Effects Of Several Sugar Coating On Quality Of Citrus Fruit

Effects of several sugar(sucrose-based polymers, glucose, fructose, sucrose andmannnitol)coating on the quality of citrus fruit has important biological sense. Inpresent study, we took Ponkan(Citrus reticulata Blanco)and Satsuma mandarins(C.unshiu Marc.cv.Miyagawa Wase) as experimental materials to explore a variety ofsugar (sucrose-based polymers, glucose, fructose, sucrose and mannitol) coating oncitrus rot rate, water loss rate, soluble solids, firmness, total sugar, pH, color index,chlorophyll and carotenoids such as post-harvest, the main results are as follows:1.0.3%(v/v) SBP(sucrose-based polymers) coating treatment could significantlyimprove the quality of Ponkan fruit.0.3%SBP treatment could improve the totalsoluble solids(TSS), reduced firmness at10-25d, improve citrus color index, promotechlorophyll a, b declined, and promote carotenoids increased in the peel andjuice accumulation at5-20d; HPLC results showed that0.3%SBP treatment couldsignificantly promote carotenoids increased in the peel, with a significantly higherpeak at20d than control, and each carotenoids (except zeaxanthin, β-cryptoxanthinand α-carotene) was suppressed in early time with induced in latter time;2. Four different sugars (glucose, mannitol, fructose and sucrose) at differentconcentration(0.1%,0.5%,1.0%, w/v) coating treatment on Miyagawa fruit, the mainresults are as follows:1) Considering the fruit quality indexs during0-15d storage period, includingrot rate, water loss rate, soluble solids, firmness and color index,we found that0.5%,1.0%glucose,1.0%mannitol and0.1%fructose treatments were the best, withsignificantly reduced firmness induce, improved TSS, citrus colored index, total sugarcontent and pH, decreased chlorophyll a, b, increased total carotenoids contents, inearly storage time0-5d.2) HPLC analysis of Miyagawa peel showed that the effects of0.5%glucosetreatment could greatly affect β-cryptoxanthin, zeaxanthin, and α-cryptoxanthin,were18.74%,23.2%and38.1%higher than in the control group, respectively;1.0%glucose treatment could promoted trans-violaxanthin, cis-violaxanthin,α-cryptoxanthin, β-cryptoxanthin and α-carotene increased in the latter storage time,while trans-violaxanthin, α-cryptoxanthin and α-carotene reached maximum valueswith26.67μg/g FW,3.96μg/g FW and4.9μg/g FW at20d;1.0%mannitol treatment mainly promote trans-violaxanthin, cis-violaxanthin, zeaxanthin, α-cryptoxanthin,β-cryptoxanthin and α-carotene accumulation, but lutein appeared the maximum peakat15d;0.1%fructose treatment could promote cis-violaxanthin, α-cryptoxanthin andα-carotene acuumulation more obvious on25d;3) HPLC analysis of Miyagawa pulp showed that the effects of0.5%and1.0%glucose treatment had little affect on carotenoid, except zeaxanthin and luteinappeared the maximum peak at15d;1.0%mannitol and0.1%fructose treatments hadthe maximum peaks at15d, while the peak of the control group was appeared at20d,in addition to cis-violaxanthin and zeaxanthin in1.0%mannitol treatment appearedpeaks at10d, the others carotenoid had maximum peaks5days earlier than the control,suggesting that the two treatment groups could make contribute to the carotenoidcontent accumulation in the juice, make early appearance of the peak, and shorten theripe time.3.0.5%and1.0%(w/v) glucose coating on Miyagawa fruit could significantlyincreased lightness(L*), chroma(C*) and citrus color index (CCI), reduced hueangle(H°) values in the first2-3d of storage, however, the effect of0.5%glucosetreatment had no significant effect(p＞0.05);1.0%glucose treatment could aparentlypromote chlorophyll a, b degradation and increased peel carotenoid contents,including cis-violaxanthin, trans-violaxanthin, β-cryptoxanthin, α-carotene,β-carotene, α-cryptoxanthin, zeaxanthin, and total carotenoids were significantlypromoted in storage period2-3d.