Shoot Processing of Highland Bamboo: Fermented Salt Stock Bamboo Shoot

Abstract

Fermented bamboo shoot is a short shelf life product and a high market's demand. It could be produced from bamboo shoot grown in Thailand which may be fresh or intermediate shoot. Shoots of highland bamboo from Royal Agricultural Station Angkhang were to study as a salt stock bamboo shoot prior to a further processing. Bamboo shoots of 2 species, i.e., Dendrocalamus latiflorus and Bambusa oldhamii were brought to depeel, slice and keep under 10% salt in order to remove astringency. Then, the treated bamboo shoot was continued to keep in 16% salt by a dry salting method for storage during 30, 45, 60 and 75 days. Freshen salt stock bamboo shoots need to do prior to a further fermentation with low salt. The periodical analyst of chemical quality was carried out in duplicate. It was found that the samples contained 12-14% NaCl, 0.23 - 0.32% and 0.28 - 0.38% of the titratable acidity as lactic acid and pH value of 4.76-5.27 and 4.61-5.08 for the shoots of Dendrocalamus and Bambusa, respectively. Whereas the microbial analysis of the freshen salt stock bamboo shoot fermentation was found 10⁵ – 10⁹ cfu/g and 10⁴-10⁸ cfu/g of TVC and lactic acid bacteria, respectively. A comparative fermentation between the fresh bamboo shoot after removing the astringency and the freshen salt stock bamboo shoot after 75 days storage without and with sugar added for 15 days were also studied. It was observed that changes in chemical composition of the fermented bamboo shoot showed a range of the chemical quality, such as, increased in the titratable acidity as 0.37-0.35%, 0.42-0.45% and 0.41-0.43%, 0.43-0.47% of lactic acid; decreased in pH as 3.73-3.70, 3.79-3.76 and 3.65-3.64, 3.74-3.60 for the shoots of Dendrocalamus and Bambusa, respectively. Inspite of the different contents of NaCl at the started fermentation were about 4.50-4.42 and 9.19-8.42, respectively. In conclusion, the salt stock bamboo shoot used 16% of salt by the dry salting technique could maintain the quality of the bamboo shoot for further processing into the fermented bamboo shoot during out of season.

Keywords: salt stock bamboo shoot, fermented bamboo shoot, Dendrocalamus latiflorus, Bambusa oldhamii