Fruit Harvest Time Research Articles

Seed physiological quality and harvest point of dovyalis fruits

ABSTRACT The main propagation mode of dovyalis is by seeds, what makes important to determine the ideal moment of fruit harvest. This study aimed to evaluate the physiological seed quality and harvest time of dovyalis fruits. To determine the fruit physical attributes, they were visually classified into five classes, according to the maturity stages, based on the external color of the exocarp: stage 1: green fruit; stage 2: yellowish-green; stage 3: yellowish-brown; stage 4: brown; stage 5: intense brown. The seed extraction to evaluate the physiological quality was based on the seed water content, germination percentage, germination speed index and determination of the dry biomass of the shoot, root and seedlings originated from these seeds. The experimental design was completely randomized, containing 25 seeds per treatment and 4 replicates. The fruit color during ripening varies from green to intense brown. The fruits reach their largest size and fresh biomass accumulation in the stage 4, with the brown exocarp color represented in the Munsell chart by 2.5YR 3/4. The removal of seeds for propagation should occur from the stage 2 (2.5GY 5/8), when the fruits have a yellowish-green color, although no statistical variation is observed in the number of seeds during maturation.

Various Color Models and Color Feature Indexes to Predict Fruit Ripeness Stages

In general, farmers who grow fruits such as strawberry or tomato in greenhouses are very eager to predict the optimal harvesting time for fruits in advance. Therefore, in order to solve these farmers needs, this paper suggests the appropriate color indexes representing a ripeness of fruit images which are essential to develop a system that can automatically determine the degree of maturity of fruit. First, we consider the definitions and properties of three color models such as CIE XYZ, CIE LAB, and CIE LUV that are commonly used to represent fruit images. Second, we examine the color components and the extracting method of color feature vectors that is most suitable to accurately determine the ripening stage of the fruit. From the experimental results, the color components that can accurately distinguish the stages of ripening of strawberry were Y component in XYZ color model, A component in LAB color model, and V component in LUV color model. Also, it can be seen that the average, skewness and kurtosis of color values can be used as color feature vectors effective for determining the degree of ripening of strawberry. Therefore, the results of our study are expected to be useful to develop a system that can automatically determine the harvesting time of fruits.

Development of yield and harvesting time monitoring system for tomato greenhouse production

Tomato greenhouse growers need information about yield and harvesting time as a majority of working time to improve a yield, cultivating technique, and management of labor. We developed a tomato yield and harvesting time monitoring system for selective hand harvesting of fresh tomato. The monitoring system consists of an electronic balance, a handheld type barcode scanner, a microprocessor, and cart. Each barcode was set on each tomato plant. The monitoring system can measure and record harvested fruit weight and harvesting time, and save to micro SD card. The yield and harvesting time map were constructed using a spreadsheet software. We conducted a harvesting experiment to investigate monitoring data for 7 months, using 3 varieties. The developed monitoring system could be used in greenhouse environment without any trouble and any disturbance of harvesting work for all experimental term. By using monitoring system, we could get yield map, harvesting time map, and effect of greenhouse climate on yield and harvesting time. It is found that spatial deviation of the total harvested fruit's weight of DR03-103 was the highest. The results showed that in harvesting of fruits of DR03-103, more labor is needed and deviation of harvesting labor is higher. The result of investigation of effect of greenhouse climate and yield indicated that when greenhouse inside temperature increased, the number of harvested fruit and harvesting time is increasing from winter to spring. It was considered it was possible for growers to use yield and harvesting time information by using monitoring system.

Nutritional properties of Tempranillo grapevine leaves are affected by clonal diversity, mycorrhizal symbiosis and air temperature regime

Tempranillo grapevine is widely cultivated in Spain and other countries over the world (Portugal, USA, France, Australia, and Argentina, among others) for its wine, but leaves are scarcely used for human or animal nutrition. Since high temperatures affect quality of fruits and leaves in grapevine and the association of Tempranillo with arbuscular mycorrhizal fungi (AMF) enhances the antioxidant properties of berries and leaves, we assessed the effect of elevated air temperature and mycorrhization, separately or combined, on the nutritional properties of Tempranillo leaves at the time of fruit harvest. Experimental assay included three clones (CL-260, CL-1048, and CL-1089) and two temperature regimes (24/14 °C or 28/18 °C day/night) during fruit ripening. Within each clone and temperature regime there were plants not inoculated or inoculated with AMF. The nutritional value of leaves increased under warming climate: elevated temperatures induced the accumulation of minerals, especially in CL-1089; antioxidant capacity and soluble sugars also increased in CL-1089; CL-260 showed enhanced amounts of pigments, and chlorophylls and soluble proteins increased in CL-1048. Results suggested the possibility of collecting leaves together with fruit harvest with different applications of every clone: those from CL-1089 would be adequate for an energetic diet and leaves from CL-260 and CL-1048 would be suitable for culinary processes. Mycorrhization improved the nutritional value of leaves by enhancing flavonols in all clones, hydroxycinnamic acids in CL-1089 and carotenoids in CL-260.

Effects of Polyethylene Film Liner, 1-Methylcyclopropene, and Aminoethoxyvinylglycine Treatments on Fruit Quality Attributes of ‘Tonewase’ Persimmon Fruits During Cold Storage

This study was carried out over two consecutive years to evaluate the effects of polyethylene (PE) film liner, 1-methylcyclopropene (1-MCP), and aminoethoxyvinylglycine (AVG) treatments on fruit quality attributes of ‘Tonewase’ persimmon in cold storage. Fruit was harvested at two different levels of maturity, at a normal commercial harvest date in the first year and 10 days earlier in the second year. The PE film liner treatment significantly suppressed losses of fresh weight during cold storage, compared with the other treatments in both years. However, peel color variables (L*, a*, and b*) in the calyx-end regions declined when treated with the PE film liner, compared with the other treatments in both years. None of the treatments affected ethylene production and fruit decay was not detected during storage between the treatments. The highest level of fruit softening was observed in persimmon fruit treated with the PE film liner, while the softening rate in the other treatments was less than 50% at the end of cold storage. Fruits in all treatments were unmarketable after 2 months of storage. For the persimmon fruit harvested at the normal harvest date, the treatment with 1-MCP resulted in the highest average respiration rate and the lowest soluble solids content (SSC), compared with fruit in the other treatments. For the persimmon fruit harvested at the early harvest date, flesh firmness of fruit treated with the PE film liner declined significantly, but less so than for fruit in the other treatments by the end of storage, whereas the SSC and respiration rate were not affected by any of the treatments during cold storage. The PE film liner significantly reduced fresh weight loss during cold storage and flesh firmness and peel color were significantly affected by this treatment in second year. Overall, the results suggested that fruit harvest time in terms of fruit maturity and PE film liner treatment would retain greater fruit quality attributes during storage.ibuting to cholinesterase inhibition decreases during preharvest and postharvest fruit maturation.

Quality of bananas harvested at different development stages and subjected to cold storage

ABSTRACT One of the biggest problems faced by banana growers is to determine the most appropriate harvest time. This study aimed to evaluate the post-harvest conservation of 'Prata-Anã' bananas harvested at 16, 17, 18, 19 and 20 weeks after the inflorescence emergence and subjected to 25 days of cold storage at the temperature of 13.5 ºC (± 1 ºC) and 90 % (± 5 %) of relative humidity. The bananas harvested at 19 and 20 weeks after the inflorescence emergence showed a more advanced maturity stage after 25 days of cold storage at 13.5 ºC. The bananas showed an increase in the content of soluble solids, as well as sugars, during the evaluations, after withdrawal from the cold room. Regardless of the fruit age, there was a decrease in the pH values over the 9 days of evaluation, after the 25-day storage period. The fruits at the ages of 19 and 20 weeks presented, on average, starch contents lower than those of the fruits with 16, 17 and 18 weeks. Fruits at the ages of 19 and 20 weeks showed higher extravasation levels on the second day of evaluation. Both the fruit harvest time and storage temperature directly influenced the post-harvest conservation and the physical and chemical characteristics of the 'Prata-Anã' bananas.

Swingle citrumelo seed vigor and storability associated with fruit maturity classes based on RGB parameters

Citrus seeds normally have low storability. Identifying an optimal fruit harvest time for production of high vigor seeds is important for nurseries; however, identifying this stage for Swingle citrumelo fruits has been based only on visual color examination, and research related to this parameter has been inconsistent. The main objective of this study was to evaluate a red-green-blue (RGB) color measurement system for successful identification of Swingle citrumelo fruits possessing seeds with maximum physiological potential and storability. Fruits were harvested at three ripening stages identified as green (G), greenish-yellow (GY), and yellow (Y) pericarp, photographed, and the images processed using ImageJ software. Data were expressed as the average pixel value of R, G and B color components and a mean RGB pixel value (R+G+B/3). After harvest, seeds were evaluated for water content, germination, seedling emergence, length, dry mass and vigor as measured by the Seed Vigor Imaging System - SVIS (uniformity and vigor indexes) after 0 and 5 months storage (5 °C and 65 % relative humidity). Percentage of ruptured coat seeds was also evaluated after extraction. The R color component provided the best identification of each G, GY and Y fruits. Seeds extracted from GY fruits had higher storage potential compared with seeds from G and Y fruits. Thus, precise fruit ripening classification can be generated using the RGB color system to identify the best time for harvest to obtain seeds with greater physiological and storage potential.

Evaluation of the quality and shelf life of gamma irradiated blueberries by quarantine purposes

Fresh blueberries (Vaccinium spp.) are considered one of the richest sources of phenolic compounds and are appreciated for their high antioxidant capacity. But they are hosts in Argentina of the quarantine pests Ceratitis capitata and Anastrepha fraterculus, and have to be treated to avoid its spreading. Irradiation is being introduced in the Agricultural World trade, increasing exponentially on the last years. In order to guarantee the success of this process, it is required previous to the rutinary treatment, to define the irradiation dose range to be applied. The minimum dose for these pests has been already approved in the IPPC standard 28. The maximum dose depends on the tolerance of the fruit cultivars, maturity, pre-harvest conditions, harvest time, storage conditions, and interactions among these factors. The postharvest quality of Argentina´s blueberry treated with irradiation doses of 150 (generic quarantine dose used for fruit flies) and 300Gy (to evaluate tolerance) was evaluated. The studies included blueberries from different harvest seasons 2009–2012). Misty, O'Neal and Emeral varieties were chosen, because they represent the biggest volume of exported blueberry from Argentina. The results indicated that irradiation at 150Gy and 300Gy did not significantly affect the postharvest quality and slightly improved shelf life of the different blueberries varieties. Therefore, it is possible to use irradiation as an alternative quarantine treatment for Argentina´s blueberries, establishing a dose range appropriate to be applied on a commercial irradiation facility.

Chemical Composition and Sensory Quality of Tunisian ‘Sayali’ Virgin Olive Oils as Affected by Fruit Ripening: Toward an Appropriate Harvesting Time

AbstractHerein, the influence of the ripeness of Tunisian Sayali olives on the chemical composition and sensory quality of virgin olive oils have been investigated, with a particular focus on minor metabolites. Towards this end, five samples (S1–S5) were produced from fruits at increasing stages of maturity and then analyzed. Quality indices (free acidity, peroxide value, specific extinction in UV, sensory characteristics) and composition in major (fatty acids) and minor compounds (squalene, pigments, tocopherols, phenolic compounds, volatile compounds), as well as oxidative stability, were evaluated. Significant variations for the most analytical parameters of Sayali samples were demonstrated, highlighting the impact of stage of ripening. In particular, at later stages of ripening a decreased tendency was seen in minor compounds that are able to inhibit lipid oxidation (tocopherols, carotenoids, squalene and polar phenolic compounds) and, as a consequence, in the oxidative stability value. Moreover, a higher intensity of positive sensory notes (fruity, bitter and pungent) characteristic of extra virgin olive oil were found for samples produced with less ripe olives. Finally, a deeper knowledge of the influence of this factor would be helpful to correctly manage the optimal fruit harvesting time for producers for this variety and to improve the marketing of extra virgin olive oils by using a promising secondary variety (with a high oxidative stability and an interesting fatty acid composition).

Effect of row orientation, trellis type, shoot and bunch position on the variability of Sauvignon Blanc (Vitis viniferaL.) juice composition

Background and Aims Variation in grape berry composition around the mean has seldom been studied in its own right. From the perspective of the researcher and the viticulturist, increased variation requires greater replication to achieve good estimates of composition. Bunch position on the vine, berry position on the bunch and/or vine location in the vineyard may all contribute to differences in composition (TSS, titratable acidity, pH and malic acid) between berries. Our aim was to understand how variation may be influenced by maturity, row orientation and vine training. Methods and Results Berries were sampled regularly to study the effect of harvest time, training system, row orientation and position of fruit in the canopy on Sauvignon Blanc fruit composition. Variance, skewness (symmetry) and kurtosis (range about the mean) reduced as fruit ripened. Bunch position on a shoot contributed to >60% of the variance at harvest. Conclusions Differences in berry TSS at harvest largely reflected the date of flowering. The least mature bunches at harvest were generally the secondary bunches on basal shoots; the most mature were primary bunches on distal (Scott-Henry trained) or mid-cane (vertical shoot positioned trained) shoots. Differences in leaf area : fruit mass ratio per shoot had little effect on TSS between bunches. Significance of the Study Changes in berry population distribution as the fruit ripen have implications on the interpretation of experimental results from field trials. For convenience, experiments are harvested on a single date; however, our data clearly demonstrate differences in the population of berries at different times as fruit ripen and may be obscured by sampling strategies.

Determination of physiological maturity of wood-apple [Feronia limonia (L.) Swingle] seed

Wood-apple [Feronia limonia (L.) Swingle] is a fruit plant in the Rutaceae family with many uses. Wood-apple is usually propagated by using its seeds, but information about wood-apple seed quality is hardly available. One of the factors that determine the quality of the seeds is seed maturity. The maximum vigour of seed was achieved when the seeds reached physiological maturity. There was no information of wood-apple fruit harvest time related to seed physiological maturity. Therefore, the research on seed physiological maturity of wood-apple based on fruit age was conducted. Wood-apple fruits used for this study were taken from the village Dasun, district Lasem, Rembang, Central Java Province, Indonesia. The experimental design used was a completely randomized design (CRD) consisting of eight fruit age of 2, 3, 4, 5, 6, 7 and 8 months after anthesis and mature fruit exactly detached from the tree, hereinafter called the fallen mature fruit. The results showed that wood-apple seeds reached their physiological maturity when mature fruits exactly detached from the tree, or called the fallen mature fruit at the age of 8.25 to 8.75 months after anthesis. Physiological maturity of wood-apple seed was chracterized by the seed dry weight, germination percentage and seedling emergence percentage which had reached the maximum i. e. 0.0306 g, 97.71% and 96.67%, respectively. Conversely seed moisture content and electrical conductivity had reached the minimum 13.01% and 1.16 mS, respectively.

Determination of harvest time and quality of native camu-camu fruits (Myrciaria dubia(Kunth) Mc Vaugh) during storage

Introduction. Camu-camu (Myrciaria dubia (Kunth) Mc Vaugh) is a fruit species of the Myrtaceae family. It presents great economic potential due to its nutritional and antioxidant capacity and high vitamin C contents, reaching 7355 mg ascorbic acid 100 g-1 pulp. The present work aimed to determine the harvest time and quality of camu-camu native fruits during storage. Materials and methods. The experiment was carried out in a completely randomized design with three replications, containing 30 fruits each, in a factorial scheme (3×8), composed of three different maturation stages (immature, semi-mature and mature) and eight days of storage. Fruits were evaluated every day regarding the following variables: loss of fresh mass, pH, soluble solid contents (SS), titratable acidity (TA), ascorbic acid (AA), chlorophyll A and B content, and the maturation index (SS:TA). Results and discussion. Fruits at the semi-mature stage presented the greatest amount of ascorbic acid, conserving the quality attributes (SS, AT and fresh mass) and the ascorbic acid contents for longer. Fruits at the immature stage presented the highest values for chlorophylls A and B, and this stage is also recommended for the extraction of these biocompounds. Conclusion. The recommended harvest time of the camu-camu fruit is the semi-mature stage, when the fruit presents better quality and a longer shelf life, and conserves the desired nutritional values for longer.

Evaluation of fruit quality and antioxidant activity of kiwifruit during ripening and after storage

BACKGROUND: In the Northern hemisphere kiwifruit harvest time is conditioned by low temperatures occurring during the harvesting season while in Southern Italy minimum temperatures in autumn are high enough to support fruit growth and ripening. To evaluate the influence of delayed harvest time on kiwifruit quality attributes. METHODS: The experiment was carried out in a commercial kiwifruit, ‘Hayward’, orchard located in Southern Italy. In this area, the conventional harvest time occurs 160 days after full bloom (DAFB), during the first decade of November. Fruits were collected from 130 DAFB to 192 DAFB. Fresh fruit and dry weight, flesh color, firmness, total soluble solids content (TSS), titratable acidity (TA), ascorbic acid (AA), total polyphenols content (TPH) and antioxidant capacity (TAC) were determined. After 120 days of storage, fruit harvested 178 DAFB, had higher fresh and dry weight, flesh firmness, TSS, TA and lower water loss than fruit harvested at 160 DAFB, with no significant differences in AA, TPH and TAC. TAC was correlated more to TPH than to AA. Early (130–158 DAFB) harvests, resulted in poor fruit quality and scarce post harvest maintenance. Delaying fruit harvest time, in mild winter areas such as Southern Italy, resulted in an improved fruit

Effect of Fruit Harvest Time on Oil Yield and Quality of Some Olive Olea europaea L.) Cultivars in Roudbar Region

Effect of Fruit Harvest Time on Oil Yield and Quality of Some Olive Olea europaea L.) Cultivars in Roudbar Region

Influência da época de colheita no teor de sólidos solúveis em frutos de minitomate

Existem poucas informações publicadas sobre o efeito da época de colheita no teor de sólidos solúveis - SS (°Brix) de frutos de minitomate. Diante disso, o objetivo do trabalho foi comparar o teor de sólidos solúveis de híbridos de minitomate, portadores do hábito de crescimento determinado versus indeterminado em função da época de colheita. O experimento foi realizado em estufa agrícola, com seis tratamentos: Mascot (hábito de crescimento indeterminado), TSV918 (hábito de crescimento indeterminado), TSV912 (hábito de crescimento indeterminado), TSV678 (hábito de crescimento indeterminado), TSV1278 (hábito de crescimento determinado), TSV910 (hábito de crescimento determinado). Foram realizadas três colheitas em época distintas (90, 120 e 150 dias após o semeio - DAS) formando um fatorial 6 x 3. Durante as duas primeiras épocas de colheita (90 e 120 DAS) obteve-se os melhores teores de SS. Houve diferença significativa para os frutos coletados no ciclo final das plantas (150 DAS). O teor de sólidos solúveis variou durante as colheitas (90, 120 e 150 DAS), sendo inferior na última colheita (150 DAS). O hábito de crescimento influenciou o teor de SS apenas no início da colheita (90 DAS).

Direct quantitative indices for ripening of olive oil fruits to predict harvest time

The aim of this work was both the monitoring of selected indices, directly connected to biochemical phenomena of olive oil fruit ripening, and the processing of experimental results to choose the most appropriate harvesting time for olives. Two different olive cultivars (Frantoio and Moraiolo) in two different olive orchards were studied, picking olives by hand once a week from the beginning of September to the beginning of December. Olive samples were analyzed for average weight, pulp/stone ratio, and Maturity Index. A homogeneous batch of olives was crushed, and the olive paste was used for the measurement of water, oil, sugar, and phenolic compounds contents in olive oil fruits. Formally similar kinetics of oil and sugar contents were obtained for both studied cultivars and orchards. Oil contents showed an increasing sigmoidal trend tending to an asymptote; sugar contents showed an opposite behavior with a decreasing sigmoidal trend tending to an asymptote. The total phenolic compounds content showed a decreasing trend during ripening. The secoiridoids oleuropein aglycon and oleuropein were among the most abundant phenolic compounds. Their contents showed a linear decrease during olive ripening, modelled by a significant pseudo‐zero order kinetics; trends were cultivar‐dependent, though similar for both orchards.Practical applications: Both monitoring and processing of chemical ripening indices in olive oil fruits may be useful to define an adequate ripening degree and to predict harvest time. Modeling of oil and sugar content kinetics during ripening may improve the prediction approach to harvesting time of olive oil fruits, as compared to the common Maturity Index method. For instance, the harvest target of maximizing processing yield may be attained on the basis of the following phenomenological evidence: A constant maximum value for oil content corresponds to attainment of a constant minimum value of sugar content. A sensible choice of the most appropriate harvesting time for olives may be made by performing a combined evaluation of kinetics for oil, sugar, and phenolic compounds contents. An example to understand how a change in harvesting time may affect olive composition and, potentially, the quality of oil to be extracted, was reported in this paper.An example of combined kinetic trends of the sugar (·····), oil (—), and oleuropein (‐‐‐‐) contents to choose the harvesting time of olive oil fruits for Frantoio cultivar on one of the orchards studied.

Effects of Elevated Spring Temperatures on the Growth and Fruit Quality of the Mandarin Hybrid ‘Shiranuhi’

본 연구에서는 제주지역에서 재배되고 있는 부지화[不知火, Shiranuhi, (Citrus unshiu <TEX>${\times}$</TEX> C. sinensis) <TEX>${\times}$</TEX> C. reticulata)]의 과실품질 향상을 위한 재배체계를 확립하고 부지화 재배농가의 소득 증대를 위하여 봄철 눈의 발아 및 개화 시기의 가온처리가 부지화의 생장 및 과실 품질에 미치는 영향을 살펴보았다. 이른 봄철에 가온처리I(<TEX>$25/15^{\circ}C$</TEX>, 주간/야간) 또는 가온처리II(<TEX>$28/18^{\circ}C$</TEX>, 주간/야간) 조건에서 2월 중순부터 5월 말까지 100일 동안 재배하였을 때 대조구인 무가온 시설재배에 비하여 눈의 발아가 각각 11일, 15일 정도, 만개시기는 각각 22일, 45일 정도 앞당겨졌다. 구엽당 발생하는 봄순의 수는 가온처리구에서 감소하지만 봄순의 평균 길이와 엽면적은 증가하였다. 평균 과중 또한 봄철 가온처리에 의해 더 증가하였으며 과형지수는 측정시기에 관계없이 가온처리구에서 1.0 이상을 나타내었다. 그리고 봄철 가온처리 시에는 과피가 일찍 착색되어 수확시기를 1-2개월 앞당길 수 있을 것으로 보였다. 수확기의 가용성고형물 함량은 대조구와 가온처리I에서 각각 13.9와 <TEX>$13.6^{\circ}Brix$</TEX> 정도로 가온처리II에서 보다 더 높았다. 그리고 산 함량은 가온처리II에서 가장 낮았으나 유의성이 없었고, 당산비는 처리간 유의성이 관찰되지 않았다. 따라서 부지화 과실의 조기 수확 및 수확량 증대, 크기가 크고 당도가 높은 고품질 과실의 생산 등을 위해 봄철 생육기의 온도를 <TEX>$25/15^{\circ}C$</TEX>(주간/야간) 조건으로 재배하는 것이 적절한 것으로 보인다. The effects of elevated spring temperatures on the growth and fruit quality of the mandarin hybrid 'Shiranuhi' [(Citrus unshiu <TEX>${\times}$</TEX> C. sinensis) <TEX>${\times}$</TEX> C. reticulata] were investigated in plastic greenhouses, to develop a cropping system to improve the quality of the fruit and increase the income of growers on Jeju Island, South Korea. Under conditions of elevated temperature I (<TEX>$25/15^{\circ}C$</TEX>, day/night) and elevated temperature II (<TEX>$28/18^{\circ}C$</TEX>, day/night) during early spring, budburst was advanced by 11 and 15 d, and full bloom by 22 and 45 d, respectively, compared to those of the plants grown at ambient air temperature in a plastic greenhouse. Elevated temperatures decreased the number of spring shoots but increased mean spring shoot length and leaf area. Growing 'Shiranuhi' trees at elevated temperatures resulted in increases in mean fruit weight and fruit L/D ratio (> 1.0). In addition, fruit color development was significantly advanced in trees grown under elevated temperatures during early spring, which allowed the fruit to be harvested 1-2 months earlier than trees grown under ambient air temperature. Fruit soluble solids content (SSC) and titratable acidity (TA) at harvest were similar between elevated temperature I and ambient air temperature, but were significantly higher than at elevated temperature II. Considering fruit quality, harvest time, and yield, the elevated temperature treatment regime of <TEX>$25/15^{\circ}C$</TEX> (day/night) during early spring could be useful for cultivation of the mandarin hybrid 'Shiranuhi' to increase the income of growers.

Características físicas e físico-químicas de pitaia vermelha durante a maturação

Due to the increase of exotic fruit consumption worldwide, the cultivation of dragon fruit has been favored. To increase the agronomic potential of the culture, knowledge aiming the increase of fruit quality is necessary. The aim of this study was to evaluate the physical-chemical and pyhisical characteristics of dragon fruit during maturation, in order to define the best harvest point. Fresh weight, longitudinal and transverse diameter, skin color, flesh firmness, soluble solids content, titratable acidity, ratio and flesh pH were evaluated. A completely randomized design was carried out, represented by harvest time (days after anthesis). In each evaluation time, seven fruits were harvested, representing the replications, being one fruit per parcel. The averages of each evaluation time were subjected to polynomial evaluation, being selected according to the significance of F test and the coefficient of determination. The best dragon fruit harvest time was observed 41 days after anthesis. At this stage, fruits presented higher weight and higher red skin color intensity, lower flesh firmness, higher contents of total soluble solids and lower acidity.

A Study on Soluble Solids Content Assessment Using Electronic Nose: Persimmon Fruit Picked on Different Dates

Soluble solids content is an important internal quality attribute in determining fruit maturity and harvesting time. In this study, an electronic nose was used to monitor the soluble solids content based on the change of volatile compounds of persimmon fruit during different picking-dates. Principal component analysis was applied to investigate whether the sensors’ response of the electronic nose was able to distinguish persimmons among different picking dates corresponding to different maturity levels. The loading analysis was used to identify those sensors that contribute most for flavor modeling. The results indicated that the electronic nose could distinguish the different picking dates using principal component analysis. The model testing showed that a support vector machine could achieve better prediction accuracy and generalization than multiple linear regression and back-propagation neural network and the average prediction accuracy, root mean square error, and mean relative error of the soluble solids content. By using support vector machine models were 91.36, 0.71, and 0.58%, respectively, which implied that the electronic nose was effective for soluble solids content prediction of persimmons on the basis of the support vector machine model.

Effect of Harvesting Date and Variety of Date Palm on Antioxidant Capacity, Phenolic and Flavonoid Content of Date Palm (Phoenix Dactylifera)

The effect of date palm variety and harvesting date on total phenolic content, total flavonoid content, and antioxidant capacity of seven varieties of date palm fruits collected at different maturation stages obtained from date palm farms located in the Jericho area of the Jordan valley was investigated in this study. During different harvesting times (from June to September 2011), total phenolic content, total flavonoid content, and antioxidant capacity varied between 13.75-231.40 mg gallic acid equivalents (GAE), 1.72-9.6 mg catechin equivalents, and 142.0-719.3 µmol Trolox equivalents per 100 g dry weight sample for the seven varieties of date palm, respectively. Pearson correlation indicated that there is a strong significant correlation between antioxidant capacity and total phenolic content, as well as between antioxidant capacity and total flavonoid content for all date palm varieties investigated in this study. It is expected that these results will be useful to farmers particularly in their selection of harvesting time of the date palm fruits with high content of the bioactive compounds to meet the increasing demand on such healthy products.