Application of near-infrared spectroscopy for fast germplasm analysis and classification in multi-environment using intact-seed peanut(Arachis hypogaea L.)

Peanut is a worldwide oilseed crop and the need to assess germplasm in a non-destructive manner is important for seed nutritional breeding.In this study,Near Infrared Spectroscopy(NIRS)was applied to rapidly assess germplasm variability from whole seed of 699 samples,field-collected and assembled in four genetic and environmentbased sets:one set of 300 varieties of a core-collection and three sets of 133 genotypes of an interspecific population,evaluated in three environments in a large spatial scale of two countries,Mbalmayo and Bafia in Cameroon and Nioro in Senegal,under rainfed conditions.NIR elemental spectra were gathered on six subsets of seeds of each sample,after three rotation scans,with a spectral resolution of 16 cm-1over the spectral range of867 nm to 2530 nm.Spectra were then processed by principal component analysis(PCA)coupled with Partial least squares-discriminant analysis(PLS-DA).As results,a huge variability was found between varieties and genotypes for all NIR wavelength within and between environments.The magnitude of genetic variation was particularly observed at 11 relevant wavelengths such as 1723 nm,usually related to oil content and fatty acid composition.PCA yielded the most chemical attributes in three significant PCs(i.e.,eigenvalues>10),which together captured 93%of the total variation,revealing genetic and environment structure of varieties and genotypes into four clusters,corresponding to the four samples sets.The pattern of genetic variability of the interspecific population covers,remarkably half of spectrum of the core-collection,turning out to be the largest.Interestingly,a PLS-DA model was developed and a strong accuracy of 99.6%was achieved for the four sets,aiming to classify each seed sample according to environment origin.The confusion matrix achieved for the two sets of Bafia and Nioro showed 100%of instances classified correctly with 100%at both sensitivity and specificity,confirming that their seed quality was different from each other and all other samples.Overall,NIRS chemometrics is useful to assess and distinguish seeds from different environments and highlights the value of the interspecific population and core-collection,as a source of nutritional diversity,to support the breeding efforts.

Effect of Pure Culture Fermentation on Biochemical Composition of <i>Moringa oleifera</i>Lam Leaves Powders

This study was carried out to determine the effect of the age of the leaves and fermentation on in vitro protein digestibility and biochemical properties of leaves powder of Moringa oleifera. A 6 × 2 × 2 factorial design with two ages of the leaves (one and seven-month-old leaves), six times of fermentation and two fermentation temperatures was used for this purpose. One and seven-month-old fresh leaves were dried at 45 ℃ for 24 h, crushed to 1000 μm then fermented at 30℃ and 37℃ for 120 hours with Lactobacillus plantarum A6 at 108 CFU/g. Samples were withdrawn every 24 hours for physico-chemical analyses. Results showed that 7 month-old leaves were richer in iron, proteins, polyphenols and phytates than one month old leaves. The phytates content dropped from 66.92% and 61.95% in the seven and one month-old leaves powders respectively fermented at 37℃, and from 54.15% and 67.95% in the seven and one month-old leaves powders respectively fermented at 30℃. Protein content increased by 26.34% and 24.48% for the 1and 7-month-old leaves powders respectively fermented at 37℃, and by 13.06% and 13.97% for the 1and 7month-old leaves powders respectively, fermented at 30℃. Iron availability increased from 35.97% to 40.57% and 20.74% to 30.98% for the 1and 7-month-old leaves powders respectively, fermented at 37℃ and from 35.97% to 39.79% and 20.76% to 23.72% for the 1and 7-month-old leaves powders respectively, fermented at 30℃. There was a negative correlation between pH, total and reducing sugar contents, time as well as fermentation temperature, whereas there was a positive correlation between total protein content and pepsic digestibility of protein and fermentation time. From these results, fermentation of M. oleifera leaf powder by Lactobacillus plantarum A6 increases protein content, pepsic digestibility of protein and availability of iron and reduces the phytates content of these powders.

Lipid Profile and Antioxidant Activity of Macadamia Nuts (<i>Macadamia integrifolia</i>) Cultivated in Venezuela

Macadamia nuts (Macadamia integrifolia) grown in Venezuela have showed an average total fat content of 70%. Oleic acid (18:1) was the main monounsaturated fatty acid (MUFA) (51.3%), followed by palmitoleic acid (16:1, 22.6%). The content of polyunsaturated fatty acids (PUFAs), C18:2 and C18:3 represented 5.4%. Thus, MUFAs and PUFAs together constituted more than 80% of the total fatty acids present. Trans-vaccenic acid was also present (3%). As regards to other phytochemical compounds, tocopherols and tocotrienols were not found in the sample, but the presence of squalene was detected.The antioxidant activity (44.2%) of the extract was produced by the phytochemicals present.

Impact of Extraction Method on Physicochemical Characteristics and Antioxidant Potential of <i>Adansonia digitata</i>Oil

In this study, the effect of extraction processes on the physicochemical characteristics and antioxidant potential of baobab (Adansonia digitata L.) seed oil was evaluated. The oils were extracted, on the one hand, by cold pressing, and on the other hand, with three types of organic solvents (acetone, chloroform, n-hexane). The recorded results indicated that the extraction yield of baobab oil was significantly impacted by both the extraction method and the polarity of the solvent used. In addition, chloroform provides the best extraction yield (40.12 ± 0.607). However, extraction by cold pressure preserves at best the physicochemical and bioactive properties of the extracted oils. Indeed, the pressing oil contains a content of phenolic compounds (0.047 ± 0.0024 mgEAG/g of oil) and a very high radical scavenging activity (DPPH) (31.71% ± 0.61%). For the various oils extracted, the minimum and maximum values were 0.50 and 3.17 mEq?kg-1;56.26 and 99.113 mgI2?100 g-1;1.457 and 1.465;205.37 and 233.587 mgKOH/g respectively for the peroxide, iodine, refractive and saponification values. The color parameters (L*, a* and b*) of the oils also differ depending on the nature of the organic solvent used. Principal component analysis (PCA) and correlation analysis were performed on the physicochemical properties and the antioxidant potential of the extracted oils. Therefore, the results suggest the mixed use of acetone and hexane to obtain oil comparable to that extracted by cold pressing.

New Bacterial Agents to Limit <i>Colletotrichum gloeosporioides</i>Development on Mango

Mango anthracnose disease forms typical irregular-shaped black necrotic spots on the fruit peel of mature fruit and is caused by Colletotrichum gloeosporioides. In order to improve the disease control with a limited use of fungicides, new microbial agents able to limit the growth of the pathogen were searched in the indigenous natural flora of mango surface. In order to find a suitable biocontrol agent, a screening was applied to 305 epiphytic bacteria isolated from the carposphere of 17 mango cultivars sampled from eight locations on Reunion Island. The screening approach involved a first step based on the ability of the isolates to form a biofilm, to grow under fruit storage conditions, and to interfere with the development of C. gloeosporioides. In a second step, the capability of selected isolates to limit C. gloeosporioides in vitro mycelial growth and conidia germination was assessed and species identified. The most effective bacteria belonged to the Enterobacter, Pantoea, Kosakonia and Leuconostoc genera, but for some of them, their safe use has to be demonstrated. Efficacy in vivo, performed on wounded mature mango fruit, was limited, probably because of the wounding inoculation strategy favoring the pathogen. Future biocontrol treatments should focus on preharvest applications to enhance the protective benefit.

Determination of the Geographical Origin of Fruits by Using 26S rDNA Fingerprinting of Yeast Communities by PCR-DGGE： An Application to Shea Tree Fruits

International trade intensifies the process of globalization which has extended to the entire planet and extends to the entire planet. In view of the difficulties of installing these documentary systems in developing countries, in particularly the countries of sub-Saharan Africa, the new strategies of traceability emerge. Among the new tools of tracing the products of vegetable origin, a ＂biological code bar＂ based on the analysis of the DNA of micro-organisms present on the fruits is an interesting tool. A molecular technique employing 26S rDNA profiles generated by PCR-DGGE was used to detect the variation in yeast community structures of Shea tree fruits （Vitellaria paradoxa） from Senegal, Ghana and Mali. When the 26S rDNA profiles were analyzed by image analysis and multivariate analysis, distinct microbial communities were detected on Shea tree fruits. The band profiles of yeasts from different countries were specific for each location and could be used as a bar code to discriminate the origin of the fruits. This method is a new traceability tool which provides fruit products with an unique biological bar code and makes it possible to trace back the fruits to their original location.

Optimisation of the Postharvest Treatment with Thymol to Control Mango Anthracnose

Anthracnose, caused by the fungus called Colletotrichum gloeosporioides, is the main postharvest disease that affects mango production on Reunion Island. Fruits for the export market are always treated with chemicals. The use of chemical treatment is not in adequation with consumer expectations, and the increasing emergence of fungicide-resistant isolates promotes the development of alternatives methods. The principal objective of this work was to use antimicrobial properties of thymol as an alternative postharvest treatment on mango. Thymol diluated in a penetrating agent solution was effective on mango anthracnose. At a concentration of 0.025%, Thymol limited necrosis development due to pathogens during fruit storage. This treatment can stimulate some of polyphenols biosynthesis involved in the fruit resistance to postharvest disease, particularly thesynthesis of gallic acid and resorcinol. With this final concentration of 0.025% thymol, the treatment did not affect fruit maturation and quality, especially the peel colour and sugar content. Importantly, the treatment did not show any detectable effect on organoleptic qualities of the fruit.

Potential Use of Essentials Oils to Control Fruitlet Core Rot (FCR) in Pineapple (Queen Victoria Variety) in Reunion Island

Fruitlet Core Rot (FCR) is one of the major postharvest diseases of pineapple (Ananas comosus var. comosus), especially on the prone variety Queen Victoria cultivated in Reunion Island. This aggressive disease is generally due to two pathogens: Fusarium ananatum and Thalaromyces stolii, and needs to be controlled during postharvest. In Reunion Island, F. ananatum is the principal causal agent impacting fruit exportation. Fruit produced for the export market is generally treated with chemicals. This type of postharvest treatment is not in line with consumer expectations, as consumers prefer fruits treated with nonharmful and natural products. The objective of this work was to study alternative postharvest treatments using the fungitoxic properties of essential oils and their ability to elicit the resistance mechanisms of the fruit. Six EAs were tested in vitro on mycelial growth of F. ananatum. Whether by volatilization or included in the culture medium, some essential oils such as thymol, eugenol, geraniol and the carvone/menthol mixture have a strong fungistatic effect. But only thymol has a fungitoxic effect. The thymol, a natural molecule synthesized by thyme (Thymus vulgaris L. thymoliferum) is the more effective in vitro and is the strongest potential to be used in postharvest treatment. Thymol, prepared at 0.025% in a terpene solvent that acts as a penetrating agent, was tested in vivo with inoculated fruits. The treatment was effective only on necrosis development from the upper part of the fruits. Pineapple polyphenol biosynthesis appears to have been suppressed by thymol treatment. Results and opportunities for this treatment are discussed. Additional experiments must be carried out in order to decide on the advisability of this type of treatment.

Biological Activity of <i>Syzygium aromaticum</i>and <i>Ravensara aromatica</i>Essential Oils from Madagascar and Their Possible Use against Postharvest Mango Anthracnose

The fungitoxicity of five Malagasy essential oils (Eos) against Colletotrichum asianum was assessed in terms of conidial germination and mycelial growth. Their effect on defense-related compounds content, physicochemical properties and anthracnose lesions in mango fruits was also determined. Four of the tested Eos were from Ravensara aromatica leaves, and the last Eo was extracted from clove leaves. Their chemical compositions were then determined through GC-MS analysis and the active compound of the most fungitoxic Eo was determined by testing the toxicity of its major component to C. asianums spore germination, mycelial growth and its ability to inhibit anthracnose development on mango fruits. The R. aromatica Eos tested were fungistatic to C. asianum, whereas clove Eo was fungitoxic and the 4 chemotypes of R. aromatica Eo exhibited variable inhibiting capabilities: 1) all tested doses of all Eos (112.5 and 225 μL/L of air) were effective against C. asianum mycelial growth (10% - 100% inhibition) but doses of 225 μL/L were more inhibitory than those of 112.5 μL/L, 2) Conidial germination was more resistant to Eos toxicity since only 225 μL/L of methyl eugenol chemotype of R. aromatica Eo, all tested doses of the sabinene chemotype of R. aromatica Eo and clove Eo were found inhibitory toward conidial germination of C. asianum. 30 μL/L of sprayed clove Eoweretested on inoculated mangoes and were found to be effective against anthracnose development without affecting the resorcinol content in mango peel and the physicochemical properties of mango pulp. Tests on the major components of clove Eo showed fungitoxic activities against mycelial growth and conidial germination of C. asianum similar to those of clove Eo.

The Determination of Geographical Origin of Foodstuffs by Using Innovative Biological Bar-Code

Abstract： One of the great concerns of the customers is the traceability of the products. The authors proposed to link microbial ecology to geographical origin of foodstuffs by a molecular technique joined to an image analysis. Molecular techniques employing 16S and 28S rDNA profiles generated by PCR-DGGE were used to detect the variation in microbial community （bacteria, fungi） of Pangasius fish from Viet Nam harvested in different aquaculture farms and during different seasons and Shea tree fruits from five different districts in Mali. The bacterial DNA profiles from Pangasius fish and the fungal DNA profile from Shea tree fruits were specific to each place of production and could be used as a biological bar code certifying the origin of fish and fruit. To follow the product during processing, the authors proposed to identify and validate some pertinent biological markers which come from the environment of the food to assure their traceability during international trade. It is new analytical method which permits to determine the origin of food or to follow them during international trade.

Protein Quality of Amaranth Grains Cultivated in Ethiopia as Affected by Popping and Fermentation

The effect of popping and fermentation on protein quality of three different varieties of amaranth grains cultivated in Ethiopia was evaluated. Total lysine content of the grains was higher than that of commonly available cereals but close to that of legumes. Methionine and cysteine contents in the grains were also higher than that found in cereal and legume proteins. Percentage of total indispensable amino acids, excluding tryptophan, was 43% - 49%, which was higher than WHO reference pattern (31%). Popping resulted in 36% and 37% reduction in total lysine and cysteine contents, respectively, whereas fermentation reduced cysteine, lysine and methionine contents by 16%, 20% and 20%, respectively. From the free amino acids, histidine was the major indispensable amino acid but threonine was not detected. During popping, all free amino acids, except threonine, were reduced. On the other hand, fermentation significantly increased (p < 0.01) most amino acids except arginine, which was significantly decreased (p < 0.01), and tyrosine and glutamic acid, for which no change was observed. Popping decreased in vitro protein digestibility (IVPD) by 8.3% - 17.1% while fermentation increased IVPD by 4.8% - 7.5%. Substitution of amaranth for wheat and/or maize during complementary food formulation could contribute much to the daily requirements of indispensable amino acids of young children.

Monitoring of Lactic Fermentation with a Coupling Electronic Nose and Gas Chromatography

In this work, the performance of dehydratation-desalcoholization system based on an electronic nose coupled to gas chromatography was tested. The system was used for monitoring the volatile compounds produced during a lactic fermentation with a heterofermentative bacteria (Lactobacillus fermentum Ogi E1). The monitoring was carried out with dehydratation and desalcoholization or dehydratation only, on the basis of low ethanol concentration produced by this bacteria. In the first case, fermentation head-space analyses showed low signals from each gas sensor, then the principal components analyses (PCA) resulted confused. However with the only dehydratation system, the electronic nose was able to detect some volatile compounds during bioprocess. The PCA showed a single distribution, permitting to conclude that principal component 1 represented the ethanol concentration. The system is appropriate to monitor some parameters during the fermentations process as ethanol, lactate and biomass concentration.

Optimization of the Design and Drying Process Adapted to Pineapple Slices

The present work is a study on the influence of temperature and the velocity of air on the drying kinetics of pineapple slices. The main objective is to define from this drying kinetics rules to help a designer choose an adequate principle or drying configuration and optimize the design of dryers adapted to the use of it. The experiments were made in an electric dryer using a parallel flow system. The air was used at three different temperatures （40, 50 and 60 ~C） and at four different velocities （0.27, 0.5, 1 and 1.8 m/s） during the experiment. The results show that an increase of 10 ℃ of the drying temperature reduced the drying time by 45% and increased the drying velocity by 30%. On the set of air velocities tested, it was noticed that the influence of air velocity on drying was more striking at the beginning than at the end of the drying process （variation of less than 20%）. Whatever the variation of parameters during the drying process, the best performance was observed when the products water content during the drying process was between 50% and 80%.

Effect of physiological harvest stages on the composition of bioactive compounds in Cavendish bananas

The combined influence of maturation,ripening,and climate on the profile of bioactive compounds was studied in banana(Musa acuminata,AAA,Cavendish,cv.Grande Naine).Their bioactive compounds were determined by the Folin-Ciocalteu assay and high-performance thin layer chromatographic(HPTLC) method.The polyphenol content of bananas harvested after 400 degree days remained unchanged during ripening,while bananas harvested after 600 and 900 degree days exhibited a significant polyphenol increase.Although dopamine was the polyphenol with the highest concentration in banana peels during the green developmental stage and ripening,its kinetics differed from the total polyphenol profile.Our results showed that this matrix of choice(maturation,ripening,and climate) may allow selection of the banana(M.acuminata,AAA,Cavendish,cv.Grande Naine) status that will produce optimal concentrations of identified compounds with human health relevance.