Introduction. Concerns about the potentially harmful effects of fungicides on human health and the environment encourage the search for alternative treatments for perishable fruit postharvest disease control. To this end, the potential use of oligochitosan as a natural antifungal compound to control postharvest anthracnose caused by Colletotrichum musae was investigated in banana fruits from the Cavendish group (genome AAA). Materials and methods. The influence of oligochitosan on the growth of C. musae was determined in vitro by micrographic analysis, while its in situ antifungal activity was monitored in banana fruits that were artificially injury-inoculated with C. musae; the activities of several defense-related enzymes were measured. Results and discussion. Oligochitosan at (4 and 8) g·L–1 markedly inhibited radial mycelial growth of C. musae in vitro. The scanning electron micrograph of C. musae treated with oligochitosan at inhibitory concentrations showed distortion and thinning of the hyphal wall and reduction in fungus colony diameter. Dipping banana fruits in oligochitosan solution at (5 to 20) g·L–1 significantly reduced the diameter of the anthracnose lesion, and 20 g oligochitosan·L–1 almost reached the same inhibitory effect as 0.5 g·L–1 of Sportak®, a synthetic fungicide. Activities of defense-related enzymes such as phenylalanine ammonia-lyase (PAL), β-1, 3-glucanase (GLU) and chitinase (CHT), but not polyphenol oxidase (PPO), increased in banana fruits treated with 0.5 g oligochitosan·L–1. Conclusion. The inhibitory effect of oligochitosan on anthracnose development is due to the combination of a direct antifungal effect on the pathogen and an indirect effect, whereby the activities of defense-related enzymes in the banana fruit were enhanced. To control anthracnose in harvested bananas, treatment with oligochitosan above 20 g·L–1 may substitute the use of synthetic fungicide.

The product. Coconut water (Cocos nucifera L.) is an ancient tropical beverage whose original properties have drawn the attention of manufacturers as a natural functional drink. Preservation. This refreshing liquid comes mainly from immature coconuts which are difficult to collect, store and thus to commercialise. Nevertheless, some studies, mostly from Asian countries, tend to prove that the shelf life of immature coconut fruits could be prolonged thanks to post-harvest treatments. Processing. Coconut water itself, extracted from the nut, is obviously easier to handle but is also very sensitive to biological and chemical injuries. Thermal treatment combined with chemical additives are already used by the industry but other technologies such as micro- and ultrafiltration are not yet available on an industrial scale. Whatever the process, taste, aroma and colour (linked to enzymatic activities) are still difficult to control. Discussion. Results of former and recent investigations are discussed. Finally, suggestions are made for further research to increase our knowledge of this original tropical juice.

Introduction. Although Nigeria has the largest area planted to papaya (Carica papaya) in the world, this country has one of the lowest yields reported. A good knowledge of the available genetic variability is a first step in the exploitation of this crop for the development of improved cultivars. Until now, there has been no report on genetic diversity in the papaya accessions available in Nigeria. Materials and methods. Sixty accessions of papaya obtained from ten districts in Southeastern Nigeria were evaluated using 21 variables following the IBPGR descriptors for papaya. The data was subjected to descriptive statistics, analysis of variance (ANOVA), and multivariate analysis including principal component (PCA) and cluster analysis. Results. ANOVA showed significant variation among accessions in fruit length, fruit diameter, fruit edible volume, leaf petiole length, fruit shape, flesh color and central cavity shape. The first seven principal component axes accounted for 73.47% of total variation and five cluster groups were generated from cluster analysis. Accessions were classified into two broad groups corresponding to female (15%) and hermaphrodite (85%) plants. A strong and highly significant correlation was found between leaf blade and petiole length and fruit characteristics such as length, diameter and fruit edible volume, a variable derived for the first time in this study. There was a preponderance of yellow flesh color in fruits from female plants and reddish-orange flesh color among hermaphrodite plants. Discussion and conclusions. Each of the five cluster groups consists of accessions that could be used as parents in further breeding or clones for vegetative propagation. This study revealed significant variation that could be exploited for genetic improvement of papaya in Nigeria. It is recommended that a focused papaya genetic improvement program should be pursued to exploit the genetic variation available.

Introduction. Notre étude a porté sur l’identification des insectes nuisibles des fruits de jujubiers indiens introduits au Burkina Faso. Notre objectif a été de faire l’inventaire de ces insectes ravageurs inféodés à ces nouveaux cultivars de jujubiers et de tester diverses techniques pour leur piégeage. Après identification des insectes dont la plante hôte est le jujubier, nous avons déterminé ceux qui accomplissent leur cycle de reproduction sur les jujubes. Matériel et méthodes. Nous avons utilisé des appâts alimentaires avec des pièges de fabrication industrielle renfermant du torula et du terpinyl acétate et testé l’efficacité de complexes [pièges artisanaux / attractifs naturels] par rapport aux pièges à torula. Ensuite, nous avons mis en incubation des fruits attaqués afin d’identifier les insectes qui en émergeraient. La fluctuation des populations de Tephritidae a été suivie à partir de relevés hebdomadaires dans les pièges à torula. Simultanément l’évolution de la production fruitière a été étudiée. Résultats. L’inventaire effectué en verger de jujubiers indiens a révélé la présence de plusieurs familles appartenant à l’ordre des diptères parmi lesquelles figurent dix espèces de mouches de fruits réparties dans quatre genres (Bactrocera, Dacus, Ceratitis et Carpomya) ; une noctuelle de l’ordre des lépidoptères (genre Agrotis) a également été identifiée. Les espèces les plus représentées dans les collectes effectuées par pièges ont été Carpomya incompleta (44,86 %), Bactrocera invadens (21,58 %) et Bactrocera cucurbitae (18,49 %). Le taux d’émergence après incubation des jujubes attaqués a été de 50 %. Deux espèces seulement ont émergé de ces fruits : C. incompleta (84 %) et Agrostis sp. (16 %). Parmi les appâts alimentaires naturels testés, seul le mélange [bière locale + banane] a permis de piéger des Tephritidae (Bactrocera invadens) et la noctuelle Agrotis sp. Cependant, deux autres appâts naturels (fruits en putréfaction et lait concentré) ont permis de capturer Agrotis sp. Discussion et conclusion. Nos résultats ont mis en évidence les deux ravageurs potentiels des jujubiers indiens au Burkina Faso. Des études complémentaires sur l’identification de l’espèce d’Agrotis, et sur la biologie, l’écologie et le comportement des ravageurs incriminés seront nécessaires pour la définition de méthodes de lutte en plantations de jujubiers au Burkina.

Introduction. Chestnut represents one of the most important crops for the Portuguese economy. The most common consumption mode of these fruits is roasted or boiled. In this context, the major aim of our study was to evaluate the amino acid contents and the mineral composition of raw and cooked chestnuts. Materials and methods. Amino acids were determined by HPLC and minerals were determined by molecular absorption spectrophotometry, by atomic absorption spectrophotometry or by flame emission photometry. The most important Portuguese cultivars were evaluated: Aveleira, Boaventura, Côta, Judia, Lada, Lamela, Longal Padrela, Longal Soutos da Lapa, Negra and Martaínha. Results and discussion. The cooking method significantly affected the total amino acid composition with contents in roasted samples 13% and 12 % higher than in boiled and raw chestnuts, respectively. Roasted chestnuts presented higher alanine, arginine, isoleucine, leucine, phenylalanine, threonine, tyrosine and valine contents than either raw or boiled chestnuts. Moreover, serine presented the highest content in raw or roasted chestnut kernels. Regarding the mineral composition, potassium (K) was the predominant macronutrient in the chestnuts, whereas phosphorus (P), calcium (Ca) and magnesium (Mg) were found in low contents. Cooking significantly affected the mineral composition, except for iron (Fe), copper (Cu), and manganese (Mn) contents. In general, calcium decreased upon cooking. K, Ca, Mg and B decreased with boiling. The present data confirm that cooked chestnuts are a good source of amino acids and minerals, both affected by boiling and roasting, which have been associated with positive health benefits.

Introduction. Ultrafiltration (UF) is a single-unit operation for the clarification and fining of fruit juices. The purpose of the UF is to remove suspended solids as well as haze-inducing and turbidity-causing substances to obtain a clear juice during storage. Specifically, the polymerization of phenolic compounds and their interaction with other components (e.g., proteins) could cause a haze complex and turbidity in fruit juices, which can foul the ultrafiltration membrane. Materials and methods. Fresh pomegranate juice was clarified by the ultrafiltration process on a laboratory scale. In experimental tests performed according to the total recycle and the batch concentration mode, the effects of transmembrane pressure (TMP) and enzyme pre-treatment on permeation flux and quality of juice were studied. Results. With the total recycle mode, the effect of TMP on the color and clarity of clarified pomegranate juice was significant. The initial color of the raw pomegranate juice was reduced from 74% to 33% and the clarity decreased from 77% to 42% by UF when the TMP increased from (1 to 3.6) bar. Total phenolic rejection decreased from 45% to 21% when the TMP rose from (1 to 2) bar and remained constant above this value. With the batch concentration mode at TMP = 2 bar and velocity 1 m·s–1, the enzymatic treatment (5 U·mL–1, 300 min, T = 20 °C) of pomegranate juice provided the highest permeate flux, a decrease in total phenolics of 50% and an increased clarity of 30%. Fouling of the UF membrane during pomegranate juice processing is mainly due to the retention of polyphenols and/or proteins; thus, several blocking mechanisms were studied, using a recently developed membrane-fouling model. Analysis revealed that the membrane separation process was controlled by the gel layer mechanism of raw pomegranate juice and complete pore blocking mechanism with enzymatic pre-treatment.