sterilization procedures fitted well with the temperaturecurves in retort (R2=0.978), which showed a good applicability for ordinary sterilizationequipments. Compared with optimum CRT sterilization, product of optimal VRT sterilizationachieved improved textural properties, more compact muscle fiber structure, and betterexudates properties, sensory attributes and flavor components. The research suggests that theVRT profiles showed decreased cook value compared with CRT sterilization, and had goodapplicability for ordinary sterilization equipment, which was of great academic and practicalsignificance in maximizing the quality of canned freshwater fish product.In this paper, sterilization requirements of canned freshwater fishes with differentcharacteristics and effect of pretreatment on the thermophysical properties, sterilization effectand product quality were investigated. CRT and VRT, which were characterized by qualityretention in low cook value, were established to improve the quality of canned freshwaterfishes, which was of practical significance in solving the problem concerning qualitymaintenance after sterilization of canned freshwater fishes.更多还原