In the food industry, freezing storage has been an important process for maintaining the properties of food materials. In order to maintain the quality of blanched Colocasia esculenta (L.), Schott stem, packaging, freezing, and thawing methods were optimized by determinations of the physicochemical properties. For the comparison of packaging method, Colocasia esculenta (L.) Schott stem packed by air containment had the lowest significant differences of properties such as hardness and drip loss compared to the control samples. Overall, the drip loss of Colocasia esculenta (L.) Schott stem had lower value at fast freezing rate (immersion freezing). Considering the result of the drip loss, high frequency thawing was more effective than other thawing methods. Therefore, it was supposed that samples treated by air-containing packaging, immersion freezing, and high frequency thawing used the optimal method to maintain the original quality of Colocasia esculenta (L.) Schott stem.

There are a lot of types of wild vegetables such as Colocasia esculenta (L.) Schott stem in Korea. However, the consumption of these wild vegetables is restricted because their storage decreased dramatically after harvest. To maintain original quality of vegetables, pre-treatments such as blanching and drying are important. But conditions for these treatments were still not optimized for many vegetables including Colocasia esculenta (L.) Schott stem. Thus, the objective of this study was to set up an optimal pre-treatment method for freezing storage. Colocasia esculenta (L.) Schott stems were peeled and cut equally (10 cm) for sample preparation. Dried samples (D) were dried at 90℃ for 3 h. Blanched samples (B) were blanched in hot water at 100℃ for 2 min. Blanched and dried samples (BD) were blanched and dried as same protocol. Physicochemical properties were analyzed to evaluate the quality including texture, moisture content, total color difference and viable cell count. Raw sample had 6.85 kg/cm 3 of hardness and 78.75 of chewiness whereas B was 6.83 kg/cm 3 of hardness and 7.8 of chewiness. B had the similar value compared to raw samples. Moisture content of raw sample was 94.4% and that of B was 94.1%, though there were not any significant differences between them. ΔE value of B showed lower value than those of the others. Viable cell counts and total coliforms were not detected after treatment, while raw sample had 5.39 log CFU/g of viable cell count without total coliform. Therefore, pre-treatments are essential for microbial safety of samples. All results considered, it is supposed that blanching is the optimal pre-treatment to sustain its original quality of Colocasia esculenta (L.) Schott stems before freezing.

This study was conducted to obtain the basic breeding information of Colocasia esculenta Schott. Effect of supplemental plant growth regulators and genotype difference were investigated on dormant bud tissue for proliferation. The plant regeneration ratio, plant height and root length were the best upon mixed treatment of 0.8mg/L IAA and 2.0mg/L zeatin. Both leaf weight and root weight were heavy upon culture in a dark condition. The leaf and root weights were heaviest in 6Pie sucrose concentrations. In several collected area the heaviest one was Binnangxin and then in the order of Suwon, Wanju and Puan. Genotype differences of tuber diameter and tuber weight were found in Suwon. Tuber weight was found in the order of Suwon (862mg) >Wanju(723mg) >Puan(649mg) >Binnangxin (424mg).