Editorial
Editorial
- Dr. Jacky Ganry
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 343-344
-
- Article
-
- You have access Access
- Export citation
Research Article
Effect of processing on micronutrient content of chips produced from some plantain and banana hybrids.
- Tajudeen Adebayo Adeniji, Abdou Tenkouano
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 345-352
-
- Article
- Export citation
-
Introduction. Chips or crisps are the most important foods usually fried; they are presented in the form of thin discs (chips) or sometimes in the form of sticks (French fries). Materials and methods. Chips were prepared starting from pulp samples resulting from five hybrids of plantain and banana newly released in Nigeria and from a local cultivar used as reference. The iron, zinc and pro-vitamin A contents were investigated in the chips to unveil their micronutrient content. Results and discussion. The results showed that there was no significant difference (p < 0.05) in the iron content of the chips produced from the new plantain and banana hybrids, while a significant difference (p < 0.05) existed in both zinc and total carotenoid contents of the hybrids. Chips made from BITA 3, a hybrid cooking banana, could contribute 2.61 retinol equivalent (RE)e [1 (RE)e = 6 µg β-carotene (precursor of vitamin A)] daily, if a small packet of chips (45 g) is consumed, based on the Recommended Daily Dietary Allowance. A 45-g packet of chips made from PITA 26 can contribute 14.6% and 20.1% of the daily requirements of zinc per day, and 30.1% and 22.3% of the requirements of iron per day, for a man and a woman, respectively. Conclusions. The new plantain and banana hybrids may therefore significantly participate in a food strategy aiming at combating the lack of micronutrients in the sub-Saharan African diet.
Anthocyanins and anthocyanin-degrading enzymes in Kwai May and Wai Chee cultivars of litchis grown in Reunion Island and Spain.
- Marie-Noëlle Ducamp-Collin, Marc Lebrun, Hassina Ramarson, Guy Self
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 353-359
-
- Article
- Export citation
-
Introduction. After harvest, litchi fruits (Litchi chinensis Sonn.) rapidly lose their bright red skin color. Peel browning of harvested litchi fruit has largely been attributed to rapid degradation of red anthocyanin pigments associated with the oxidation of phenolic compounds by polyphenol oxidase (PPO) and/or peroxidase (POD). An anthocyanase has been also identified in litchi peel. Our work aimed at characterizing two specific litchi varieties that differ greatly in their color and browning behavior. Materials and methods. The anthocyanins, polyphenol oxidase (PPO), peroxidase (POD) and anthocyanase in the pericarp of two litchi cultivars, Kwai May and Wai Chee, grown in Reunion Island and Spain, respectively, were studied. Results and discussion. The qualitative composition of major anthocyanins (cyanidin-3-rutinoside and cyanidin-3-glucoside) was identical for the two cultivars studied, but, quantitatively, the variety Kwai May had a lower concentration than Wai Chee (64% less) of cyanidin-3-rutinoside. This component represented more than 90% of total anthocyanins in both cultivars. The activity of PPO was 6 times greater in the variety Kwai May than in Wai Chee and the activity of POD 30 times greater. The activity of POD was greater than that of PPO in both varieties. These differences help to explain the different behaviors of the cultivars during subsequent postharvest studies.
Morphological and molecular characterization of Cladosporium tenuissimum Cooke (Deuteromycotina: Hyphomycetes) on mango tree panicles: symptoms, pathogenicity and severity of the fungus.
- Dagoberto Guillén-Sánchez, María de Jesús Yañez-Morales, Daniel Téliz-Ortíz, Christina Siebe-Grabach, Silvia Bautista-Baños
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 361-368
-
- Article
- Export citation
-
Introduction. Mango producers of two important growing areas of the states of Guerrero and Michoacán, Mexico, reported extensive damage in mango trees caused by an abundant mycelial growth covering most diseased panicles of mango trees cv. Haden. Materials and methods. The fungus was isolated from panicles of mango. Pathogenicity was evaluated in the orchard by inoculating 20 inflorescences protected by cellophane paper bags. In vitro characterization was evaluated on monosporic cultures; conidial morphology and rate of growth were determined. A molecular characterization by DNA extraction was carried out to identify the microorganism. Results. Cladosporium tenuissimum caused necrosis of flowers, pedicels and small fruits on inoculated mango panicles cv. Haden in the long coast of Guerrero and Michoacan States of Mexico. The affected organs were covered with grey cottony mycelia and an olivaceous, green to grey sporulation. In vitro, young colonies were also olive green and velvety, turning dark green to grey with a whitish outer margin. The growth rate of colonies was 0.46 cm·day–1. Conidia were subspherical, lime-shaped and fusiform, olivaceous in color with visible scars and denticle-like extensions. The mean size of conidia was (5.85 × 2.93) µm with variations of 3.2–23 µm × 1.98–5.47 µm. The molecular characteristics rendered C. tenuissimum after identification. Symptoms of inoculated or naturally infected tree organs were similar. A diagrammatic scale was developed for the evaluation of disease severity, which varied from 69% to 100% in infected panicles. The organs were susceptible from blooming to fruit set. Discussion. Further research is proposed to evaluate the geographical distribution of C. tenuissimum in the production areas of mango with the concomitant evaluations of strategies of control.
Changes in the chemical composition of the fruits of Grewia coriacea Mast. during development and ripening.
- Attibayéba, Léon Ngantsoué, Fulbert Essamambo, Agnès Clarisse Nkourissa
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 369-375
-
- Article
- Export citation
-
Introduction. Grewia coriacea is a widespread plant species that occurs spontaneously in tropical forests of Central Africa. It is one of the most important commercial spontaneous fruit crops in the Republic of Congo (Brazzaville), where it is harvested, sold and consumed on a rather large scale. However, similar to many other spontaneous products of the tropical rain forest in Africa, G. coriacea remains poorly studied and its nutritional potential is unknown. Because the fruit of G. coriacea is an important food for indigenous people in a large portion of the Congo River Basin, we studied the evolution of some compounds of this fruit starting from its fruit setting until its maturation. Materials and methods. The contents of various pigments (chlorophyll a and b, and carotenoids), and concentrations of soluble sugars, ascorbic acid and soluble proteins of the fruit pulp of G. coriacea were analyzed in the laboratory and they were followed during maturation. Results and discussion. The curves of evolution of the studied parameters followed some anticipated trends: increasing, decreasing or relative stability. Increasing applied to the carotenoids (3,0 mg·g–1 at the beginning of the fruit development up to 8.2 mg·g–1 at the end of its maturation), soluble sugars (9,9 µg·g–1 up to 75,4 µg·g–1), ascorbic acid (25 mg·100 g–1 up to 230 mg·100 g–1) and soluble proteins (7 µg·g–1 up to 40 µg·g–1). In contrast, the two chlorophyll pigments (chlorophyll a and b) showed an overall decreasing trend. Finally, the concentration of soluble proteins remained rather constant in the later stages, despite an initial increase in the early stage of development. Conclusion. To our knowledge, these results are the first data published concerning the temporal changes in physico-chemical parameters of G. coriacea fruits in tropical Africa. The study shows that the studied fruits have high nutritional potentials, and that their ability to accumulate rather high levels of ascorbic acid could make them a potential source of vitamin C.
The electronic nose: a fast and efficient tool for characterizing dates.
- Marc Lebrun, Claire Billot, Hasnaâ Harrak, Guy Self
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 377-382
-
- Article
- Export citation
-
Introduction. Aroma is often used as a fruit quality marker. Several researchers have used the analysis of volatile compounds to characterize dates (Phoenix dactylifera). Nevertheless, it is difficult to analyze this subtle aroma in spite of the many techniques available, such as liquid-liquid extractions and headspace analysis. The global approach of the e-nose with a minimum handling of the sample is a fast and efficient alternative to these techniques. This rather new tool, simulating the behavior of the human nose, thus aroused our interest for application to dates. Materials and methods. Dates were harvested, in 2005, at the Tamar stage from nine date varieties, in Zagora, Morocco. They were frozen after harvest and sent by air to the laboratory of CIRAD (Montpellier, France). All data were collected at the same time. Five hundred g of dates were taken at random, pitted and cut into small pieces. After homogenization, an aliquot of 3.0 g was put into a 10-mL headspace flask and immediately sealed. Six replicates per sample were prepared for later electronic-nose analysis. An electronic nose (e-nose) from Alpha MOS, equipped with Metal Oxide Sensors (MOS), was used. Data were analyzed using Principal Component Analysis (PCA). The Discrimination Index (DI), created by Alpha MOS, was used to describe the discriminatory power of the groups’ separation. Alpha MOS considers that good discrimination and reliability are achieved for DI over 80%. Results. Discrimination indexes > 88% and means of the coefficients of variation obtained for each sensor < 4% demonstrate the high performance and good reproducibility of the e-nose. Conclusion. The e-nose is sensitive to date volatile emissions. All the date varieties studied were well separated. This fast screening technique, creating a specific olfactory fingerprint as a genuine identity card, could be used to follow changes in maturity, assure the identity of lots of dates and detect adulteration.
Effects of storage temperatures and 1-MCP treatment on postharvest quality of green olives.
- Ali Akbar Ramin
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 383-390
-
- Article
- Export citation
-
Introduction. Olive processing in producing countries, such as Iran, is often not well synchronized with crop harvests due to the number and size of the oil-extraction facilities. After harvest, olives might be piled in heaps and stored at ambient temperatures for up to several weeks and, during this period, the greatest deterioration takes place. Therefore, the green olive processing industry is interested in the use of an alternative to the above pre-processing storage method for fresh olives. Materials and methods. Green olives cvs. Blady, Conservolea Mission and Shengeh were harvested at the mature green stage and stored at (5, 10 and 20) °C for 10–15 weeks to evaluate their postharvest physiology and quality changes. In the second year of the experiment, olives were treated with 1-MCP at concentrations of (0.45, 0.9 and 1.8) µL·L–1 at 20 °C for 24 h and stored at 5 °C. Olive quality was measured periodically for skin color, fresh firmness, mass loss and fruit deterioration. Results and discussion. Generally, storage of olive fruits at (5, 10 and 20) °C caused a decrease in flesh firmness, but fruit softening was faster in fruits stored at (20 and 10) °C than in fruits at 5 °C. Olives stored for 60 d at 5 °C showed no symptoms of chilling injury whatever the cultivar. Olive cultivars retained satisfactory firm flesh above 2 kg for 60 d at 5 °C, 30 d at 10 °C and 15 d at 20 °C. After 60 d of storage, red skin color development did not progress much with fruits stored at 5 °C, but there was a significant difference with the other temperature treatments. However, cv. Shengeh developed red skin color greater and sooner than other cultivars did. In the second year of the experiment, 1-MCP treatment effectively reduced loss of firmness for fruits stored at 5 °C for 15 weeks. Application of (0.9 and 1.8) µL 1-MCP·L-1 was sufficient to delay significantly olive softening and color changes (P < 0.05), compared with control untreated fruits. Conclusion. Conservolea, Mission and Blady olive cvs. can be stored for up to 60 d at 5 °C and this could be extended to 15 weeks when fruits are treated with (0.9 and 1.8) µL 1-MCP·L-1 before storage.
Distribution and host plants of Bactrocera cucurbitae in West and Central Africa.
- Jean-François Vayssières, Jean-Yves Rey, Lanciné Traoré
-
- Published online by Cambridge University Press:
- 07 December 2007, pp. 391-396
-
- Article
- Export citation
-
Introduction. The data on Bactrocera cucurbitae collected over a large area of West Africa for around the past ten years enables us to make a synthesis, since this economically significant species is now widespread. Fruit samples were collected in the course of various trips to Africa; we focused on looking for the melon fly, B. cucurbitae (Coquillett). Equipment and methods. The Tephritidae were captured by means of trapping the adults and collecting holed fruit containing larvae. The fruit samples were taken from Cucurbitaceae found in the sub-region, and from other plant families hosting melon fly larvae. Fruit holed by flies were collected from untreated orchards and taken to the laboratory to be weighed, counted and classified by species, variety, date and location. The larvae collected metamorphosed into pupae. After hatching from the pupae, the adults were recovered. Results and discussion. The samples taken enabled us to determine the distribution of B. cucurbitae in West Africa; this species was found in Benin, Burkina Faso, Cameroon, Côte d’Ivoire, Guinea, Mali, Niger and Senegal. The fruit collected in these countries enabled us to draw up a list of B. cucurbitae host plants in these regions; besides Cucurbitaceae, there were two Anacardiaceae species, two Rutaceae species, one Annonaceae species, one Solanaceae species and one Oxalidaceae species. There were four economically important fruit species among them. Unlike Reunion, where the dietary pattern of the melon fly is oligophagous, in West Africa it appears to be polyphagous instead. Conclusion. The data collected from B. cucurbitae host plants is subsequently to be validated, and then refined by quantitative analyses for the different West African countries.