Transfer reactions of an endo-1, 4-β-galactanase from Penicillium citrinum and several β-galactosidases were studied using aryl compounds as acceptors. The acceptor specificity of the galactanase was much broader than those of β-galactosidases from Escherichia coli, Penicillium multicolor, Bacillus circulans and Aspergillus oryzae : Various hydroxybenzenes and hydroxybenzoic acids acted as acceptors for the galactanase, although most of them were poor or ineffective for the, β-galactosidases. Carboxyl group adjacent to OH groups reduced effectiveness as acceptors for both the enzymes. Benzyl alcohol and hydroxybenzyl alcohols were good acceptors for the enzymes. The transfer ability of galactanase was compared in detail with the β-galactosidases using 1, 3-dihydroxybenzene (2) as an acceptor. The galactanase formed the transfer products much more effectively than the β-galactosidases at 0.5-3% of the acceptor concentrations. Increasing activity of the galactanase and prolonged reaction time resulted in an increase of the transfer products. Increasing activities of β-galactosidases and longer incubation times reduced the yields due to rapid hydrolysis of the aryl galactoside formed.

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A pullulanase ([EC 3.2.1.41] pullulan 6-glucanohydrolase) from Bacillus sectorramus FERMP8973 (Amano Pharmaceutical Co . Ltd., ) was purified using Mono Q anion-exchange chromatography. Purified enzyme showed a single band on PAGE and SDS-PAGE, and a single peak on HPLC on a TSK-gel G3000SW . The molecular weight (95 kD), optimum pH (5-5.5), optimum temperature (55°C), pH stability and thermal stability were similar to the results of Mori et al. (Denpun Kagaku, 38, 9-16, 1991), but the isoelectric point (5 .3) was different from their result (4.7). Its amino acid composition was similar to those of other amylases. Its Nterminal amino acid sequence was YSNSTGVIVHTHRDSNYTN-, and thus did not resemble those of Klebsiella pneumoniae W70 pullulanase having a collagen-like sequence.

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The effects of various starch complexing : amylose-waxy gene protein complex, mylose-lipid complexes, amylopectin retrogradation and amylose retrogradation (resistant starch) were recently studied in selected rice samples differing in starch properties. Amylose-bound protein (starch synthase) is higher in indica rice than in japonica rice and the specific activity was lower in indica, consistent with their similar amylose contents. Processing temperature determines the type of amylose-lipid complex formed, with complex II formed only above 100°C. Cooked-rice and starch-gel staling that is reversed partially by reheating at 100°C was shown to be due to amylopectin staling by DSC and storage modulus G'-time profiles . They tended to be related to d.p.n of amylopectin among waxy rices. Intermediate-high GT with greater resistance to corrosion of raw granules to HC1 and Chalara paradoxa amylases showed greater amylopectin and amylose staling of cooked rice. Amylose staling was measured by glycemic index and resistant starch. These studies provide evidence on the causes of varietal differences in qualities of rices with similar amylose contents. It is worthwhile to estimate the molecular properties of amylopectin and amylose of these selected rice samples to determine what properties actually affect cooked rice texture.

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The physical characteristics after aging of Mochi prepared by several methods were studied, and the following results were obtained:. 1) Mochi prepared by stamping exhibited much of the initial rice grain structure, while that prepared by a power mixer was of a well-mashed paste form rather than rice grain tissue. 2) The hardness of each type of Mochi measured by a rheolometer depended on the storage conditions : Mochi prepared by a mixer was softer than by stamping with no storage, while that prepared by a mixer was harder than by stamping after storing for 3 hr at 5°C. 3) The creep curves of Mochi measured by a rheoner could be explained by a six-element mechanical model consisting of Hookean body, two pairs of Voigt bodies and a Newtonean body. The shift factor-1/T relationship for Mochi stored at °C resulted in two straight lines, a refraction point being observed at 50°C ; however, no such phenomenon was observed for Mochi stored at-20°C. 4) The cooking loss of Mochi stored at 5°C decreased with increasing storage time, while that of the Mochi stored at -20°C hardly changed . Mochi prepared by stamping showed a small cooking loss after storage at 5 and -20°C, respectively. 5) The crystalline structure of raw glutinous rice could be classified as a type-A pattern, although this pattern disappeared upon heating and was transformed into a type-B pattern after storing at 5°C for one week. In the case of Mochi stored at -20°C, the crystallinity was never recovered. 6) The viscosity of Mochi measured by a Brabender viscograph after storing at 5°C showed a maximum value of 800 to 1000 B. U., while that stored at -20°C showed a maximum value of 200 to 300 B. U. The viscosity of the latter reached a peak after storing for 72 hr, and then decreased with a further period of storage.

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Many fat replacers are now available in the market. All of them, however, are made of carbohydrates or proteins. In this paper another fat replacer, sucrose fatty acid polyester (SPE), is reviewed.

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The texture and stability of a starch paste can be improved by modification using a combi nation of hydroxypropylation and cross-linking.

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The physicochemical properties of starch, especially the feature of gelatinization and retro gradation of starch, were outlined. Individualities of starch grain must be taken into account to understand the gelatinizationprocess.An apparent phase diagram of starch was given, which indicates the gelatinization behavior of starch containing water of more than 60% differs from that of those of less than 30% . The rate of the retrogradation was described in relation to molecular structure and size. The effect of lipids on the gelatinization and the retrogradation was discussed .

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Some experimental results on the utilization of starch in starchy food were explained in this paper. Physicochemical properties of Harusame noodles were affected by the characteristics of thestarch used as well as the method of preparation employed. Potato starch was used as the raw material of Boro and Ebi-Senbei (shrimp craker) because of soft and refreshing taste and higher heat expansion power, respectively. The texture of Mochi can be altered, depending upon the processing methods and some additions of waxy corn or tapioca starch. It was found that the addition of potato or tapioca starch could improve the texure of the noodles. The addition of β-amylase or carbohydrate to some kinds of starchy food effectively retarded the rate of starch retrogradation. The addition of about 5% waxy corn starch was able to repress syneresis of Curdlan gel.

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