Maltose/Sucrose/D-Glucose Assay Kit

This study was conducted to examine the impacts of pre-harvest field sprouting (PHS) on wheat end-use functionality of bread wheat Canada Western Red Spring (CWRS) and durum wheat Canada Western Amber Durum (CWAD). PHS affected CWRS and CWAD differently in milling performance, dough rheological properties, and final product quality. With decreasing Falling Number (FN), key quality attributes of CWAD remained mostly unchanged but CWRS quality progressively decreased, especially when FN dropped below 200 s. Both CWRS and CWAD showed signs of in situ starch hydrolysis in field-sprouted kernels with more damage apparent in CWRS as greater maltose levels were found in flour than in semolina. Analysis of gluten fractions in flour or semolina indicated that protein composition was not affected by PHS. Unlike pasta-making, which involves low water-absorption, short mixing time, and high-temperature drying, the combination of high water absorption, lower temperature, and long fermentation times magnify the detrimental effects of excessive α-amylase on the bread-making performance of CWRS.

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.

Plant-based yogurt substitutes (“gurts”), whose market growth is steadily increasing, have emerged as a promising option to promote more sustainable diets and food systems, especially when produced with locally sourced or low-input crops like barley. In this study, a novel gurt made with rice (10%) and sprouted barley (5%), was designed. Four lactic acid bacteria strains, Levilactobacillus brevis AM7, Leuconostoc pseudomesenteroides DSM20193, Lactiplantibacillus plantarum 18S9 and H64, were used as starters for making prototypes. Although with some differences in their acidification kinetics and proteolysis, all the strains adapted to the matrix. Then the formulation and production process were optimized. The use of sprouted barley, compared to raw flours, provided a content of amino acids 9-fold higher, further increased (up to 35%) by the fermentation, and a more complex aroma profile characterized by the presence of furans and aldehydes. However, the high amylolytic activity in sprouted barley interfered with starch gelatinization decreasing the viscosity of the products from 3.3 to 0.08 Pa*s. To overcome this challenge and obtain a creamy and spoonable product, sprouted barley flour was roasted, deactivating the enzymes and conferring a nutty and toasted flavor to the gurts due to the presence of pyrazines. The stability of the key biochemical and microbiological parameters during refrigerated storage was also assessed. Hence, plant-based gurts made with sprouted barley, emerge as a sustainable and health-promoting substitute to traditional dairy yogurts.

In this work, three lactic acid bacteria (LAB) strains, specifically, Lactiplantibacillus plantarum UMCC 2996, Furfurilactobacillus rossiae UMCC 3002, and Pediococcus pentosaceus UMCC 3010, were tested in new bread-whey media composed by wheat bread and sweet cheese whey, designed as an alternative to the conventional MRS medium. The medium resulting from hydrolysis with amylase and neutrase (AN) was considered the best for the growth of all the strains. This medium was particularly optimal for the strain F. rossiae UMCC 3002, which showed an increase in growth of 114% compared to that in MRS medium. Additionally, the bio-preservative ability of the selected LAB was assessed in pectin-based coated sliced bread inoculated with Aspergillus flavus ITEM 7828, Penicillium paneum ITEM 1381, and Aspergillus niger ITEM 7090. Different LAB strain behavior was observed towards the specific molds. A good bio-preservation activity was shown from F. rossiae UMCC 3002 against A. flavus ITEM 7828 with results compared to the protection by ethanol treatment. The results obtained in this study suggest a novel strategy for the cultivation of selected starters with a bio-protection activity by valorizing bread waste and cheese whey by-products, in a circular economy perspective.

Plant-based milk alternatives have gained massive popularity among consumers because of their sustainable production compared to bovine milk and because of meeting the nutritional requests of consumers affected by cow milk allergies and lactose intolerance. In this work, hemp flour, in a blend with rice flour, was used to design a novel lactose- and gluten-free yogurt-like (YL) product with suitable nutritional, functional, and sensory features. The growth and the acidification of three different lactic acid bacteria strains were monitored to better set up the biotechnological protocol for making the YL product. Hemp flour conferred the high fiber (circa 2.6 g/100 g), protein (circa 4 g/100 g), and mineral contents of the YL product, while fermentation by selected lactic acid bacteria increased the antioxidant properties (+8%) and the soluble fiber (+0.3 g/100 g), decreasing the predicted glycemic index (-10%). As demonstrated by the sensory analysis, the biotechnological process decreased the earthy flavor (typical of raw hemp flour) and increased the acidic and creamy sensory perceptions. Supplementation with natural clean-label vanilla powder and agave syrup was proposed to further decrease the astringent and bitter flavors. The evaluation of the starter survival and biochemical properties of the product under refrigerated conditions suggests an estimated shelf-life of 30 days. This work demonstrated that hemp flour might be used as a nutritional improver, while fermentation with a selected starter represents a sustainable and effective option for exploiting its potential.

New value-adding applications of spent grain, a co-product of brewhouse operations, are considered in the context of a sustainable circular economy. Previous studies have focused on the compounds remaining in the solid phase of the spent grain. However, depending on the dewatering process, the separated water also contains relevant fractions of nutritionally and physiologically valuable compounds including proteins, carbohydrates and polyphenols. Accordingly, the work reported here considers the two fractions and presents a detailed view of relevant substances especially those from liquor. The reported mass balance is the result of these investigations, supplemented by values from the literature. The potential value of these compounds for industrial biotechnology is examined in an economic assessment.

Starch deposited in the endosperm of cereal seeds serves as a source of food and animal feed, and as a substrate for bioethanol production. To gain insights into the molecular mechanisms underlying genetic variation in seed size and seed starch content, this study investigated transcriptional regulation of starch biosynthesis genes during seed filling in two wheat genotypes that exhibit contrasting phenotype in seed size. Our data showed that variation in starch accumulation during seed filling is closely associated with modulations in the expression patterns of specific starch biosynthesis genes including TaAGPL1, TaAGPS2, TaGBSSI, TaSSI, TaSSIV, TaSBEIIa, TaISA1, and TaISA3, as well as alterations in the activity of AGPase, GBSS, and SS enzymes. Consistently, the genotype that produces larger seeds that are characterized by a higher seed starch content generated higher amounts of fermentable sugars and bioethanol before and after fermentation, respectively. Since the amount of phenol per seed dry weight is higher in the genotype that produces smaller seeds, the prevalence of lower starch to bioethanol conversion efficiency in this genotype, despite the higher amount of glucose generated per bioavailable starch, suggests that the phenolic compounds interfere with the fermentation process and thereby affecting the bioethanol yield.

Despite being considered a climate-resilient crop, sorghum is still underutilized in food processing because of the limited starch and protein functionality. For this reason, the objective of this study was to investigate the effect of sprouting time on sorghum functional properties and the possibility to exploit sprouted sorghum in bread making. In this context, red sorghum was sprouted for 24, 36, 48, 72, and 96 h at 27°C. Sprouting time did not strongly affect the sorghum composition in terms of total starch, fiber, and protein contents. On the other hand, the developed proteolytic activity had a positive effect on oil-absorption capacity, pasting, and gelation properties. Conversely, the increased α-amylase activity in sprouted samples (≥36 h) altered starch functionality. As regards sorghum-enriched bread, the blends containing 48 h-sprouted sorghum showed high specific volume and low crumb firmness. In addition, enrichment in sprouted sorghum increased both the in vitro protein digestibility and the slowly digestible starch fraction of bread. Overall, this study showed that 48 h-sprouted sorghum enhanced the bread-making performance of wheat-based products.

Plants secrete a large array of compounds into the rhizosphere to facilitate interactions with their biotic environment. Some of these exuded-compounds stimulate the hatching of obligate plant-parasitic nematodes, ultimately leading to a detrimental effect on the host plant. Determining these cues can help to provide new mechanisms for control and aid nematode management schemes. Here we show that glucose, fructose and arabinose, which are all present in potato root exudate (PRE), induce hatching of white potato cyst nematode (Globodera pallida) eggs whereas five other PRE-sugars had no effect. Although these monosaccharides resulted in significant hatching none induced the same level as PRE, suggesting that other components, possibly in combination, contribute to stimulation of nematode hatching. Glucose, but not arabinose or fructose, was also observed to attract juvenile G. pallida, indicating that these hatch-inducing components can have different roles in different stages of the life cycle. Applying a solution of these monosaccharides to G. pallida-infested soil pre-potato planting initiated hatching in the absence of a host. Host absence resulted in nematode mortality and a reduction in the G. pallida population. Therefore, subsequent invasion of the crop post-planting was also reduced, compared to untreated soil. Our data suggest that monosaccharide components of PRE play an important role in the hatching and attraction of G. pallida. As a result the hatch-inducing monosaccharides can be applied as a pre-planting treatment to induce hatching and reduce subsequent infection rates.

The bioavailability of minerals, such as zinc and magnesium, has a significant impact on the fermentation process. These metal ions are known to influence the growth and metabolic activity of yeast, but there are few reports on their effects on lactic acid bacteria (LAB) metabolism during sour brewing. This study aimed to evaluate the influence of magnesium and zinc ions on the metabolism of Lactobacillus brevis WLP672 during the fermentation of brewers’ wort. We carried out lactic acid fermentations using wort with different mineral compositions: without supplementation; supplemented with magnesium at 60 mg/L and 120 mg/L; and supplemented with zinc at 0.4 mg/L and 2 mg/L. The concentration of organic acids, pH of the wort and carbohydrate use was determined during fermentation, while aroma compounds, real extract and ethanol were measured after the mixed fermentation. The addition of magnesium ions resulted in the pH of the fermenting wort decreasing more quickly, an increase in the level of L-lactic acid (after 48 h of fermentation) and increased concentrations of some volatile compounds. While zinc supplementation had a negative impact on the L. brevis strain, resulting in a decrease in the L-lactic acid content and a higher pH in the beer. We conclude that zinc supplementation is not recommended in sour beer production using L. brevis WLP672.

This study aims at understanding the relation among sprouting time (from 12 up to 72 h), changes in protein and starch components, and flour functionality in quinoa. Changes related to the activity of sprouting-related proteases were observed after 48 h of sprouting in all protein fractions. Progressive proteolysis resulted in relevant modification in the organization of quinoa storage proteins, with a concomitant increase in the availability of physiologically relevant metals such as copper and zinc. Changes in the protein profile upon sprouting resulted in improved foam stability, but in impaired foaming capacity. The increased levels of amylolytic enzymes upon sprouting also made starch less prompt to gelatinize upon heating. Consequently, starch re-association in a more ordered structure upon cooling was less effective, resulting in low setback viscosity. The nature and the intensity of these modifications suggest various possibilities as for using flour from sprouted quinoa as an ingredient in the formulation of baked products.

Background: Pre‐harvest sprouting of wheat is viewed negatively because of the high level of enzymatic activity, which leads to a deterioration in the bread‐making performance of the related flours. On the other hand, improvements in bread properties (i.e. volume and crumb softness) are reported when sprouted wheat under controlled conditions is used in mixtures with a conventional unsprouted flour. However, knowledge about the effects of sprouting on gluten functionality and its relationship with bread features is still limited, especially in the case of whole wheat flour. Results: Under the conditions applied in this study (48 h, 20°C and 90% relative humidity), proteins of sprouted wheat were still able to aggregate, even if changes in gluten aggregation kinetics suggested gluten weakening. On the other hand, sprouting led to an increase in gluten stretching ability, suggesting an increase in dough extensibility. In the dough system, sprouting was responsible for a decrease in water absorption, development time, and stability during mixing. However, when the values for development time and water absorption indicated by the Farinograph® were followed carefully, sprouting improved bread height (~20%), specific volume (~15%), and crumb softness (~200% after 24 h of storage), even when whole wheat flour was used. Conclusion: It is possible to produce bread with improved volume and crumb softness using whole wheat flour from sprouted kernels. Thus, sprouting can be exploited as a pre‐treatment to improve the bread‐making performance of fiber‐enriched systems.

The characteristics of three non-Saccharomyces yeasts, namely, Wickerhamomyces anomalus Y13, Saccharomycopsis fibuligera Y18, and Torulaspora delbrueckii Y22, isolated from Jiaozi in dough fermentation and steamed bread making were investigated and compared with those of Saccharomyces cerevisiae Y10. The maltose levels in the dough fermented by Y13, Y18, and Y22 in the entire fermentation were higher than those in the dough fermented by Y10. The CO₂ production kinetics of Y22 was similar to that of Y10, but the total CO₂ volume was slightly less. The volume of CO₂ produced by Y13 and Y18 was less than 30% of that generated by Y10. The sensory qualities of Y22-prepared steamed bread were similar to those of Y10 and could also be accepted. The degree of whiteness of the steamed bread prepared with Y22 was higher than that produced with Y10. Steamed bread produced with each of the non-Saccharomyces yeasts contained unique volatile compounds, and the highest number of categories of volatile compounds were observed in the product prepared with Y22. The results indicated that non-Saccharomyces yeasts exhibited distinctive characteristics of dough fermentation and showed the potential for applications in dough fermentation and steamed bread making.

The famous French dessert “ile flottante” consists of a sweet egg white foam floating on a vanilla custard cream, which contains highly nutritive raw materials, including milk, sugar and egg. Spoilage issues are therefore a key concern for the manufacturers. This study explored the bacterial diversity of 64 spoiled custard cream desserts manufactured by 2 French companies. B. cereus group bacteria, coagulase negative Staphylococcus, Enterococcus and Leuconostoc spp. were isolated from spoiled products. Thirty-one bacterial isolates representative of the main spoilage species were tested for their spoilage abilities. Significant growth and pH decrease were observed regardless of species. While off-odours were detected with B. cereus group and staphylococci, yoghurt odours were detected with Enterococcus spp. And Leuconostoc spp. B. cereus group bacteria produced various esters and several compounds derived from amino acid and sugar metabolism. Most Staphylococci produced phenolic compounds. Enterococcus spp. And Leuconostoc spp. isolates produced high levels of compounds derived from sugar metabolism. Each type of spoilage bacteria was associated with a specific volatile profile and lactic acid was identified as a potential marker of spoilage of custard cream-based desserts. These findings provide valuable information for manufacturers to improve food spoilage detection and prevention of chilled desserts made with milk and egg.

Dehydrated blends of dairy-cereal combine the functional and nutritional properties of two major food groups. Fortified blended food base (FBFB) was prepared by blending fermented milk with parboiled wheat, co-fermenting the blend at 35°C, shelf-drying and milling. Increasing co-fermentation time from 0 to 72 h resulted in powder with lower lactose, phytic acid and pH, and higher contents of lactic acid and galactose. Simultaneously, the pasting viscosity of the reconstituted base (16.7%, w/w, total solids) and its yield stress (σ₀), consistency index (K) and viscosity on shearing decreased significantly. The changes in some characteristics (pH, phytic acid, η₁₂₀) were essentially complete after 24 h co-fermentation while others (lactose, galactose and lactic acid, pasting viscosities, flowability) proceeded more gradually over 72 h. The reduction in phytic acid varied from 40 to 58% depending on the pH of the fermented milk prior to blending with the parboiled cereal. The reduction in phytic acid content of milk (fermented milk)-cereal blends with co-fermentation time is nutritionally desirable as it is conducive to an enhanced bioavailability of elements, such as Ca, Mg, Fe and Zn in milk-cereal blends, and is especially important where such blends serve as a base for fortified-blended foods supplied to food-insecure regions.