Introduction. Because of the long transportation times and storage durations that are often experienced, it is important to understand how pomelo properties change over time; that will be indicative of how long samples can be stored before they drop below acceptable quality limits. As no information is available regarding storage of pomelo fruit in the literature, the goal of our work was to study the change in pomelo physicochemical and textural properties following storage over a period of approximately 4 months. Materials and methods. The changes in physical, chemical and textural properties of commercial pomelo fruit were extensively evaluated over the course of a 4-month storage period. The correlation among physical, color, chemical and textural properties were also assessed. Results. Color properties (L*, a*, b*) changed significantly with storage; however, they did not change much during the initial 45 days of storage. The change in soluble solids content (SSC), acidity (A) and the [(SSC) / (A)] ratio suggested that pomelo fruit should not be stored for more than 75 days. Crucially, our study demonstrates that the a* parameter (greenness, R = –0.556) correlates best with the chemical property the [(SSC) / (A)] ratio, which is a recognized measurement of the consumer acceptability of citrus fruit. This means that measuring a* is a non-destructive way of monitoring the taste characteristics of pomelos in storage. This property also correlated well with the average firmness of the fruit and with the flesh texture. Conclusion. This fundamental information on the pomelo fruit could prove useful in the physical handling and processing of the fruit by breeders and postharvest technologists as well as distributors, market agents, importers and exporters.

Introduction. Several studies have demonstrated that food processing affects nutrients such as bioactive compounds, protein, starch, fat, fiber, minerals and antioxidant capacity. Our study examined how heat changes the physicochemical composition and antioxidant capacity of peach-palm fruit (Bactris gasipaes H.B.K.) during flour production. Materials and methods. Five commercial batches of fruit were assessed for total contents of phenolic compounds and carotenoids, and hydrophilic oxygen radical absorbance capacity (H-ORAC). The fruit was then cooked and eventually processed into flour. Results and discussion. No significant changes were found for contents of fat, protein, starch and dietary fiber during flour production. Cooked peach-palm fruit is a source of Mg, Mn, Cu and K, with 100 g of fruit containing between 5% and 13.5% of the recommended daily intake. Cooking also increased carotenoids by 17%, thus helping to compensate for the 28% loss during drying. No stage of processing affected polyphenol contents or H-ORAC. Conclusion. Because of its high bioactive compound content, peach-palm flour shows potential for use in the development of functional foods.

Introduction. The Chinese jujube tree always presents some unfavorable performances because its vegetative growth is very vigorous. Our study was conducted to apply root pruning to test whether it can effectively inhibit the vigorous vegetative growth by regulating the competitive ability of the root system for water and nutrients. Materials and methods. For our experiment, roots were cut at three different distances from the trunk (light, moderate and severe root pruning) on both inter-row sides of jujube trees to the depth of 20 cm. Roots of control jujube trees were not pruned. Then we determined for three years the competitive indicators of Chinese jujube trees including the length, number and thickness of primary branches; photosynthetic characteristics and nutrient concentrations of leaves; hormone contents in the jujube head, flower number and fruiting percentage, yield, and fruit quality. Results and discussion. In the early stage after root treatment, root pruning decreased lots of indicators such as concentrations of nitrogen, phosphorus, and potassium in leaves, photosynthesis, transpiration, stomatal conductance, and intercellular CO2 concentration of leaves, relative to the same indicators as the control group. With the gradual emergence of new roots, these indexes appeared to have adverse patterns with respect to those in the early stage after root pruning. Compared with the control, root pruning significantly decreased the length and number of primary branches and flower number, but thickened primary branches, enhanced fruiting percentage and increased the amount of ethylene release of the jujube head in the whole experiment. Fruit quality was improved with root pruning, as indicated by increases in vitamin C and total sugar and a decrease in titrable acidity. No effects of root pruning were noticed on yield. From our results, we conclude that the removal of the root system at a distance of three times the trunk diameter (severe pruning) from the trunk is the most effective in regulating the competitive ability of the Chinese jujube tree.

Introduction. Quarantine heat treatments have not yet been introduced in West Africa and no work has been done to determine the treatment conditions needed to eliminate eggs and larvae of West African fruit fly populations, especially of the new species Bactrocera invadens, from mangoes produced in the region. The objective of our study was to carry out hot water disinfestation experiments on naturally infested mangoes to determine the exposure parameters required to kill eggs and larvae of B. invadens present in commercial-quality fruits. The effects of hot water treatment on fruit quality were also investigated. Materials and methods. A tank with a heating element and a water pump equipped with a tank sensor were used. Physiologically mature, hard, green mango fruits (cv. Kent) with potential export quality but infested by B. invadens were harvested from plantations in the Bobo-Dioulasso (Burkina Faso) area. The effect of hot water treatment by immersion at 42.0 °C, 46.5 °C or 51.0 °C was evaluated by counting identifiable sites of fruit fly oviposition before and after paring the fruit and, finally, the numbers of live and dead larvae of B. invadens were counted in the pulp. The quality of the fruit was evaluated after the hot water immersion. Results and discussion. A hot water treatment resulting in a core temperature of 46.5 °C could be the basis of a fruit fly quarantine treatment for West African mangoes produced in Burkina Faso. All of the larvae extracted from the fruits treated at 46.5 °C and 51.0 °C were dead, while, in fruit treated at 42.0 °C, only about one-third of the larvae extracted were dead.

Introduction. The aim of this work was to develop a list of suitable sensory attributes and to perform sensory quality assessment of an unprocessed peach juice and a peach juice clarified by enzymatic treatment followed by membrane processes, using the attributes chosen by the trained panel. Materials and methods. A panel of assessors was selected and trained following the quantitative descriptive analysis methodology. A descriptive terminology with eight descriptors was successfully developed. Results and discussion. The sensory analysis showed that the juices were effectively clarified. Although the clarification by microfiltration in a bench-scale unit did not change juice taste attributes, the characteristic color and aroma of peach juice were also removed. The scale-up of the membrane clarification process affected all the sensory characteristics of the clarified juice, even taste. The unpleasant cooked fruit taste and aroma could be reduced by juice clarification by enzymatic and membrane processes. The kind of membrane, membrane geometry and transmembrane pressure used in the membrane clarification did not significantly affect the juice sensory characteristics.

Introduction. Optimising agricultural water use implies the combination of physiological, technological and engineering techniques, especially those for continuously monitoring the water status of plants subjected to deficit irrigation. A methodology to estimate water stress of young almond trees from thermal images was developed based on assessing the physiological status of almond crops under limited water-supply conditions. Materials and methods. Two irrigation treatments were tested during the maximum evapotranspirative demand period (214th to the 243rd day of the year) in an experimental almond [Prunus dulcis (Mill) D.A. Webb, cv. Guara] orchard: a low-frequency deficit irrigation (LFDI) treatment, irrigated according to the plant-water status, and a fully irrigated treatment (C100) at 100% of crop evapotranspiration. Daily canopy temperature at midday (TC) was measured with an infrared camera, together with standard measurements of stem-water potential (ΨStem) and stomatal conductance (gS). The time course of these parameters and their relationships were analysed. Results and discussion. The time course of the parameters studied showed highly significant correlations among the differentials of canopy-air temperature (ΔT), ΨStem and gS. The methodological protocol for analysing thermal images allowed a time saving in processing information and additionally offered the possibility of estimating the ΨStem and gS values. Conclusion. Our results confirm that infrared thermography is a suitable technique for assessing the crop-water status and can be used as an important step towards automated plant-water stress management in almond orchards.