Slow starch hydrolysis of non-glutinous rice flour and potato starch heated with taxifolin: contribution of proteins to the former and longer amylose to the latter.

Taxifolin (dihydroquercetin), which has various pharmacological functions, is contained in edible plants. Some taxifolin-containing foodstuffs such as adzuki bean and sorghum seeds are cooked by themselves and with other starch-containing ingredients. In this study, non-glutinous rice flour (joshin-ko) and potato starch were heated with taxifolin.

Further slowing down of hydrolysis of amylose heated with black soybean extract by treating with nitrite under gastric conditions.

Black soybean (BSB), which contains cyanidin-3-O-glucoside (C3G) and procyanidins, is cooked with rice in Japan. The color of the cooked rice is purplish red due to the binding of C3G and reddish oxidation products of procyanidins. These components can slowdown pancreatin-induced hydrolysis of amylose more significantly than the hydrolysis of amylopectin, and can react with nitrous acid in the stomach.

The Procyanidin C1-Dependent Inhibition of the Hydrolysis of Potato Starch and Corn Starch Induced by Pancreatin.

Procyanidins are contained in various foods, and their effects on starch hydrolysis have been reported. In Japan, black soybeans, which contain a trimeric procyanidin, procyanidin C1 (proC1), are cooked with rice and used to prepare dumplings. In this study, the effects of proC1 on the pancreatin-induced formation of reducing sugars and starch hydrolysis were studied using potato starch and corn starch.

Pancreatin-induced liberation of starch/cyanidin 3--glucoside complexes from rice cooked with black soybean that exhibit slow hydrolysis.

Cyanidin 3--glucoside (C3G), which has various health-promoting functions, is contained in black soybean (BSB). In Japan and Korea, BSB is cooked with rice and the cooked rice appears purplish in colour. In this study, BSB was cooked with glutinous rice, non-glutinous rice, and high-amylose rice.

Contribution of amylose-procyanidin complexes to slower starch digestion of red-colored rice prepared by cooking with adzuki bean.

Combining high-carbohydrate food with polyphenol-rich food is a possible way of producing slowly digestible starch with beneficial health properties. In Japan, non-glutinous and glutinous rice are cooked with adzuki bean and the colour of the cooked rice is pale red. In this article, we show that (1) the red colour of rice could be attributed to the oxidation of adzuki bean procyanidins, (2) pancreatin-induced starch digestion of the red-coloured non-glutinous rice was slower than white rice and (3) the digestion of amylose and potato starch but not amylopectin became slower by heating with procyanidin B2.

Procyanidins in rice cooked with adzuki bean and their contribution to the reduction of nitrite to nitric oxide (NO) in artificial gastric juice.

In Japan, adzuki bean is cooked with rice. During the cooking, the colour of rice becomes pale red. It is postulated that the red pigment is produced from procyanidins and that the ingestion of red rice causes the production of nitric oxide (NO) in the stomach by reacting with salivary nitrite.

Slow starch digestion in the rice cooked with adzuki bean: Contribution of procyanidins and the oxidation products.

Adzuki bean is often cooked with non-glutinous rice in Japan, and the dish is called adzuki-meshi. By the cooking, flavonoids in adzuki bean are transferred to rice, and the color of the rice becomes pale red. However, it has not been reported on starch digestion of the rice of adzuki-meshi.

Suppression of Pancreatin-Induced Digestion of Starch in Starch Granules by Starch/Fatty Acid and Starch/Flavonoid Complexes in Retrograding Rice Flour.

Adzuki beans are used to prepare foods with glutinous and non-glutinous rice in Japan, and adzuki bean pigments are able to color rice starch a purplish red. This study deals with the adzuki bean extract-dependent suppression of starch digestion of non-glutinous rice flour (joshinko in Japanese), which was gelatinized in boiling water and then cooled to 37 °C. Accompanying the treatment of joshinko with pancreatin, amylose and amylopectin were released from the joshinko particles, and the released amylose and amylopectin were further digested.

Interactions of flavonoids with α-amylase and starch slowing down its digestion.

Starch is digested to glucose in the intestine and absorbed into the body. If the increased blood concentrations of sugar after meals decrease slowly or are maintained for a long time, various adverse effects are induced. Therefore, it is important to decrease the rate of the digestibility of starch in the intestine in the patients of hyperglycemia.

Possible Reactions of Dietary Phenolic Compounds with Salivary Nitrite and Thiocyanate in the Stomach.

Foods are mixed with saliva in the oral cavity and swallowed. While staying in the stomach, saliva is contentiously provided to mix with the ingested foods. Because a salivary component of nitrite is protonated to produce active nitrous acid at acidic pH, the redox reactions of nitrous acid with phenolic compounds in foods become possible in the stomach.

Inhibition of Pancreatin-Induced Digestion of Cooked Rice Starch by Adzuki (Vigana angularis) Bean Flavonoids and the Possibility of a Decrease in the Inhibitory Effects in the Stomach.

Flavonoids of adzuki bean bind to starch when the beans are cooked with rice. The purpose of this study is to show that adzuki flavonoids can suppress pancreatin-induced digestion of cooked rice starch. The diethyl ether extract of water boiled with adzuki bean inhibited starch digestion, and quercetin and a cyanidin-catechin conjugate (vignacyanidin) but not taxifolin in the extract contributed to the inhibition.

Reactions of polyphenols in masticated apple fruit with nitrite under stomach simulating conditions: Formation of nitroso compounds and thiocyanate conjugates.

By the ingestion of fresh apple fruit, it is masticated squeezing apple juice into the oral cavity and the juice is mixed with saliva. The mixture of saliva and apple juice is swallowed into the stomach where the pH is around 2. This paper deals with the reactions of polyphenols in the juice obtained by mastication of apple fruit with salivary nitrite under acidic conditions.

Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions.

Foods of plant origin contain flavonoids. In the adzuki bean, (+)-catechin, quercetin 3-O-rutinoside (rutin), and quercetin 7-O-β-D-glucopyranoside (Q7G) are the major flavonoids. During mastication of foods prepared from the adzuki bean, the flavonoids are mixed with saliva and swallowed into the stomach.

Interactions between (+)-catechin and quercetin during their oxidation by nitrite under the conditions simulating the stomach.

When foods that contain catechins and quercetin glycosides are ingested, quercetin glycosides are hydrolyzed to quercetin during mastication by hydrolytic enzymes derived from oral bacteria and the generated quercetin aglycone is mixed with catechins in saliva. The present study deals with the interactions between (+)-catechin and quercetin during their reactions with nitrous acid under the conditions simulating the gastric lumen. Nitrous acid reacted with (+)-catechin producing 6,8-dinitrosocatechin, and quercetin partially suppressed the dinitrosocatechin formation.

Interactions of starch with a cyanidin-catechin pigment (vignacyanidin) isolated from Vigna angularis bean.

A cyanidin-catechin pigment isolated from adzuki bean (vignacyanidin) interacted with starch. The pigment had absorption maxima at 530 and 540 nm at pH 2.0 and 6.

Effects of starch on nitrous acid-induced oxidation of kaempferol and inhibition of α-amylase-catalysed digestion of starch by kaempferol under conditions simulating the stomach and the intestine.

Kaempferol glycosides can be hydrolyzed to their aglycone kaempferol during cooking under acidic conditions and in the oral cavity and the intestine by glycosidases. Kaempferol was oxidised by nitrite under acidic conditions (pH 2.0) to produce nitric oxide (NO), and the nitrite-induced oxidation of kaempferol was enhanced and inhibited by 10 and 100mg of starch ml(-1), respectively.

Isolation and characterization of a cyanidin-catechin pigment from adzuki bean (Vigna angularis).

Adzuki bean is used to prepare many kinds of foods in east Asia, and the seed coat contains water-soluble anthocyanins, catechins, and flavonols. In the present study, ethyl acetate-soluble purplish pigments were isolated from adzuki bean. Pigments of soaked adzuki bean were extracted with 1% HCl in methanol.

Effects of the food additive sulfite on nitrite-dependent nitric oxide production under conditions simulating the mixture of saliva and gastric juice.

The food additive sulfite is mixed with saliva, which contains nitrite, in the oral cavity, and the mixture is mixed with gastric juice in the stomach. In the stomach, salivary nitrite can be transformed to nitric oxide (NO). In this study, the effects of sulfite on nitrite-dependent NO production were investigated using acidified saliva (pH 2.

Enhancement of iron(II)-dependent reduction of nitrite to nitric oxide by thiocyanate and accumulation of iron(II)/thiocyanate/nitric oxide complex under conditions simulating the mixture of saliva and gastric juice.

Iron(III) ingested as a food component or supplement for iron deficiencies can react with salivary SCN(-) to produce Fe(SCN)(2+) and can be reduced to iron(II) by ascorbic acid in the stomach. Iron(II) generated in the stomach can react with salivary nitrite and SCN(-) to produce nitric oxide (NO) and FeSCN(+), respectively. The purpose of this investigation is to make clear the reactions among nitrite, SCN(-), iron ions, and ascorbic acid under conditions simulating the mixture of saliva and gastric juice.

Inhibition of xanthine oxidase activity by an oxathiolanone derivative of quercetin.

An oxathiolanone derivative of rutin could be produced in the stomach after the ingestion of rutin containing foods, and the oxathiolanone derivative could be hydrolysed to an oxathiolanone derivative of quercetin (quercetin-oxathiolanone) in the intestine. Quercetin-oxathiolanone as well as quercetin inhibited xanthine oxidase. Approximately 0.

Inhibition of buckwheat starch digestion by the formation of starch/bile salt complexes: possibility of its occurrence in the intestine.

During the digestion of starch in foods, starch is mixed with bile in the duodenum. Because fatty acids and some kinds of polyphenols could bind to starch, it was postulated that bile salts might also bind to starch. The purpose of this paper is to study the effects of bile and bile salts on starch/iodine complex formation and pancreatin-induced starch digestion.

Fatty acids, epicatechin-dimethylgallate, and rutin interact with buckwheat starch inhibiting its digestion by amylase: implications for the decrease in glycemic index by buckwheat flour.

Glycemic indexes of bread made from mixtures of wheat flour and buckwheat flour are lower than those made from wheat flour. To discuss the mechanism of the buckwheat flour-dependent decrease in glycemic indexes, the formation of a starch-iodine complex and amylase-catalyzed digestion of starch were studied using buckwheat flour itself and buckwheat flour from which fatty acids, rutin, and proanthocyanidins including flavan-3-ols had been extracted. Absorbance due to the formation of a starch-iodine complex was larger in extracted than control flour, and starch in extracted flour was more susceptible to pancreatin-induced digestion than starch in control flour.

Nitrogen dioxide-dependent oxidation of uric acid in the human oral cavity under acidic conditions: implications for its occurrence in acidic dental plaque.

The pH in dental plaque falls to below 5 after the ingestion of foods, and it may remain low if acid-tolerant bacteria grow in the plaque. Certain nitrate-reducing bacteria in the oral cavity can proliferate in dental plaque at low pH, and nitrite is detected in such plaque. In acidic dental plaque, NO(2) can be produced by self-decomposition of nitrous acid and also by peroxidase-catalyzed oxidation of nitrite, and it may oxidize uric acid, a major antioxidant in the oral cavity.

Formation of nitric oxide, ethyl nitrite and an oxathiolone derivative of caffeic acid in a mixture of saliva and white wine.

Reactions of salivary nitrite with components of wine were studied using an acidic mixture of saliva and wine. The formation of nitric oxide (NO) in the stomach after drinking wine was observed. The formation of NO was also observed in the mixture (pH 3.