Studies On Technology, Mechanism And Model Of Salicornia Bigelovii Torr. MAP Storage With Silicon Gum Film Window

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.