Raw Starch Digestion Research Articles

アミラーゼの生でんぷん分解能と生でんぷんへの吸着能

1. Fungal amylases 1) Aspergillus awamori : Alpha-amylase has an extremely weak activity to digest raw starch, but glucoamylase has strong activity to digest raw starch. Glucoamylase I, can adsorb on raw starch, is the principle of raw starch digestion. Glucoamylase II, can not adsorb on raw starch, has an extremely weak activity to digest raw starch. 2) Rhizopus sp. and Aspergillus oryzae: These two fungi have the similar amylase system with those of Asp, awamori on raw starch digestion and raw starch adsorption. 2. Comparison of four kinds of α-amylase 1) Pancreactic α-amylase digests raw starch most strongly and can adsorb on raw starch most easily. Asp, oryzae α-amylase digests raw starch most weakly and adsorbs on raw starch imperceptibly. In the case of α-amylases from bacteria and malt, α-amylase adsorption curves give reverse position from those shown for digestion. Apparently the ability to adsorb on raw starch does not necessarily indicate ability to digest the raw starch. 2) Glucose and maltose, especially the latter, inhibit both amylase adsorption on raw starch and raw starch digestion, and so the raw starch digestion is accelerated by dialysis. 3. Debranehing enzymes 1) Pseudomonas isoamylase: This enzyme, can adsorb on raw starch, assists the raw starch, especially waxy starch, digestion by Aspi awamori glucoamylase I or II. 2) Aerobacter pullulanase: This enzyme, can not adsorb on raw starch, assists the raw starch digestion by Rhizopus glucoamylase I. 4. Beta-amylases 1) Plant β-amylase can not adsorb on raw starch and has no activity to digest raw starch. 2) Bacterial β-amylase can adsorb on raw starch and has a strong activity to digest raw starch.

Multiplicity of Glucoamylase of Aspergillus oryzae Part 2. Enzymatic and Physicochemical Properties of Three Forms of Glucoamylase

AbstractThree forms of glucoamylase of Aspergillus oryzae had optimum pH range between 4.5 to 5.0 at 40°C and optimum temperature range between 40 and 60°C. They were most stable at pH range between 4.0 and 7.0 and temperatures up to 40°C. The molecular weights were 76.000, 38.000 and 38.000, respectively. Hydrolysis activities of the three glucoamylases on different substrates were studied. They differed in their rate of attack on many substrates. Glucoamylase I had strong debranching activity and was highly active in raw corn starch digestion. Glucoamylase II and III had weak debranching activities and could hardly digest raw starch.

アミロメイズVIIデンプンの人工消化と幼若ラットの成長に及ぼす影響

アミロメイズVIIデンプンの人工消化と幼若ラットの成長に及ぼす影響

Pullulanase Responsible for Digesting Raw Starch

AbstractIn a previous publication (Stärke 27 [1975], 123) the fractionation of glucoamylase from Rhizopus sp. into two fractions, glucoamylase I and glucoamylase II, was reported. Referring to the interaction of these two fractions with pullulanase the following observations were made: Pullulanase accelerated the raw waxy corn starch digestion by glucoamylase I of Rhizopus sp. Glucoamylase II was less active on the raw starch digestion than glucoamylase I, and pullulanase could not accelerate the raw waxy corn starch digestion by glucoamylase II. Intracellular and extracellular pullulanases had the same acclerating activity on the raw starch digestion by glucoamylase I or II. Pullulanase had a less acclerating activity on the raw non waxy corn starch digestion than raw waxy corn starch digestion. From this fact, it was suggested that the amylose in raw non waxy corn starch may hinder the raw starch digestion by glucoamylase.

The formation and properties of subtilisn-modified glucoamylase.

The glucoamylase I which was purified from a culture of Aspergillus awamori var. kawachi as an enzyme having an ability to digest raw starch, was converted to a modified enzyme with decrease in molecular weight and carbohydrate content by incubation with subtilisin in 0.01 m phosphate buffer, pH 6.8, at 30°C. The modified glucoamylase, isolated by the DEAE-Sephadex A–50 column chromatography, showed a 77% specific activity, and the same manner of the hydrolysis curve for gelatinized potato starch and maltose as the native enzyme, but showed no digestibility for raw starches nor adsorbability onto raw corn-starch, and a lower hydrolysis limit of 80 per cent for glycogen. Stabilities also decreased at pH 9 and at 65°C, respectively. Protease was proved to change the properties of glucoamylase.

Starch Digestion with Microbial Enzymes

(1) Raw starch digestion by black-koji amylase system was studied. a) The ability of the black-koji amylase system to digest raw starch may be associated with the ability to adsorb on raw starch. b) Alpha-amylase had an extremely weak activity to digest raw starch, but glucoamylase had a strong activity to digest raw starch. c) Alpha-amylase and glucoamylase, when used jointly, interacted with each other increasing digestion of raw starch to about 3 times the sum of their separate activities. d) Glucoamylase consisted of two kinds of glucoamylase, that is, glucoamylase I and glucoamylase II. The raw waxy corn starch digestion by glucoamylase I was accelerated by adding a-amylase or isoamylase. The raw non waxy corn starch digestion by glucoamylase I was accelerated by a-amylase but not so much by isoamylase as by a-amylase. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated extremely by adding isoamylase, but not by a-amylase. (2) Alpha amylase adsorption on raw starch and its relation to raw starch digestion were investigated. a) Pancreatic a-amylase digested raw starch most strongly and was adsorbed on raw starch most easily. In the case of a-amylases from bacteria and malt, α-amylase adsorption curves reversed positions from those shown for digestion. b) Glucose and maltose, especially the latter, inhibite both amylase adsorption and raw starch digestion, and so the raw starch digestion was accelerated by dialysis . (3) Raw starch digestion by Rhizopus amylase system was studied. a) The glucoamylase system of Rhizopus sp. was fractionated into two kinds of glucoamylase, that is, glucoamylase I and II. b) Glucoamylase I could be adsorbed on raw starch and was highly active in raw starch digestion. The raw waxy corn starch digestion by glucoamylase I was accelerated by adding α-amylase or pullulanase. c) Glucoamylase II could not be adsorbed on raw starch. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated by adding α-amylase contrary to the case of glucoamylase II of black-koji.

Multiple Forms of Glucoamylase of Rhizopus Species

AbstractThe glucoamylase system of Rhizopus sp. was fractionated into two kinds of glucoamylase by using the corn starch adsorption technique supplemented by CM‐cellulose chromatography. One of these fractions, referred to as glucoamylase I, has a strong debranching activity and is highly active in raw starch digestion.The raw waxy corn starch digestion by glucoamylase I was accelerated by adding a‐amylase from Rhizopus sp. or from Aspergillus oryzae. The raw non‐waxy corn starch digestion by glucoamylase I was more difficult than the raw waxy corn starch digestion, which was also accelerated by adding α‐amylase from Aspergillus oryzae.On the other hand, another fraction, referred to as glucoamylase II, has a weak debranching activity and can not be adsorbed on raw starch. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated by adding α‐amylase from Rhizopus sp.

アミラーゼによる生でんぷん分解

(1) Raw starch digestion by black-koji amylase system was studied. (a) The ability of the black-koji amylase system to digest raw starch may be associated with ability to adsorb on raw starch. (b) Alpha-amylase has an extremely weak activity to digest raw starch, but glucoamylase has a strong activity to digest raw starch. (c) Alpha-amylase and glucoamylase, when used jointly, interact with each other increasing digestion of raw starch to about 3 times the sum of their separate activities . (d) Glucoamylase consists of two kinds of glucoamylases, that is, glucoamylase I and glucoamylase II. The former can adsorb on raw starch and is the principle of raw starch digestion. This enzyme also can hydrolyze β-limit dextrin from glycogen very easily. On the other hand, the latter, glucoamylase II, can not adsorb on raw starch and has an extremely weak activity to digest raw starch. This enzyme can scarcely hydrolyze β-limit dextrin from glycogen. (2) Alpha-amylase adsorption on raw starch and its relation to raw starch digestion were investigated. (a) Pancreatic a-amylase digests raw starch most strongly and is adsorbed on raw starch most easily. Fungal α-amylase digests raw starch most weakly and is adsorbed on raw starch imperceptibly. In the case of α-amylases from bacteria and malt, α-amylase adsorption curves reverse positions from those shown for digestion. (b) The adsorption of pancreatic α-amylase on raw starch is rapid and the adsorbed amylase is desorbed at a decelerating rate with time and is similar to the digestion activity curve. (c) Glucose and maltose, especially the latter, inhibit both amylase adsorption on raw starch and raw starch digestion, and so the raw starch digestion is accelerated by dialysis . (3) Pseudomonas isoamylase assists the raw starch, especially waxy starch, digestion by the black-koji glucoamylase I.

Fractionation of the Glucoamylase System from Black‐koji Mold and the Effects of Adding Isoamylase and Alpha‐amylase on Amylolysis by the Glucoamylase Fractions

AbstractThe glucoamylase system of black koji mold was fractionated into four kinds of glucoamylase by using the corn starch adsorption technique supplement by DEAE‐cellulose column chromatography. One of these fractions, referred to as glucoamylase I, had a strong debranching activity and is highly active in raw starch digestion.The raw waxy corn starch digestion by glucoamylase I was accelerated by adding α‐amylase or isoamylase. The raw non‐waxy corn starch digestion by glucoamylase I was accelerated by α‐amylase but not so much by isoamylase as by α‐amylase.On the other hand, another fraction, referred to as glucoamylase II, had very weak debranching activity and was most feeble in the digestion of raw starch. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated extremely by adding isoamylase, but not by α‐amylase.

The influence of processing upon the nutritive value of the potato. Digestibility studies with pigs.

AbstractDigestibility trials were undertaken with pigs weighing 40 kg to determine the nutritive value of cooked potato flour, dried potato dice and raw potato mash. Apparent digestibility coefficients were, respectively, 0.96, 0.95 and 0.92 for energy and 0.89, 0.80 and 0.69 for nitrogen (N). The digestible energy values were 16.5, 16.3 and 15.7 MJ/kg d.m., and the contents of digestible N were 1.35, 1.05 and 1.02 g N/100 g d.m.When fed with balancer meals based on either maize or oat husk meal, the raw potato caused an apparent depression in the digestibility of N in the diet as a whole, and a reduction in the efficiency of utilisation of digested N.The findings are discussed in relation to the ability of the pigs to digest raw potato starch and the possibility of a component of raw potato, rendered ineffective by cooking but only partly so by drying, interfering with N digestibility and utilisation.

Alpha-amylase Adsorption on Raw Starch and Its Relation to Raw Starch Digestion

Alpha-amylase adsorption on raw starch and its relation to raw starch digestion were investigated. Four kinds of α-amylases-pancreatic, malt, fungal, and bacterial amylaseswere used. The relation of digestion of raw starch by a-amylases to adsorption of the enzyme was complicated and it was dependent on the specific enzyme, its concentration, time of action and on the specific starch involved. The adsorption of the enzyme on raw starch was rapid and was desorbed at a decelerating rate with time and was similar to the digestion activity curve.

Digestion of Starch and Some of Its Degradation Products by Newborn Pigs

The capacity of newborn pigs to digest raw corn starch and several of its degradation products was tested by various techniques. Glucose, maltose, and a soluble starch preparation were digested more rapidly than raw starch. The rate of digestion of raw starch introduced directly into the intestine was not improved with supplemental pancreatic amylase. The data suggest that the prime factor restricting the digestion of raw starch by newborn pigs is that responsible for the initial rupture of the starch granule. The rate of digestion of soluble starch is just below that of maltose and it is difficult to determine if the rate of digestion of soluble starch is limited by the availability of amylase or maltase. The rate of digestion of soluble starch, maltose and glucose by newborn pigs would appear to be sufficiently high to meet a large proportion of the pig's energy requirements, although consumption of such quantities of these carbohydrates may result in diarrhea.

On the Susceptibility of the Crystalline and Retrograded Forms of Amylose of Different Molecular Weights toward Black-koji Amylase System

The crystalline and retrograded amylose preparations were digested by black-koji amylase system in the heterogeneous state such as in the case of raw starch digestion. It was found that the usual retrograded amylose should be fractionated into two parts—one easily digestible and the other resistant toward black-koji amylase system. The latter part, when recrystallized by n-butanol, however, turned highly susceptible toward the enzyme action. Its molecular weight, as determined by the light scattering method, was found to be 32,000, a value much smaller than that of the original amylose (140,000).

On the Susceptibility of the Crystalline and Retrograded Forms of Amylose of Different Molecular Weights toward Black-koji Amylase System

The crystalline and retrograded amylose preparations were digested by black-koji amylase system in the heterogeneous state such as in the case of raw starch digestion. It was found that the usual retrograded amylose should be fractionated into two parts—one easily digestible and the other resistant toward black-koji amylase system. The latter part, when recrystallized by n-butanol, however, turned highly susceptible toward the enzyme action. Its molecular weight, as determined by the light scattering method, was found to be 32,000, a value much smaller than that of the original amylose (140,000).

Studies on the Amylolytic System of the Black-koji Molds

The amylase system of black-koji molds was fractionated, in respect to its activity, into two fractions, the dextrinogenic and saccharogenic. Their separate and combined activities to digest raw starch were investigated. Contrary to the knowledge established so far, the dextrinogenic amylase fraction was found to be capable of digesting the raw starch though only weakly, while the saccharogenic amylase fraction much more strongly. When the two fractions were combined, digestion proceeded with twice or thrice the velocity of the, sum of each component. This accelerating interaction, which never occurs in cooked-starch digestion, is worthy to be stressed as a characteristic of raw starch digestion by this amylase system. The raw starches of corn, wheat and glutinous rice are in this way, digested completely to glucose. Among them, glutinous rice starch displays peculiar facility in the digestion.

The Effect of Amylases on the Digestibility of Starch by Baby Pigs

Experiments were performed with two-day-old baby pigs to observe the effect of supplementing various purified starch-containing diets with amylolytic enzymes. Supplemental pancreatic and malt amylases had no effect on growth rate, survival time, or digestibility of raw or cooked starch. Cooked starch appeared to be inferior to raw starch as a source of carbohydrate in baby pig diets.

8. A Microscopic Study on the Inner Structure of Starch Granules

Showing the microphotographs, writers report in this paper that “Black-Koji-amylase system” can easily digest raw starch granules, even that of potato, and by the use of this enzyme system the existence of the lamellation structure in the inner part of potato starch granules can be observed.