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Durum wheat semolina is the preferred and most often used raw material for the production of dried pasta. The high quality of pasta is attributed to its specific structure, obtained after successive structural changes of the two main semolina components, starch and proteins, gliadins and glutenins, in presence of water. The present study was conducted to examine the contributions of gliadins, glutenins and starch to the structure and functionality of gluten by means of scanning electron microscopy (SEM) and of differential scanning calorimetry (DSC). Isolated samples of the main semolina components (starch, gliadins, glutenins) and gluten were considered. Experimental models were then prepared from defined binary mixtures of starch and proteins (gliadins or gluteins or gluten) and from respective doughs with water (50 % w/w). SEM of surface morphology provided stereoscopic images with high magnification. Semolina starch was composed of small spherical B-type granules (average diameter 2-3 μm) and larger lenticular A-type granules (average diameter 30 μm). The micrographs from starch - gliadins dough showed a distinct film surrounding the small and large starch granules. In the starch - glutenins doughs, most of the starch granules appeared naked, it seems that the proteins are unable to surround all of the starch gran ules. A possible explanation for this is that the lack of gliadins can be affecting the formation of the film structure in fact gliadins may be involved in the development of the structure of the gluten film networks through covalent and non-covalent bonding with other gluten proteins. DSC allowed the observatio n of all phenomena that involves the heat exchange in models: protein denaturation and starch gelatinization

Functional and enriched foods are increasingly in demand in the global market due to their benefits for human health and their prevention of several diseases. The aim of this work was to develop a functional pizza base, produced in the Neapolitan style, exploiting the beneficial properties of jujube. The jujube fruit is rich in phenolic compounds with high antioxidant activity and represents a good candidate for functional food development. The doughs were prepared by replacing the wheat flour with 2.5%, 5.0%, and 7.5% (w/w) of Ziziphus jujube powder (ZJP) and were subsequently cooked. Chemical analyses showed that both total phenolic compounds and antioxidant activity grew with the increase of ZJP. The addition of ZJP darkened the pizza base and raised its hardness, gumminess, and chewiness. However, no difference was found in the springiness and cohesiveness of the samples with or without ZJP. These results suggest that jujube powder can be successfully introduced into pizza dough as a functional ingredient.

Aim of this work was to evaluate the impact of bread enrichment with different concentrations of lentil flour (LF) (0 g/100g, 10 g/100g and 20 g/100g) on some physico-chemical, structural, and nutritional features of bread. The addition of LF in formulation affected its properties, leading to a darker appearance and to a more compact structure (e.g., higher density and lower gas bubble area fraction). Besides, it led to a significant rise in the protein, free glucose, and rapidly digestible starch content as well as in the expected glycemic index. Concerning the investigation of nutritional properties, starch and protein digestibility has been evaluated by the combination of different digestion models. Each type of bread was subjected to an in vivo oral phase followed by a semi-dynamic in vitro gastrointestinal digestion. During the oral and the gastric phases of digestion, bread with the greatest LF content (20 g/100g) exhibited an extensive starch digestibility and a partial protein digestibility compared to the other samples, due to its higher protein content. In contrast, during the intestinal phase, control (0 g/100g) showed a stronger starch digestibility compared with the LF samples, while no differences could be observed in terms of protein digestibility investigated by SDS-PAGE., This work has received financial support from project PID2019-107663RB-I00 from the Spanish Ministry of Science and Innovation (MICINN).

• Dry pasta is a staple food in many countries of the world and it is traditionally made of durum wheat semolina. The aim of this study was to evaluate the impact of pasta composition on microstructure, water absorption and mobility during cooking and nutritional properties of two commercial spaghetti made of durum wheat semolina (S) and whole durum wheat semolina (WS). Scanning Electron Microscopy (SEM) revealed no significant microstructural differences between the uncooked pasta samples, whereas the presence of fibre altered the integrity of the protein network in the cooked samples. Moreover, the water absorption during cooking and the water mobility at molecular level were investigated as weight increase and by low-resolution 1H NMR experiments, respectively. Compared to durum wheat spaghetti, the presence of fibre increased the water absorption while decreased the proton relaxation times 1H T2 and 1H T1 indicating an increased degree of water-polymers interaction. Lastly, the rate of starch hydrolysis, evaluated by means of in vitro methods, increased in presence of fibre, resulting in higher RDS and estimated Glycemic Index (eGI) for whole durum wheat spaghetti compared to the traditional ones. These findings were quite unexpected.

Re-milled semolina used for bread making is appreciated from consumers for its typical sensory features and nutritional attributes. Fluid bed drying treatment can be applied to semolina to change its bacteriological properties, to prolong shelf life by decreasing the risk of mould development, and to degrade some mycotoxins. The main goal of the present work was to evaluate the impact of heat treatment on structural development of semolina dough during mixing and leavening and on bread characteristics. Semolina was treated with fluidized bed drying at 90°C, 120°C, or 150°C for 5, 15 or 30 min. The heat treatment affected colour, moisture content, and farinograph indices of semolina. Results showed that the use of heat treated re-milled semolina significantly (P

Common beans (Phaseolus vulgaris L.) are rich in nutrients and have significant amounts of proteins and complex carbohydrates, besides to be rich in unsaturated fatty acids and dietary fibres. Consumption of beans could be improved by processing them into flour. In this study the effect of microbial transglutaminase (TG) on the structure, physical (colour parameters, moisture, water holding capacity), thermal properties and in vitro digestion of undehulled (WB) and manually dehulled (SB) flour samples from white common beans (P. vulgaris L.) was evaluated. Flour samples were incubated in the absence and presence of TG (WB/TG and SB/TG). We observed that the enzyme is able to catalyse the formation of polymers, suggesting that the proteins occurring in the bean flour act as TG substrates. Microstructure of samples was examined by Scanning Electron Microscopy (SEM), while thermal properties were studied by Differential Scanning Calorimetry. Microstructural results showed that the TG-treated samples possess a more compact structure, made of starch granules surrounded by proteins that, presumably, contain TG-catalysed polymers. Moreover, TG treatment had a major impact on colour, water holding capacity (WHC) and thermal properties. In particular, WB and SB samples presented a darker colour than WB/TG and SB/TG samples, while the latter showed reduced WHC that was only 30% and 37% of WB and SB samples, respectively. The transition enthalpy (ΔH) in the temperature range from 57 to 70 °C (WB, WB/TG) and from 60 to 68 °C (SB, SB/TG) followed the order: WB/TG > WB and SB/TG > WB, respectively. In vitro digestion experiments indicate that the presence of isopeptide bonds decreased the digestibility of TG-treated flour samples.

The study is aimed at developing a new cereal-based product, with increased nutritional quality, by using quinoa flour. The effect of the use of transglutaminase (TGase) and proteolytic enzymes on the microstructure, properties and in vitro digestion of gluten-free bakery products based on quinoa flour was evaluated. Microstructural results evaluated by means of Scanning Electron Microscopy (SEM) showed that the quinoa starch granules are rather small (0.4–2 μm) and the presence of TGase induced significantly changes in dough and baked samples microstructures. The overall acceptability of the breads was improved by TGase addition. The results achieved showed that these enzymes have different effects on the bread characteristics and may improve properties of formulations, setting the basis for development of baked quinoa products.

The objective of this study was to study the effect of dehulling on the microstructural, physico-chemical characteristics, and in vitro protein digestion of common bean flours with particular regard to differences between adult and infant human beings. The microstructure of flour samples from undehulled (WB) and manually dehulled (SB) beans, observed through scanning electron microscopy, showed that WB starch granules appeared surrounded by an integral matrix, while the SB starch granule structure was still visible although covered by protein clusters. The starch granules were oval and spherical, with heterogeneous sizes ranging from 19 to 30 μm in diameter. Particle size analysis determined with a laser diffraction particle size analyzer showed similar bimodal particle size distributions of small (1–25 μm) and large (>100 μm) granules, though the particle size of WB was obviously higher than SB. Color and other physico-chemical analyses showed that dehulling had significant (P < 0.05) influence on all investigated characteristics. The in vitro gastric and duodenal digestion experiments carried out under physiological conditions showed that the SB samples are more prone to be digested by infants. From our results, it is possible to conclude that the dehulling process improves bean flour nutritional functionality which could be utilized in various food applications.

The objectives of this research were to study tuber starch characteristics and chemical - thermal properties of 21 potato varieties, and to determine their genetic diversity through SSR markers. Starch granular size varied among samples, with a wide diameter distribution (5–85 μm), while granule shapes were similar. Differential Scanning Calorimeter analysis showed that the transition temperatures (69 °C–74 °C) and enthalpies of gelatinization (0.9 J/g–3.8 J/g) of tubers were also variety dependent. SSR analysis allowed the detection of 157 alleles across all varieties, with an average value of 6.8 alleles per locus. Variety-specific alleles were also identified. SSR-based cluster analysis revealed that varieties with interesting quality attributes were distributed among all clusters and sub-clusters, suggesting that the genetic basis of traits analyzed may differ among our varieties. The information obtained in this study may be useful to identify and develop varieties with slowly digestible starch.

The effect of sourdough obtained with selected exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) on the sensory quality of bread during shelf life was investigated. Moreover, the relationship between sensory and instrumental data was studied. Results showed that sourdough containing EPS had a positive effect on sensory perception of bread samples. EPS+ samples showed a lighter brown crust and lighter crumb color and a more open crumb structure than EPS- samples. Only for EPS+ sample, the springiness intensity of the bread did not vary at all during the 21 days, and the hardness and chewiness of bread during storage were well preserved. In addition, EPS+ samples showed a higher acidity than EPS- samples, but no difference was perceived in terms of flavor attributes between samples. A good correlation was found between sensory and instrumental variables, and principal component analysis (PCA) was an effective instrument to classify bread samples on the base of quality changes.

Proanthocyanidins (OPC) are polyphenolic compounds, derivatives of flavan-3-ol flavonoids. They are abundant in grape seeds and skins, and contribute to most of the polyphenols in red wine. Proanthocyanidins from grape seed have been reported to show various health as well as technological properties. Aim of the study was to investigate the coating efficiency of maltodextrin (MD) in different molecular ratios with arabic gum (AG) on encapsulation of phenolic compounds extracted from grape pomace. The present study was planned to examine the contributions of MD, AG and OPC to the structural architecture of encapsulated OPC by means of scanning electron microscopy (SEM), their encapsulation efficiency and their functionality (antioxidant activity and bioavailability) by spectrophotometric assays and mass spectrometry analysis (MALDI-TOF-MS). The effect of encapsulated OPC on in vitro polyphenol digestibility was also evaluated according to the Infogest protocol. Encapsulated products were obtained by a mild ultrasonication method in controlled conditions based on the phenomenon of acoustic cavitation, and then freeze-dried. The content of coating material had significant (p>0.05) impact on particle morphology of spray-dried suspensions. SEM analysis of samples of AG/MD and AG/MD/OPC were similar and exhibited cracks and sharp edges, but samples with OPC showed a more enclosed structure. Total and Surface phenolic content of microcapsules showed the best encapsulation efficiency for samples with 4% of AG and 12% of MD. MALDI-TOF-MS characterization of encapsulated samples showed integrity of OPC components in the microcapsules with no changes with respect to original OPC. The in vitro digestion experiments showed also that composition and functionality of encapsulated OPC were better preserved along gastrointestinal digestion process. In conclusion, OPC microcapsules could be utilized both as nutraceuticals and additives in various food applications.

Sweeteners and flavors are generally added to yogurt to make them more palatable. However, the addition of these ingredients may affect the fermentation process of yogurt as well as its physical and sensory characteristics. Consumers prioritize yogurt products that are "natural." A modified single-chain form of the natural sweet protein monellin extracted from the fruit of Dioscoreophyllum cumminsii, called MNEI, could be a useful alternative to artificial sweeteners. The aim of the present work was to evaluate new rapid sensory methods in combination with rheology to assess the viability of using MNEI to develop sweetened yogurts without the calories of sugar. We studied the gelation and cooling kinetics of 4 yogurt samples (unsweetened or sweetened with MNEI, aspartame, or sucrose) by using a rheometer. Furthermore, the 4 yogurts, with and without addition of a flavoring agent, were characterized from a sensory perspective using a combination of 2 rapid sensory methods, ultra flash profile and flash profile. Rheological results showed that, when added at typical usage levels, aspartame, sucrose, and MNEI did not generally affect the yogurt fermentation process or its rheological properties. Sensory results demonstrated that texture attributes of yogurts with aspartame and sucrose were strongly linked to sweetness and flavor perception, but this was not true for MNEI-sweetened yogurts. In contrast to results obtained from samples sweetened with sucrose and aspartame, MNEI protein did not sweeten the yogurt when added before fermentation. This study highlights the enhancing effect of flavor on sweetness perception, supporting previous reports that noted synergistic effects between sucrose or aspartame and flavors. Hence, future studies should be conducted to determine how sweet proteins behave in yogurt when added after fermentation.

In this study uncooked starches as ingredients (corn, rice, wheat, tapioca and potato) were characterized according to microstructure, some (physicochemical, functional and thermal) properties, in vitro digestibility and expected glycemic index. There was a significant variation in the granule shape and size distribution of the starches. Particle size results distinguished among starches in monomodal (corn, tapioca, potato) and bimodal (rice, wheat) populations. The potato starch showed the biggest size distribution granules while the rice showed the lowest. The examined properties and nutritional characteristics of starches were significantly different. Thermal properties were studied by means of Differential Scanning Calorimeter (DSC). DSC studies found that the transition temperatures (58.8 °C - 78.7 °C) and enthalpies of gelatinization (2.3 J/g - 8.2 J/g) of the starches appeared to be greatly influenced by microstructure and chemical composition (e.g. resistant starch). Nutritional properties such as slowly digestible starch and expected glycemic index values followed the order: rice > wheat > tapioca >corn > potato. In particular, the highest resistant starch was recorded for potato starch.

The permeability characteristics and water-solubility of edible pectin-soy flour films obtained in the absence or presence of the enzyme transglutaminase were investigated and compared with those possessed by both the commonly used high density polyethylene film and the biodegradable Mater-Bi(R) film. The soy protein transglutaminase-catalyzed crosslinking was found to determine a marked decrease in the solubility of the pectin-soy flour films both at different pH and in different denaturing conditions with respect to the films obtained in the absence of the enzyme, even though their solubility remains higher than that of the commercially available polyethylene and Mater-Bi(R) films. Transglutaminase treatment was also shown to significantly increase pectin-soy flour film barrier properties to oxygen, carbon dioxide and water vapour. In particular, the films obtained in the presence of the enzyme exhibited a permeability to oxygen and carbon dioxide even lower than that possessed by polyethylene films. Our results suggest a possible use of the transglutaminase-polymerized pectin-soy flour films as wrapping of food products requiring a packaging allowing low gas exchange with the environment. Furthermore, the application of these films as coatings to conventional oral dosage forms could provide a viable means of delivering drugs to the colon.

The study is aimed at developing a new cereal-based product, with increased nutritional quality, by using natural fermentation of blends of chestnut and rye flour. In spite of the remarkable similarity, the technological potential of combinations of both flours has never been explored before. Three spontaneous chestnut/rye sourdough fermentations were performed over a period of twelve days with daily back-slopping. Samples taken at all refreshment steps were used for culture-dependent and culture-independent evaluation of the microbiota present. Dominant species basically overlapped to those associated to sourdoughs strengthened with chestnut flour, such as Pediococcus pentosaceus or Weissella paramesenteroides. Microstructures, evaluated by means of Scanning Electron Microscopy, revealed the presence in chestnut sourdoughs of a distinguishable network surrounding starch granules, while rye flour-added sourdoughs showed a less structured matrix. By gas chromatography coupled to mass spectrometry, 51 volatile organic compounds were identified at 24 h and after prolonged fermentation. Within volatile organic compounds, alcohols, esters, acids, aldehydes and ketones, all well-known flavour compounds in sourdough fermentation, appeared as dominant. The PCA discriminated the sourdoughs into three distinct clusters and highlighted a clear influence of fermentation time on the volatile composition of sourdoughs. (C) 2014 Elsevier Ltd. All rights reserved.

The objective of this work was to study the effect of sourdough obtained with selected exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) strains on the quality of bread and its shelf life. Two sourdough concentrations were used in order to ascertain the best bread composition. Fresh bread quality was studied by means of microbiological, physical, chemical and mechanical analysis, whereas physical, thermal and mechanical properties were investigated to study the product shelf life. The results showed that dough prepared with 30 g/100 g of sourdough had a negative impact on bread quality properties in the absence of EPS-producing LAB strains, whereas the opposite was observed in the presence of EPS-producing strains: bread samples at 30 g/100 g of sourdough showed higher volume, higher moisture content and better mechanical properties during storage than samples at 20 g/100 g of sourdough. Moreover, 30 g/100 g of sourdough showed a protective effect on bread staling, thus confirming the effect of sourdough concentration and the positive role of EPS on functional properties.

The aims of this study were the monitoring of the microbial dynamics by means of a polyphasic approach based on conventional isolation techniques and PCR-DGGE-based methods in different chestnut-based sourdoughs and the Evaluation of the impact of fermentation on volatile organic compounds formation during sourdoughs ripening. Members of the Lactobacillus plantarum group and Pediococcus pentosaceous dominated the sourdough ecosystems. Nevertheless, RAPD-PCR allowed recording a relevant genotypic biodiversity among strains coming from gluten-free flour combinations. Volatile compounds were characterised by GC/MS. A total of 59 volatile compounds were identified, mainly alcohols, esters, acids, aldehydes and ketones. Principal component analysis of samples at the beginning and at the end of ripening offered a good separation of the samples and highlighted the effect of fermentation on the sensorial profile.

Capillary electrophoresis was used to characterize glutenin proteins from ancient varieties of Southern Italy common wheat and to determine the technological properties of wheat flours based on a glutenin index. Three zones were identified in the electropherograms, indicated as A, B, and C according to electroelution order. The three zones corresponded to the low molecular weight glutenin subunits and to the y- and x-type high molecular weight subunits, respectively. The ratio B/C was correlated to the alveographic parameter P/L. These results indicated that flours resulting in a B/C ratio lower than 2 produced elastic doughs whereas flours resulting in a B/C ratio higher than 2 produced doughs more resistant to extension. This study showed that capillary electrophoresis is useful for determining the types and quantities of gluten proteins in the evaluation of wheat-flour technological properties of a limited number of noncommercial varieties as evidenced by the x-type content which seems to strongly influence the flour technological parameters.

The aim of this study was to assess the microbial populations causing the spoilage of chilled beef during storage and to evaluate the effect of the use of an antimicrobial packaging for the meat storage. A nisin activated antimicrobial packaging was developed by using a nisin, HCL and EDTA solution and used for the storage of beef cuts at 1 degrees C. The common spoilage related microbial groups were monitored during the storage of beef in activated and non activated plastic bags by using selective media. The use of the antimicrobial packaging caused an overall significant reduction of viable counts of Gram positive bacteria such as carnobacteria, lactic acid bacteria and Brochotrix thermosphacta whose development was inhibited for at least 11 days of storage compared to the control. Moreover, a 1-3 log cycles reduction of enterobacteria was also registered between 22 and 32 days of storage. The microbiota was assessed at species level by using Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis of 16S rRNA gene of DNA extracted directly from meat and from bulk cells from selective media plates and showed that the species occurring within the targeted microbial groups did not change according to storage conditions. In conclusion, the use of the nisin activated packaging reduced the number of spoilage populations but did not affect the species diversity. Improved antimicrobial packaging is needed, possibly coupled with vacuum storage, to possibly achieve a simultaneous inhibition of more spoilage microbial groups and to preserve the microbiological quality of beef during chilled storage.

Dietary fibre is a common and important ingredient of a new generation of healthy food products which is experiencing rapidly increasing consumer demand. Dietary fibre increases the nutritional value of bread but usually at the same time affects rheological properties of dough and, in turn, the sensory properties of the resulting bread. The effect of fibres on bread baking performance has not been fully explored. Our investigation concerned the potential use of soluble and insoluble dietary fibres in wheat bread technology. The influence on dough rheological behaviour, leavening and baking performance was studied. Doughs prepared from wheat flour containing various amounts of fibres were submitted to a lubricated squeezing test and to small amplitude oscillatory measurements. Bubble evolution during leavening and baking phases was studied by measuring the variation in time of the total volume of the sample by means of image analysis. Experimental evidence of the different behaviour of the doughs and bread, with fibres added, are presented and discussed. In general, the addition of insoluble fibres causes the dough's strength to increase, mainly at high fibre content. By contrast, the presence of soluble fibres reduces the resistance of dough to large deformation. A negative effect of fibres on leavening is observed. The highest volume increase of the baked bread corresponds to the dough with the lowest content of fibres. The experimental evidence suggests some interesting conclusions: a) results from rheological measurements agree with those of macrostructure analysis and b) the functional role of fibres in bubble evolution depends on both the fibre source and fibre contents.

The microbial spoilage of beef was monitored during storage at 5°C under three different conditions of modified-atmosphere packaging (MAP): (i) air (MAP1), (ii) 60% O 2 and 40% CO 2 (MAP2), and (iii) 20% O 2 and 40% CO 2 (MAP3). Pseudomonas , Enterobacteriaceae , Brochothrix thermosphacta , and lactic acid bacteria were monitored by viable counts and PCR-denaturing gradient gel electrophoresis (DGGE) analysis during 14 days of storage. Moreover, headspace gas composition, weight loss, and beef color change were also determined at each sampling time. Overall, MAP2 was shown to have the best protective effect, keeping the microbial loads and color change to acceptable levels in the first 7 days of refrigerated storage. The microbial colonies from the plate counts of each microbial group were identified by PCR-DGGE of the variable V6-V8 region of the 16S rRNA gene. Thirteen different genera and at least 17 different species were identified after sequencing of DGGE fragments that showed a wide diversity of spoilage-related bacteria taking turns during beef storage in the function of the packaging conditions. The countable species for each spoilage-related microbial group were different according to packaging conditions and times of storage. In fact, the DGGE profiles displayed significant changes during time and depending on the initial atmosphere used. The spoilage occurred between 7 and 14 days of storage, and the microbial species found in the spoiled meat varied according to the packaging conditions. Rahnella aquatilis , Rahnella spp., Pseudomonas spp., and Carnobacterium divergens were identified as acting during beef storage in air (MAP1). Pseudomonas spp. and Lactobacillus sakei were found in beef stored under MAP conditions with high oxygen content (MAP2), while Rahnella spp. and L. sakei were the main species found during storage using MAP3. The identification of the spoilage-related microbiota by molecular methods can help in the effective establishment of storage conditions for fresh meat.

A Ca(2+)-independent microbial TGase (transglutaminase) isolated from Streptoverticillium mobaraense was used to obtain whey protein containing novel dairy products. We evaluated the difference both in the curd formation time as well as in the hardness and deformability of the cheese obtained from cow's milk in the presence or absence of the enzyme. The results of our experiments showed that the milk coagulation time was dependent on the step in cheese manufacture at which TGase was added. We analysed the deformability and the hardness of the dairy products obtained either by adding both TGase and the milk-clotting enzyme to the milk sample at the same time or by adding TGase after treating the milk sample for 30 min with the clotting enzyme and cutting the obtained coagulum. TGase treatment conferred a strongly decreased protein content to derived whey. Moreover, when further amounts of whey were added to the milk during the manufacturing process in the presence of TGase, whey-protein-enriched dairy products could also be obtained. Our findings may lead to new biotechnologies for the re-utilization of by-products from dairy plants and contribute to reduction of environmental pollution from whey-protein disposal.