【作者】 陆东和；

【导师】 张慜；

【作者基本信息】 江南大学 ， 食品科学， 2009， 博士

【摘要】 由于土地盐碱化日益严重,发展盐土农业已成为全球关注的焦点。海芦笋（Salicornia bigelovii Torr.）被认为是最有开发利用前景的盐生植物,已经在国内外得到成功栽培,并开始规模化生产。然而采后海芦笋在春秋季室温下只能贮藏1周左右,目前还没有关于海芦笋可食性评价及其保鲜技术的报道。本研究较系统的测定了海芦笋的组成成分,并对其可食性进行分析；采用真空预冷结合硅窗气调包装保鲜技术延长海芦笋的贮藏保鲜期,并构建相关数学模型,旨在为海芦笋产业的可持续发展提供理论指导。较系统的测定了海芦笋营养成分和微量有害元素含量,研究了贮藏温度及真空预冷处理对采后海芦笋品质和生理生化的影响规律。结果表明,海芦笋氨基酸组成齐全、比例合理,还含有多种维生素和—些功能性成分以及丰富的矿物质元素,因此具有较高的营养价值；另一方面,海芦笋的微量有害元素含量都低于相应的国家限量标准,符合食品卫生要求。海芦笋为非呼吸跃变型果蔬,其乙烯释放量较少或不释放乙烯；25℃下海芦笋只能贮藏1周左右；虽然低温及真空预冷处理都能不同程度地延缓其品质劣变速度,但是0℃贮藏则会产生冷害,海芦笋适宜的冷藏温度为2℃左右,该温度下其贮藏期可达28天:真空预冷处理及低温贮藏延缓海芦笋衰老的主要机制为：延缓抗坏血酸的降解,维持较高的POD, SOD、CAT活性,从而抑制膜脂过氧化作用。为了延缓采后海芦笋的品质劣变和衰老进程,研究了初始气体组成、硅窗面积对贮藏过程包装内气体组成、海芦笋品质和生理生化指标的影响；在单因素试验的基础上,以抗坏血酸和总叶绿素含量为指标,采用响应面分析方法对海芦笋硅窗气调包装保鲜工艺进行了优化。结果表明,真空预冷处理结合硅窗气调包装可以有效的延缓海芦笋采后品质劣变；海芦笋硅窗气调包装保鲜（180g/袋）的最佳工艺参数为：温度1.9℃；硅窗面积0.58cm²；初始气体组成5.6%CO₂和5%O₂。探讨了硅窗气调包装提高海芦笋保鲜效果的机理。硅窗气调包装能抑制LOX活性和O₂-生成速率,延缓膜脂过氧化作用；并调控相关酶的活性,从而延缓叶绿素降解和纤维素、木质素的积累,进而控制失绿和老化进程；硅窗气调包装可提高海芦笋贮藏期间几丁质酶、β-1,3葡聚糖酶的活性,并维持较高的总酚含量,从而提高海芦笋的抗病性,减少腐烂损失。构建了相关数学模型,旨在为海芦笋硅窗气调包装保鲜技术的实际应用提供理论指导。通过研究包装内CO₂、O₂的变化规律,建立了基于酶动力学原理的海芦笋呼吸速率模型；将其与气体交换模型相结合,对不同规格的包装所需硅窗面积进行了预测,其结果为3.38cm²/kg;基于呼吸速率模型,以1.45%的干物质损失率作为贮藏寿命终点能较准确地预测硅窗气调包装海芦笋的贮藏寿命（P<0.05）,因此可将其应用于指导海芦笋的硅窗气调包装保鲜生产。更多还原

【Abstract】 As soil salinity has become increasingly serious in recent years, the development of saline agriculture has become the focus of worldwide attention. Salicornia bigelovii Torr. has been recognized as the most promising halophytes and successfully cultivated both at home and abroad, and there have large-scale productions as well. However, the shelf-life of harvested Salicornia bigelovii Torr. is about only 1 week under ambient conditions in the spring and fall. On the other hand, there are no published reports on the postharvest biology and preservation of Salicornia bigelovii Torr. or taking it as a human staple food. In this study, the compositions of Salicornia bigelovii Torr. were systematic analyzed, and then its nutritional value and suitability of taking as a human staple food were comprehensively discussed. To extending the shelf-life of Salicornia bigelovii Torr., modified atmosphere packaging with silicon gum film window （SMAP） combining with vacuum cooling pretreatment was applied, and a mathematical model was built too. The results can provide theoretical guidance for the development of Salicornia bigelovii Torr. industry.The nutritional compositions and toxic trace elements content of Salicornia bigelovii Torr. were systematic analyzed, and the effects of storage temperatures and vacuum cooling pretreated on postharvest quality and physiological biochemical of Salicornia bigelovii Torr. were studied. The results showed that Salicornia bigelovii Torr. not only contains considerable proximate nutritional compositions, but its amino acid composition is complete and the proportion of composition is reasonable as well. Additionally, Salicornia bigelovii Torr. contains a variety of vitamins and a number of functional components, as well as a wealth of mineral elements. Therefore, this crop is nutritional. On the other hand, although the content of mineral elements of Salicornia bigelovii Torr. is exceptional high, its toxic trace element contents were lower than the corresponding national limit standard, and then it met the food hygiene requirements. Salicornia bigelovii Torr. is a non-climacteric crop, which release little or none ethylene during storage period. Salicornia bigelovii Torr. has a shelf-life of only about 1 week when stored at 25℃. Both low temperature and vacuum cooling treated can delayed its quality deterioration, however, it could develop chilling injury when stored at 0℃. The optimal temperature for Salicornia bigelovii Torr. storage was about 2℃, which result in a storage period of up to 28 days. The main mechanism of vacuum cooling pretreatment and cold storage delaying aging processing is to slow down the degradation of ascorbic acid and maintain a high activity of POD, SOD, CAT, which will inhibit lipid peroxidation.To delay the quality deteriorateion and aging process of harvested Salicornia bigelovii Torr., the effects of the initial gas compositon, size of silicon gum film window on the gas composition in packaging, the index of quality and physicalogical and biochemical of samples were studied. On the basis of single-factor tests, response surface analysis was carried out to obtain the optimum technological parameters with ascorbic acid and total chlorophyll content as indicators. The results showed that SMAP combining with vacuum cooling pretreatment could clearly prevent the product quality deterioration during storage and the optimum technological parameters were as follow, the storage temperature was 1.9℃, silicon window area was 0.58cm2 and the initial gas composition was 5.6% CO₂ and 5%O₂.The mechanism of SMAP slowing mature and senescence process of Salicornia bigelovii Torr. was studied. SMAP could inhibit the activity of LOX and the generation rate of O₂^·-, slow the peroxidation of membrane lipid and regulate the activity of related enzymes, which resulted in delaying chlorophyll degradation, cellulose and lignin accumulation, and such controlled the green loss and the aging process of Salicornia bigelovii Torr. during storage. On the other hand, SMAP could increase the activity of chitinase andβ-1,3 glucanase, and maintain the content of total phenol, which will improved the resistance of samples and reduced decay losses.Mathematical models were built to provide theoretical guidance for the practical application of SMAP technique. A respiration mathematical model based on enzyme kinetics was established by studying the change in compositions of CO₂ and O₂ in packaging. Combined with the gas exchange model and established respiration model, the window sizes of silicon gum film for different packaging were predicted and that was 3.38cm²/kg. Based on respiration model, the shelf-life of SMAP Salicornia bigelovii Torr. could be reliably predicted using 1.45% of dry matter loss as the index of storage end-point （P＜0.05）. Therefore, the models could be a useful tool to guide the production of Salicornia bigelovii Torr. SMAP.更多还原