Taste of common prebiotic oligosaccharides: impact of molecular structure.

Prebiotic oligosaccharides are naturally occurring nondigestible carbohydrates with demonstrated health benefits. They are also a chemically diverse class of nutrients, offering an opportunity to investigate the impact of molecular structure on oligosaccharide taste perception. Accordingly, a relevant question is whether these compounds are detected by the human gustatory system, and if so, whether they elicit sweet or "starchy" taste.

Evaluation of Functional Spray Coatings for Mitigating the Uptake of Volatile Phenols by Pinot Noir Wine Grapes via Blocking, Absorption, and/or Adsorption.

Spray coatings have shown promising potential in preventing the uptake of smoke phenols from wildfires into wine grapes. Three cellulose nanofiber-based coatings with low methoxyl pectin or varying concentrations of chitosan were made into films and their potential for blocking, absorption, or adsorption of phenols (guaiacol, -cresol, and syringol) was evaluated using a custom-built smoke diffusion box. The coatings were also applied to Pinot noir grapes in a vineyard.

Taste perception of oligosaccharides derived from pullulan.

Recent studies indicate that humans can taste starch hydrolysis products (i.e. maltooligosaccharides; MOS).

Taste Detection of Maltooligosaccharides with Varying Degrees of Polymerization.

Previous studies have shown that humans can taste maltooligosaccharides [MOS; degree of polymerization (DP) of 3-20] but not maltopolysaccharides (MPS; DP of >20) and that their taste detection is independent of the canonical sweet taste receptor. The objectives of this study were to determine the DP ranges of target stimuli that are tasted and further to investigate the impact of DP on taste detectability. To achieve this goal, we prepared three food-grade MOS samples with narrow DP ranges using flash chromatography: low (4-6), medium (7-12), and high (14-21) DP samples.

Impact of functional spray coatings on smoke volatile phenol compounds and Pinot noir grape growth.

The frequency and intensity of wildfires have been increasing over the last 50 years and negatively impacted the wine industry. Previous methods of smoke mitigation during grape processing have shown little impact in reducing smoke taint in wines. Therefore, a novel method of using edible spray coatings for vineyard application was developed to help prevent volatile smoke phenol uptake in wine grapes.

Chromatographic fractionation of food-grade oligosaccharides: Recognizing and avoiding sensory-relevant impurities.

Flash chromatography utilizing microcrystalline cellulose (MCC) stationary phases and aqueous ethanol mobile phases have shown promise for the production of food-grade oligosaccharides. The current work extends the scope of these systems by demonstrating their use for the production of food-grade maltooligosaccharide preparations enriched in high degree of polymerization (DP) components. Furthermore, it is shown herein that caution must be exercised when using these MCC-based chromatographic systems in order to avoid sensory-relevant contamination of the final oligosaccharide preparations.

The Effect of -Coumaric Acid on Browning Inhibition in Potato Polyphenol Oxidase-Catalyzed Reaction Mixtures.

There has been considerable interest in using natural polyphenol oxidase (PPO) inhibitors to control browning in fruit and vegetable products. -Coumaric acid (CA), a common secondary metabolite of plants, has been studied as an inhibitor of PPOs/tyrosinases from several foods (e.g.

Chromatographic preparation of food-grade prebiotic oligosaccharides with defined degree of polymerization.

Prebiotic oligosaccharides are of widespread interest in the food industry due to their potential health benefits. This has triggered a need for research into their sensory properties. Such research is currently limited due to the lack of available food-grade oligosaccharide preparations with specific degree of polymerization (DP).

Role of Ascorbic Acid in the Extraction and Quantification of Potato Polyphenol Oxidase Activity.

The ability to accurately measure the activity of polyphenol oxidase (PPO) in complex matrices is essential. A problem encountered when using spectrophotometric methods is interference due to ascorbic acid (AA), often used as an enzyme "protecting agent" during PPO extraction. This study focuses on the nature of AA's effect on spectrophotometric determinations of PPO activity as well as enzyme extraction.

Information Retrieval in Food Science Research II: Accounting for Relevance When Evaluating Database Performance.

The impetus for this study is the limited amount of information on performance characteristics of food science-encompassing online bibliographic databases. Database usage is an important element in modern research because a comprehensive understanding of current knowledge is essential for effective, unbiased hypothesis formulation and testing. Six databases commonly recommended by academic libraries for information retrieval in the food sciences (Academic Search Premier [ASP], Agricultural Online Access [AGRICOLA], CAB Direct, Food Science and Technology Abstracts [FSTA], PubMed, and Web of Science [WoS]) were compared in a case study based on the research topic "in vitro bile acid binding properties of dietary lignin.

The nature of β-cyclodextrin inhibition of potato polyphenol oxidase-catalyzed reactions.

There is general interest in strategies to control polyphenol oxidase (PPO)-initiated enzymatic browning because it is often associated with declining food quality. Cyclodextrins are cyclic glucan oligosaccharides that form inclusion complexes with a number of PPO substrates. This study focuses on the effect of β-cyclodextrins (βCyD) on PPO-catalyzed reactions.

The Sweet Taste of Acarbose and Maltotriose: Relative Detection and Underlying Mechanism.

Although sweet-tasting saccharides possess similar molecular structures, their relative sweetness often varies to a considerable degree. Current understanding of saccharide structure/sweetness interrelationships is limited. Understanding how certain structural features of saccharides and/or saccharide analogs correlate to their relative sweetness can provide insight on the mechanisms underlying sweetness potency.

Information Retrieval in Food Science Research: A Bibliographic Database Analysis.

The aim of the present research was to ascertain the importance of electronic bibliographic database selection and multiple database usage during the information retrieval phase of research in the food sciences. Six commonly recommended databases were compared with respect to overall journal coverage and journal overlap. Databases were also evaluated with respect to coverage of food science-based journals and the extent of article coverage therein.

Preparation and characterization of isolated low degree of polymerization food-grade maltooligosaccharides.

Research involving human responses to the consumption of starch and its hydrolysis products would benefit from convenient sources of well defined, low cost, food-grade maltooligosaccharides (MOS). This report addresses such need by presenting an approach to obtain aforementioned MOS. A chromatography-ready MOS sample containing proportionately high amounts of low degree of polymerization (DP) MOS is initially prepared from commercially-available maltodextrins (MD) by taking advantage of the DP-dependent differential solubility of MOS in aqueous-ethanol solutions.

Furfural and 5-hydroxymethyl-furfural degradation using recombinant manganese peroxidase.

Biomass pretreatment-derived degradation compounds, such as furfural and 5-hydroxymethyl-furfural (HMF), inhibit the growth of fermentation microorganisms that utilize biomass to produce fuels and chemicals. Here we report that recombinant manganese peroxidase (rMnP) produced from the yeast Pichia pastoris can degrade furfural and HMF making them less toxic to microorganisms. Treatment with rMnP or manganese(III) acetate reduced furfural and HMF concentrations in a dose-dependent manner.

Oral Digestion and Perception of Starch: Effects of Cooking, Tasting Time, and Salivary α-Amylase Activity.

Since starch is a significant part of human diet, its oral detection would be highly beneficial. This study was designed to determine whether starch or its degradation products can be tasted and what factors influence its perception. Subjects were asked 1) to taste 8% raw and cooked starch samples for 5, 15, and 35 s and rate perceived intensities of sweetness and "other" taste (i.

Human taste detection of glucose oligomers with low degree of polymerization.

Studies have reported that some animals, including humans, can taste mixtures of glucose oligomers (i.e., maltooligosaccharides, MOS) and that their detection is independent of the known T1R2/T1R3 sweet taste receptor.

Methylene blue as a lignin surrogate in manganese peroxidase reaction systems.

Manganese peroxidase (MnP) is associated with lignin degradation and is thus relevant to lignocellulosic-utilization technologies. Technological applications require reaction mixture optimization. A surrogate substrate can facilitate this if its susceptibility to degradation is easily monitored and mirrors that of lignin.

Overcoming Reductant Interference in Peroxidase-Based Assays for Hydrogen Peroxide Quantification.

A problem commonly encountered when using peroxidase-based methods for hydrogen peroxide quantification in biobased matrixes is interference due to the presence of endogenous reductants. Such assays are typically based on the generation of an oxidized reporter molecule in direct proportion to the amount of hydrogen peroxide reduced in the peroxidase-catalyzed reaction. Endogenous reductants confound such assays by reducing the oxidized reporter molecule, thus resulting in underestimates of hydrogen peroxide content.

Humans Can Taste Glucose Oligomers Independent of the hT1R2/hT1R3 Sweet Taste Receptor.

It is widely accepted that humans can taste mono- and disaccharides as sweet substances, but they cannot taste longer chain oligo- and polysaccharides. From the evolutionary standpoint, the ability to taste starch or its oligomeric hydrolysis products would be highly adaptive, given their nutritional value. Here, we report that humans can taste glucose oligomer preparations (average degree of polymerization 7 and 14) without any other sensorial cues.

On the use of differential solubility in aqueous ethanol solutions to narrow the DP range of food-grade starch hydrolysis products.

Considerable research is focused on understanding the functionality of starch hydrolysis products (SHP) consisting of glucose, maltose, maltooligosaccharides (MOS), and maltopolysaccharides (MPS). A confounding factor in this research is the high molecular dispersity of commercially available SHP. The study presented herein characterizes a flexible fractionation approach for lowering the dispersity of such products.

PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress.

In fungi, two recognized mechanisms contribute to pH homeostasis: the plasma membrane proton-pumping ATPase that exports excess protons and the vacuolar proton-pumping ATPase (V-ATPase) that mediates vacuolar proton uptake. Here, we report that overexpression of PEP3 which encodes a component of the HOPS and CORVET complexes involved in vacuolar biogenesis, shortened lag phase in Saccharomyces cerevisiae exposed to acetic acid stress. By confocal microscopy, PEP3-overexpressing cells stained with the vacuolar membrane-specific dye, FM4-64 had more fragmented vacuoles than the wild-type control.

Overexpression of acetyl-CoA synthetase in Saccharomyces cerevisiae increases acetic acid tolerance.

Acetic acid-mediated inhibition of the fermentation of lignocellulose-derived sugars impedes development of plant biomass as a source of renewable ethanol. In order to overcome this inhibition, the capacity of Saccharomyces cerevisiae to synthesize acetyl-CoA from acetic acid was increased by overexpressing ACS2 encoding acetyl-coenzyme A synthetase. Overexpression of ACS2 resulted in higher resistance to acetic acid as measured by an increased growth rate and shorter lag phase relative to a wild-type control strain, suggesting that Acs2-mediated consumption of acetic acid during fermentation contributes to acetic acid detoxification.

Selective oxidation of enzyme extracts for improved quantification of peroxidase activity.

Natural components endogenous to plant material extracts often interfere with traditional peroxidase assays by reducing the oxidized product generated as a result of the peroxidase-catalyzed reaction. This leads to an underestimation of peroxidase activity when the oxidized product provides the signal for enzyme activity quantification. This article describes a relatively simple way to alleviate complications arising due to the presence of such confounding compounds.

Evidence that humans can taste glucose polymers.

The sense of taste is essential for identifying potential nutrients and poisons. Accordingly, specialized taste receptor cells are activated by food-derived chemicals. Because of its importance in the human diet, oral detection of starch, or its degradation products, would presumably be highly beneficial.