77 research outputs found
Characterization of Wild Corsican Hops and Assessment of the Performances of German Hops in Corsican Environmental Conditions through a Multidisciplinary Approach
Hops (Humulus lupulus L.) is a species that grows spontaneously in Corsica, but the characterization of this species in this territory has not yet been investigated. The main objectives of this study are to explore the features of wild hops from Corsica and to determine the effect of the island terroir on some cultivars in the first year of growth. A multidisciplinary approach consisting of the genetic analysis, morphological comparison and chemical characterization of essential oils was carried out on four wild Corsican hops and three hop cultivars grown in Tettnang, Germany and Corsica, France. The morphological and GC-MS analysis of Corsican wild hops, set cluster coastal samples apart from the one far from the coast. This dissimilarity is supported by the SSR analysis
by two of the three coastal accessions. The genetics demonstrate a proximity between the European noble cultivar Tettnanger and the mountain Corsican wild hop from Corte. The morphological comparison between German hops cultivated in Tettnang and in Corsican soil, and the GC-MS characterization of their essential oils’ chemical profiles, show different features between year 0 and year +1 for each sample. This multidisciplinary approach highlights an acclimatization of hop cultivars to the Corsican terroir one year after planting
Effects of high hydrostatic pressure on physico-chemical and structural properties of two pumpkin species
The effects of high pressure treatments (200, 400, 600MPa for 5 min) and a thermal treatment (85°C for 5 min) were evaluated on cubes of two pumpkin species (Cucurbita maxima L. var. Delica and Cucurbita moschata Duchesne var. Butternut) up to 2 months of refrigerated storage. Increasing the pressure, small parenchyma cells from the pumpkin tissue exhibited collapses and separations, especially for Butternut. This species showed a lower hardness than Delica at time 0. For both species, 400MPa and thermal treatment were the most effective in the inactivation of pectinmethylesterase, which reactivated after 2 months, especially for Butternut. Colorimetric parameters decreased after all treatments. Antioxidant activity resulted affected by pressure, showing a significant increase during storage especially for the samples treated at 200MPa after 2 months, comparable to the thermal treated ones. Among the tested treatments, 400MPa may be considered as the best option for the quality retention during storage
Effects of Thermal and High-Pressure Processing on Quality Features and the Volatile Profiles of Cloudy Juices Obtained from Golden Delicious, Pinova, and Red Delicious Apple Cultivars
In this study, juices extracted from three apple cultivars (Golden Delicious, Pinova, and Red
Delicious) were stabilized by means of thermal treatment (TT) and high-pressure processing (HPP,
600 MPa 3 min); pH, total titratable acidity, total soluble solids content, color, and viscosity, as well
as volatile profile, were investigated. Qualitative characteristics (pH, titratable acidity, colorimetric
parameters, viscosity, and volatile profile) results were significantly influenced by both cultivars and
treatments; for example, juice viscosity greatly increased after HPP treatment for Golden Delicious,
and after both TT and HPP for Pinova, while no influence of stabilization treatment was registered
for Red Delicious juices. Regarding the volatile profile, for Golden Delicious cultivar, HPP treatment
determined an increase in volatile compounds for most of the classes considered, leading to a
supposed quality implementation. For the other two cultivars, the stabilization treatment that better
preserved the volatile profile was the HPP one, even if the results were quite similar to the thermal
treatment. Further studies are needed to evaluate different time/pressure combinations that could
give better results, depending on the specific apple cultivar
In vitro leaf-derived organogenesis and somaclonal variant detection in Humulus lupulus L
The exploitation of somaclonal variation potentially could be a valid strategy to overcome the depletion of hop intraspecific
agrobiodiversity. To increase somaclonal variation induction, it is possible to resort to several strategies including a differentiated
starting explant material such as leaves, roots and stems, an extended time in which cultures are maintained in vitro, and a wellbalanced cytokinin/auxin ratio. In this research, firstly, the influence of growth regulator type and concentration and the effect of
the period of in vitro hop leaf culture (6, 12, and 18 wk) were investigated. Secondly, cytofluorimetric and Random Amplification
of Polymorphic DNA (RAPD) analyses were carried out to verify the occurrence of somaclonal variation. Adventitious shoots
were obtained in all media containing 6-benzylaminopurine (BAP) (except BAP at lowest concentration tested), with no
influence detected by culture period. Mutants were detected among regenerants (16.8%) with more than half of the tetraploids
obtained from medium containing the highest BAP concentration (35.55 mM). Mutants detected by RAPD analysis were
independent of the medium composition and time in culture. A strong influence regarding explant was observed where nearly
half of mutants obtained originated from cultured leaf tissues. Further studies are needed to characterize the field performance of
mutants
The use of red lentil flour in bakery products: How do particle size and substitution level affect rheological properties of wheat bread dough?
Inclusion of pulses flour in bread formulation has important nutritional effects but its successful implementation is challenging and requires a good understanding of the effect of flour functionality, granulometry and substitution level on bread quality. Accordingly, this work studied red lentil flour and its dimensional fractions (coarse, medium, fine, extra-fine), considering compositional, morphological, functional, and thermal properties. Additionally, the effect of substituting wheat flour with lentil flour and its fractions at different levels (0, 10, 15, 20, 25 and 30% [w/w] flour basis) on dough rheology was studied using a Mixolab device, to predict bread quality. Although flour's properties were significantly affected by particle size, multivariate statistics suggested that the substitution level was the major factor affecting rheological properties of doughs made with blends of wheat and lentil flours. A 10% substitution level of wheat flour by lentil flour provides optimum rheological properties regardless of lentil flour particle size, while at higher substitution level (15–30%), a coarse fraction can provide higher performance compared to unfractionated flour and finer fractions. The results of this study pose an important base to intelligently develop wheat-lentil bread applications in the future.info:eu-repo/semantics/acceptedVersio
High pressure and thermal processing on the quality of zucchini slices
AbstractIn response to the market demand for low processed vegetables, high-pressure treatments (400,600 MPa; 1,5 min) were applied on zucchini slices and compared to a traditional blanching treatment. Histological observations, texture and color analysis, pectinmethylesterase (PME) and antioxidant (DPPH) activities were measured and compared to untreated samples. The histological observations revealed that the longer high-pressure treatments (5 min) led to more extended cell lysis and dehydration than the shorter ones (1 min) and blanching. High-pressure treatments resulted less effective than blanching on PME inactivation, with the best results obtained at 400 MPa for 1 min. Comparable texture parameters were observed for high-pressured and blanched samples. The negative correlation found between PME activity and the texture parameter 'distance of the first peak force' revealed an effect of PME on the texture recovery after treatments. High pressure led to a general browning of zucchini parenchyma and to DPPH drop. The correlations found between DPPH and color suggest the common nature of the phenomena. The influence of pressure and time on the studied parameters was revealed by two-way ANOVA. Principal component analysis clustered together the four high-pressure-treated samples, being clearly divided by blanched and untreated ones
Effect of different atmospheric and subatmospheric cooking techniques on qualitative properties and microstructure of artichoke heads
Quartered Violetto artichokes were cooked with different treatments (boiling, steaming, sous vide and vacuum cooking) at the same cooking value at the thermal centre. Then, the physical (moisture content, texture and colour), histological and chemical (phenolic, 5-hydroxymethylfurfural (HMF) and furan content, total antioxidant capacity) features of bracts and hearts were assessed. A deeply modified microstructure was observed in boiled and steamed samples with an evident decrease in hardness both for bracts and hearts. Lightness of two anatomical parts was decreased by all the treatments (with the exception of sous vide bracts). The highest total colour difference was recorded for steamed samples, whereas the lowest was noted for sous vide samples. Steamed and sous vide artichoke exhibited the highest total phenolic content and total antioxidant capacity. Sous vide samples exhibited the highest concentrations of HMF, 2-furan-methanol and 2,4-dihydroxy-2,5-dimetyl-3(2H)-furanone, whereas the by-product 5-metylfuraldheide was only detected in the steamed product
Comparison of physical, microstructural and antioxidative properties of pumpkin cubes cooked by conventional, vacuum cooking and sous vide methods
BACKGROUND
Current dietary guidelines recommend five or more fruit, vegetable, and legume servings per day. Often, these products are eaten cooked, resulting in organoleptic and nutritional changes. Vacuum cooking is gaining attention as an alternative cooking technique, due to its ability to preserve or even enhance sensory and healthy properties of food. Its household application is, however, poorly explored. In this work, the effect of vacuum cooking, performed with a new patented system, was studied for the first time on pumpkin cubes and compared to sous vide and traditional steam cooking, through a multidisciplinary approach.
RESULTS
All the cooking treatments damaged pumpkin microstructure, leading to cell separation and plasmolysis; vacuum cooking was the most aggressive method, as confirmed by texture softening. Vacuum cooking was also the method with less impact on pumpkin color, in relation to the largest extraction of some classes of carotenoids from the broken cells. Significant polyphenol extraction, especially of gallic acid and naringenin, was instead observed for sous vide and steamed pumpkins. The total antioxidant activity, ascribable to the effect of both carotenoids and polyphenols, resulted enhanced after cooking compared to raw one mainly for cook vide samples, followed by steamed and sous vide ones.
CONCLUSIONS
Vacuum cooking, followed by sous vide, has often shown better performance than traditional steam cooking for pumpkin cubes. The implementation of sous vide and vacuum cooking at domestic level or in professional kitchens, and in the food industry, would allow the consumption of vegetables with improved nutritional and sensorial characteristics. © 2020 Society of Chemical Industr
Olive Germplasm: Varieties, Descriptor List and Molecular Markers
The olive tree is of strategic importance for the Mediterranean basin, and olive oil is an important component of Mediterranean diet, with beneficial properties for human health. The longevity of this species and the low breeding pressure have largely determined the genetic diversity that exists in the olive tree. Today, olive resources are represented by very wide germplasm estimated in more than 1.700 cultivars. This chapter is a report on the synthesis of what is known about the botanical and historical origin of olive tree. Furthermore, the morphological and genetic methodologies used to identify olive cultivar are examined
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