Suitability of enzymatic hydrolyzates of extracted gluten from fresh pasta by-product used as bread improvers

Gluten extracted from fresh pasta by-products (PG) was enzymatically hydrolyzed by two different commercial proteases (Alcalase 2.4 L and Pancreatin) to different degrees of hydrolysis (DH 2.0, 4.0 and 8.0%). Commercial gluten (CG) was used as reference. The evaluation of functional properties of hydrolyzates from pasta gluten (PGH) and commercial gluten (CGH) showed that Pancreatin hydrolyzates had the highest emulsifying capacities. Regarding the foaming activity, all hydrolyzates performed better than unhydrolyzed gluten. PGH and CGH were added to wheat flour (1%) and their effects on dough rheology were studied. Most hydrolyzates with DH 8% increased dough thermal stability and elasticity during mixing, accelerated the denaturation rate of the protein network, and delayed the gelatinization speed of starch as the temperature increased. Texture profiles and specific volumes of breads from low quality wheat flour with added Pancreatin hydrolyzates (DH 8%) were comparable to those of breads from high quality flour. This showed the potential suitability of PGH and CGH as bread improvers.     

Effects of nymphal density (Bactericera trigonica) and feeding on photosynthetic pigments,proline content and phenolic compounds in carrot plants

European Journal of Plant Pathology - Insect feeding induces physiological and biochemical changes in host plants. Indeed, symptom severity often depends on insect density. Recently, the carrot...     

Effects of Whitening Agents and Frozen Storage on the Quality of Sardine (Sardina pilchardus) Surimi: Physicochemical and Mechanical Properties

This work is focused on the effect of using whitening agents (WA) during a process followed by frozen storage (4 months at ?18°C) on the whiteness, quality parameters, and mechanical properties of sardine surimi. The whiteness of surimi exhibited a significant improvement when whitening agents (calcium carbonate and peroxide hydrogen) were used (48.75 to 60.24). Dynamic rheological measurement showed that storage moduli, G′, was considerably higher than loss moduli, G″, for both surimi with WA and control; however, the highest viscoelastic moduli were found in the treated surimi. In addition, the microstructure of surimi with WA showed more compact matrix and higher water holding capacity. On the other hand, most tested indexes showed quality losses throughout the frozen storage in both samples. Proteins underwent denaturation as indicated by the reduction in band intensities, especially myosin heavy chain (MHC) bands. Peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) measurements showed that lipid oxidation took place during storage; however, the degree of lipid oxidation was not relevant. Therefore, it was proved that the addition of whitening agents had a marked effect on the production of surimi with better functional attributes including whiteness, water holding capacity, and mechanical properties.     

Effect of drought on the biochemical composition and antioxidant activities of cumin (Cuminum cyminum L.) seeds

This study is designed to examine the yield components, fatty acid, and essential oil compositions and phenolic contents fruit essential oil composition, the total phenolic amounts as well as the antioxidant activities of cumin (Cuminum cyminum L.) seeds under drought. This plant is one of the most common aromatics in the Mediterranean kitchen. Plants were treated with different levels of water deficit: control (C), moderate water deficit (MWD) and severe water deficit (SWD). Our results indicated that MWD improved the number of umbels per plant as well as the number of umbellets per umbel and the seed yield, in comparison to the control, but it decreased under SWD. Fatty acid composition analysis indicated that petroselinic acid was the major fatty acid (55.9%) followed by palmitic (23.82%) and linoleic (12.40%) acids. Water deficit enhanced the palmitic acid percentage and affected the double bound index of the fatty acid pool and thus the oil quality. The essential oil yield was 1.64% based on the dry weight and increased by 1.40 folds under MWD. Nevertheless it decreased by 37.19% under SWD in comparison to the non treated seeds. Drought results on the modification of the essential oil chemotype from γ-terpinene/phenyl-1,2 ethanediol in the control seeds to γ-terpinene/cuminaldehyde in stressed ones. Besides, total phenolic contents were higher in the treated seeds (MWD and SWD). Results suggest that water deficit treatment may regulate the production of bioactive compounds in cumin seeds, influencing their nutritional and industrial values. Besides, antioxidant activities of the extracts were determined by four different test systems, namely DPPH, β-carotene/linoleic acid chelating and reducing power assays and showed that treated seeds (MWD and SWD) exhibited the highest activity.     

<Emphasis Type="Italic">Alternaria</Emphasis> species associated with early blight epidemics on tomato and other <Emphasis Type="Italic">Solanaceae</Emphasis> crops in northwestern Algeria

Clubroot, caused by the protozoan parasite Plasmodiophora brassicae Woronin, is one of the most damaging diseases of Brassica napus worldwide. Resistant plant material is valuable for cultivation in all areas of high incidence of the disease and intensive growth of oilseed rape. We have evaluated clubroot resistance, plant morphology and seed quality in 15 lines of an F₄ generation and selected six lines of F₅ generation of interspecific hybrids obtained from a cross between a male sterile line of B. napus ‘MS8’, selected from resynthesized oilseed rape (B. rapa ssp. chinensis × B. oleracea var. gemmifera) and an ecotype of B. rapa ssp. pekinensis. Clubroot resistance was evaluated using a bioassay with P₁-P₅ pathotypes of P. brassicae (according to the classification of Somé et al. 1996). The resistance to the pathotype P₁ was successfully fixed in the F₅ generation, and improved in some lines in respect to the pathotypes P₂-P₄. The resistance to P₁ and the other tested pathotypes was not linked. Characterization of plant material included recent techniques of FISH and BAC-FISH with a special focus on the analysis of ribosomal DNA (rDNA) of selected individuals. Two hybrid lines combined high levels of resistance with appropriate plant morphology, good seed quality traits and a stable chromosome number and arrangement. Recent techniques of ‘chromosome painting’ provided good insight into chromosome organization in the hybrids obtained, and offered opportunities of further improvement of the breeding process.     

Does olive mill wastewater stimulate olive plants growth?

Olive mill wastewater (OMW) is annually produced in enormous quantities and it constitutes a serious environmental problem. For several years OMW was used as an amendment in olive orchards which given beneficial effects on growth and soil properties. The present work aimed to study the effect of OMW used after one year from the oil extraction, where phenol content decreased. One-year-old plants of “Chemlali” olive cultivar were subjected to three treatments. C0, C1, and C2 were respectively 0%, 30%, and 45% of OMW used for amendment. Each rate was adjusted with water supplied every 15?days (1?L/plantlet). Results showed significant differences between treatments especially for growth, chlorophyll content of leaves (SPAD), and leaf nutrient content (P, K, Ca, and Na). Always C2 was better than C1. Substrate properties were clearly ameliorated particularly an increase of organic matter but the pH and the electric conductivity were unaffected.     

Potassium Mineral Nutrition Combined with Sustained Deficit Irrigation to Improve Yield and Quality of a Late Season Peach Cultivar (Prunus persica L. cv ‘Chatos’)

ABSTRACT

Fruit quality traits are directly related to agronomic practices such as irrigation and fertilization, especially potassium supply since its effects on quality and water drought resistance. The objective of this study was to evaluate the effect of different combinations of potassium rate and application mode (in soil: 200S and 100S, foliar spray: 100F) with two irrigation regimes (FI: irrigation with 100%ETc and DI: irrigation with 66%ETc) on peach yield and quality parameters. The experiment was performed during two consecutive years. At harvest, only in the second year significant differences between treatments were observed in yield. In fact, potassium foliar spray, even in DI regime, improved yield. The fruit diameter was slightly affected by treatments in the first year. However, in the following season foliar potassium spray even in DI water regime increased fruit size. Concerning the firmness, no significant differences were observed in the first year except for the second year it decreased with DI strategy independently of potassium treatment. The soluble solids content was strongly affected by the treatments. The highest values were observed in 100F+DI treatment with no significant effect on acidity. Vegetative growth was affected only by water regime which DI reduced shoot length.     

Composition and insecticidal activity of essential oil from Ruta graveolens,Mentha pulegium and Ocimum basilicum against Ectomyelois ceratoniae Zeller and Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Journal of Plant Diseases and Protection - The aim of this research was to explore the chemical composition and evaluate the insecticidal activities of Ruta graveolens, Mentha pulegium and Ocimum...     

Natural variation of Medicago truncatula resistance to Aphanomyces euteiches

We analysed the resistance variation in 14 natural populations of Medicago truncatula from Tunisia to Aphanomyces euteiches infection. The reaction of M. truncatula lines to A. euteiches infection varied from susceptibility to full resistance. Of the overall level of phenotypic variation, 65.4 % was found to occur within populations. Principal component analysis showed a high spread of lines belonging to the same population, indicating no clear structure in the Tunisian M. truncatula populations and supporting the hypothesis of gene flow among populations. Likewise, there was no association between local resistance composition and the geographical distances between populations, ruling out isolation by distance as an explanation. Furthermore, significant correlations were observed between quantitative traits and ecological factors consistent with the local adaptation hypothesis. A cluster analysis of the populations showed the presence of three groups. The first group comprised the populations originating from the centre of the country, containing the main resistant lines. The second group included the populations collected in the south and the mountain region of Thala and contained the main partially resistant lines. The third group comprised the populations sampled from the north regions and saline soils and included the main susceptible lines. Overall, we found that the natural M. truncatula lines were more likely to be susceptible (71.3 %) than resistant (28.7 %) to A. euteiches attack. Nevertheless, many resistant lines exhibiting new reaction patterns to A. euteiches attack were identified in the natural populations and these can be used for the identification of potentially new resistance genes.