高档绿茶加工机械现状及展望

近年来随着茶叶机械化加工技术的不断进步,高档绿茶机械化进程也得到了重大突破,不仅提高了生产效率,还提高了产品质量.文章结合我国高档绿茶加工机械发展现状,对未来高档绿茶加工机械发展趋势进行了分析,为我国茶业产业更好更快的发展提出了建议.     

城市绿地生态管理概念、理论与应用——以马鞍山市园林绿化养护管理为例

在介绍生态管理概念和理论的基础上,结合马鞍山园林绿化养护生态管理实例,试图为城市绿地管理提供依据,为解决其中出现的多方面问题提供了科学、经济、合理的措施。       

Response of Bacterial Biofilms in Recirculating Aquaculture Systems to Various Sanitizers

ABSTRACT

Pathogenic microorganisms may be incorporated into biofilms found in aquaculture systems, causing recurring exposure to potential disease agents. Aerobic plate counts, the presence of Enterobacteriaceae, and the presence of Escherichia coli, modified to express a green fluorescent protein (GFP E. coli), was used to evaluate the effectiveness of various sanitizers in decreasing bacterial incorporation into newly generated biofilms in recirculating aquaculture systems. Disks of Buna-N rubber, polyvinyl chloride (PVC), chlorinated PVC, glass, fiberglass, and stainless steel were placed in aquariums stocked with Nile tilapia, Oreochromis niloticus. The effectiveness of water, an alkaline cleanser, sodium hypochlorite, a quaternary ammonium compound, or peracetic acid as a sanitizer was evaluated on each substrate by enumerating total plate counts, GFP E. coli, and Enterobacteriaceae. Sodium hypochlorite and peracetic acid were the most effective sanitizers, with an overall percentage reduction of GFP E. coli of approximately 2 logs₁₀. The quaternary ammonium compound was moderately effective, 1 log₁₀, against the target organisms. Water demonstrated a 2 log₁₀ reduction of the total plate count, suggesting that some mechanical cleaning was achieved. The type of material used as substrate for the biofilm had no significant (P?>?0.05) effect on the effectiveness of the sanitizers.     

Synergic Effects of Light Salting,Vacuum Packaging,and Onion Extract on the Quality Retention of Refrigerated Rainbow Trout (Oncorhynchus mykiss) Fillets

This experiment investigated the synergistic effects of vacuum packaging, light salting, and onion extract on the shelf life of rainbow trout (Oncorhynchus mykiss) fillets stored under refrigeration. The chemical, microbial, and organoleptic changes were monitored for up to 18 days in fillets. Total volatile basic nitrogen (TVB-N) and free fatty acid (FFA) values were evident in the order: control (without salting, vacuum packaging, and extract) > air packaged, salted (APS) > vacuum packaged, salted (VPS) > and vacuum packaged, salted, containing 2% and 4% (v/w) onion extract (2% and 4% VPSOE) throughout the storage period. Thiobarbituric acid values in APS groups were higher than control groups. Data from microbial assay showed that treatment with 2% and 4% VPSOE decreased total viable microbial count (TVC) compared with other treatments. APS, VPS, and VPSOE samples remained acceptable for up to 8, 12, and 15 days, respectively. The most suitable indices for determining shelf life of rainbow trout fillets are TVC.     

Preservation of Stuffed Mussels at 4°C in Modified Atmosphere Packaging

The stuffed mussel is a traditional, ready-to-eat food in Turkey which is produced by cooking rice and various spices filled inside the mussel. This article examines the effect on sensory, chemical, and microbiological parameters of stuffed mussels of two gas mixtures—MAP1 50% N₂/50% CO₂ and MAP2 100% CO₂—used as modified atmospheres for cold storage at +4°C. Air packaged samples were chosen as the control group. Based primarily on sensory characteristics, MAP1 gas mixture was the most effective for stuffed mussel. According to sensory results, it has been determined that the control samples kept until the 11th day, while the MAP1 and the MAP2 groups kept until the 13th day. Of the chemical indices determined, the TVB-N values of MAP1 and MAP2 remained lower than the proposed acceptability limits of 20 mg N/100 g, up to 13 days of storage. Microbiological analysis results did not find any differences between the groups. It was found that the shelf life of air and MAP1-MAP2 packaged samples were 7 and 11 days, respectively.     

Pasteurization Conditions and Evaluation of Quality Parameters of Frozen Packaged Crab Meat

ABSTRACT

Ovalipes trimaculatus is a crab recognized as a new resource with fishing value to obtain frozen products. Pasteurization conditions of meat crab at temperatures below 85ºC (60, 72, and 82ºC) were established to achieve better quality attributes in the frozen product. The lethality curves of Staphylococcus aureus and Listeria monocytogenes were measured, and the decimal reduction times (D) and Z values were determined. Heat transfer during the pasteurization process of pouches containing crab meat was simulated using a computational code in finite elements, and the mathematical model was experimentally validated. Thermal histories were coupled to the microbial lethality kinetics of the most heat resistant pathogen microorganism in order to establish pasteurization times necessary for the process system design. The predicted pasteurization conditions were microbiologically validated. The pouches were frozen under industrial conditions and stored at ?22ºC for 1 year. The influence of the type of packaging (vacuum and nonvacuum plastic pouches) on physicochemical and sensory quality parameters of frozen crab meat (color, exudate, lipid oxidation, water holding capacity, and overall acceptability) were analyzed observing better performance under vacuum conditions.     

Monitoring Quality of Packaged Pacific Ocean Perch (Sebastes alutus) in Storage

Pacific ocean perch stored under vacuum, 100% CO₂ or air at -3°C and 3°C was subjected to sensory, trimethylamine (TMA), color, microbial and volatile analyses. Unpleasant sensory attributes, TMA and microbial content were negatively correlated to overall quality, and Hunter 'L' value increased with storage time. Principal factor analysis of sensory data resulted in three factors that accounted for 71% of the variance, with factor 1 (53%) mainly related to poor quality attributes. Volatiles analyzed by the dynamic headspace technique included alkanes, alkenes, aldehydes, aromatics and alcohols. Canonical variate analysis on volatile compounds separated excellent and poor quality fish samples, while good and medium samples were grouped together.     

自然元素在农特产品包装设计中的生态呈现

用生态学和美学的观点论述了农特产品包装设计中的生态美,阐释了自然元素在农特产品包装设计中的审美呈现要素及其生态审美内涵,同时,也论述了农特产品包装设计必须具有的生态观及审美观。依据自然生态包装方式和理念,论述了自然生态元素在农特产品包装设计中的生态呈现形式和生态呈现理念。认为传统的包装工艺和理念应该与现代的生态理念相互融合,在改造利用自然的同时,也要顺应自然。在农特产品的包装设计中应该树立正确的包装生态观和审美观,提升对自然生态元素的利用水平,使农特产品包装得到更好的生态呈现。参16     

基于低碳理念的上海公共绿地空间结构初探

介绍低碳城市的理论与实践研究进展,并从城市公共绿地空间的呈现入手,引入低碳理念探讨城市公共绿地空间存在的问题,最后从3个层面提出优化城市公共绿地空间的低碳化策略。