Growth and salting properties influenced by culture methods, cultivars and storage packaging of kimchi cabbage (Brassica rapa) in spring

Abstract

This experiment was conducted to determine the effects of the pre- and post-harvest variable factors on the processed product of kimchi cabbage. Two kimchi cabbage cultivars, namely 'Chungwang' and 'Dongpung,' were grown in a field and under a plastic greenhouse condition and stored at $5^{\circ}C$ after harvesting with and without low-density polyethylene (LDPE) film packaging. Growths were determined after harvesting while salting characteristics were determined after the processing and storage. The results show that the height, weight and leaf thickness were higher in kimchi cabbages grown in the greenhouse than those grown in the field. The plastic house culture increased the kimchi cabbage growth of the head weight, head height and leaf thickness compared with that of the open field culture. However, the osmolality and firmness were higher in the outdoor cultivated kimchi cabbages. Kimchi cabbage packed in film covered sacks and stored at $5^{\circ}C$ showed lower weight loss than unpacked cabbages during storage. Salt concentration and pH were also affected by the different pre- and post-harvest factors after salting the kimchi cabbages. Salt concentrations of the kimchi cabbage were influenced by various factors such as the cultivars, cultivation methods and storage covering. Though the present findings showed a limited difference in salt concentration and pH between the cultivars of kimchi cabbages, this study suggests that there is a relationship between processed agricultural products and their pre- and post-harvest methods.

Fig. 1. Appearance of ‘Chungwang’ kimchi cabbage as affected by cultivation methods under plastic house and open field culture. (A) Outside plant appearance of plastic house culture before trimming, (B) Outside plant appearance of open field culture before trimming, (C) Outside head appearance of plastic house culture, (D) Outside head appearance of open field culture, (E) Inside head appearance of plastic house culture, (F) Inside head appearance of open field culture.

Fig. 2. Cross section of vascular bundle on ‘Chungwang’ kimchi cabbage as affected by cultivation methods: Under plastic house and open field culture (× 200). (A) Kimchi cabbage vascular bundle of midrib on plastic house culture, (B) Kimchi cabbage vascular bundle of midrib on open field culture.

Fig. 3. Fresh weight loss of ‘Chungwang’ and ‘Dongpung’ kimchi cabbage as affected by cultivation methods and packaging during storage at 5℃.

Table 1. Growth, moisture content, osmolality and frmness of two kimchi cabbage cultivars as afected by cultivation methods.

Table 2. Salted kimchi cabbage characteristics such as salt concentration, pH, and osmolality as affected by cultivation and storage methods.