Water Loss Of Fruit Research Articles

Revealing the crucial role of cuticular wax components in postharvest water loss in passion fruit (Passiflora edulis Sims.)

Passion fruit (Passiflora edulis Sims.) is highly prone to water loss and shrinkage after harvesting. The fruit cuticle serves as a crucial barrier to prevent non-stomatal water loss. However, the impact of cuticle on water loss in passion fruit remains unclear. Therefore, the present study primarily focuses on the influence of the cuticle on postharvest water loss of passion fruit, specifically emphasizing the changes in cuticular wax components. Our results showed that both the thickness and content of cutin decreased during storage. The degradation of wax components exhibited a similar trend to fruit water loss. At the end of the storage, n-triacontane content was stored at 25 °C retained 2.8% of that at 7 °C. Follwed by stearic acid, palmitate, and so on, with amounts at 25 °C are 9.3% and 13.8% at 7 °C, respectively. Interestingly, the reduction of amides, erucamide and hexadecanamide lead to water loss in fruit. So far as we know, this is the first report demonstrating that cuticle amides influence water loss in fruit. This study provides new insights into the role of cuticle in the water loss of passion fruit.

Slltpg3, a non-specific lipid transfer protein, acts on the cuticle synthetic pathway to delay water loss and softening of tomato fruit

Non-specific lipid transfer proteins (nsLTPs) are a class of small, omnipresent proteins that are involved in the transport of cuticular wax and other cell wall precursors. Although the cuticle serves as an outer barrier that protects plants from abiotic and biotic stresses and maintains postharvest storage quality, the regulatory role of nsLTPs on the cuticle remains unclear. Here, we isolated the Slltpg3 gene (a member of the tomato nsLTPs family) from tomato (Solanum lycopersicum) and overexpressed Slltpg3 in Micro-Tom tomato cultivars. We found that Slltpg3-overexpression optimized cuticle characteristics by increasing cuticular wax, cutin content, and cuticle thickness and by decreasing cuticle permeability. Our results suggested that Slltpg3 gene is involved in dynamic cuticle synthesis by increasing the content of cuticular wax components and delaying fruit softening and dehydration. Thus, this study revealed a direct relationship between cuticle characteristics and fruit softening and dehydration and provided new insights into tomato adaptation under drought conditions.

Effects of Various Polymeric Films on the Pericarp Microstructure and Storability of Longan (cv. Shixia) Fruit Treated with Propyl Disulfide Essential Oil from the Neem (Azadirachta indica) Plant.

Plant extracts represent a rich repository of metabolites with antioxidant and antimicrobial properties. Neem (Azadirachta indica) is a medicinal plant considered the tree of the 21st century. In this study, we investigated the antioxidant and antimicrobial effects of propyl disulfide (PD), a major volatile compound in neem seed, against the pericarp browning (BI), microbial decay incidence (DI), and water loss of longan fruit. Fresh longan cv. Shixia samples were packaged in oriented polypropylene (OPP) and polyethene (PE) packages of different thicknesses (20, 40, and 60 µm). Sterile gauze was fixed inside the packages and 500 uL of PD was placed on them to avoid the direct contact of PD with fruit samples. Packages were sealed immediately to minimize vaporization and stored at 12 ± 1 °C for 18 days. Fruit samples packaged in open net packages served as controls. The results showed that fruit treated with PD in OPP and PE packages significantly prevented losses of water, DI, and BI compared to control treatment. PD also maintained the color, TSS values, TA values, pH values, high peel firmness, high TPC content, and high TFC content, and reduced the activity levels of PPO and POD. Scanning electron microscope (SEM) analysis indicated that the exocarp, mesocarp, and endocarp of longan peel were smooth, uniform, and compact with no free space compared to control, where crakes, a damaged and loose structure, and a lot of fungal mycelia were found. The shortest shelf life of 9 days was observed in control as compared to 18 days in OPP-20 and OPP-40; 15 days in OPP-60, PE-20, and PE-40; and 12 days in PE-60 packaging films. Therefore, PD as a natural antioxidant and antimicrobial agent, in combination with OPP-20 and OPP-40 polymeric films, could successfully be applied commercially to extend the postharvest shelf life of longan.

Transcript profiles analysis of citrus aquaporins in response to fruit water loss during storage.

Water loss is an essential factor that affects the maintenance of quality of citrus fruit during postharvest handling and storage. Aquaporins (AQPs) play an important role in the transport of water across membranes. However, the expression profiling of AQPs is incomplete for citrus fruits during storage. In this study, a post-harvest storage experiment was performed using sweet orange fruits to determine changes in water loss and fruit quality. Also, genome-wide expression analysis of CsAQP genes was carried out in fruit of different citrus varieties during storage. Low humidity storage conditions accelerated the postharvest water loss and texture decline and increased the TSS content in the fruit. A total of 39 non-redundant CsAQP genes were identified. A comprehensive analysis of these genes demonstrated that all AQPs had conserved filter motifs in the different citrus varieties examined. Moreover, multiple expression analysis revealed AQPs had complex expression profiles upon water loss in citrus fruit, being time-specific in tight-skin varieties (orange and pomelo varieties), tissue-specific between peel and pulp, and variety-specific between loose-skin (mandarin varieties) and tight-skin varieties (such as sweet orange and pummelo). These results indicated that the relative humidity in storage environment affected the postharvest water loss and quality of citrus fruit. Besides, the alternation in AQPs expression may partially account for the different water loss ratio in citrus varieties and the transfer of water between the peel and the pulp of citrus fruit during storage.

Ultrasound-assisted osmotic dehydration of litchi: effect of pretreatment on mass transfer and quality attributes during frozen storage

Litchi (Litchi chinensis Sonn.), fruits being the perishable and high amount of moisture content, are very susceptible to fruit deterioration and reduced shelf life. A novel method of ultrasound-assisted osmotic dehydration can improve fruit quality by increasing mass transfer rate and maintaining texture characteristics. Therefore, this study aimed to investigate the effect of ultrasound-assisted osmotic dehydration on the mass transfer parameters, physicochemical and microbiological qualities of litchi fruits during frozen periods. For this purpose, litchi fruits were subjected to ultrasound-assisted osmotic dehydration as a pretreatment prior to the freezing step. The pretreatment consisted of three processing conditions: the use of osmotic dehydration at 50% (w/w) of sucrose (OD); ultrasound in an osmotic solution for 10 min before osmotic dehydration (US10 + OD); and ultrasound in an osmotic solution for 15 min before osmotic dehydration (US15 + OD). All samples were frozen and stored at − 18 °C. The obtained results indicated that ultrasound pretreatment effectively increases water loss (28.73 ± 3.25%) and solid gain (45.44 ± 6.85%) levels of litchi fruit. During the frozen storage for 90 days, the use of ultrasound, remarkably, US10 + OD treatment reduced the moisture content (76.46 ± 1.38%), drip loss (15.93 ± 1.01%), and microbial load (2.58 ± 0.06 log CFU/g) of the frozen litchi while increasing the firmness (1.46 ± 0.24 N), and a total soluble solid (17.50 ± 0.87 oBrix) amount of the samples in comparison to their controls (p < 0.05). Therefore, these results demonstrated that ultrasound-assisted osmotic dehydration could significantly improve the quality of litchi fruit in freezing and thawing processes.

Relationship of cuticle development with water loss and texture of pepper fruit

Postharvest water loss in pepper fruit (Capsicum annuum L.) reduces its shelf life. Fruit texture is one of the most important components of fruit quality for consumers. In this study, the anatomical traits of pepper fruit related to postharvest water loss and texture were assessed. There was a strong positive relationship between postharvest water loss and the thickness of the cuticular membrane, cuticular weight, total cutin weight, and polysaccharide-cutan weight. An amorphous fibrous structure that forms a path for diffusion and increases water loss was observed in the thick cuticle of the pericarp. In addition, positive correlations between the hardness of the exocarp and the weight of cuticular membrane, cutin content, and polysaccharide-cutan content were found. These results indicate that the thickness of the cuticular membrane wedged between subepidermal cells may influence water loss through the pericarp of pepper fruit and fruit with a high cutin and polysaccharide content have a hard tough texture.

Functional characterisation of lenticels, micro-cracks, wax patterns, peel tissue fractions and water loss of pomegranate fruit (cv. Wonderful) during storage

Pomegranate fruit is prone to moisture loss irrespective of its thick rind and tough leathery outer skin, resulting in compromised visual appearance and financial loss. The aim of this study was to identify and characterise structural changes in lenticels, micro-cracks, wax patterns and peel tissue fractions to aid the understanding of water loss trends in pomegranate fruit during storage. Fruit were stored at 7 °C and 90 % RH for 42 d and thereafter transferred to shelf conditions (23 °C and 58 % RH) for 8 d. Peel samples were obtained from the calyx-end, equatorial-region and stem-end of randomly selected fruit. Lenticels, micro-cracks, thickness of waxy cuticle and wax layer patterns were examined under scanning microscopes. The trends of water loss with respect to peel tissues and location on fruit were examined by monitoring changes in tissue thickness. Increased fragmentation of waxy cuticle and widening of micro-cracks were observed during fruit storage. Higher count of lenticels, larger lenticel size and generally low peel thickness were observed at the calyx-end and equatorial-region as compared to the stem-end of the fruit. A noticeable water loss trend was detectable with respect to region on the fruit, the calyx-end being more susceptible compared to the equatorial-region and stem-end.

Impact of electron-beam irradiation combined with shellac coating on the suppression of chlorophyll degradation and water loss of lime fruit during storage

The change in the color of the lime peel from green to yellow is the main postharvest-period problem that is unacceptable to consumers. The purpose of this research was to study the effect of electron-beam (E-beam) irradiation and shellac coating on chlorophyll degradation and qualities in lime fruit. Lime fruit cv. Paan were treated with E-beam irradiation at dosages of 0 (control), 0.5 and 1 kGy and stored at 13 °C for 30 d. E-beam treatment at 1 kGy delayed the change in peel color (b* and ΔE values), total chlorophyll content and the increase of chlorophyllase activity more compared to the 0.5 kGy E-beam and control treatments. However, 1 kGy E-beam irradiation increased the respiration rate, resulting in high weight loss. Therefore, shellac coating at 10 % (w/v) applied prior to irradiation with 1 kGy E-beam could minimize the respiration rate and water loss. In addition, shellac coating combined with E-beam irradiation delayed the color change of lime peel (L*, a*, b* and ΔE values), maintained the total chlorophyll content and suppressed the activity of chlorophyll degrading enzymes (chlorophyllase, Mg-dechelatase and pheophytinase) compared to non-treated fruit. However, the combined treatments affected the reduction of titratable acidity and enhanced the accumulation of total ascorbic acid and the hydrogen peroxide (H2O2) content. The results imply that shellac coating combined with E-beam irradiation is an alternative approach to delay chlorophyll degradation and maintain the quality of lime fruit.

Excess water loss induced by simulated transport vibration in postharvest kiwifruit

Fruit usually suffers from water loss after transportation and storage, which largely blemishes the quality characteristics including appearance, saleable weight and texture. This study was conducted to interpret the potential relations between fruit water loss and transport vibration. Kiwifruit were subjected to vibration using an electrodynamic shaker followed by storing at 25 °C and 75% RH (relative humidity) in dark for 12 d. Fruit weight loss and water content in the epidermis (EP), outer pericarp (OP), inner pericarp (IP) and core tissues were determined. Shrinkage of EP cells and water movement were evaluated using laser scanning confocal microscopy and magnetic resonance imaging, respectively. Cell damage was investigated by observing the ultrastructure and electrolyte leakage. The results showed that fruit water loss was accompanied with the spatial movement of water from interior IP, OP and external EP. Vibration damaged the fruit cells with plasmolysis, membrane contracting and increased electrolyte leakage, which accelerated movement of water from the tissues to outward resulting in severe water loss of fruit. However, the electrolyte leakage and water content in the core were little changed in both control and vibrated fruit. Shrinkage of EP cells coupled with fruit shrivel appeared by 4 d of storage after vibration. However, the symptom in control fruit was not observed until 8 d of storage. It could be concluded that the simulated transport vibration caused intracellular damage in fruit tissues, which accelerated the water loss and shriveling process.

Russeting partially restores apple skin permeability to water vapour.

The higher water loss of russeted fruit results from the higher permeance of the periderm of the russeted skin as compared to that of the intact cuticle and epidermis. Apple fruit surfaces are often in-parallel composites, comprising areas of intact cuticle (atop a healthy epidermis) adjacent to areas covered by periderm (so-called russet). The occurrence of non-russeting and russeting genotypes makes this species an ideal model to study the barrier properties of its composite skin. The objective was to quantify the water vapour permeances of non-russeted ([Formula: see text]) and russeted fruit skins ([Formula: see text]). Rates of water loss from whole fruit ([Formula: see text]) and excised epidermal skin segments (ES) or peridermal skin segments (PS) were quantified gravimetrically. The [Formula: see text] was larger in russeting than in non-russeting genotypes because [Formula: see text] exceeded [Formula: see text] by about twofold. Also, the [Formula: see text] of russeting genotypes was larger than that of non-russeting genotypes. Generally, [Formula: see text] was more variable than [Formula: see text]. These differences were consistent across seasons and genotypes. The lower [Formula: see text] as compared to [Formula: see text] resulted primarily from the higher wax content of the cuticle of the [Formula: see text]. For non-russeted genotypes, the value of [Formula: see text] was significantly related to the permeance determined on the same intact fruit ([Formula: see text]). Close relationships were also found between the [Formula: see text] calculated from [Formula: see text] determined on the same fruit and the measured [Formula: see text]. For russeting genotypes, the [Formula: see text] or [Formula: see text] were not correlated with [Formula: see text]. The [Formula: see text] calculated from [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] (all determined on an individual-fruit basis) was significantly correlated with the measured [Formula: see text]. Our results demonstrate that the periderm permeance exceeds the cuticle permeance and that permeances of non-russeted surfaces of russeting genotypes exceed those of non-russeting genotypes.

Microscale modeling of coupled water transport and mechanical deformation of fruit tissue during dehydration

Water loss of fruit typically results in fruit tissue deformation and consequent quality loss. To better understand the mechanism of water loss, a model of water transport between cells and intercellular spaces coupled with cell deformation was developed. Pear (Pyrus communis L. cv. Conference) was chosen as a model system as this fruit suffers from shriveling with excessive water loss. A 2D geometric model of cortex tissue was obtained by a virtual fruit tissue generator that is based on cell growth modeling. The transport of water in the intercellular space, the cell wall network and cytoplasm was predicted using transport laws using the chemical potential as the driving force for water exchange between different microstructural compartments. The different water transport properties of the microstructural components were obtained experimentally or from literature. An equivalent microscale model that incorporates the dynamics of mechanical deformation of the cellular structure was implemented. The model predicted the apparent tissue conductivity of pear cortex tissue to be 9.42±0.40×10−15kgm−1s−1Pa−1, in the same range as those measured experimentally. The largest gradients in water content were observed across the cell walls and cell membranes. A sensitivity analysis of membrane permeability and elastic modulus of the wall on the water transport properties and deformation showed that the membrane permeability has the largest influence. The model can be improved further by taking into account 3-D connectivity of cells and intercellular pore spaces. It will then become feasible to evaluate measures to reduce water loss of fruit during storage and distribution using the microscale model in a multiscale modeling framework.

Modeling of Coupled Water Transport and Large Deformation During Dehydration of Apple Tissue

Water loss of fruit during storage has a large impact on fruit quality and shelf life and is essential to fruit drying. Dehydration of fruit tissues is often accompanied by large deformations. One-dimensional water transport and large deformation of cylindrical samples of apple tissue during dehydration were modeled by coupled mass transfer and mechanics and validated by calibrated X-ray CT measurements. Uni-axial compression–relaxation tests were carried out to determine the nonlinear viscoelastic properties of apple tissue. The Mooney–Rivlin and Yeoh hyperelastic potentials with three parameters were effective to reproduce the nonlinear behavior during the loading region. Maxwell model was successful to quantify the viscoelastic behavior of the tissue during stress relaxation. The nonlinear models were superior to linear elastic and viscoelastic models to predict deformation and water loss. The sensitivity of different model parameters using the nonlinear viscoelastic model using Yeoh hyperelastic potentials was studied. The model predictions proved to be more sensitive to water transport parameters than to the mechanical parameters. The large effect of relative humidity and temperature on the deformation of apple tissue was confirmed by this study. The validated model can be employed to better understand postharvest storage and drying processes of apple fruit and thus improve product quality in the cold chain.

TRANSPIRATION LOSS OF FRESH PRODUCE IN TRANSPORT PACKAGES - A BASE FOR A SHELF LIFE PREDICTION MODEL

The kind of packaging affects the boundary layer resistance (s/cm) respecting the water loss of fruit and vegetables in the process chain. This study aims to determine the effects of airflow on the climatic conditions respecting the boundary layer resistance (s/cm) of single products inside transport packaging. Therefore, 30 evaporation spheres were put in three layers in a plastic box with a size of 40×30× 17 cm filled with plastic spheres at natural convection and forced airflow (0.8 m/s). The results showed differences in the transpiration of produce depending on the position inside the box and the airflow.

WATER LOSS IN HORTICULTURAL PRODUCTS - MODELLING, DATA ANALYSIS AND THEORETICAL CONSIDERATIONS

The water loss of individual fruit (melon, plum and mandarin) was analysed using the traditional diffusion based approach and a kinetic approach. Applying simple non linear regression, both approaches are the same, resulting in a quite acceptable analysis. However, by applying mixed effects non linear regression analysis, explicitly including the variation over the individuals, the kinetic approach was found to reflect the processes occurring during mass loss better than the diffusion approach. All the variation between the individuals in a batch could be attributed to the initial mass or size of the individuals. The fraction of the fruit mass that is available for transpiration is the key item in the water loss process, rather than the skin resistance and fruit area. Obtained explained parts are well over 99%.

Water on the Surface Aggravates Microscopic Cracking of the Sweet Cherry Fruit Cuticle

The effect of surface water on the frequency of microcracks in the cuticular membrane (CM) of exocarp segments (ES) of developing sweet cherry fruit (Prunus avium L.) was studied. Strain of CM and ES on the fruit surface was preserved by mounting a stainless steel washer on the fruit surface in the cheek region using an ethyl-cyanacrylate adhesive. ES were excised by tangentially cutting underneath the washer. Frequency of microcracks in the CM of ES was determined following infiltration for 10 minutes with a 0.1% acridine orange solution by fluorescence microscopy before and after exposure to deionized water (generally 48 hours). Exposing the surface of ES of mature `Burlat' sweet cherry fruit to water resulted in a rapid increase in microcracks in the CM that approached an asymptote at about 30 microcracks/cm2 within 24 hours. There was no change in microcracks in the CM when the surface of the ES remained dry. Incubating ES in polyethylene glycol solution that was isotonic to fruit juice extracted from the same batch of fruit resulted in a greater increase in frequency of microcracks as compared to incubation in deionized water. The water-induced increase in microcracks was closely related to strain of the CM across different developmental stages within a cultivar [between 45 and 94 days after full bloom (DAFB); r2 = 0.96, P ≤ 0.001, n = 9] or across different cultivars at maturity (r2 = 0.92, P ≤ 0.0022, n = 6). Incubating ES of developing fruit in enzyme solution containing pectinase and cellulase such that the outer surface remained dry resulted in complete rupture and failure of the ES. Time to rupture and percentage of ruptured ES were closely related to the strain of the CM (r2 = 0.92, P ≤ 0.001, n = 9 and r2 = 0.68, P ≤ 0.0063, n = 9, respectively). Removal of epicuticular wax had no effect on frequency of water-induced microcracks. Also, temperature had no effect on frequency of water-induced microcracks, but frequency of microcracks increased exponentially when exposing the outer surface of ES to relative humidities above 75%. At 100% humidity the increase in frequency of microcracks did not differ from that induced by liquid water. Local wetting the surface of intact fruit in the pedicel cavity or stylar end region resulted in formation of macroscopically visible cracks despite of a net water loss of fruit. Uniaxiale tensile tests using dry and fully hydrated CM strips isolated from mature `Sam' sweet cherry fruit established that hydration increased fracture strain, but decreased fracture stress and moduli of elasticity. Our data demonstrate that exposure of the fruit surface to liquid water or high concentrations of water vapor resulted in formation of microcracks in the CM.

貯蔵果実の水損失を低減させる熱ストレスの知能的制御

In this study, an optimal control of heat stress was applied to minimize the water loss of fruit during storage using an intelligent control system. The control system consists of a decision system and a feedback control system. In the decision system, the dynamic change in the rate of the water loss, as affected by temperature, is first identified using neural networks and then the optimall-step set points of temperatures that minimize the rate of the water loss are sought through simulation of the identified neural-network model using genetic algorithms. Here, anl (=6) -step control process was supposed. The length of each step was 24 h. Two optimal values, a single heat stressT= {40, 15, 15, 15, 15, 15°C} and double heat stressT= {40, 15, 40, 15, 15, 15°C}, were obtained as the optimal values under the range of 15 to 40°C. Especially, a temperature operation first rising to the highest level and then dropping to the lowest level in the given range provided a lower rate of the water loss than by keeping constant at the lowest level through whole the control process.

Elevated growing temperatures during the day improve the postharvest chilling tolerance of greenhouse-grown cucumber (Cucumis sativus) fruit

Abstract Growing cucumber fruit in a greenhouse at elevated temperatures during the day increased their tolerance to postharvest chilling. Fruit grown with an average day temperature of 32±1 °C (high temperature) had a storage life (i.e. time to loose 7% fresh weight) of 16 days at 10 °C and did not exhibit chilling injury, while fruit grown at 27±1 °C (control) developed symptoms of chilling injury (i.e. appearance of translucent, water-soaked areas in the mesocarp) after 12 days at 10 °C. The rate of fresh weight loss and the storage life (i.e. 7% water loss) of fruit from both treatments was 12 days when stored at 20 °C. Chilling-induced ion leakage from mesocarp disks was lower from high temperature grown fruit than from control fruit. During storage at 10 °C, firmness, vitamin C content, and activity of superoxide dismutase (SOD; EC 1.15.1.1), and catalase (CAT; EC 1.11.1.6) were higher in high temperature grown fruit than in control fruit. Enhanced antioxidant enzyme activity in high temperature grown fruit may have contributed to increased chilling tolerance.

Identification and Optimal Control of the Water loss of Fruit During Storage, As Affected by Temperature

Lower temperature is usually effective to maintain the quality of fruit during storage. However, it is also reported that a short-term exposure to high temperature between 35 and 50°C delayed the ripening of fruit. The water loss of the fruit is a major contributor to quality losses and depends on the temperature. In this study, the control process was divided into l-steps, and an optimal temperature operation (optimal l-step set points of temperatures) that minimizes the rate of the water loss was determined using neural networks and genetic algorithms. The reciprocal number of the average rate of the water loss gave an objective function. First, the dynamic change in the rate of the water loss, as affected by temperature between 5 and 40°C, was identified using neural networks. A neural-network model obtained here showed a good agreement with the observed responses. Then, the optimal l-step set points of temperatures, which maximize the objective function, were searched for through simulation of the identified model, using genetic algorithms. Several types of optimal values were obtained under different constraints of the temperature. Especially, a temperature operation that first raises to the high level and then drops to the lowest level in the given range provided a lower rate ofthe water loss than that keeping constant at the lowest level throughout the control process.