Maltose/Sucrose/D-Glucose Assay Kit

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.