- 著者
- Shinichi Furuyama Hideki Okamoto Tatsuru Jishi
- 出版者
- The Japanese Society for Horticultural Science
- 雑誌
- The Horticulture Journal (ISSN:21890102)
- 巻号頁・発行日
- pp.QH-003, (Released:2022-12-28)
Borecole (curly kale) was cultivated without heating during autumn and winter in a multi-film-covered greenhouse in Hokkaido, Japan. Borecole survived even when the greenhouse air temperature dropped to −6.2°C with an accompanying drastic increase in Brix value. This rapid increase of Brix value was observed under conditions where the minimum air temperature in the greenhouse was less than 0°C. Cold temperatures caused the plant to freeze, inducing extracellular freezing. Although the Brix value increased at low temperatures irrespective of leaf order, the Brix values for leaves of lower order, at the top of the plant, were much larger than the higher order leaves, closer to the base of the plant. Leaf Brix values started to increase when the average minimum temperature was 1.3°C or less for 10 days before harvest. Moreover, the nitrate concentration, reported to correlate with bitterness intensity, decreased at low temperatures. These results revealed that leaves with reduced bitterness and improved sweetness can be produced in low temperatures from the upper portions of borecole plants.
- 著者
- Kana Nikaido Tatsuru Jishi Tomoo Maeda Takashi Suzuki Hajime Araki
- 出版者
- 園芸学会
- 雑誌
- Journal of the Japanese Society for Horticultural Science (ISSN:18823351)
- 巻号頁・発行日
- pp.CH-113, (Released:2014-09-02)
- 被引用文献数
- 7
Asparagus has a short shelf life. A temperature of 0–2°C with a relative humidity of 95–100% is well known as the ideal storage environment for asparagus spears. The quality of spears stored in a snow vault and snow mount (Snow) was compared with those stored in an electric refrigerator (Refrigerator). Asparagus spears of ‘Grande’ and ‘Gijnlim’ were stored in Snow and Refrigerator for 0, 2, 5, 10, and 20 days; then, 1) physical and external appearance characteristics such as hardness, weight, and surface color, and 2) features of internal quality such as Brix, sugar, ascorbic acid, and rutin content in the spears were investigated. Although temperature and relative humidity fluctuated largely in the ranges of 3–6°C and 65–85% in Refrigerator, those in Snow were almost completely stable at 0–1°C and 100%. In ‘Grande’, the weight of the spears stored in Refrigerator decreased dramatically compared with that of spears stored in Snow. The external appearance of ‘Gijnlim’ spears was preserved until the 10th day, but loose tips were observed on the spears in both Snow and Refrigerator on the 20th day. ‘Grande’ spears stored in Refrigerator turned slightly brown and wilted at the surface of the basal part compared with Snow-stored spears. No loose tips were observed on ‘Grande’ spears. There was also no significant difference in the internal quality of spears between those stored in Snow and Refrigerator, in both varieties. CO2 emissions in snow storage were reduced to half of those in refrigerator storage in LCA analysis and no CO2 emissions were identified during the storage period in Snow. From the perspectives of energy utilization and quality preservation, snow appears to be one of the better alternatives for spear preservation than use of a refrigerator.