Study Of Fresh-cut Taro Preservation Technology

Taro is a perennial herbaceous plant tuber with edible and medicinal values.The skin of taro is difficult to remove, and it’s contacting with the skin can causeskin itching, so fresh-cuting and package is necessary for sale. In this study, taroproduced from Yantai City Shandong Province, was selected as research material,and the research contents are as follows: the influences of fresh-cut on taro quality;the influences of different packages on the shelf-life of fresh-cut of taro, theinfluences of blanching treatment and color-protecting treatment on the shelf-lifeof fresh-cut taro. All of this were to provide a theoretical basis for the productionand product development of fresh-cut taro. The research contents and results are asfollows:1. At (4±0.5℃), the fresh-cut taro and the whole taro were packaged by MAP,and physical and chemical indicators of taro were measured the during the storageperiod to research the physical and chemical changes on fresh-cuting treatment.The results showed that: after fresh-cuting the contents of sugar, Vc and othernutrients consumed faster, and MDA, relative conductivity, BD and otherindicators increased gradually.According to the rapid decrease of moisture content,hardness, spring, chewiness of fresh-cut taro were significantly lower than thewhole taro.2. Three different packages (MAP packaging, pallet packaging and vacuumpackaging) were designed in this research. During the storage, the physical andchemical indicators and sensory evaluation of Taro were determined to study thepreservation effect of different packages on shelf-life. The results showed that: thecontents of sugar, Vc, moisture content and other indicators of vacuum packagingwere significantly higher than pallet packaging and MAP packaging; MDA,relative conductivity were significantly lower than the pallet packaging and MAPpackaging. Sensory evaluation of vacuum packaging was also higher than theother two packages. In terms of texture, hardness, cohesiveness, chewiness ofpallet packaging and vacuum packaging were nearly the same, but better than MAP packaging significantly.3. Single-factor experiment was firstly conducted to determine the range ofblanching temperature and blanching time, then the optimization of blanchingtemperature and blanching time was conducted by using the response surfacemethodology. The results showed that browning was lowest with blanchingtemperature76~80℃and blanching time185~190s; hardness1was best withblanching temperature78-82℃and blanching time178~183s; hardness2wasbest with blanching temperature77~81℃and blanching time175~180s; cohesion,spring and chewiness were best with blanching temperature76~80℃andblanching time180-184s; the adhesion was lowest with blanching temperature75~79℃and blanching time178-182s.4. In this research, single-factor experiment of three different color-protectingagentia (L-cysteine, NaCl and Vc) was conducted firstly, then the responsesurface design of three factors and five levels was used to obtain a optimization ofcolor-protecting agentia. The results were as follows: the BD of fresh-cut taro wasrelatively lower with the the concerntration of L-cysteine0.7%~0.98%, Vc0.3%~0.5%and NaCl0.6%~0.85%; the hardness1was relatively higher with theconcentration of L-cysteine from0.7%, the concentration of NaCl from0.5%to0.7%and Vc0.3%~0.5%; chewiness was best with L-cysteine0.7%, Vc0.22%~0.4%and NaCl0.75%~0.9%. So the effect of color-protecting was bestwith the concerntration of L-cysteine0.7%~0.9%, Vc0.22%~0.5%and NaCl0.5%~0.9%.5. Relative to the CK, the results showed that blanching processing treatmentdecreased sugar content, moisture content, hardness1and chewiness, decreasedBD and MDA.Fresh cut taro to protect color treated, reducing sugar content,hardness1, chewiness and the difference is small compared to the control group,the moisture content decreased, browning and MDA content decreasedsignificantly. Fresh cut taro be blanched before processing further protect colortreated, found this approach and performed only blanching process or just toprotect color treated or less storage effect. In actual production, should also take into account the effect of storage and production costs, you can choose to onlyblanching treatment or care only color processing.