Effect Of Sulfur Dioxide Treatment On Postharvest Diseases And Physiology Of Table Grapes Storage

Table grapes were well received by consumers, and occupied an important position in the horticulturalcrops in Xinjiang, because of its sweet taste, nutrient-rich, excellent quality. Table grapes are perishability,shattering and other issues reduced grape quality during the storage. SO₂is currently the most effectivepreservative, but occurs bleaching injury. The key to find storage effect of table grapes meets effectivelyinhibit the disease, and proper SO₂concentration while does not lead to bleaching injury. Grape varieties ofthompson seedless, red globe were tested with the study, the indexes of postharvest diseases and better doseof SO₂were controled, and the injury of sulfur dioxide processing grapes were researched. A theoreticalbasis for the grapes post-harvest storage and preservation was provided.Different quality of sodium metabisulfite, calcium chloride anhydrous/silica gel, distilled water,suitable SO₂preparation ratio was derived. The different concentrations of SO₂were used to treat withinhibition test in vitro and surface of grape inoculated bacteria storaged at the room temperature. Theresults show that the use of Na2S2O5: water: anhydrous calcium chloride=1:3:1, the regular was stable andeasy to control the concentration of SO₂, so that was the suitable results. And200μl/l,250μl/l SO₂treatments can significantly inhibit colony diameter, reduce the incidence rate of grapes surface inoculatedwith pathogens and disease index.Using different concentrations of SO₂processing grapes, the damage to the grapes by SO₂and grapequality were researched. the result found that above on300μl/l SO₂had varying degrees of damage, andfollowing200μl/l SO₂to treat with grapes could maintain a stable pH, reduced the accumulation ofmalondialdehyde （MDA）, and the relative electrical conductivity increasesing.200μl/l·30min couldmaintain SSC, reduce water loss rate, dropping rate, decay rate, the bleaching rate and sulfur dioxideresidue effectively.Using200μl/l·30min SO₂treat with greape, the effect of low temperatures on Thompson Seedless, Red Globe quality were studied,and treatment wae compared with grapes antistaling agent. The result show thatthe treatment could inhibit the consumption of fruit sugar, titratable acid and VC, increase the tensileresistance and the pressure resistance of grape, reduce decay rate, water loss rate, dropping rate, thebleaching rate and sulfur dioxide residue. Its effect was better than or closed to the grapes antistaling agent.Using200μl/l·30min SO₂treat with red globe greape, SO₂treatment to the enzymes related to rot,shattering in low temperature conditions were researched. The results show that could increase PAL, GLU,CHT, PPO, POD, LOX activity, reduce CX, PG activity.