Research On Pretreatment Methods Of Lemon Pectin Materials

This subject was mainly studied about the precondition stage of lemon pectin and dscussed to kill enzyme, break cell wall, drying. From all kinds of conditions the best process condition and parameter were found out. It support a solid foundation for the pectin study in the future.While the subject is implemented, experiments and production was linked in closely. From the view of production to consider actually, we divided the subject into two sides: One used fresh lemon as raw materials to produce pectin because lemon have harvest season. Another has dryness materials to produce pectin. In this way, it makes the production of pectin in whole year.The technology of pectin production mainly include preconditioning, extraction, concentration, precipitation and drying. Among them, the preconditioning (eg. kill enzyme, organize the cell broken wall and dry) in the production technology was important. The preconditioning method optimized was not only simplify the operation, lower costs but also improved raw materials utilization ratio and extraction rate of pectin greatly.The raw materials of lemon pectin (lemon peel) killed enzyme was studied. The fresh materials should be processed in time, otherwise apt to ferment rottenly, and pectin enzymes enzynolysis among them and cause pectin losses. If you want to guarantee production keeping on the whole year, storing raw materials should act as treatment to raw materials. Different preconditions of raw materials have different treatments. The fresh lemon directly killed enzyme, and raw materials had better be dry. It is dry to moisture under 6% under certain temperature condition. Pectin enzyme can tolerant temperature 80-82 ℃. In the paper, we adopt 3 method to kill pectin enzyme of the raw materials: 1) heater, 2) treatment of sour and alcohol, 3 )microwave. Comparing different methods and parameter is tried to find the best method.The raw materials (lemon peel) are crushed and the method of broken wall of cell was studied. Pectin exist in cell wall of plant;if you want to improve pectin extraction who must organize cell wall and destroy it;in order to help pectin dissolving. The other factor element which is granularity of raw materials influences pectin to extract. Appropriate granularity can make raw materials obtain increasing than the surface area most heavy;convenient pectin appears. So that it was selected granularity of ones that are used as l~3mm. For pectin abstraction go on smoothly;there must be broken wall method suitable. The broken method to organize cell was numerous;there are mechanical method;physical method;chemical method and biochemical method;etc. In this paper;we chose six kinds of methods to break cell wall of raw materials: Organization mashing machine;mortar;freezing and dissolving;urgent hot sudden cold repeatedly;supersonic wave;etc.The drying method of raw materials (lemon peel) was studied. Among the real pectin production procession;as to the thing that lemon get bumper crops issue;production can use fresh raw materials in order to improve pectin get rate directly and reduce the production cost. But this period of time is relatively short. If you want to produce all year;we must go on processing;preparing against;and taking comparatively simple to large quantities of raw materials in harvest season in enterprise. Drying is a good method in actual production. The drying method to carry on in this subject was according to various temperature periods and difference of dry time;in order to find out the best dry treatment;adopting pair warm to cross dry method maximum reducing dry to speak;opposing raw materials pectin influence;thus improved the pectin extraction rate greatly.Throughout this subject;the best preconditioning process conditions are: Crushing (1~3 mm);microwave treatment (Power 700W;granularity l~3mm;function time 9 min;material liquid is than in 1:3.5);90x70 °C crossing dry(90°C6h/70°C;5~8h);the treatment of phosphates compound(Dry materials: Na3PC>4 2;NaH2PC>4 0.5;pyrophosphate sodium 0.3;six leans towards phosphoric acid sodium 0.6;putting 24h quietly;Fresh raw materials: Na3PO43;0.9 NaH2PC>4;pyrophosphate sodium 0.5;six lean towards phosphoric acid 0.6 sodium;putting 24h quietly).