About a million ton of rice is produced in Hokkaido Province, but a very little study on the taste of thee rice has been done compared with that produced in Honshu Islands.
To elucidate the cause of this poor taste, amylose contents of rice starches were analyzed . Starch specimens were obtained from different varieties of rice grown in different experimental fields of Hokkaido and Honshu during three harvesting years .
Clear difference was found between the amylose contents of rice starches obtained from Hokkaido and Honshu. Namely, the amylose contents of Hokkaido rice starches were 21.1 24.5%, while those of Honshu rice starches were 17.621.4% .
These differences depended mainly on rice varieties. However, some dependence was also found on location and weather of the experimental fields in the case of the same rice varieties, suggesting that peaty soil and cold weather will cause high amylose content.
Thus, it was suggested that higher amylose content is one of the cause of the poor taste of rice grown in Hokkaido.

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Maltosaccharides up to maltohexaose were gaschromatographically determined by use of the severely conditioned short column. Fifty cm of 2% silicone OV-17 column was conditioned at 350°C for 72 hours . This conditioning enabled to elute higher saccharides such as G₅ and G₆. The trimethylsilylation procedure essentially as by Brobst was modified into a short time derivatization by micro scale. According to this modified method, maltosaccharides up to G₆ are determined less than 2% relative error within 30 min. including the TMS derivative preparation.

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A quantitative determination by a simple detection system for carbohydrates with elution chromatography was developed. This method depends upon the detection of ultraviolet absorbing chromophere, with absorption maximum in the 260-270 mμ region, produced by heating the carbohydrates in the eluent solution without reagent. In the product from fructose, the existence of furfural and formic acid was confirmed . The heating condition and eluant buffer (conc., pH) affected the intensity of ultraviolet absorption produced. Under the condition of heating below 190°C and shorter than 20 min, the greater efficiency was obtained at higher temperature and longer period . Higher concentration and neutral pH of borate buffer were more effective . The molar absorption coefficient at 260 mp of mono- and oligosaccharides heated in a solution of 0.8 M borate buffer pH 7.0 for 9.5 min at 190°C was 500-3000 . The coefficient of variation of this method was less than 3.5%. A heating period was obtained by adjusting the diameter and length of teflon tube connected with the chromatographic column. In order to decrease the extra column effect, it was effective to decrease the diameter of tube (0.5 mm) and heating period, and increase the heating temperature . Several examples for mono- and oligosaccharides and oligodextrines were shown.

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A new enzymatic method to determine cyclodextrins was described in this paper. The principle of the method consists of the combination of specific enzyme actions and the determination of reducing value. Cyclodextrins do not show any reducing value, because of no reducing end. In a mixture containing maltosaccharides, a and ?A-cyclodextrin, glucoamylase hydrolyses only maltosaccharides. Reducing value was determined by Somogyi-Nelson method after degradation of maltosaccharides to glucose (GAV). Total cyclodextrin content was obtained by subtraction GAV from total sugar (PS) which was determined by the phenol-H₂SO₄ method. Aspergillus oryzae α-amylase hydrolysed fast β-cyclodextrin and extremely slow α-cyclodextrin. β-Cyclodextrin and maltosaccharides were degraded to glucose by the combination of glucoamylase and Aspergillus oryzae a-amylase (reducing value of this enzyme system: GTV). Therefore, a-cyclodextrin content was obtained by subtracting GTV from PS, correction of a-cyclodextrin degradation should be done if necessary. Cyclodextrins were determined by this enzymatic method within the relative error of 5% in the mixture of cyclodextrins and oligosaccharides.

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A rapid and convenient measurement of a-amylase was achieved by a discrete type analyzer, EEL Auto Chemist. This automated method was developed according to the manual method established by Fuwa, which is based on the determination of color decrease in iodine reaction due to degradation of the substrate by a-amylase .

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The literature on cyclodextrins, which are a unique homologous series of carbohydrates, is rapidly increasing. This reviews the literature through 1973 on some intriguing properties of cyclodextrins. The contents are as follows: cyclodextrin forming enzyme, hydrolysis by enzyme and acid, preparation methods of r-dextrin and higher members of cyclodextrins, analytical methods of cyclodextrins, crystalline structures of cyclodexirins and their complexes (inclusion compounds), conformations in solution, formation of the complexes and effects induced on host and guest molecules, cyclodextrins as enzyme model, and selectively substituted derivative of cyclodextrins.

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