Sucrose/D-Fructose/D-Glucose Assay Kit

Many of the enzymatic test kits are official methods of prestigious organisations such as the Association of Official Analytical Chemicals (AOAC) and the American Association of Cereal Chemists (AACC) in response to the interest from oenologists. Megazyme decided to use its long history of enzymatic bio-analysis to make a significant contribution to the wine industry, by the development of a range of advanced enzymatic test kits. This task has now been successfully completed through the strategic and comprehensive process of identifying limitations of existing enzymatic bio-analysis test kits where they occurred, and then using advanced techniques, such as molecular biology (photo 1), to rapidly overcome them. Novel test kits have also been developed for analytes of emerging interest to the oenologist, such as yeast available nitrogen (YAN; see pages 2-3 of issue 117 article), or where previously enzymes were simply either not available, or were too expensive to employ, such as for D-mannitol analysis.

It is without doubt that testing plays a pivotal role throughout the whole of the vinification process. To produce the best possible quality wine and to minimise process problems such as “stuck” fermentation or troublesome infections, it is now recognised that if possible testing should begin prior to harvesting of the grapes and continue through to bottling. Traditional methods of wine analysis are often expensive, time consuming, require either elaborate equipment or specialist expertise and frequently lack accuracy. However, enzymatic bio-analysis enables the accurate measurement of the vast majority of analytes of interest to the wine maker, using just one piece of apparatus, the spectrophotometer (see previous issue No. 116 for a detailed technical review). Grape juice and wine are amenable to enzymatic testing as being liquids they are homogenous, easy to manipulate, and can generally be analysed without any sample preparation.

Growing demand for environmentally sustainable protein sources is shifting dietary preferences toward plant-derived alternatives such as legumes. Pea (Pisum sativum L.) seeds offer great potential for expanded human consumption, but sensory quality is key for consumer acceptance and cultivar development. In this study, a diversity panel of 15 pea accessions was evaluated for nutrients and phytochemicals (protein, resistant and non-resistant starch, fatty acids, choline, phytate, saponins, and sucrose) and their sensory attributes (taste, aroma, mouthfeel, and aftertaste). Among the sensory attributes, mouthfeel and aroma contributed most to the variation. Principal component analysis revealed two large, distinct clusters, primarily separated by seed coat (testa) colour. Accessions with a dark-coloured testa were generally perceived more odour intense and with more texture, while accessions with light-coloured testa were sweeter and juicier. Accessions with wrinkled seeds stood out in their content of non-resistant starch, sucrose, total choline, and phytate, when compared to smooth and dimpled seeds. Shorter cooking times were positively correlated to the perception of higher bitterness. This study highlights the potential in combining seed compositional analysis and sensory evaluations for screening pea accessions suitable for the development of future food products.

The phytochrome B (phyB) photoreceptor and EARLY FLOWERING 3 (ELF3) are two major plant thermosensors that monitor high temperatures primarily at night. However, high temperatures naturally occur during the daytime; the mechanism of daytime thermosensing and whether these thermosensors can also operate under intense sunlight remain ambiguous. Here, we show that phyB plays a substantial role in daytime thermosensing in Arabidopsis, and its thermosensing function becomes negligible only when the red light intensity reaches 50 μmol m⁻² s⁻¹. Leveraging this restrictive condition for phyB thermosensing, we reveal that triggering daytime thermomorphogenesis requires two additional thermosensory pathways. High temperatures induce starch breakdown in chloroplasts and the production of sucrose, which stabilizes the central thermal regulator PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) by antagonizing phyB-dependent PIF4 degradation. In parallel, high temperatures release the inhibition of PIF4 transcription and PIF4 activity by ELF3. Thus, our study elucidates a multisensor high-temperature signaling framework for understanding diverse thermo-inducible plant behaviors in daylight.

Although there is increasing understanding of the regulatory effects of particular epigenetic marks, much less is known about how crosstalk among multiple marks affects genetic regulation. Here, we show that Dwarf-related WD40 protein 1 (DRW1) is involved in DNA 6mA demethylation, H3K27 trimethylation, and RNA m⁵C methylation in rice through its respective recruitment of the DNA demethylase AlkB homolog 1 (OsALKBH1), the histone methyltransferase CURLY LEAF (OsCLF), and NOP2/Sun RNA methyltransferase family member 2 (OsNSUN2). Knockout of DRW1 significantly reduces the extent of chromatin occupancy by OsALKBH1, OsCLF, and OsNSUN2, resulting in increased chromatin accessibility and enhanced expression of genes associated with brassinosteroid biosynthesis and signaling. Gene editing at a CAAT-box (ATTGG→ATTGA) and a GATA motif (GATAGGG→GAT) in the DRW1 promoter leads to elevated DRW1 transcription and thereby enhanced rice grain yield and salt tolerance. In field trials, DRW1-overexpressing rice lines displayed yield increases of ∼30.2% (in both normal and saline soils), accompanied by decreases in DNA 6mA and increases in H3K27me3 and RNA m⁵C levels at target genes. Overall, our study uncovers DRW1-mediated crosstalk among three epigenetic marks (DNA 6mA, H3K27me3, and RNA m⁵C) and reveals how this crosstalk controls transcriptional and post-transcriptional regulation to affect rice yield and salt tolerance.

In the last thirty years, the factors driving the establishment and composition of the sourdough biota have been deeply studied. Nevertheless, to date, no study has ever evaluated the biochemical and microbial dynamics of sourdoughs propagated using the different traditional methods integrated into procedural back-slopping practices worldwide. A mature type I sourdough was propagated for 10 days according to four managing conditions (Milanese, In Water, Free and Piedmontese) entailing incubations in a jute sack, submerged in water, in a jar or a combination of them. Sourdoughs obtained under the different conditions (and corresponding breads) were extensively characterized. When processing parameters modified the sourdough environment, the microbial community changed. In the first days of propagation Fructilactobacillus sanfranciscensis was the main dominant species regardless of the type of propagation, remaining present in all sourdoughs, especially those maintained in a jar. Differences among the propagation methods emerged from the biochemical analysis. Sourdoughs propagated in water exhibited higher titratable acidity, mainly due to the acetic acid produced, and were characterized by a more complex aromatic profile which differentiated them from the others. Biochemical features of breads mainly reflected those of the corresponding sourdough, whereas nutritional (protein digestibility and glycemic index) and technological (texture profile, colorimetric coordinates) features were hardly affected by the propagation method. Thus, investigation on the effect of the variation of the ecological determinants within the same propagation methods and their role in the definition of sourdough potential could be the subject of further studies.

Trehalose has sparked considerable interest in a variety of pharmaceutical applications as well as in cryopreservation. Recently, there have been growing efforts in the development of trehalose delivery nanocarriers to address the issue of the poor bioavailability of trehalose. The majority of the strategies comprise physical entrapment of trehalose, since its covalent, yet biolabile, conjugation is challenging. Here, we present research on trehalose-releasing nanogels, in which covalent, yet biolabile, conjugation of trehalose was achieved through the co-incorporation of trehalose (meth)acrylate(s) together with hydrophilic primary/secondary acrylamides in one polymeric network. In this case, the primary and secondary amide groups participated in ester hydrolysis in the (meth)acrylate units, making the hydrolysis feasible under physiologically relevant conditions. A set of nanogels with precisely selected compositions were synthesized, characterized, and then studied to evaluate the influence of various structural and environmental factors on the release rate of trehalose. The study also provides insights into some other aspects that are important in view of potential biomedical applications, including specific interactions of nanogels through their terminal α-d-glucopyranosyl moieties from pendant trehalose, protein corona formation, and cellular uptake.

The growing interest in the replacement of eggs by the food industry is driven by many factors, including consumer demand, allergen reduction, improved food safety, healthier nutritional profiles, easier handling and storage, improved functionality, and environmental sustainability. Egg replacement represents a challenge for the bakery industry since their substitution implies emulsifying, coagulating, binding, and bubble-entrapping capacity losses. For this purpose, pulses can mimic the functional properties of animal-derived ingredients like oil- and water-holding, solubility, gelling, foaming, and emulsion properties. The objectives of this work were to study the physicochemical and functional properties of pulse protein concentrates and isolates (PPCIs) from different plant origins (namely, chickpeas, peas, mung beans, soy, lentils, and broad beans) to replace the egg in pancake formulations. The protein concentrates and isolate from pulses have been characterized by their water- and oil-holding capacity, solubility, gelling, foaming, and emulsifying properties. Then, the pancakes were studied for their textural, chemical-physical, and colorimetric properties. The protein concentrates differed from the isolates, especially in the Water Solubility Index and the swelling power, while the isolates were characterized for the foaming capacity, the oil-binding capacity, the water-holding capacity, and the minimum gelling concentration. Overall, the soy concentrates better mimic egg functionalities compared to the control pancake, especially for the volume and height properties and Consistency Index of the batters. Using soy concentrate as a “stand-alone” ingredient for egg replacement represents an interesting solution since it is available on the market, has a clean label, and is environmentally sustainable compared to eggs, even though it could represent an insidious allergen for the food industry.

Kombucha is a unique, naturally fermented sweetened tea produced for thousands of years, relying on a symbiotic microbiota in a floating biofilm, used for successive fermentations. The microbial communities consist of yeast and bacteria species, distributed across two phases: the liquid and the biofilm fractions. In the fermentation of kombucha, various starters of different shapes and origins are used, and there are multiple brewing practices. By metabarcoding, we explored here the consortia and their evolution from a collection of 23 starters coming from various origins summarizing the diversity of kombucha fermentation processes. A core microbiota of yeast and bacteria has been identified in these diverse kombucha symbiotic consortia, revealing consistent core taxa across symbiotic consortium of bacteria and yeasts from different starters. The common core consists of five taxa: two yeast species from the Brettanomyces genus (B. bruxellensis and B. anomalus) and bacterial taxa Komagataeibacter, Lactobacillus, and Acetobacteraceae, including the Acetobacter genus. The distribution of yeast and bacteria core taxa differs between the liquid and biofilm fractions, as well as between the “mother” and “daughter” biofilms used in successive fermentations. In terms of microbial composition, the diversity is relatively low, with only a few accessory taxa identified. Overall, our study provides a deeper understanding of the core and accessory taxa involved in kombucha fermentation.

Background: Legumes are a key component of the human diet and a primary source of plant‐based protein. They have attracted global attention as potential plant‐based meat alternatives due to their numerous health benefits, and they contribute to a more sustainable and healthy food system. Among pulses, peas (Pisum sativum L.) are considered a good source of proteins, fibers, starch, minerals, and vitamins. This study evaluated the effect of environmental conditions on nutritional profile of peas cultivated in an organic farming system, in different Italian environments (mountainous and hilly), during different cultivation years (2021 and 2022). Pea grain from peas cultivated under the various conditions was used to prepare pea‐based crackers containing 6% pea flour. The appearance, physical properties (rheology and texture), and nutritional profile of the snacks were evaluated, and sensory analysis was conducted. Results: The nutritional and bioactive compounds were strongly related and the environment exerted a substantial impact on most of the nutritional components (proteins and carbohydrates), due to climatic conditions during the vegetative and reproductive stage of the crop. The incorporation of cultivated peas into wheat‐based crackers improved their functional and nutritional quality while maintaining consumer acceptability, as demonstrated by sensory analysis. Conclusions: The results confirmed that growing conditions significantly influence the nutritional composition of peas, enhancing their quality and that of the resulting crackers. This aligns with the increasing global demand for high‐quality, sustainable food products.

This study investigated the interaction between apple juice (AJ) and acarbose (A) in modulating glycaemic responses, with the aim of validating in vivo results previously observed in vitro. When administered to rats, AJ alone reduced the glycemic curve, but the combination of AJ with increasing doses of A resulted in higher glycemic responses, suggesting an antagonistic interaction in α-glucosidase inhibition. To explore this mechanism, quercetin-3-glucoside (Q-3-G), a major phenolic compound in AJ, was tested for α-glucosidase inhibition in vitro. Q-3-G and A together showed reduced inhibitory efficacy compared to either compound alone, consistent with in vivo findings. Ex vivo studies in Caco-2 cells further supported this antagonism. Sucrose hydrolysis experiments showed that low concentrations of Q-3-G increased residual sucrose when combined with moderate concentrations of A, but higher concentrations of Q-3-G favoured sucrose hydrolysis regardless of A levels. The results highlight the antagonistic interaction between Q-3-G and A in inhibiting α-glucosidase and emphasise the need to combine in vitro, ex vivo and in vivo studies to evaluate food-drug interactions. This comprehensive approach is essential before advocating the use of functional foods alongside pharmacological therapies.

Among the species used for syrup production, sugar maple (Acer saccharum Marsh.) is preferred by producers, while red maple (Acer rubrum L.) is considered less productive in terms of sap yield and sugar content. This study aims to measure the volume and physicochemical characteristics of the sap produced from two red maples and two sugar maples during the 2023 sugar season in a commercial sugarbush in Laterrière (QC, Canada). Sap exudation was measured continuously with the gravity method using automatic rain gauges. Sap production was discontinuous and heterogeneous, reaching 2.6 L during the most productive day. No significant difference was found in the daily production between species, but we observed a difference in the cumulative sap production (7 L in red maple vs. 13.5 L in sugar maple) due to a longer period of sap exudation in the latter. Despite daily variations in pH, Brix values, sucrose concentration, osmolality, and conductivity, no differences in physicochemical characteristics were detected between species.

In this study a plant-based spread was developed using dextran-enriched ingredients derived from pea flours, supplemented with defatted durum wheat germ and almond flour. Optimization of fermentation with Leuconostoc pseudomesenteroides DSM 20193, both with and without enzymatic hydrolysis, aimed to enhance exopolysaccharide production and the nutritional value of pea flours. Best results were achieved through enzymatic hydrolysis with Veron PS protease followed by fermentation at 25°C, resulting in elevated dextran levels and increased peptides and total free amino acid concentration in green and yellow pea-based ingredients. The yellow pea-based ingredient was selected for the final plant-based spread formulation, blended at 35% w/w, with 45% w/w defatted durum wheat germ, and 20% w/w almond flour. The resultant spread exhibited elastic and solid-like characteristics like milk-based spreadable cheese and yogurt, boasting 'high protein' (12.49 g/100g) and 'high fiber' (11.01 g/100g) designations. It maintained chemical, biochemical, and microbiological stability over a 10-day shelf-life under refrigerated conditions. Sensory evaluation confirmed the acceptability of the plant-based spread (PBS), highlighting a well-balanced aroma and a grainy, adhesive texture. This research underscores the potential of an integrated approach utilizing food-grade enzymes and fermentation for the in-situ production of dextran to create innovative, clean label, and plant-based foods.

Biological nitrogen fixation (BNF) occurring in the rhizosphere is a sustainable source of nitrogen for plants. BNF in cereal crops can be promoted by inoculation of a single or consortium of associative and endophytic diazotrophs. Creating a successful nitrogen-fixing biofertilizer necessitates the study of the core microbiome of the plant rhizosphere and the functional relationship of the members. This study compares the endosphere and rhizoplane microbial diversity of three aromatic landraces and one high-yielding variety of rice using culture-independent methods. The V3-V4 variable regions of 16S rRNA were used for amplicon sequencing of soil DNA. Patescibacteria, Planctomycetota, and Proteobacteria were the predominant phyla in all four genotypes. Richness (Chao-1 and ACE) and microbial diversity indices (Shannon and Simpson indices) showed that microbial diversity among the genotypes varies subtly at the phylum level. Beta diversity analysis with the phylum identified and comparisons of the microbiome at the genus level revealed a more prominent effect of plant genotype on microbial diversity. Canonical component analysis drew a correlation between microbial diversity in each genotype with the sugar and N content of these landraces. Paraburkholderia was identified as one of the major OTUs among the known nitrogen fixing followed by Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium group, Azospirillum, Hebarspirillum, and Azotobacter.

The main mango cultivars produced in the southern Pacific region of Mexico are Ataulfo, Manila, Haden, and Criollo. However, mineral, nutritional, and nutraceutical composition studies are limited. This study aimed to evaluate the effect of cultivars on the nutritional, mineral, and nutraceutical qualities of mango produced in Mexico. The cultivar significantly affected (p ≤ 0.05) the fruit composition across these indices. Criollo had the highest potassium, magnesium, sodium, and zinc concentrations, while Haden showed the highest calcium content. Manila had the highest iron content, contributing 0.76% of the recommended daily intake. Ataulfo and Haden were statistically similar in manganese content, both higher than Criollo, with Ataulfo reaching the maximum copper concentration. Ataulfo also had the highest sugar content, while Criollo had the most dietary fiber (3.1%), double that of Ataulfo and Haden. Haden had the lowest dry matter (14.8%) and lowest protein content (0.46%), with Manila showing the lowest ash content. The cultivars also differed in nutraceutical composition: Ataulfo was highest in total phenols, DPPH, and vitamin A; Haden in carotenoids and flavonoids; and Criollo in vitamin C. Cultivar selection induces changes in mango nutritional composition.