A yogurt-type product from saccharified rice was developed. Jasmine rice was saccharified with amylolytic enzymes at 55 °C. Changes of reducing sugars, sugar components and compositions during hydrolysis were studied to obtain optimum condition and yield of glucose. Rice milk was prepared by fortification of saccharified rice with 3 % casein, 3% soybean oil and 0.4 % calcium lactate to improve both nutritive quality and organoleptic properties. Mixed cultures of Lactobacillus acidophilus and L. casei subsp. rhamnosus were used for lactic fermentation of rice milk. The effect of beta glycerophosphate, inoculum size and incubation period were investigated. Improvement for a more palatable yogurt was achieved by blending rice yogurt with pectin and strawberry preserve. Resulted rice-based yogurt with strawberry contained 3.05 % protein, 2.67 % fat, 24.4 % glucose, 1.5 % sucrose, 47 mg/100g of calcium, 0.86 % acidity as lactic, pH 3.48 and lactic bacteria count of 7.6 × 10 7 CFU/g. Sensory evaluation revealed that rice-based yogurt with strawberry was well

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Development of a Yogurt-type Product from Saccharified Rice

In the beer brewing industry throughout the world about 8 × 106 tons of starch is annually converted into fermentable sugars and dextrins. Determining factors for the degradation of starch are the conditions of mashing and the action pattern of the amylases, α-amylase and β-amylase. Although present in germinating barley and in barley malt, α-glucosidase and debranching enzyme (plant pullulanase) exert little action in normal brewing procedures. Accordingly, the majority of the α-1, 6 linkages in amylopectin survive the brewing process. In a series of studies the formation and the composition of the dextrins present in beer wort have been examined by enzymic methods and quantitative gel filtration chromatography. The results show:-About 75% of the starch degradation products are glucose, maltose, and maltotriose. The remaining 25% constitutes the unf ermentable residue, generally known as dextrins.-About half of the dextrins consists of oligosaccharides with less than 10 glucose units, either linear or singly-branched.-About half of the dextrins contains 10 or more glucose units per molecule and may be termed megalosaccharides. These dextrins are multiply-branched.-The weight distribution of the dextrins versus their molecular weight exhibits a characteristic pattern for which the term "wavy distribution" has been coined, inter alia to indicate that the dextrins in wort and beer seem to fall into distinct groups. Subsequent structural analysis has revealed that these groups of dextrins are characterized by their number of α-1, 6 linkages.-The multiply-branched dextrins in wort and beer represent structural entities of dense branching in the original amylopectin (starch) molecules. Thus the study of dextrins in brewing also provides information of the fine structure of starch. Based on these findings a model for the degradation of starch in beer brewing by a-amylase and β-amylase will be proposed.

Degradation of Starch by Amylases in Beer Brewing (アミラ-ゼシンポジウム(1977)特集)

Starch makes up the nutritive reserves of many plants. Starch biosynthesis is a complex process, which may be summarized as during the growing season, the green leaves collect energy from the sun, this energy is transported as a sugar solution to the starch storage cells, and the sugar is converted into starch in the form of tiny granules occupying most of the cell interior. The conversion of sugar into starch takes place through enzymes (Corn Production Source, 2011; Tester et al., 2006).

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Physical and/or Chemical Modifications of Starch by Thermoplastic Extrusion

For the preparation of a tasty fermented beverage from rice flour, suitable amylases and lactic acid bacteria were explored and selected. A glucoamylase from Rhizopus commercially named as gluczyme formed less reducing sugars from gelatinized rice flour than glucoamylase from Aspergillus. However, saccharified solution prepared by gluczyme was well utilized by a lactic acid bacterium isolated from a kefir, which is considered to be a bacterium closely related to Leuconostoc mesenteroides. The substances such as amino acids formed by some contaminating enzymes like protease in gluczyme are presumed to stimulate the growth of the kefir-bacterium and contribute to the formation of a favorable fermented beverage.

Lactic Acid Fermentation of Saccharified Solution from Rice Flour

Controlled aeration ofLeuconostoc mesenteroides was studied as a possible mechanism for control of the formation of acetic acid a metabolite of major influence on the taste of lactic fermented foods. Fermentations were carried out in small scale in a medium in which growth was limited by the buffer capacity only. Ethanol and acetic acid formed during the fermentation were analyzed by rapid head space gas chromatography, and the ratio of the molar concentrations of these two volatiles quantitatively predicted the balance between the formation of acetic acid and lactic acid. The oxygen concentration during the fermentations decreased rapidly to zero, meaning that oxygen transfer was limited by the volumetric oxygen transfer rate,k1aC*. A linear correlation between k1aC* and the quantity of acetic acid produced was established, and it is suggested that such oxygenated heterolactic fermentation processes should be analyzed as fed-batch fermentations with oxygen as the limiting substrate. Addition of fructose in limited amounts leads to the formation of one half mole of acetic acid for each mole fructose, thus offering an alternative mechanism for controlling acetic acid formation.

Aeration-controlled formation of acetic acid in heterolactic fermentations

The acid‐ and flavor‐forming properties of Lactobacillus plantarum and Leuconostoc mesenteroides isolated from Sikhae, a Korean traditional lactic acid fermented fish product, were examined and compared to those of Lactobacillus casei and Lactococcus lactis subsp. diacetylactis DRC3. The effects of prefermentation of rice flour in solid‐state with Bacillus laevolacticus and Saccharomyces‐cerevisiae, extrusion cooking and addition of soymilk as the substrate of lactic acid fermentation vere tested. Extrusion cooking and prefermentation of rice increased the soluble solid and sugar contents before malt digestion. The amount of sugar consumption during lactic fermentation varied with the type of bacteria. Leuconostoc mesenteroides(sikhae) and Lactobacillus plantarum(sikhae) increased up to 6 times of original cell number by 24 hrs of fermentation in rice + soymilk substrate, but Lactococcus lactis decreased in the same substrates. The final pH of the cereal lactic beverage was in the range of 3.4 ‐ ...

T.E. Mathiasen

Papers

Fermentation of prefermented and extruded rice flour by the lactic acid bacteria from sikhae