Does post‐anthesis heat stress affect plant phenology,physiology, grain yield and protein content of durum wheat in a semi‐arid Mediterranean environment?

Increasing air temperature due to changing climate is projected to decrease the length of the growing season, hasten vegetative development and maturation, and ultimately affect yield of many C3 crops. Previous multilocation trials highlighted strong relationships between thermal trends in the interval “beginning of flowering‐end of grain filling” and grain yield, and protein content in durum wheat (Triticum turgidum subsp. durum (Desf.) Husn.). With the aim to confirm these relationships, nine durum wheat genotypes, including old (Capeiti 8, Senatore Cappelli and Trinakria) and modern (Amedeo, Arcangelo, Mongibello, Simeto, and Svevo) varieties and a Sicilian landrace (Russello) were grown at three different sites representing a climate gradient in Sicily, Italy. Moreover, the effect of post‐anthesis heat stress on these durum wheats was further investigated in two contrasting environments: open‐field (control—C) and greenhouse heat stress (HS). HS shortened the interval “beginning‐end of flowering” of 1.5 days across genotypes, and the “end of flowering‐beginning of grain filling” and maturation of 4.9 days, with a range of 1 day in Arcangelo to 11 days in Cappelli. Advances in main phenophases significantly decreased kernel weight (KW) and grain yield (GY), whereas grain protein content (PC) increased. As expected, a negative relationship was observed between GY and PC, while positive relationships were found for GY and grain‐filling duration (GFD), and GY and KW. Genotypes responded differently to heat stress, as evidenced by the net photosynthesis, transpiration rate, instantaneous water use efficiency and dry matter accumulation in kernels. Genotypes were ranked according to the heat susceptibility index (HSI): Amedeo, Arcangelo, Capeiti 8, Svevo and Trinakria resulted heat‐tolerant. These varieties were characterized by an early trigger of dry matter accumulation in kernels under HS (Amedeo, Arcangelo and Trinakria), or showed similar length of the GFD (Capeiti 8) between environments. The multilocation trial confirmed a negative relationship between maximum temperatures and grain yield, and a positive relationship between minimum temperatures and protein content during grain–filling periods. Research focusing on agronomic strategies, phenology and breeding for tolerance to heat stress is of strategic importance to cope with the detrimental effect of global warming in semi‐arid climates.     

From field to health: a simple way to increase the nutraceutical content of grape as shown by NO-dependent vascular relaxation

Polyphenolic grapevine components involved in plant resistance against pathogens possess various pharmacological properties that include nitric oxide (NO)-dependent vasodilation and anti-inflammatory and free radical scavenging activities, which may explain the protective effect of moderate red wine consumption against cardiovascular disease. The aim of this work was (a) to verify the possibility that preharvest treatments of grapevine with a plant activator, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), could lead to an enriched nutraceutical potential of wine and (b) to characterize the profile of metabolites responsible for pharmacological activity. Plant spraying at the end of veraison, with a water suspension of BTH (0.3 mM), led to increased whole anthocyanin content as confirmed by HPLC comparative analysis. Extracts from berry skins of BTH-treated grapevines caused NO-dependent vasorelaxation, with a concentration-response curve that was significantly shifted to the left of the control non-BTH-treated curve. Moreover, 1:1000 dilutions of berry extracts from BTH-treated plants significantly increased basal production of guanosine 3',5'-cyclic monophosphate (cGMP) in human vascular endothelial cells when compared to the corresponding extracts of untreated plants. These results show that BTH treatment increases anthocyanin content of grape extracts, as well as their ability to induce NO-mediated vasoprotection. No increase of anthocyanin content was observed in the wine extracts from BTH-treated vines. It is concluded that BTH treatment could be exploited to increase the nutraceutical potential of grapes.     

A Maltose Biosensor for Determining Gelatinized Starch in Processed Cereal Foods

A reliable method for the quantitative determination of gelatinized starch in processed cereal foods was developed. It consists of an electrochemical biosensor based on amyloglucosidase and glucose oxidase enzymes co‐immobilized on a Pt electrode surface, and a third enzyme, α‐amylase, added in solution. Analytical parameters such as time, temperature, and enzyme units were optimized. The degree of starch gelatinization was determined in different processed cereal foods using the biosensor method and the results were commensurate to those obtained with the reference method. The biosensor methods showed good accuracy (r² = 0.9629; relative error <12%) and comparable precision (RSD <5%). This electrochemical system is rapid, reliable, inexpensive, user‐friendly for unskilled operators, and can be a valid alternative to the methods traditionally used for gelatinized starch analysis.     

Impact of sourdough on buckwheat flour, batter and bread: Biochemical, rheological and textural insights

In this study, the impact of sourdough fermentation on the biochemical, rheological and bread-making performances of buckwheat flour was investigated. In order to assess the effects of the solely acidification, a chemically acidified batter with the same pH of the sourdough was prepared. Extensive hydrolysis of the globulin fraction and release of small polypeptides occurred upon fermentation. A major reduction in the extent of interactions was observed in the sourdough, mainly due to the modification of the major structural components of buckwheat during the fermentation. The hydrolysis of proteins and, possibly, starch was in turn responsible for the major decrease in elasticity observed in the sourdough. In the batters destined for bread-making, the presence of acids was the major cause for reduced elasticity and increased strength, which could be related to the enhanced water-holding capacity of the proteins and/or protein/starch complexes. The addition of sourdough induced dramatic inhibition of the CO₂ production by the baker’s yeasts during proofing, resulting in lower volume and harder crumb of the sourdough bread. On the other hand, the solely acidification induced hardening of the starch gel upon cooking, which was responsible for lower volume and irregular crumb grain in buckwheat bread.     

Diagnosis and outcome of nasal polyposis in 23 dogs treated medically or by endoscopic debridement

This study describes the clinical, diagnostic, and pathological characteristics of canine nasal polyps and how they responded to medical, endoscopic, and surgical treatments. The database of a multi-center veterinary endoscopy group was searched from 2010 to 2018. All dogs with a histological diagnosis of nasal polyposis that were undergoing endoscopic investigation (N = 23), were included. Clinical signs at presentation were sneezing (91%), nasal discharge (83%), stertor (74%), and frontonasal deformation (17%). Skull radiography on 13 dogs had alterations in 77% of cases, including turbinate lysis (6/13), increased radiopacity of one (4/13) or both (6/13) nasal cavities, and lysis of the nasal vomer bone (3/13). Nasal polyposis had a characteristic endoscopic appearance. There were clinical and diagnostic similarities between this cohort of dogs and dogs with nasal neoplasia, although dogs with nasal polyps were often younger and polypoid tissue was external to the nose. Steroid therapy alone was not effective in treating polyposis in dogs; however, endoscopic debulking with a laser and forceps was more effective.     

Analysis of fatty acid steryl esters in tetraploid and hexaploid wheats: identification and comparison between chromatographic methods

Fatty acid steryl esters (FASE) in whole meal of 14 genotypes of tetraploid wheats (Triticum dicocconand T. durum) and 17 genotypes of hexaploid wheats (T. spelta and T. aestivum) were analyzed using different chromatographic strategies. By both GC-FID and HPLC-ELSD, tetraploid wheats are lacking two major peaks. The amounts of FASE, calculated on the basis of the GC-FID analysis, were double in hexaploid species as compared to tetraploids (40 and 20 mg/100 g db, respectively). HPLC with ESI-MS detection enabled the identification of FASE by the characteristic fragmentations and ion-adducts of each molecule. The distribution of steryl residues was not different between the wheat species: the main class of steryl derivatives found was the beta-sitosteryl derivatives, followed by campesteryl derivatives with small amounts of stigmasteryl esters. The esterified fatty acids explain the difference between the hexaploid and tetraploid wheats. In particular, small amounts of campesteryl and beta-sitosteryl, while no trace of stigmasteryl palmitates, were found in T. durum or its hulled ancestor T. dicoccon. Steryl oleates were not detectable in T. aestivum or its hulled ancestor T. spelta, which is consistent with the filogenesis of tetraploid and hexaploid species. Both chromatographic techniques (GC and HPLC) showed that FASE are useful to discriminate between hexaploid and tetraploid wheats from both qualitative and quantitative points of view.     

Recovery of anthocyanins from pulp wash of pigmented oranges by concentration on resins

A pulp wash (PW) coming from a plant for citrus processing of pigmented oranges was utilized as a starting material to recover anthocyanins, using the procedure of concentration on resin. Six commercial food-grade resins were tested to find the more suitable ones for adsorbing anthocyanins, and 96% ethanol was used as eluent for desorbing them. An automated experimental apparatus was developed to perform the adsorption-desorption procedure on column. The kinetics results in a batch system and experiments on column showed that the more efficient resins are those made of styrene-divinylbenzene having a pore radius ranging from 70 to 150 A and a surface area from 600 to 800 m(2)/g, namely, Sepabeads SP 70 and Relite EXA 90. The richest fractions collected from these resins contained about 95% of the anthocyanins in a volume of about 2% of the loaded PW. The HPLC profile of the desorbed anthocyanins is the same as that in PW. These fractions contain other phenol compounds, such as hesperidin and derivatives of hydroxycinnamic acids, in remarkable amounts. Ethanol can be easily removed from the solution and recycled, thus affording a much more concentrated product which can find application as a food colorant or antioxidant ingredient for a nutritional integrator.     

Antioxidant phenols in barley (Hordeum vulgare L.) flour: comparative spectrophotometric study among extraction methods of free and bound phenolic compounds

Phenolic compounds are found in both free and bound forms in cereals. The majority is in the insoluble bound form, that is, bound to cell wall material, such as ferulic acid and its derivatives. The antioxidant properties of the phenolic compounds in grains are associated with the health benefits of grains and grain products. The extraction capacity of several solvent mixtures, for extracting free phenols from barley flours, and the possibility of employing a rapid automated solvent extraction method were studied. The extraction yield of each method was evaluated by correlating several spectrophotometric indices (absorption at 280, 320, and 370 nm and total phenolic compounds by the Folin-Ciocalteu method) with the antioxidant activities of the barley extracts (scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl method). Interesting results were obtained when ethanol and acetone-based extraction mixtures were employed to extract free phenols. A comparison was made between alkaline and acid hydrolysis. The extraction yield of bound phenolic compounds increased when the digestion time for alkaline hydrolysis was prolonged.