The action of endo-xylanase and endo-glucanase on cereal cell wall polysaccharides and its implications for starch digestion kinetics in an in vitro poultry model.

Endo-xylanase and endo-glucanase are supplemented to poultry diets in order to improve nutrient digestion and non-starch polysaccharide (NSP) fermentation. Here, the action of these enzymes on alcohol insoluble solids (AIS) from wheat and maize grains as well as its implications for starch digestion in milled grains were evaluated in vitro, under conditions mimicking the poultry digestive tract. For wheat AIS, GH11 endo-xylanase depolymerized soluble arabinoxylan (AX) during the gizzard phase, and proceeded to release insoluble AX under small intestine conditions. At the end of the in vitro digestion (480 min), the endo-xylanase, combined with a GH7 endo-ß-1,4-glucanase, released 30.5 % of total AX and 18.1 % of total glucan in the form of arabinoxylo- and gluco-oligosaccharides, as detected by HPAEC-PAD and MALDI-TOF-MS. For maize AIS, the combined enzyme action released 2.2 % and 7.0 % of total AX and glucan, respectively. Analogous in vitro digestion experiments of whole grains demonstrated that the enzymatic release of oligomers coincided with altered grain microstructure, as examined by SEM. In the present study, cell wall hydrolysis did not affect in vitro starch digestion kinetics for cereal grains. This study contributes to understanding the action of feed enzymes on cereal NSP under conditions mimicking the poultry digestive tract.

How physicochemical and nutritional traits of potatoes may vary under field conditions over long periods.

BACKGROUND: Potato is the most important non-grain crop worldwide, whose quality characteristics are always affected by temporal and spatial variability. Knowledge of the performance consistency of quality characteristics over long periods could prove very important to identify which quality traits are less variable over time, and therefore provide greater guarantees of stability. In this research, variations in physicochemical and nutritional traits of tubers over five consecutive growing seasons of two potato genotypes (Arizona and Vogue) were monitored in two locations. RESULTS: Although qualitative performances of genotypes fluctuated across the seasons in both locations, two physicochemical traits (pH and dry matter content) and starch content showed less variability throughout the five seasons compared to total soluble solids and most of the nutritional traits (namely reducing sugars, citric acid, vitamin C, total phenolics and antioxidant capacity), which were considerably influenced by weather conditions. CONCLUSION: The results suggest that pH, dry matter content and starch content traits could be used advantageously in studies of temporal stability in potatoes. This approach could prove useful in providing scientific support for the setup of potato protected geographical identifications. © 2024 Society of Chemical Industry.

Mechanism for gel formation of pectin from mealy and crisp lotus rhizome induced by Na+ and D-glucono-d-lactone.

Lotus rhizome residue, a cell wall material produced during the production of lotus rhizome starch, has long been underutilized. This study aims to extract pectin-rich polysaccharides from the cell wall of lotus rhizome and investigate their gelation mechanism in order to improve their industrial applicability. The results indicated that both CP and MP (pectin extracted from crisp and mealy lotus rhizome) exhibited a highly linear low methoxyl pectin structure, with the primary linkage mode being →4)-GalpA-(1→. The pectin chains in MP were found to be more flexible than those in CP. Then the impact of Na+, D-glucono-d-lactone (GDL), urea, sodium dodecyl sulfate (SDS), either individually or in combination, on the rheological characteristics of gels was evaluated. The results indicated that gels induced by GDL exhibited favorable thermoreversible properties, whereas the thermoreversibility of Na+-induced gels is poor. In addition to hydrogen bonding and ionic interactions, hydrophobic interactions also play a significant role in the formation of pectin gels. This study offers theoretical guidance and methodologies to improve the utilization rate of lotus rhizome starch processing by-products, while also provides novel insights into the correlation between LMP structure and gelation mechanism.

Microwave-assisted UV digestion of starch and skimmed milk powder: Environmentally friendly protocol for essential and toxic elements determination.

The present work evaluated a microwave-assisted wet digestion method using diluted HNO3 with in situ UV radiation for the digestion of starch and skimmed milk powder for further metals determination by spectrometric plasma-based techniques. The sample digestion was conducted using an in situ UV lamp (electrodeless discharge lamp), and the digestion efficiency was improved by employing O2 (20 bar) and 2 mL 30 % H2O2 as auxiliary reagents. The accuracy of the proposed digestion method was evaluated by metals determination (Ca, Cd, Cu, Fe, K, Mg, Mo, Mn, Na, Pb, and Zn) in certificated reference material, which agreed with certified values (Student t-test <0,05). With the use of a UV lamp an environmentally friendly protocol was developed for starch and skimmed milk powder digestion using 0.1 mol L-1 HNO3 with auxiliary reagents (H2O2 or O2). The RCC value ranged from 0.9 to 1.2 % (starch and skimmed milk powder, respectively). The simultaneous cooling approach further improved the digestion efficiency (RCC <0,3 % for both samples), allowing to use milder digestion conditions, or even just water, being environmentally friendly, reducing the waste generation and reagents consumption, allowing food quality control through a greener approach.

In vitro digestion properties and use of automatic image analysis to assess the quality of wheat bread enriched with whole faba bean (Vicia faba L.) flour and its protein-rich fraction.

The trend of incorporating faba bean (Vicia faba L.) in breadmaking has been increasing, but its application is still facing technological difficulties. The objective of this study was to understand the influence of substituting the wheat flour (WF) with 10, 20, 30 and 40 % mass of whole bean flour (FBF) or 10 and 20 % mass of faba bean protein-rich fraction (FBPI) on the quality (volume, specific volume, density, colour, and texture), nutritional composition (total starch, free glucose, and protein contents), and kinetics of in vitro starch and protein digestibility (IVSD and IVPD, respectively) of the breads. Automated image analysis algorithm was developed to quantitatively estimate the changes in the crumb (i.e., air pockets) and crust (i.e., thickness) due to the use of FBF or FBPI as part of the partial substitution of wheat flour. Higher levels of both FBF and FBPI substitution were associated with breads having significant (p < 0.05) lower (specific) volume (at least 25 % reduction) and higher density (up to 35 %), increased brownness (up to 49 % and 78 % for crust and crumb respectively), and up to 2.3-fold increase in hardness. Result from the image analysis has provided useful insights on how FBF and FBPI affecting bread characteristics during baking such as loss of crumb expansion, decrease in air pocket expansion and increase in crust thickness. Overall, incorporation of FBF or FBPI in wheat bread were favourable in reducing the starch content and improving the protein content and IVPD of wheat bread. Since bread remains as a staple food due to its convenience, versatility and affordability for individuals and families on a budget, wheat bread enriched with faba bean could be a perfect food matrix to increase daily protein intake.

Applications and safety aspects of bioactives obtained from by-products/wastes.

Due to the negative impacts of food loss and food waste on the environment, economy, and social contexts, it is a necessity to take action in order to reduce these wastes from post-harvest to distribution. In addition to waste reduction, bioactives obtained from by-products or wastes can be utilized by new end-users by considering the safety aspects. It has been reported that physical, biological, and chemical safety features of raw materials, instruments, environment, and processing methods should be assessed before and during valorization. It has also been indicated that meat by-products/wastes including collagen, gelatin, polysaccharides, proteins, amino acids, lipids, enzymes and chitosan; dairy by-products/wastes including whey products, buttermilk and ghee residue; fruit and vegetable by-products/wastes such as pomace, leaves, skins, seeds, stems, seed oils, gums, fiber, polyphenols, starch, cellulose, galactomannan, pectin; cereal by-products/wastes like vitamins, dietary fibers, fats, proteins, starch, husk, and trub have been utilized as animal feed, food supplements, edible coating, bio-based active packaging systems, emulsifiers, water binders, gelling, stabilizing, foaming or whipping agents. This chapter will explain the safety aspects of bioactives obtained from various by-products/wastes. Additionally, applications of bioactives obtained from by-products/wastes have been included in detail by emphasizing the source, form of bioactive compound as well as the effect of said bioactive compound.

Reduced in vitro starch hydrolysis and in vivo glycemic effects after addition of soy presscake to corn tortillas.

BACKGROUND: Chronically elevated blood glucose leads to development of prediabetes and type 2 diabetes, as well as increased risk for heart and kidney disease and vision loss. For many, elevated blood glucose can be managed through diet and exercise. Consequently, the availability of foods that limit blood glucose elevation would aid in addressing this global problem. This paper investigated the effect of adding soy presscake (SP) to corn tortillas on starch hydrolysis in vitro as well as the glycemic responses elicited in vivo upon consumption of these modified tortillas. RESULTS: SP in corn tortillas decreased the rate and extent of starch hydrolysis in vitro. The in vivo glycemic index (GI) values decreased from 43 for corn control tortillas to 31 with 40% SP fortification. A high correlation (r = 0.9781) was found between the GI values from in vivo analysis and the area under the curve of starch hydrolysis in vitro. The best correlations (r > 0.96) between GI and degree of hydrolysis were found at 45-90 min of in vitro starch hydrolysis. CONCLUSIONS: Incorporating SP into corn-based tortillas lowers glycemic responses to them. In addition, in vitro starch hydrolysis could be used to estimate the GI values of food products and, in particular, the comparison of multiple items during food product development. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Preparation of fat substitute based on maize starch hydrolysates and application in reduced-fat acidified milk gel.

Reduced-fat food has become a popular choice among contemporary consumers. This study aims to develop a starch-based fat substitute and incorporate it into reduced-fat milk gel acidified with glucono-δ-lactone (GDL) to achieve similar rheological properties as a full-fat gel. The gel properties of the fat substitute were assessed. The study examined the rheological properties, syneresis, textural properties and microstructure of acidified milk gels while also monitoring acidification process. Starch hydrolysates with low dextrose equivalent (DE) (<5.1 %) can serve as an effective fat substitute due to their excellent gelling properties The rheological and textural properties of the reduced-fat acidified milk gel with DE at 3.1 % of starch hydrolysate and 30 % fat substitution are similar to those of the full-fat milk gel. The syneresis and confocal laser scanning microscopy (CLSM) results indicated that the microstructure of the reduced-fat acidified milk gel was similar to the full-fat version. Moreover, the sensory properties of the reduced-fat acidified milk gel were acceptable when the DE was 3.1 %, and 30 % fat was replaced. In our study, we utilized hydrolyzed starch to produce reduced-fat acidified milk gels, which could potentially be used in the development of reduced-fat yogurt formulations.

Brazilian native fruit pomace as a source of bioactive compounds on starch-based films: Antimicrobial activities and food simulator release.

The bioactive compounds extraction from fruit pomace is an ecological alternative for these abundant and low-added-value by-products. This study aimed to evaluate the antimicrobial potential of pomace extracts from Brazilian native fruits (araçá, uvaia, guabiroba and butiá) and the effect on physicochemical, mechanical properties and the migration of antioxidants and phenolic compounds from starch-based films. The film with butiá extract had the lowest mechanical resistance (1.42 MPa) but the highest elongation (63 %). In comparison, uvaia extract had less impact on film mechanical properties (3.70 MPa and 58 %) compared to the other extracts. The extracts and films showed antimicrobial activity against Listeria monocytogenes, L. inoccua, B. cereus and S. aureu. Approximately 2 cm inhibition halo was noticed for the extracts, while films ranged from 0.33 to 1.46 cm inhibition halo. Films with guabiroba extract had the lowest antimicrobial activity (0.33 to 0.5 cm). The phenolic compounds were released from the film matrix in the first hour at 4 °C with maintenance in the stability. The fatty-food simulator showed a controlled release of antioxidant compounds, which can assist in controlling food oxidation. Brazilian native fruit has shown to be a viable alternative to isolate bioactive compounds and produce film packaging with antimicrobial and antioxidant activities.

More than the main structural genes: Regulation of resistant starch formation in rice endosperm and its potential application.

In the past decade, research on resistant starch has evoked interest due to the prevention and inhibition of chronic human diseases, such as diabetes, cancer, and obesity. Increasing the amylose content (AC) and resistant starch (RS) has been pivotal in improving the nutritional benefit of rice. However, the exact mechanism of RS formation is complex due to interconnected genetic factors regulating amylose-amylopectin variation. In this review, we discussed the regulatory factors influencing the RS formation centered on the transcription, post-transcriptional, and post-translational processes. Furthermore, we described the developments in RS and AC levels in rice compared with other high RS cereals. Briefly, we enumerated potential applications of high RS mutants in health, medical, and other industries. We contest that the information captured herein can be deployed for marker-assisted breeding and precision breeding techniques through genome editing to improve rice varieties with enhanced RS content.

Associations between types and sources of dietary carbohydrates and cardiovascular disease risk: a prospective cohort study of UK Biobank participants.

BACKGROUND: Recent studies have reported that the associations between dietary carbohydrates and cardiovascular disease (CVD) may depend on the quality, rather than the quantity, of carbohydrates consumed. This study aimed to assess the associations between types and sources of dietary carbohydrates and CVD incidence. A secondary aim was to examine the associations of carbohydrate intakes with triglycerides within lipoprotein subclasses. METHODS: A total of 110,497 UK Biobank participants with ≥ two (maximum five) 24-h dietary assessments who were free from CVD and diabetes at baseline were included. Multivariable-adjusted Cox regressions were used to estimate risks of incident total CVD (4188 cases), ischaemic heart disease (IHD; 3138) and stroke (1124) by carbohydrate intakes over a median follow-up time of 9.4 years, and the effect of modelled dietary substitutions. The associations of carbohydrate intakes with plasma triglycerides within lipoprotein subclasses as measured by nuclear magnetic resonance (NMR) spectroscopy were examined in 26,095 participants with baseline NMR spectroscopy measurements. RESULTS: Total carbohydrate intake was not associated with CVD outcomes. Free sugar intake was positively associated with total CVD (HR; 95% CI per 5% of energy, 1.07;1.03-1.10), IHD (1.06;1.02-1.10), and stroke (1.10;1.04-1.17). Fibre intake was inversely associated with total CVD (HR; 95% CI per 5 g/d, 0.96;0.93-0.99). Modelled isoenergetic substitution of 5% of energy from refined grain starch with wholegrain starch was inversely associated with total CVD (0.94;0.91-0.98) and IHD (0.94;0.90-0.98), and substitution of free sugars with non-free sugars was inversely associated with total CVD (0.95;0.92-0.98) and stroke (0.91;0.86-0.97). Free sugar intake was positively associated with triglycerides within all lipoproteins. CONCLUSIONS: Higher free sugar intake was associated with higher CVD incidence and higher triglyceride concentrations within all lipoproteins. Higher fibre intake and replacement of refined grain starch and free sugars with wholegrain starch and non-free sugars, respectively, may be protective for incident CVD.

Variations in gut microbiome and metabolites of dogs with acute diarrhea in poodles and Labrador retrievers.

For different breeds of dogs with acute diarrhea, the gut microbiota and metabolome profiles are unclear. This prospective observational study analyzed the gut microbiomes of poodles with acute diarrhea and Labrador retrievers with acute diarrhea based on 16S amplicon sequencing, with respective healthy dogs as controls. Fecal non-target metabolomics and metagenomics were performed on poodles with acute diarrhea. This study found that the diversity and structure of the microbial community differed significantly between the two breeds in cohorts of healthy dogs. Two breeds of dogs with acute diarrhea demonstrated different changes in microbial communities and metabolic functions. The metabolism of starch and sucrose was significantly decreased in dogs with acute diarrhea, which may be attributed to the reduced activity of dextran dextrinase. Non-targeted metabolomics identified 21 abnormal metabolic pathways exhibited by dogs with acute diarrhea, including starch, amino acid, bile acid metabolism, etc., and were closely related to specific intestinal flora. This study provided new insights into breed specificity and the development of dietary treatment strategy in canine gastrointestinal disease.

Extraction, identification, and starch-digestion inhibition of phenolics from Euryale ferox seed coat.

BACKGROUND: Euryale ferox is an important cash crop and valuable tonic in traditional medicine. The seeds of E. ferox are rich in starch, which is hard to digest, and the digestion speed is significantly slower than that of rice starch. The goal of this study was to evaluate the effects of E. ferox seed-coat phenolics (EFCPs) on the digestion of E. ferox seed starch. RESULTS: EFCPs were extracted and identified by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. We optimized the extraction parameters, and the final extraction yield was about 1.49%. We identified seven phenolics from the E. ferox seed-coat extracts: gallic acid, digalloylhexoside, catechin, procyanidin B2, epicatechin, ellagic acid, and epicatechin gallate. Quantitative analysis results showed that the E. ferox seed phenolics mainly distributed in the seed coat and the gallic acid, digalloylhexoside, and epicatechin gallate were three main phenolic compounds. The phenolics displayed strong inhibitory activities on α-glucosidase and α-amylase with an IC50 of 3.25 µg mL-1 and 1.36 mg mL-1 respectively. Furthermore, these phenolics could interact with starch by hydrogen bonds, which might make its starch more difficult to digest. CONCLUSION: Our investigation suggests that the EFCPs can strongly inhibit the digestion of E. ferox seed starch by inhibiting the α-amylase and α-glucosidase activities and interacting with starch by hydrogen bonds; therefore, E. ferox seeds have a promising application prospect in foods for hypoglycemia. © 2023 Society of Chemical Industry.

Impact of climate change on wheat grain composition and quality.

Wheat grain quality, an important determinant for human nutrition, is often overlooked when improving crop production for stressed environments. Climate change makes this task more difficult by imposing combined stresses. The scenarios relevant to climate change include elevated CO2 concentrations (eCO2 ) and extreme climatic events such as drought, heat waves, and salinity stresses. However, data on wheat quality in terms of climate change are limited, with no concerted efforts at the global level to provide an equitable and consistent climate risk assessment for wheat grain quality. Climate change induces changes in the quality and composition of wheat grain, a premier staple food crop globally. Climate-change events, such as eCO2 , heat, drought, salinity stress stresses, heat + drought, eCO2 + drought, and eCO2 + heat stresses, alter wheat grain quality in terms of grain weight, nutrient, anti-nutrient, fiber, and protein content and composition, starch granules, and free amino acid composition. Interestingly, in comparison with other stresses, heat stress and drought stress increase phytate content, which restricts the bioavailability of essential mineral elements. All climatic events, except for eCO2 + heat stress, increase grain gliadin content in different wheat varieties. However, grain quality components depend more on inter-varietal difference, stress type, and exposure time and intensity. The climatic events show differential regulation of protein and starch accumulation, and mineral metabolism in wheat grains. Rapid climate shifting impairs wheat productivity and causes grain quality to deteriorate by interrupting the allocation of essential nutrients and photoassimilates. © 2022 Society of Chemical Industry.

Effect of Euryale ferox seed shell extract addition on the in vitro starch digestibility and predicted glycemic index of wheat-based bread.

The inhibitory effects of Euryale ferox seed shell extract (EFSSE) on the activity of α-amylase and α-glucosidase were studied. EFSSE (0.25 % to 2 %) was used to fortify bread and analyzed the in vitro starch digestibility (IVSD) digestion kinetics, and the predicted glycemic index (pGI) was estimated. The swarm intelligence supervised neural network (SISNN) technique was applied for the predictive simulation of digestion kinetics and pGI. Principal component analysis (PCA) with proportional odds modeling (POM) was used to find the most sensitive component based on the sensory attributes of bread. The inhibitory effect of EFSSE on α-amylase and α-glucosidase in terms of IC50 was 62.95 and 52.06 µg/mL, respectively. Fortification of bread with EFSSE could affect loaf volume, hardness, and color. Euryale ferox seed shell extract could decreased the rate of hydrolysis of bread. EFSSE (2 %) had a strong inhibitory impact, as evidenced by the drop in glycemic index from 94.61 to 61.66. SISNN-based kinetics was much better as compared to mathematical modeling-based digestion kinetics. Findings of the present study have shown that EFSSE could be employed as an additive to produce lower glycemic index functional bread.

Symposium review: Effects of carbohydrate digestion on feed intake and fuel supply.

Carbohydrates are the primary energy source for lactating dairy cows, and dairy diets are usually formulated for certain concentrations of forage neutral detergent fiber (NDF) and starch due to their direct effects on dry matter intake and milk production. Forage NDF exerts greater filling effects in the rumen than other dietary components and can limit maximum voluntary feed intake of lactating dairy cows. Since an analytical method for NDF was developed more than a half century ago, it has been used widely to characterize forages and diets for dairy cows. However, because NDF is a chemical measurement varying in its digestibility, in vitro digestibility measurements were developed as a biological approach to assess forage quality. Research efforts over the last several decades led to the development of forage cultivars or hybrids with enhanced in vitro NDF digestibility, such as brown midrib, and management practices considering differences in NDF digestibility of forages. In addition, in vitro NDF digestibility and undigested NDF are commonly measured in commercial labs, and estimated rates of digestion are used in dynamic models in an effort to improve the accuracy and precision of diet formulation. Starch digestion in the rumen also varies among starch sources, being affected by grain type, extent of processing, and conservation method. The site and rate of starch digestion affect dry matter intake and nutrient partitioning in dairy cows by modifying temporal supply of fuel. In addition, dietary starch content and its fermentability can affect digestion rates of starch itself and NDF in the rumen. Previous research has increased our understanding of dietary carbohydrates, but its application for diet formulations requires integrated approaches accounting for factors affecting the filling effects of forage NDF, starch digestion, and temporal fuel supply.

Citrus Huanglongbing detection and semi-quantification of the carbohydrate concentration based on micro-FTIR spectroscopy.

Citrus Huanglongbing (HLB) is nowadays one of the most fatal citrus diseases worldwide. Once the citrus tree is infected by the HLB disease, the biochemistry of the phloem region in midribs would change. In order to investigate the carbohydrate changes in phloem region of citrus midrib, the semi-quantification models were established to predict the carbohydrate concentration in it based on Fourier transform infrared microscopy (micro-FTIR) spectroscopy coupled with chemometrics. Healthy, asymptomatic-HLB, symptomatic-HLB, and nutrient-deficient citrus midribs were collected in this study. The results showed that the intensity of the characteristic peak varied with the carbohydrate (starch and soluble sugar) concentration in citrus midrib, especially at the fingerprint regions of 1175-900 cm-1, 1500-1175 cm-1, and 1800-1500 cm-1. Furthermore, semi-quantitative prediction models of starch and soluble sugar were established using the full micro-FTIR spectra and selected characteristic wavebands. The least squares support vector machine regression (LS-SVR) model combined with the random frog (RF) algorithm achieved the best prediction result with the determination coefficient of prediction ([Formula: see text]) of 0.85, the root mean square error of prediction (RMSEP) of 0.36%, residual predictive deviation (RPD) of 2.54, and [Formula: see text] of 0.87, RMSEP of 0.37%, RPD of 2.76, for starch and soluble sugar concentration prediction, respectively. In addition, multi-layer perceptron (MLP) classification models were established to identify HLB disease, achieving the overall classification accuracy of 94% and 87%, based on the full-range spectra and the optimal wavenumbers selected by the random frog (RF) algorithm, respectively. The results demonstrated that micro-FTIR spectroscopy can be a valuable tool for the prediction of carbohydrate concentration in citrus midribs and the detection of HLB disease, which would provide useful guidelines to detect citrus HLB disease.

Cell wall polysaccharides and mono-/disaccharides as chemical determinants for the texture and hygroscopicity of freeze-dried fruit and vegetable cubes.

In order to select the critical factors on the texture and hygroscopic characteristics of freeze-dried fruit and vegetable cubes, the correlation analysis was performed on the major chemical compositions of 12 fresh materials, and the microstructure, texture, hygroscopicity of corresponding freeze-dried samples. The dry proportion of starch-rich materials, such as taro, was mainly composed of polysaccharides (0.76-0.89 g/g db), while the dry proportion of starch-poor materials such as apple was mainly composed of mono-/disaccharides (0.70-0.95/g db). Data from the microscopy showed that cell wall polysaccharides constituted the scaffold of freeze-dried cubes and natural starch granules attached to the scaffold as fillers. Both of them inhibited structural collapse. Mono-/disaccharides were accountable for the hardness and crispiness of freeze-dried cubes, however, excessive mono-/disaccharides could reduce the size of the pores and cause severe shrinkage. Polysaccharides reduced the hygroscopicity of freeze-dried cubes, on the contrary, mono-/disaccharides promoted hygroscopicity, especially fructose.

Characterization and differentiation of pollen lipidomes and proteomes from different intrafloral stamens in heterantherous Senna bicapsularis.

Numerous compounds in pollen can affect the foraging decision-making of bees. Clarification of phytochemical components and identification of key substances for bee foraging preference in pollen are essential steps for apiculture and developing a conservation strategy. Senna bicapsularis, a heterantherous plant that possesses three different stamen types in the same flower, among which bees forage selectively, provides us with an ideal research model for identification of potential substances of bee foraging preference. The lipid and protein compositions of pollen from the anthers of different stamens of S. bicapsularis were investigated and compared. The polyunsaturated fatty acids (PUFAs) and monounsaturated FAs (MUFAs) were highest among lipid molecules in pollen from short (S) stamens than from long (L) and medium (M) stamens. This result is consistent with the FA content measurement, showing the highest FAs and UFAs content in S pollen, especially α-linolenic acid. We inferred that α-linolenic acid might be one of the key substances for bee foraging preference in pollen. Moreover, proteomic analysis showed that several differentially expressed proteins involved in lipid biosynthesis were highly accumulated in S pollen, such as choline kinase 2, 3-oxoacyl-ACP synthase-like protein and choline/ethanolamine phosphotransferase 1, in line with the highest FA content of S pollen. Additionally, DEPs involved in 'starch and sucrose metabolism', 'phenylpropanoid biosynthesis' and 'cyanoamino acid metabolism' were more represented in S compared with L and M pollen. The study suggests that differences in proteomic and lipidomic profiling among the three different stamen types might affect foraging decision-making of bumblebees.

Investigation on simultaneous change of deformation, color and aroma of 4D printed starch-based pastes from fruit and vegetable as induced by microwave.

Conventional 3D printing exhibits serious limitation for it requires a support layer upon which more layers can be formed. A designed structure that lacks such a layer is therefore very difficult, if not impossible, to be printed. A novel means to allow 4D deformation of simple 3D-printed object into complex suspended structure is therefore proposed; microwave irradiation was used to induce the desired directed deformation. In this study, yellow flesh peach-buckwheat paste was used to study the effects of model structure and microwave power on directed 4D deformation behavior. Then, finite-element based simulation was conducted to investigate interactions between the printed object and microwave irradiation. Experiments and simulations showed that local high temperature generated by microwave (200 W) caused directional micro puffing at resulting hot spots, forming a driving force to allow 3D-printed objects to rapidly undergo 4D deformation (within 90 s). The verification test also proved that puffing was the main factor driving 4D deformation. This strategy could combine with color and flavor changing microcapsules to realize the synchronous 4D printing process of deformation, color changing, and aroma changing within 15 s, induced by a household microwave oven (700 W). The purpose of this study is to provide a new 4D printing method interacting with consumers in a short time, which could be applied to children's food.