Bamboo shoots are immature, expanding portions of new culms that develop from the rhizome of bamboo plants (Liese, 1998). Young bamboo culms with compressed internodes and including a culm neck are generally harvested for edible shoots. The edible part of the shoots consists of meristematic tissue with regions of rapid cell division and differentiation, which is enveloped in protective leaf sheaths (Kleinhenz et al., 2000). Bamboo shoot is a well-known ingredient used in numerous types of Japanese, Chinese, and other Asian cuisine and is important for the human diet. Furthermore, bamboo shoots are commonly available as canned food, although fresh bamboo shoots are far superior in taste and texture. According to importance of bamboo shoots in food material, previous studies on the consumption and nutritional benefits of bamboo shoots have focused on dietary fiber, lipid, fatty acid, protein, and amino acid contents. Postharvest attributes, including water loss, discoloration, and microbial decay, have also been studied (Fuchigami, 1990; Kleinhenz et al., 2000; Kozukue and Kozukue, 1981; Nirmala et al., 2007).
Sweetness is one of the most predominant factors affecting eating quality of fruits and vegetables. Lu and Xu (2004) have suggested that total sugar content and sugar in the basal, middle, and apical sections of fresh-cut bamboo shoots initially decreased and then changed variably thereafter in different sections of the shoots during storage at 4 °C for 16 d. Kozukue et al. (1983) also found that fructose, glucose, and sucrose were the major sugar constituents in all bamboo sections. The content of both fructose and glucose in the basal section was twice as high as in the apical section. These studies showed a difference in sugar content in different sections along the length of a bamboo shoot. However, comprehensive and accurate data on the sugar profiles in various bamboo shoots (four different sections along the length, different harvest maturity, and different cultivation areas) are not available.
Maturity stage at harvest is another determinant influencing compositions, eating quality, and storage life of fresh produce. Although there have been many studies on determining suitable maturity indices, only limited studies have dealt with the relationship between maturity and eating quality of fruit and vegetables (Kader, 1996). Temperature also plays a major role in maintaining quality after harvest. Lowering temperature reduces respiration as well as other metabolic processes and therefore delays quality deterioration. On the other hand, high temperature accelerates many chemical reactions, causing senescence, softening, loss of nutrition, and other cellular components (Bron et al., 2005; Kattan and Pharr, 1971; Platenius, 1942; Saltveit, 2004). In unpeeled fresh bamboo shoots, however, the effects of harvest maturity and temperature on the changes in eating quality during storage have not been well analyzed.
Therefore, in this study, the individual sugar contents of bamboo shoots harvested from different maturities (emerged and underground position) were determined. This work also investigates the effects of storage conditions on the changing characteristics of cellular sugar components in bamboo shoots, which, in turn, influence eating quality.
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