Publications by authors named "Katsuyuki Ishihara"

Background: Limited crop production due to lower rainfall has a major impact on the supply and demand of food for the human population. In potato (Solanum tuberosum L.), one of the major crops, there is also concern about a lack of production due to drought stress.

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Edible crickets have recently been used as a new alternative protein source with high nutritional value. The nutritional and flavor-related value of edible crickets varies greatly depending on the species, growth conditions and processing conditions. However, few studies have investigated the effects of the diet fed to crickets during their growth phase on flavor.

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Background And Aims: Cereal-based foods such as fruit granola (FG) and corn flakes (CF) form part of a fiber-rich diet. Dietary fiber has a good effect on human health. However, changes in gut microbiota and intestinal immunity have not been investigated.

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Sweet potato is a crop that is widely consumed all over the world and is thought to contribute to health maintenance due to its abundant nutrients and phytochemicals. Previous studies on the functionality of sweet potatoes have focused on varieties that have colored pulp, such as purple and orange, which contain high levels of specific phytochemicals. Therefore, in the present study, we evaluated the anti-inflammatory effects of light-yellow-fleshed sweet potatoes, which have received little attention.

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The contribution of breakfast to daily nutrient intake is low, particularly among children, at only about 20%, and it is difficult to determine whether children are receiving adequate nutrients at breakfast. Although alterations in breakfast content are considered to affect lifestyle habits such as sleep and defecation, there have been few intervention studies in children. The relationship between nutritional balance, dietary intake, and lifestyle habits in children remains unclear.

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Article Synopsis
  • The study investigates how different afternoon snacks (fruit granola, potato chips, roasted sweet potato, and black beans) affect glucose levels during dinner, particularly the second-meal effect.
  • Results show that certain snacks like fruit granola and roasted sweet potato suppress post-meal glucose spikes better when consumed at specific times (3 PM vs. 5 PM).
  • The findings suggest that choosing snacks high in carbohydrates and soluble fiber could positively influence glucose management, which has implications for dietary recommendations and future research.
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Article Synopsis
  • - The study focuses on a specific glycolipid from oats, known as digalactosyldiacylglycerol-monoestolide (DGDG-monoestolide), which has a unique structure where a fatty acid is replaced by a hydroxy fatty acid ester.
  • - DGDG-monoestolide identified in oats, specifically DGDG-LAHLA, was shown to reduce the production of inflammatory markers in cell experiments, highlighting its potential anti-inflammatory properties.
  • - The research suggests that both intact DGDG-LAHLA and its metabolites might play a role in its anti-inflammatory effects, potentially promoting the health benefits of oats as a functional food.
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The ability of dermal fibroblasts to synthesize collagen decreases with ages. The integrity of collagen fibers severely decreases in aged skin, causing its characteristic morphological changes such as wrinkles and sagging. To prevent and improve skin aging, the stimulation of collagen synthesis in dermal fibroblasts is important.

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A potato fraction library was constructed to investigate functional secondary metabolites from 8 cultivars: Kitahime, Pilka, Sakurafubuki, Atlantic, Toyoshiro, Snowden, Kitamurasaki, and Northern Ruby, which were divided into flower, leaf, stem, roots, tuber peel, and tuber. Each fraction was a semi-purified extract and about 800 fractions were prepared for the library. They were analyzed by DAD-LC/MS to obtain structural information and were evaluated for various biological activities.

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Potato chips (PC) contain abundant amounts of the free radical scavenger ascorbic acid (AA) due to the rapid dehydration of potato tubers (Solanum tuberosum) that occurs during frying. To evaluate the antioxidant activity of PC, this study examined reactive oxygen species (ROS) levels in tissues from SMP30/GNL knockout (KO) mice that cannot synthesize AA and determined AA and ROS levels after the animals were fed 20 and 10% PC diets for 7 weeks. Compared with AA-sufficient mice, AA-depleted SMP30/GNL KO mice showed high ROS levels in tissues.

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Potato (Solanum tuberosum) tubers contain vitamin C (VC) and commercial potato chips have more VC content per wet weight by dehydration during frying. However, intestinal absorption of VC from orally ingested potatoes and its transfer to the blood remains questionable. The present study was designed to determine whether the dietary consumption of potatoes affects VC concentration in plasma and urinary excretion of VC in human subjects.

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Acrylamide (AAm) is produced in food through the reaction of asparagine and reducing sugar. We examined several methods of reducing the level of AAm using potato tubers. The fried model system that we employed consisted of thin slices that were first treated in water under different conditions before frying.

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Acrylamide (AAm) is formed from asparagine (Asn) and reducing sugar during cooking of foods at high temperature. We examined the formation of AAm in a model system using a glass fiber filter paper, and looked for suitable conditions for inhibiting AAm formation. In frying, the formation rate was about 10 times that in a moistureless oven.

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