基于品质易逝期的模拟中转基地处置对凡纳滨对虾活品和锁鲜品贮藏稳定性的影响

Effects of quality-determination-period handling in collection and distribution center on storage stability of farmed live and freshness-locked Pacific white leg shrimp Litopenaeus vannamei

为改变小型分散对虾养殖产区的渔后被动现状,以大连地区池塘养殖凡纳滨对虾Litopenaeus vannamei为研究对象(体质量为20~25 g),模拟构建一个在产区具有集散性质的中转基地,将离水后的品质管理分为两个阶段,塘头至中转基地(品质易逝期)和中转基地进入鲜活品贮运销售阶段(后品质易逝期),塘头至中转基地设置为4 h无水保湿运输,中转基地处置分复水活品组和冰卒锁鲜组,随后进入贮运环节,活品组保活贮藏60 h,锁鲜组覆冰冷藏132 h,并检测不同阶段对虾肌肉白度、pH、糖原、ATP及其关联物、蛋白溶解度、琥珀酸脱氢酶(SDH)及活体血糖等指标。结果表明:品质易逝期处置对活品的可恢复性试验显示,无水运输后活体肌肉的pH和ATP值略有上升,血糖与糖原含量则略有下降,复水后的血糖、pH、糖原及ATP及其关联物等各项指标分析结果均表明活体活力恢复,随后的活品贮运期间,活体在初期呈现一定的稳定性,36 h后快速下降且出现大批量死亡;品质易逝期锁鲜处置的延迟效应试验显示,无水运输后直接进行冰卒随后冰藏,锁鲜品在销售过程中其糖原、ATP等含量虽有所下降,但前108 h期间下降速度较慢,pH始终维持在7.98以下,呈现了5 d的锁鲜品货架期,锁鲜品各项指标均高于活品,这表明易逝期处置能够有效地实施锁鲜,延缓了鲜品贮藏期间品质的下降速度。研究表明,离水后对虾具有一个品质易逝期,且对后品质易逝期有延迟效应,水产品产区建立中转基地可以有效地实施易逝期品质调控并可主动实施产品设计,进而改变小型分散养殖产业渔后被动现状。

To reconstruct less organized local shrimp supply chains for scattered shrimp-farming operations areas,a post-harvest handling center(PHHC)around production area was designed with operations of collection and distribution of local pond-farmed Pacific white leg shrimp Litopenaeus vannamei with body mass of 20-25 g.Shrimp supply chain was divided into two stages,from pond-farmed to PHHC for 4 h wet transportation as the quality-determination-period(QDP),and from PHHC to markets as the post quality-determination-period(P-QDP).The products in the PHHC were divided into two groups:the rewatered live product group and the freshness-locked product group,and then entered the storage and transportation link.The live product group was kept alive for 60 hours,while the freshness-locked group was iced cold storage for 132 hours.The detection indices included muscle whiteness,pH,glycogen,ATP related compound,protein solubility and SDH(succinate dehydrogenase)as well as glucose as an indicator of fitness of live shrimp.The recoverability of QDP-treatment to live product revealed that pH and ATP content of live products muscle were increased slightly,while the glucose and glycogen contents were decreased slightly after waterless transportation.The analysis of glucose,pH,glycogen and ATP related compound was recovery after rehydration.During the subsequent storage and transportation of live products,the live products showed to some extent stability at the initial stage,and then rapid decrease and a high mortality was observed after 36 hours,with delayed effect of fresh-locked treatment during QDP.The glycogen and ATP contents of the iced collection were decreased somewhat during the sales process,with the slow decline rate during the first 108 h,and the pH value always remained below 7.98,presenting a 5 d shelf life of the freshness-locked products.It was worth noting that the indices of freshness-locked were all higher than those of live products,indicating that the perishable period disposal effectively implemented freshness-locking and delayed the quality decline rate of fresh products during storage.Pacific white leg shrimp had a QDP after waterless,and had a delayed effect on the P-QDP after waterless.The findings indicated that the establishment of post-harvest handling center effectively implemented quality control in the QDP and actively implemented product design,thus changing the passive status of small scattered aquaculture industry after harvesting,and that improved the economic income of fishermen,which provided high-quality prawn products for the market.