Functionality of Sugars in Foods and Health Clemens, Roger A.; Jones, Julie M.; Kern, Mark ...
Comprehensive reviews in food science and food safety,
20/May , Letnik:
15, Številka:
3
Journal Article
Recenzirano
Overweight and obesity are global health problems that affect more than 1.9 billion adults who are overweight, and of these 600 million are obese. In the United States, these problems affect 60% of ...the population. Critical to these statistics is the association with increased risk of cardiovascular disease, type 2 diabetes, and metabolic syndrome among other noncommunicable diseases. Many factors, including sugars, have been charged as potential causes. However, obesity and overweight and their attendant health problems continue to increase despite the fact that there is a decline in the consumption of sugars. Sugars vary in their types and structure. From a food science perspective, sugars present an array of attributes that extend beyond taste, flavor, color, and texture to aspects such as structure and shelf‐life of foods. From a public health perspective, there is considerable controversy about the effect of sugar relative to satiety, digestion, and noncommunicable diseases. This comprehensive overview from experts in food science, nutrition and health, sensory science, and biochemistry describes the technical and functional roles of sugar in food production, provides a balanced evidence‐based assessment of the literature and addresses many prevalent health issues commonly ascribed to sugar by the media, consumer groups, international scientific organizations, and policy makers. The preponderance of the evidence indicates that sugar as such does not contribute to adverse health outcomes when consumed under isocaloric conditions. The evidence generally indicates, as noted by the 2010 Dietary Guidelines Advisory Committee, that sugar, like any other caloric macronutrient, such as protein and fat, when consumed in excess leads to conditions such as obesity and related comorbidities. More recently, the 2015‐2020 Dietary Guidelines for Americans recommended limiting dietary sugar to 10% of total energy in an effort to reduced the risk of these noncommunicable diseases.
Transport features predict if a molecule is odorous Mayhew, Emily J; Arayata, Charles J; Gerkin, Richard C ...
Proceedings of the National Academy of Sciences - PNAS,
04/2022, Letnik:
119, Številka:
15
Journal Article
Recenzirano
Odprti dostop
In studies of vision and audition, stimuli can be chosen to span the visible or audible spectrum; in olfaction, the axes and boundaries defining the analogous odorous space are unknown. As a result, ...the population of olfactory space is likewise unknown, and anecdotal estimates of 10,000 odorants have endured. The journey a molecule must take to reach olfactory receptors (ORs) and produce an odor percept suggests some chemical criteria for odorants: a molecule must 1) be volatile enough to enter the air phase, 2) be nonvolatile and hydrophilic enough to sorb into the mucous layer coating the olfactory epithelium, 3) be hydrophobic enough to enter an OR binding pocket, and 4) activate at least one OR. Here, we develop a simple and interpretable quantitative model that reliably predicts whether a molecule is odorous or odorless based solely on the first three criteria. Applying our model to a database of all possible small organic molecules, we estimate that at least 40 billion possible compounds are odorous, six orders of magnitude larger than current estimates of 10,000. With this model in hand, we can define the boundaries of olfactory space in terms of molecular volatility and hydrophobicity, enabling representative sampling of olfactory stimulus space.
Mapping molecular structure to odor perception is a key challenge in olfaction. We used graph neural networks to generate a principal odor map (POM) that preserves perceptual relationships and ...enables odor quality prediction for previously uncharacterized odorants. The model was as reliable as a human in describing odor quality: On a prospective validation set of 400 out-of-sample odorants, the model-generated odor profile more closely matched the trained panel mean than did the median panelist. By applying simple, interpretable, theoretically rooted transformations, the POM outperformed chemoinformatic models on several other odor prediction tasks, indicating that the POM successfully encoded a generalized map of structure-odor relationships. This approach broadly enables odor prediction and paves the way toward digitizing odors.
Editor’s summary
For vision and hearing, there are well-developed maps that relate physical properties such as frequency and wavelength to perceptual properties such as pitch and color. The sense of olfaction does not yet have such a map. Using a graph neural network, Lee
et al
. developed a principal odor map (POM) that faithfully represents known perceptual hierarchies and distances. This map outperforms previously published models to the point that replacing a trained human’s responses with the model output would improve overall panel description. The POM coordinates were able to predict odor intensity and perceptual similarity, even though these perceptual features were not explicitly part of the model training. These results were used to build a variety of olfactory predictions that outperformed previous feature sets even without fine-tuning. —Peter Stern
An odor map achieved human-level odor description performance and generalized to diverse odor-prediction tasks.
•Trained panelist and consumer evaluations of stickiness are compared.•Texture attributes with relevance to sticky perception are identified.•Trained panelists and consumers agree on relative ...stickiness.•Use of single- and multiple-selection methods reveals hierarchy of sticky textures.•Tacky, stringy, and enveloping textures relate most strongly to overall stickiness.
Stickiness is a critical, but complex attribute with relevance to many food systems. Consumer perception of stickiness is subjective and variable; however, stickiness ratings and texture insights from trained panels are often used to make decisions about consumer products. Our objectives were to correlate trained panel evaluations to consumer perception of stickiness and to identify texture attributes that contribute to stickiness. Nine diverse caramel samples were assessed by two panels. First, trained panelists participated in texture term generation, Temporal Dominance of Sensation (TDS), and tactile and oral stickiness intensity rating. Next, 75 consumers participated in a two-part test: first, they completed a Check-All-That-Apply (CATA) exercise with the TDS panel-generated terms; second, they rated each sample for overall tactile and oral stickiness intensity. Trained panelist and consumer stickiness ratings were then correlated to each other and to TDS parameters for each attribute. Consumers and trained panelists showed good agreement in tactile (r = 0.85, p < .01) and oral (r = 0.94, p < .001) stickiness ratings. Samples presenting high levels of tacky, stringy, and enveloping attributes were rated the stickiest. A subset of attributes, including toothpacking and deformable, correlated positively with stickiness when multiple selections were permitted (CATA) and negatively when only one selection was permitted (TDS). This contradiction suggests two tiers of stickiness-contributing attributes; tier-two attributes (toothpacking, deformable, cohesive) increased stickiness perception, but less so than tier-one attributes (tacky, stringy, enveloping). Identification of texture factors that most strongly relate to consumer perception of stickiness will enable informed testing of stickiness properties and formulation of sticky products.
Stickiness is an important texture attribute in many food systems, but its meaning can vary by person, product, and throughout mastication. This variability and complexity makes it difficult to ...devise analytical tests that accurately and consistently predict sensory stickiness. Glass transition temperature (Tg) is a promising candidate for texture prediction. Our objective is to elucidate the temporal profile of stickiness in order to probe the relationship between Tg and dynamic stickiness perception. Nine caramel samples with diverse texture and thermal profiles were produced for sensory testing and differential scanning calorimetry. Sixteen trained panelists generated stickiness‐relevant terms to be used in a subsequent temporal dominance of sensation (TDS) test with the same panelists. Following the TDS study, these panelists also rated samples for overall tactile and oral stickiness. Stickiness ratings were then correlated to TDS dominance parameters across the full evaluation period and within the first, middle, and final thirds of the evaluation period. Samples with temporal texture profiles dominated by tacky, stringy, and enveloping attributes consistently received the highest stickiness scores, although the correlation strength varied by time period. Tg was found to correlate well with trained panelist and consumer ratings of oral (R2trained = 0.85; R2consumer = 0.96) and tactile (R2trained = 0.78; R2consumer = 0.79) stickiness intensity, and stickiness intensity ratings decreased with Tg of completely amorphous samples. Further, glassy samples followed a different texture trajectory (brittle‐cohesive‐toothpacking) than rubbery samples (deformable‐tacky‐enveloping). These results illuminate the dynamic perception of stickiness and support the potential of Tg to predict both stickiness intensity and texture trajectory in caramel systems.
Practical Application
Sensory texture is critical to consumer acceptance and challenging to measure. Reliable instrumental predictors of sensory texture aid the food scientist by providing a time‐effective method for screening sample prototypes and streamlining the product development and refinement process. This study shows that the glass transition temperature (Tg) is strongly correlated to oral and tactile stickiness ratings in caramel systems. Additionally, initial physical state of the caramel samples (glassy, rubbery, or intermediate state) can predict the dominant temporal texture profile. Based on these findings, Tg shows strong promise as a metric for prediction of sensory texture profile with possible applications in confectionary and other low moisture food systems.
Our objectives were to compare the Couchman-Karasz-predicted glass transition temperature, TCK, to the measured glass transition temperature of a mixture, Tgm, of model confectionary systems and ...develop an empirical correction to improve the accuracy of prediction. Results showed that the original Couchman-Karasz equation fit the data better than the modified equation; although both generally overestimated Tgm. Blends containing sorbitol had the largest ΔTgmCK, where ΔTgmCK=TCK−Tgm. While Tgm varied with composition, the increase in Tgm with decreasing moisture content was linear (R2¯=0.984) and consistent across blends (4.5 ± 0.9°C/1% moisture, wb). The increase in Tgm with increasing cook temperature was best described by a polynomial model (R2¯=0.998), but adequately described by a more generalizable linear model (R2¯=0.979). Application of an empirical correction based on moisture content or cook temperature and TCK of dry ingredients reduced the average ΔTgmCK from 20.1 °C and 11.3 °C for modified and original equations, respectively, to <5.6 °C.
•Original and modified Couchman-Karasz equations are applied to model confections.•Modified Couchman-Karasz equation overestimates measured Tg of samples.•Original Couchman-Karasz equation provides better fit to measured Tg data.•Tg decreases linearly with moisture content and increases with cook temperature.•Empirical corrections improve Couchman-Karasz accuracy to within 5 °C on average.
Sugar reduction in processed foods is a pressing and complex problem, as sugars contribute important sensory and physical properties to foods. Composed of sugars and lipids, caramel coating systems, ...like the coating in caramel popcorns, exemplify this challenge. In order to probe the feasibility and consequences of sugar reduction, both sensory and physical properties were measured for 3 types of caramel coating systems. Four commonly used sugar alcohols, isomalt, maltitol, mannitol, and sorbitol, with different thermal properties and relative sweetness values were chosen to replace sugar in the caramel coating systems at 25% and 50% sugar reduction levels. Full sugar (control) and reduced sugar caramel coating samples were prepared in duplicate. Ten trained panelists participated in a 6‐wk descriptive analysis panel to define and quantify the intensity of important sensory characteristics. All 24 sensory terms generated by the panel differed significantly across caramel type and sugar replacer. Thermal properties were measured through differential scanning calorimetry, and textural properties were measured through texture profile analysis. Replacement of sugar with sugar alcohols was found to decrease the glass transition temperature and systematically alter the hardness and resilience of caramel samples. Principal component analysis of sensory and physical data revealed that caramel coating type dictates caramel aroma, aroma by mouth, taste, and aftertaste, while sugar replacer and replacement level dictate texture. This research represents the first comprehensive study of the effects of sugar reduction in a caramel coating system and suggests successful strategies for sugar reduction and key parameters to control in reduced sugar systems.
Practical Application
This research explores the effect of sugar replacement using 4 different sugar replacers, isomalt, maltitol, mannitol, sorbitol, at 2 sugar replacement levels, 25% and 50%, on the sensory and physical properties of 3 caramel coating systems varying in sugar and lipid type and amount. The caramel coating systems are representative of the coating material found in commercial caramel popcorn products. Results indicate that isomalt and maltitol are preferable sugar replacers in the caramel coating systems studied. Additionally, this research identified key physical parameters, including glass transition temperature and moisture content, and sensory parameters, including stickiness, toothpacking, cohesiveness, crumbliness, force to pierce sample, to monitor when reducing or replacing sugar in caramel coating or other low‐moisture confectionary systems.
Research shows that students struggle to develop higher order thinking skills and effective study strategies during the transition from high school to college. Therefore, in addition to teaching ...course content, effective instructors should assist students in developing metacognitive skills, that is, the practice of thinking about their thinking. An effective assignment that assists students in thinking about their exam performance is the exam wrapper. The objectives of this study were to examine students’ metacognitive skills, evaluate the correlation between study behaviors and student performance, and assess student perception of exam wrappers. Exam wrapper assignments were offered as extra credit after the first 3 exams in a large introductory Food Science and Human Nutrition course, and student responses and exam performance were analyzed. Many students with poor exam performance overestimated their exam scores, indicating students’ self‐assessment skills could be sharpened. However, students demonstrated the ability to make and implement goals to improve study strategies throughout the semester. A modest relationship between use of study strategies and improved exam performance was observed, particularly for students with a B exam average, suggesting that students in the middle of the grade distribution may benefit most from this type of intervention. Finally, most students expressed a belief that exam wrappers helped them improve their study habits and exam scores, and that they planned to use the exam wrapper process in future classes. In summary, this study shows that the exam wrapper is a valued and effective postexam reflection tool for improving students’ self‐reported study habits.
The fossil record has suggested that clade growth may differ in marine and terrestrial taxa, supporting equilibrial models in the former and expansionist models in the latter. However, incomplete ...sampling may bias findings based on fossil data alone. To attempt to correct for such bias, we assemble phylogenetic supertrees on one of the oldest clades of insects, the Odonatoidea (dragonflies, damselflies and their extinct relatives), using MRP and MRC. We use the trees to determine when, and in what clades, changes in taxonomic richness have occurred. We then test whether equilibrial or expansionist models are supported by fossil data alone, and whether findings differ when phylogenetic information is used to infer gaps in the fossil record.
There is broad agreement in family-level relationships between both supertrees, though with some uncertainty along the backbone of the tree regarding dragonflies (Anisoptera). "Anisozygoptera" are shown to be paraphyletic when fossil information is taken into account. In both trees, decreases in net diversification are associated with species-poor extant families (Neopetaliidae, Hemiphlebiidae), and an upshift is associated with Calopterygidae + Polythoridae. When ghost ranges are inferred from the fossil record, many families are shown to have much earlier origination dates. In a phylogenetic context, the number of family-level lineages is shown to be up to twice as high as the fossil record alone suggests through the Cretaceous and Cenozoic, and a logistic increase in richness is detected in contrast to an exponential increase indicated by fossils alone.
Our analysis supports the notion that taxa, which appear to have diversified exponentially using fossil data, may in fact have diversified more logistically. This in turn suggests that one of the major apparent differences between the marine and terrestrial fossil record may simply be an artifact of incomplete sampling. Our results also support previous notions that adult colouration plays an important role in odonate radiation, and that Anisozygoptera should be grouped in a single inclusive taxon with Anisoptera, separate from Zygoptera.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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