Sugar Composition Research Articles

Characterization of indigenous Durio species from Sarawak, Borneo: relationships between chemical composition and sensory attributes.

Sarawak, Borneo, harbours 16 unique Durio species, half of which are edible, with only Durio zibethinus widely cultivated. Despite their nutritional and economic significance to the rural communities in Sarawak, the lesser-known indigenous durians remain underrepresented in the scientific literature while facing the risk of extinction in the wild. Thus, the aim of this study was to conduct comprehensive chemical analyses of these wild edible durians, offering insights into their nutritional and sensory taste attributes. The edible part was separated at optimal ripeness, and the samples were subjected to further analysis. Wild edible durian genotypes exhibit varied characteristics, even within the same species. The majority of wild durians are characterized by a sugar composition consisting predominantly of sucrose, constituting 67.38-96.96%, except for the red-fleshed Durio graveolens renowned for its low total sugar content (0.49 ± 0.17 g per 100 g). Despite its bland taste, this species possessed significantly greater fat (14.50 ± 0.16%) and fibre (12.30 ± 0.14%) content. Durio dulcis exhibited a significantly greater carbohydrate content (29.37-30.60%), and its intense smell was attributed to its low protein content (2.03-2.04%). Indigenous durians offer substantial percentages of daily mineral intake, with 100 g servings providing approximately 15.71-26.80% of potassium, 71.72-86.52% of phosphorus, 9.33-27.31% of magnesium, and sufficient trace minerals. The vibrant flesh colours of yellow-, orange- and red-fleshed Durio graveolens and Durio kutejensis show high levels of ascorbic acid (31.41-61.56 mg 100 g-1), carotenoids (976.36-2627.18 µg 100 g-1) and antioxidant properties, while Durio dulcis and Durio oxleyanus, despite their dull flesh, contained high phenolic (67.95-74.77 mg GAE 100 g-1) and flavonoid (8.71-13.81 QE mg 100 g-1) levels. These endeavours provide a deeper understanding of the nutritional richness of wild edible durians, thereby supporting commercialization and conservation efforts.

Development, bioactive and sensory analysis of the honey-filled chocolate pralines infused with ground ivy (Glechoma hederacea L.) extract

Chocolate is consumed largely worldwide and it is known as one of the most craved foods. The market of chocolate products is growing steadily and is expected to continue to grow in the coming years. The aim of the present study was to formulate chocolate pralines with enriched sensory and bioactive attributes by incorporating different types of honey (false indigo, buckwheat, rapeseed, mandarin and sage) and ground ivy (Glechoma hederacea L.) extract as ingredients of the filler. The honey samples were subjected to physico-chemical analysis, sugar analysis using the HPLC-RID methodology, as well as to evaluation of antioxidant capacity. The bioactive and sensory properties and sugar composition of the formulated pralines were determined. Bioactive characterization included the determination of phenolic profile by HPLC-PAD methodology. Buckwheat honey showed the most pronounced antioxidant capacity with the value of 3.21 and 2.06 µmol Trolox/g dmb, determined by ABTS and DPPH assays, respectively, while the lowest values were measured for mandarin honey (0.41 and 0.32 µmol Trolox/g dmb). Specific bioactive compounds of cocoa: epicatechin, theobromine and caffeine, were detected in all formulated chocolate pralines, as well as the most predominant phenolic compounds of ground ivy: chlorogenic, caffeic, rosmarinic acid and rutin. Such enriched bioactive composition contributed to the pronounced antioxidant capacity of chocolate pralines. Finally, chocolate pralines prepared with mandarin honey were sensory evaluated as the sweetest and gained the highest scores for the overall acceptability.

Biochemical composition of fruit must from small-fruit apple varieties grown in the Southern Baikal Region

Most climatic zones of the Russian Federation include vast apple plantations that serve as the primary source of raw materials for the production of cider and fruit alcoholic beverages. The technological potential of new apple varieties in the production of fruit alcoholic beverages is understudied. The present study aims to examine the chemical composition (including the fractional composition of sugars and organic acids) of fruit must from small-fruit apple varieties grown in the Southern Baikal region and to identify the most suitable varieties for cider production.The biochemical composition of must was determined via conventional methods as per state standards. Smallfruit semi-cultivars grown in the Southern Baikal Region are characterized by variability in the content of extractive substances. In different years, the fruit of the same variety accumulates different amounts of dissolved solids (12.5–14.5%), primarily sugars (109.3–135.3 g/dm3). Among sugars, fructose is the most abundant (over 50%), followed by glucose. The proportion of disaccharides in the composition of sugars in the fruits of different varieties ranges from 9.1 to 21.5%. The concentration of organic acids in the studied varieties ranges from 7.2 to 13.0 g/dm3. The detected organic acids include malic acid (up to 83.4%), citric acid (up to 6.7%), lactic acid (up to 6.4%), succinic acid (up to 2.5%), as well as trace amounts of tartaric and acetic acids. The amount of phenolic compounds in the specimens varies from 522.5 to 1704.6 mg/dm3. The studied semi-cultivars were classified as sharp and bittersharp cider apple varieties.

KOMBUCHA CELLULOSE GROWTH COMPARISON: UTILIZING BRANDED TEA FOR ACCELERATING ARCHITECTURAL BIOMATERIAL PRODUCTION IN INDONESIA

One of the most recent phenomenal biomaterial trends is produced by kombucha. Its cellulose becomes viral once it is experimented on as a synthetic fabric in architectural and fashion products. The uttermost issues still lie on the unstable layer and larger plane production, while most experimentation goes slow on organic processes. Kombucha cellulose production depends on the quality of 3 fundamental materials such as tea, sugar, and water. Growing on the surface of a liquid, the most challenging problem is media sensitivity towards the surrounding environment, as it reflects cellulose productivity. The debates involve a critique of the utilization of high-quality material that generally does not impact the cellulose building, even if producing a more delicious tea. However, the traditional home-brewed technique is still dominant in most places, especially in developing countries like Indonesia. This paper aims to suggest a reasonable material shift in traditional fermentation, especially for improving kombucha cellulose thickness, which is core in biomaterial production. A comparison is presented to compare kombucha cellulose productions using better quality ingredients. The kombucha is fermented under a natural tropic storing environment: a temperature between 26°C-30°C in a dark room and a humidity of 60%. An initiated sugar composition of 10%, a pH between 3-5.5, with final alcohol less than 5%. A variation of mixtures is introduced to verify stable cellulose productivity. A compilation of measurements is taken in 3 consecutive weeks to reveal the growth pattern. The result is a maximal range of thickness growth and a stable and productive layer of kombucha cellulose.

Exogenous application of ALA enhanced sugar, acid and aroma qualities in tomato fruit.

The content and proportion of sugars and acids in tomato fruit directly affect its flavor quality. Previous studies have shown that 5-aminolevulinic acid (ALA) could promote fruit ripening and improve its aroma quality. In order to explore the effect of ALA on sugar and acid quality during tomato fruit development, 0, 100, and 200 mg L-1 ALA solutions were sprayed on the fruit surface 10 days after pollination of the fourth inflorescence, and the regulation of ALA on sugar, acid metabolism and flavor quality of tomato fruit was analyzed. The results showed that ALA treatment could enhance the activities of acid invertase (AI), neutral invertase (NI), and sucrose synthase (SS), reduce the activity of sucrose phosphate synthase (SPS), up-regulate the expression of SlAI, SlNI and SlSS, change the composition and content of sugar in tomato fruit at three stages, significantly increase the content of sugars in fruit, and promote the accumulation of sugars into flesh. Secondly, ALA treatments increased the activities of phosphoenolpyruvate carboxykinase (PEPC), malic enzyme (ME), and citrate synthase (CS), up-regulated the expression of SlPPC2, SlME1, and SlCS, and reduced the citric acid content at maturity stage, thereby reducing the total organic acid content. In addition, ALA could also increase the number and mass fraction of volatile components in mature tomato fruits. These results indicated that exogenous application of ALA during tomato fruit development could promote the formation of fruit aroma quality and were also conducive to the formation of fruit sugar and acid quality.

Studying specificity in protein-glycosaminoglycan recognition with umbrella sampling.

In the past few decades, glycosaminoglycan (GAG) research has been crucial for gaining insights into various physiological, pathological, and therapeutic aspects mediated by the direct interactions between the GAG molecules and diverse proteins. The structural and functional heterogeneities of GAGs as well as their ability to bind specific proteins are determined by the sugar composition of the GAG, the size of the GAG chains, and the degree and pattern of sulfation. A deep understanding of the interactions in protein-GAG complexes is essential to explain their biological functions. In this study, the umbrella sampling (US) approach is used to pull away a GAG ligand from the binding site and then pull it back in. We analyze the binding interactions between GAGs of three types (heparin, desulfated heparan sulfate, and chondroitin sulfate) with three different proteins (basic fibroblast growth factor, acidic fibroblast growth factor, and cathepsin K). The main focus of our study was to evaluate whether the US approach is able to reproduce experimentally obtained structures, and how useful it can be for getting a deeper understanding of GAG properties, especially protein recognition specificity and multipose binding. We found that the binding free energy landscape in the proximity of the GAG native binding pose is complex and implies the co-existence of several binding poses. The sliding of a GAG chain along a protein surface could be a potential mechanism of GAG particular sequence recognition by proteins.

Bee Bread Boosts Probiotic Yoghurt: Unveiling the Impact on Physiochemical, Microbiological, and Sensory Attributes

This study aimed to investigate the effects of bee bread on some parameters in probiotic yoghurt production. The bee bread composition contained the elements B, Ca, Fe, K, Mg, Na, P, and Zn. The analysis of sugar composition revealed the presence of fructose, glucose, and sucrose. The organic acid and phenolic substance content were assessed. The following values were obtained: oxalic acid (1.26 mg/g), malic acid (7.79 mg/g), ascorbic acid (0.91 mg/g), citric acid (2.73 mg/g), p-coumaric acid (15.3 µg/g) and kaempferol (5,562.4 µg/g). The study determined the tocopherol content, specifically alpha (7.09 µg/g), beta (0.4 µg/g), gamma (0.77 µg/g), and delta (0.31 µg/g). A total of 55 distinct components were identified while analyzing the volatile and aroma profiles. This study found that the IC50 value of bee bread was 1.414 mg/mL. Bee bread did not affect physicochemical parameters such as pH, acidity, dry matter, ash, milk fat, and water holding capacity (P>0.05) but affected protein and syneresis (P

Analysis of Differences in the Chemical Composition of Glycosides and Sugars between Four Forms of Fresh Rehmanniae Radix.

Fresh Rehmanniae Radix, as well as its processed products, are widely used in the clinical practice of traditional Chinese medicine. It is mainly available in four forms: fresh Rehmanniae Radix, raw Rehmanniae Radix, prepared Rehmanniae Radix, and nine-steamed, nine-dried Rehmanniae Radix. Pharmacological studies have shown that all Rehmanniae Radix forms contain iridoid glycosides and sugar compounds with various effects, including hypoglycemic, anti-inflammatory, neuroprotective, immunological enhancement, and bone marrow hematopoiesis-promoting activities. Differences in the efficacy among these Rehmanniae Radix forms and their processed products have been attributed to variations in their chemical compositions, particularly in iridoid glycosides and sugar compounds; however, the specific compositional differences in glycosides and sugars among the four forms of Rehmanniae Radix have not been clarified. Therefore, this study aims to qualitatively characterize the iridoid glycosides and sugar compounds in fresh Rehmanniae Radix, raw Rehmanniae Radix, prepared Rehmanniae Radix, and nine-steamed, nine-dried Rehmanniae Radix.

PbrbZIP15 promotes sugar accumulation in pear via activating the transcription of the glucose isomerase gene PbrXylA1.

The composition and abundance of soluble sugars in mature pear (Pyrus) fruit are important for its acceptance by consumers. However, our understanding of the genes responsible for soluble sugar accumulation remains limited. In this study, a S1-group member of bZIP gene family, PbrbZIP15, was characterized from pear genome through the combined analyses of metabolite and transcriptome data followed by experimental validation. PbrbZIP15, located in nucleus, was found to function in fructose, sucrose, and total soluble sugar accumulation in pear fruit and calli. After analyzing the expression profiles of sugar-metabolism-related genes and the distribution of cis-acting elements in their promoters, the glucose isomerase 1 gene (PbrXylA1), whose corresponding protein catalyzed the isomerization of glucose and fructose in vitro, was identified as a downstream target gene of PbrbZIP15. PbrbZIP15 could directly bind to the G-box element in PbrXylA1 promoter and activate its transcription, as evidenced by chromatin immunoprecipitation-quantitative PCR, yeast one-hybrid, electrophoretic mobility shift assay, and dual-luciferase assay. PbrXylA1, featuring a leucine-rich signal peptide in its N-terminal, was localized to the endoplasmic reticulum. It was validated to play a significant role in fructose, sucrose, and total soluble sugar accumulation in pear fruit and calli, which was associated with the upregulated fructose/glucose ratio. Further studies revealed a positive correlation between the sucrose content and the expression levels of several sucrose-biosynthesis-related genes (PbrFRK3/8, PbrSPS1/3/4/8, and PbrSPP1) in PbrbZIP15-/PbrXylA1-transgenic fruit/calli. In conclusion, our results suggest that PbrbZIP15-induced soluble sugar accumulation during pear development is at least partly attributed to the activation of PbrXylA1 transcription.

NUTRITION DESIGN MODELING METHOD DEVELOPMENT FOR STRUCTURAL AND ELEMENTAL ANALYSIS OF BERTİZ GRAPE PEKMEZ USING FIELD EMISSION GUN – SCANNING ELECTRON MICROSCOPE (FEG-SEM)

Bertiz kabarcık (buble) grape pekmez nutrition design modeling method development was studied by structure analysis and composition modeling using the Field Emission Gun – Scanning Electron Microscope (FEG-SEM). A uniform static, soil-mineral like and non-crystal solid surface was detected in pekmez sample structural images. The high value of carbon (69.89%), oxygen (28.14%), phosphorus (0.69%) and potassium (1.28%) peak patterns indicated that the pekmez is a sugar and mineral composition model. Deficiency of purification and clarification were presented in the pekmez samples produced by traditional way, and less pure and clear pekmez product was detected in the structural images. However, the liquid concentrated form of these grape samples completely dissolved at room temperature. Pekmez soft drinks; Pekmez Cola including caffeine, Pekmez Gazoz with no additives and Pekmez Limon comprising lemon flavor were prepared using the carbonated pekmez solutions without any sugar additives.

Pectin-derived oligogalacturonic acids ameliorate high-fat diet-induced obesity in mice by regulating gut microbiota and inflammation

Pectic oligosaccharides have been proposed as a novel prebiotic to prevent obesity and associated with metabolic disorders by regulating gut microbiota, but their various probiotic functions in the gut depended on their complex and heterogeneous sugar composition. This study aimed to obtain specific oligogalacturonic acids (POAS) from pectin and investigate the effects of POAS on high-fat diet-induced obesity in mice. The results showed that POAS improved body weight gain, serum lipids and hepatic steatosis in obese mice. POAS notably enhanced intestinal barrier function, reduced inflammatory response and regulated the expression of key genes in lipid synthesis and metabolism. Besides, POAS also promoted short-chain fatty acids (SCFAs) production. Furthermore, POAS alleviated the gut microbiota dysbiosis caused by HFD with significantly increasing beneficial gut microbiota such as Akkermansia and Lactobacillus. Spearman's correlation analysis indicated that these bacteria were strongly correlated with obesity-related parameters. We conclude that POAS is a potential prebiotic to treat obesity and related complications.

Impact of different salt concentrations on growth, biochemical composition and nutrition quality of Phaeodactylum tricornutum and Spirulina platensis.

The effects of different salt concentrations on the growth, aroma and quality parameters of P. tricornutum and S. platensis were investigated for the first time.Salt contents were 15, 25, 30 and 35‰ for the P. tricornutum and 20, 25, 30 and 35‰ for the S. platensis culture. Aroma compounds were analyzed by HS-SPME-GC/MS while the organic acid and sugar composition were studied by HPLC-PDA-RID.The main amino acids were glutamic acid (6.24-12.96mg/100g) and alanine (3.67-13.65mg/100g) while the prevailing sugars were sucrose (229-1099mg/100g) and glucose (192-2322mg/100g) in the P. tricornutum and S. platensis samples.The most prevailing aroma compound was acetic acid (113µg/kg) in the P. tricornutum samples and heptadecane (36941µg/kg) in the S. platensis samples.A significant reduction was found in the amount of aroma compounds, amino acids, sugars and organic acids with increasing salt concentration.The study results are valuable for producing high-quality and flavorful P. tricornutum and S. platensis products.

Development and Economic Analysis of Bioethanol Production from Palm (Arenga Pinatta) Biomass with Ionic Liquid Pretreatment Using SuperPro Designer Software

Bioethanol has many functions both as a chemical, food and as a source of energy. The development of bioethanol production is currently leading to the residue of the main product. So that in this study the biomass of arena or Arenga Pinatta was used with a large availability of waste. Therefore, a performance and economic analysis was carried out in the production of bioethanol from palm biomass with ionic liquid (IL) using SuperPro Designer (SPD) Software. As a preparatory stage, the process of testing the characteristics of the biomass is carried out to obtain the most optimal composition of palm sugar in bioethanol production. After simulating the conditions according to the experimental process on the most optimal palm biomass composition, it was found that the most optimal Ionic Liquid (IL) and biomass ratio was at 0.5 g/g with the ethanol concentration obtained at 90.6 g/L at 13 hours which corresponds to theoretical yield of 96% conversion of biomass to ethanol. Meanwhile, the production of ethanol in a factory for energy can minimize the price of ethanol by 30% from the initial price. Thus, with the abundant availability of biomass, bioethanol production with aren biomass has the potential to be developed in Indonesia

Cell wall polysaccharides from Annona squamosa: Chemical and functional characterization

Several extraction methods were used to find out what the custard apple cell wall polysaccharides were made of and how they were structured. These included water (WSP), chelator (CSP), sodium carbonate (NSP), potassium hydroxide at 1 mol/L (KSH-1), and potassium hydroxide at 4 mol/L (KSH-4). The five fractions had different structures and make-ups, as shown by FT-IR, molecular weight measurements, sugar composition analysis, and methylation experiments. The results indicated that NSP made up the majority of the fruit's cell wall polysaccharide fraction. As for apparent viscosity, the viscosity and thermal stability of WSP were highest. In terms of apparent viscosity and thermal stability, WSP ranked highest. The stability of NSP and KSH-1 was better. Methylation analysis showed that CSP had galactose and galacturonic acid as the main chains. KSH-4 had a xyloglucan backbone. Compared to the other three fractions, NSP and CSP had the highest antioxidant capacity. Through this study, there is potential for custard apple polysaccharides to be used in the food and biological industries.

Study on the preference of rosella mangrove syrup with different concentrations of sucrose

Syrup products are preferred considering the tropical climate of Indonesia. One of the mangrove fruits that can be processed into syrup is pedada (Sonneratia caseolaris) which is combined with the natural colour of roselle flower petals. With the addition of roselle, the resulting syrup colour becomes attractive with a pink color. The manufacture of roselle mangrove syrup requires the addition of the right sugar. In this study, the manufacture of 1 kg of mangrove fruit was added with 3 concentrations of sucrose sugar (1; 1.5, and 2 kg). Tests were carried out by measuring antioxidant activity, the value of sucrose content, viscosity, and hedonic test. The test results showed that the value of sucrose content increased along with the addition of sucrose sugar to the syrup, namely 65.61 to 71.46%. The value of this sucrose content has met the SNI for syrup. The highest antioxidant value in the 2 kg sugar treatment was 79.58. In the study of the viscosity, the highest value at treatment with the composition of 2 kg sugar additional. However, the panelists preferred syrup with a sugar composition of 1.5 kg with the highest score marked on the hedonic test.

Transcriptome and Metabolome Analyses Reveal Sugar and Acid Accumulation during Apricot Fruit Development

The apricot (Prunus armeniaca L.) is a fruit that belongs to the Rosaceae family; it has a unique flavor and is of important economic and nutritional value. The composition and content of soluble sugars and organic acids in fruit are key factors in determining the flavor quality. However, the molecular mechanism of sugar and acid accumulation in apricots remains unclear. We measured sucrose, fructose, glucose, sorbitol, starch, malate, citric acid, titratable acid, and pH, and investigated the transcriptome profiles of three apricots (the high-sugar cultivar ‘Shushanggan’, common-sugar cultivar ‘Sungold’, and low-sugar cultivar ‘F43’) at three distinct developmental phases. The findings indicated that ‘Shushanggan’ accumulates a greater amount of sucrose, glucose, fructose, and sorbitol, and less citric acid and titratable acid, resulting in a better flavor; ‘Sungold’ mainly accumulates more sucrose and less citric acid and starch for the second flavor; and ‘F43’ mainly accumulates more titratable acid, citric acid, and starch for a lesser degree of sweetness. We investigated the DEGs associated with the starch and sucrose metabolism pathways, citrate cycle pathway, glycolysis pathway, and a handful of sugar transporter proteins, which were considered to be important regulators of sugar and acid accumulation. Additionally, an analysis of the co-expression network of weighted genes unveiled a robust correlation between the brown module and sucrose, glucose, and fructose, with VIP being identified as a hub gene that interacted with four sugar transporter proteins (SLC35B3, SLC32A, SLC2A8, and SLC2A13), as well as three structural genes for sugar and acid metabolism (MUR3, E3.2.1.67, and CSLD). Furthermore, we found some lncRNAs and miRNAs that regulate these genes. Our findings provide clues to the functional genes related to sugar metabolism, and lay the foundation for the selection and cultivation of high-sugar apricots in the future.

Rootstock and Crop Load Effects on ‘Honeycrisp’ Photosynthetic Performance and Carbohydrate Accumulation

Rootstock selection and crop load adjustment are key practices in apple orchard management; nevertheless, the effects of rootstocks and crop load levels on important physiological processes of the scions, such as photosynthetic performance and carbohydrate accumulation, are still unclear. To investigate the impact of different rootstocks and crop load levels on scion photosynthesis and carbohydrate buildup, in 2020, ‘Honeycrisp’ trees grafted on rootstocks ‘G.41’, ‘G.935’, and ‘M.9-T337’ were thinned to low and high crop load levels, and photosynthetic performance and carbohydrate accumulation in leaves and fruit were evaluated. Leaves from ‘G.935’ showed the highest net photosynthesis and electron use efficiency of photosynthesis and the lowest activity for non-net carboxylative processes, all together indicative of enhanced photosynthetic performance. High crop load determined an increase in gas exchange, suggesting a positive feedback of high fruit competition on carbon assimilation. While rootstock ‘M.9-T337’ showed a higher accumulation of starch in leaves, no pattern regarding the composition of leaf-soluble sugars among rootstocks could be identified. Conversely, by the end of the harvest season, leaves from low-cropping trees had higher fructose, glucose, and sorbitol than those from high-cropping trees, but differences in starch content were not significant. Fructose and sorbitol concentrations were affected by rootstock and crop load, respectively. Overall, this study showed that high cropping enhanced photosynthesis in ‘Honeycrisp’ apple and determined lower accumulation of some soluble carbohydrates (fructose, glucose, sorbitol) in leaves. This study also provided insights into how rootstocks affect photosynthetic performance of ‘Honeycrisp’, highlighting ‘G.935’ as the rootstock conferring the highest photosynthetic capacity under the present experimental conditions.

Composition of free sugars and organic acids in Japanese strawberry cultivars and their influence on the perception of sweetness and sourness.

This study aimed to determine the extent of variations in the ratio of major free sugars to total sugars and major organic acids to total organic acids in strawberry juice with cultivar and harvest season and investigate whether these differences affect the perceived intensity of sweetness and sourness. Eight Japanese strawberry cultivars were simultaneously grown and harvested in different seasons for sugar and organic acid content analyses. In addition, simulated strawberry juices, containing equal total amounts of sugars and organic acids but in different ratios, were prepared based on their analytical values. The perceived intensities of sweetness and sourness of the juices were subjected to sensory evaluation. The results showed a wide range of sucrose compositions, ranging from almost zero to the highest ratio of 36.7% to total sugar. Glucose and fructose were present in approximately equal amounts, with a slight inclination toward more fructose. For organic acids, the highest ratio of citric acid was 87.6%, the lowest was approximately 60.1%, and the remainder comprised malic acid. The results of the sensory evaluation using simulated strawberry juice indicated that sweetness and sourness were significantly more pronounced as the ratio of sucrose to total sugar and the ratio of malic acid to total organic acid increased, respectively. These results suggest that it is essential to consider not only total soluble solids and titratable acidity but also the composition of the sugars and organic acids comprising them when evaluating strawberry taste. PRACTICAL APPLICATION: Total soluble solids and titratable acidity have been used to evaluate strawberry taste; however, how the composition and ratios of the sugars and organic acids that comprise them affect the taste is unclear. This study revealed that, for sugars, an increase in the proportion of sucrose resulted in a stronger perception of sweetness, and for organic acids, an increase in the proportion of malic acid resulted in a stronger perception of sourness. These findings are expected to be useful in future studies evaluating strawberry taste and palatability.

Stable carbon isotopic composition of amino sugars in heterotrophic bacteria and phytoplankton: Implications for assessment of marine organic matter degradation

AbstractCompound‐specific isotope analysis has opened up a new realm for resolving the sources and transformation processes of marine organic matter. However, the stable carbon isotope patterns of amino sugars remain unknown. We examined δ13C of amino sugars in marine phytoplankton and heterotrophic bacteria, and the variations in amino sugar δ13C during 66‐d planktonic organic matter degradation experiments, to investigate the metabolic sources and transformations of amino sugars by bacterial reworking. The δ13C values of glucosamine (GlcN) and galactosamine (GalN) were comparable in heterotrophic bacteria (difference Δδ13CGlcN–GalN = 0.4–4.0‰) but pronouncedly different in phytoplankton (Δδ13CGlcN–GalN = 4.3–16.6‰), suggesting similar synthesis pathways of GlcN and GalN in bacteria that differed from phytoplankton. Compared to GlcN and GalN, bacteria preferentially use isotopically light organic compounds for muramic acid (MurA) synthesis. During simulated microbial degradation of organic matter, the δ13C difference between GlcN and GalN decreased from 5.8‰ on the initial day to 1‰ at a late stage in the experiment, but the difference between GlcN and MurA remained at 5.3‰. This difference is consistent with the pattern in cultured phytoplankton (average Δδ13CGlcN–GalN = 5.9‰ ± 1.4‰) and heterotrophic bacteria (average Δδ13CGlcN–MurA = 4.6‰ ± 3.4‰), indicating enhanced bacterial resynthesis as degradation proceeded. Based on the difference in δ13C among GlcN, GalN, and MurA, we propose a novel index of variation in amino sugar δ13C, representing amino sugar resynthesis, to describe the diagenetic state of organic matter. Together, these findings suggest that amino sugar δ13C can be used as a new tool to track heterotrophic processes of marine organic matter.

Physicochemical homogeneity of stingless bee honey (Heterotrigona itama) produced in the west coast, east coast and inland area of Peninsular Malaysia.

The nutritional composition of stingless bee honey (SBH) can be affected by different climates and soil composition across different geographical areas. However, the range of attributes set for a honey quality standard should be inclusive. This study analysed the sugar profile's physiochemical properties, including quantifying the rare sugar trehalulose, organic acid and mineral composition of SBH collected from inland, and west and east coasts of Peninsular Malaysia. Forty-three SBH (Heterotrigona itama) samples were collected and labelled as <20 and <40 West Coast (<20WC, <40WC), <20 and <40 East Coast (<20EC, <40EC) and Inland, according to their distance from the coasts. The moisture, pH and sugar composition of all SBH samples adhered to the Malaysian Kelulut Honey Standard (MS2683:2017) but not to the International Codex Standard (CODEX) for honey. Trehalulose presence in all samples, regardless of geographical area, was predominant alongside fructose and glucose. Only hydroxymethylfurfural (HMF) content and electrical conductivity (EC) results complied with both standards. The principal component analysis biplot showed that the discrimination of SBH according to the five different areas was not feasible, indicating sample homogeneity. The physicochemical evaluation of SBH from Peninsular Malaysia shows mainly homogeneous attributes of samples across geographical locations. These findings demonstrated that the current MS2683:2017 is relevant and accommodates all SBH of H. itama species produced in Peninsular Malaysia. Furthermore, the trehalulose range calculated in this study can be implemented as a new benchmark for the indicator of SBH honey quality standard by national and international food standard committees. © 2023 Society of Chemical Industry.