Effect of Postharvest Transport and Storage on Color and Firmness Quality of Tomato

Low storage temperature affects quality and volatile compounds in fresh tomatoes

To investigate the impact of low temperature on the quality and flavor of ripe red tomatoes, we analyzed transcriptomes and volatile metabolomes of ripe red fruits stored at 0 °C and 20 °C for 8 days. The results showed that 0 °C maintained the sugar content by increasing the expression of sucrose synthetase (SUS) and sucrose transporter (SUT). Low expression of aroma synthesis-related genes, such as alcohol dehydrogenase 1 (ADH1), amino acid decarboxylase 1 A (AADC1A), and branched-chain amino acid aminotransferase 2 (BCAT2), were associated with reduced levels of pentanal, hexanal, 3-methylbutanal, 2-methylbutanal, and 2-phenylethanol. Additionally, the expression of pectinesterase (PE), beta-galactosidase (β-GAL), and beta-glucosidase (β-Glu), as well as phytoene synthase1 (PSY1) involved in carotenoid synthesis, was inhibited, thereby maintaining fruits texture and color. Furthermore, storage at 0 °C induced the expression of numerous genes regulating antioxidant and heat shock proteins, which further preserved the postharvest quality of tomatoes.

Impact of the Temperature Reconditioning of Cold-Stored Potatoes on the Color of Potato Chips and French Fries

The effect of temperature reconditioning on cold-stored potato tubers was investigated for three popularly consumed potato varieties (Shangi, Unica, and Dutch robjin) grown in Kenya. The potatoes were stored at 4 °C for 30 days, followed by removal and storage at 22 ± 3 °C for 9 days during which changes in sugar concentration were evaluated every two days. In parallel, potato chips and French fries were processed, and their colors were determined. The results showed that sugar content decreased significantly with increasing reconditioning time. The relative decrease in fructose content was the highest (p < 0.05) in Dutch robjin (57.49%), followed by Shangi (49.22%) and Unica (38.18%). Glucose content decreased by 54.1% in Dutch robjin, 49.5% in Shangi, and 50.8% in Unica. The lightness (L*) of French fries and chips increased significantly (p < 0.05) with reconditioning time while the redness (a*) values decreased significantly (p < 0.05) across all varieties. The correlation between lightness and the total reducing sugar content of the potatoes was r < -0.93, indicating a strong negative correlation for both products. The coefficient of determination showed that the glucose content of the tubers accounted for 80.5-97.6% of the lightness of French fries and 88.4-94.2% for potato chips. The critical glucose content range for acceptable products in French fries and chips based on the color (L* and a*) values was 12-22 mg/100g and 8-14 mg/100g, respectively, for the varieties in this study.

Effect on physiological properties of banana fruit based on pendulum impact test and storage

This study investigated the effect of mechanical damage of different impact energies (0.074 J, 0.160 J, 0.273 J) generated by a pendulum impactor and evaluated the bruise intensity and quality changes of bananas after 12 days of storage at 5, 13, and 22 °C. The bruise area (BA) and bruise susceptibility (BS) in the banana fruit were significantly increased as impact damage increased. The results of weight loss % and electrolyte leakage (EL%) were highly dependent on all studied factors; in the order of storage temperature > storage days > impact level. Storage temperature and impact damage accelerated the incidence of transpiration rate (TRm) during storage. Regarding color measurements, the results of image processing emphasized that storage at 13 °C exhibited the ideal color change in bruised fruit, which revealed a slow increment in lightness (L*) and yellowness (b*) until the last day of storage. The ethylene production rate (EPR) was recorded at its maximum peak on days 2 and 12 with values of 3.85 × 10-3 and 3.08 × 10-3 mg kg-1h-1 in banana fruit bruised by high-impact (0.273 J) and stored at 22 °C. Regardless of impact level, all size measurements reduction % including, surface area (As), geometric mean diameter (Dg), and fruit volume (Vf) of bruised bananas were higher at ambient storage conditions than those stored at 5 and 13 °C. The results of regression analysis can confirm the possibility of bruise susceptibility (BS) to estimate the quality changes of bruised fruit during storage.

Post-harvest biocontrol of Fusarium infection in tomato fruits using bio-mediated selenium nanoparticles

The protection of post-harvest infection by Fusarium spp. is a major worldwide demand, especially using effective natural alternatives to chemical fungicides. In this respect, selenium nanoparticles (SeNPs) were biosynthesized using Fenugreek seeds aqueous extract. Bio-mediated SeNPs were characterized using XRD, FTIR, UV-Vis, TEM, and EDX. XRD confirmed the crystalline nature with six characteristic peaks corresponding to Se-nanocrystals. TEM showed spherical-shaped SeNPs with 34.02-63.61 nm diameter. FTIR verified the presence of different bio-functional groups, such as, N-H, O-H, C-N, and C-NH2 acting as stabilizing/reducing agents during the biosynthesis. Bio-mediated SeNPs exhibited excellent biocidal activity against F. oxysporum and F. moniliforme, with MIC of 0.25 and 1.7 mg/mL, respectively. Direct treatment of F. oxysporum with SeNPs led to significant deformation and lysis of the fungal hyphae within 18 h. The treatment of infected fruits with MIC of SeNPs reduced the infection signs by 100% and preserved the fresh-like appearance of treated fruits for 25 and 35 days when stored at 25 °C and 5 °C, respectively. Therefore, SeNPs is considered efficacious fungicidal against Fusarium spp. in-vitro and in-vivo. The treatment of tomato fruits with MIC of SeNPs positively affected its chemical properties, as well as decreased weight loss %, confirming the barrier effect of SeNPs, thus increasing fruits' shelf-life. Bio-mediated SeNPs appeared safe towards normal HSF and OEC cell lines with IC50> 300 μg/mL. Overall results recommend the usage of bio-mediated SeNPs as safe powerful bioagent against Fusarium infection, maintaining tomato quality, and providing protection from post-harvest invasion and/or destroying existing infections.

Physiological Response of Stored Pomegranate Fruit Affected by Simulated Impact

Mechanical damage resulting from excessive impact force during handling and other postharvest operations from harvesting to consumption is a critical quality problem in fresh produce marketing. The study investigates the impact of bruise damage, storage temperature, and storage period on the physiological responses of Omani pomegranate fruit cultivar ‘Helow’. Fruits were subjected to low (45°; 1.18 J) and high (65°; 2.29 J) impact levels using a pendulum test by hitting the fruit on the cheek side. Bruised and non-bruised fruit were stored at 5 and 22 °C for 28 days. Bruise measurements, water loss per unit mass, water loss per surface area, firmness, fruit size measurements, geometric mean diameter, surface area, fruit volume, color parameters, respiration rate, and ethylene production rate were evaluated. Bruise area, bruise volume, and bruise susceptibility of damaged pomegranate fruit were increased as impact level, storage duration, and storage temperature increased. Pomegranates damaged at a high impact level and conditioned at 22 °C showed 20.39% weight loss on the last day of storage compared to the control and low-impact-bruised fruit. Firmness and geometric mean diameter were significantly (p < 0.05) reduced by bruising at a high impact level. Impact bruising level and storage temperature decreased lightness, yellowness, browning index, and increased redness over time. Furthermore, the respiration rate was five times higher in the non-bruised and low- and high-impact-injured fruit stored at 22 °C than that stored at 5 °C. The ethylene production rate recorded its highest value on day 21 in high-level-impact-bruised pomegranate fruit. The bruise susceptibility was strongly correlated with the majority of the studied parameters. This study can confirm that bruising can affect not only the visual quality characteristics but also the physiological attributes of pomegranate fruit; therefore, much care is required to preserve fresh produce and avoid any mechanical damage and losses during postharvest handling.

Quality Assessment of Burdekin Plum (Pleiogynium timoriense) during Ambient Storage

Pleiogynium timoriense, commonly known as Burdekin plum (BP), is among many Australian native plants traditionally used by Indigenous people. However, only limited information is available on the nutritional and sensory quality of BP grown in Australia as well as its changes during storage. Therefore, this study evaluated the quality of BP during one week of ambient storage (temperature 21 °C, humidity 69%). Proximate analysis revealed a relatively high dietary fiber content in BP (7-10 g/100 g FW). A significant reduction in fruit weight and firmness (15-30% and 60-90%, respectively) with distinguishable changes in flesh color (ΔE > 3) and an increase in total soluble solids (from 11 to 21 °Brix) could be observed during storage. The vitamin C and folate contents in BP ranged from 29 to 59 mg/100g FW and 0.3 to 5.9 μg/100g FW, respectively, after harvesting. A total phenolic content of up to 20 mg GAE/g FW and ferric reducing antioxidant power of up to 400 μmol Fe2+/g FW in BP indicate a strong antioxidant capacity. In total, 34 individual phenolic compounds were tentatively identified in BP including cyanidin 3-galactoside, ellagic acid and gallotannins as the main phenolics. Principle component analysis (PCA) of the quantified phenolics indicated that tree to tree variation had a bigger impact on the phenolic composition of BP than ambient storage. Sensory evaluation also revealed the diversity in aroma, appearance, texture, flavor and aftertaste of BP. The results of this study provide crucial information for consumers, growers and food processors.

Simulated Handling to Investigate the Effect of Mechanical Damage on Stored Pomegranate Fruit

Mechanical damage is a threat to both food security and sustainability. Bruising is the most common type of mechanical damage, and it causes a huge economic loss due to rejection of fresh produce and downgrading of the appearance quality by consumers. Therefore, this study aims to examine the effect of bruising during postharvest handling using a pendulum test technique. Pomegranate fruit were bruised once at two impact levels (1.189 ± 0.109 and 2.298 ± 0.239 J) and then stored (at 5 °C ± 1 °C and 22 °C ± 1 °C) for 28 days. The study evaluated the effect of impact bruising, storage temperature, and duration on the bruise magnitude and quality attributes of the bruised and non-bruised pomegranates. The results showed that the investigated factors affect the bruise size of bruised pomegranates. Increasing storage temperature from 5 to 22 °C and impact level from 1.189 to 2.298 J increased the bruise area, bruise volume, and bruise susceptibility over time. Alterations in total soluble solids (TSS) and titratable acidity (TA%) were statistically (p < 0.05) induced by bruising, particularly at a high impact. The total soluble solids (TSS) content was reduced in all tested pomegranate fruit (bruised and non-bruised) and recorded the highest percentage decline in those impacted at a high level and stored at 22 °C, at 16.81%. The combination of both studied factors did not affect the water activity (Aw) of aril or the mesocarp of bruised or non-bruised fruit. Bruising parameters and quality attributes were strongly correlated in this study, excluding water activity (Aw). The regression models showed a good determination coefficient (R2) between the predicted and measured values of bruise susceptibility (BS), total soluble solids (TSS), titratable acidity (TA%), and sugar: acid ratio (TSS:TA). The study demonstrates that bruising at a high impact level and long-term storage both affected the susceptibility of pomegranates to bruise, and altered fruit quality. Thus, these factors need to be considered during the postharvest supply chain.

Genome-Wide Identification and Expression Analysis of RR-Type MYB-Related Transcription Factors in Tomato (Solanum lycopersicum L.)

Evidence have indicated that RR-type MYB-related transcription factors (TFs) are functionally diverse in regulating floral development, fruit development, leaf senescence, ABA response, and drought and salt responses. Several RR-type MYB-related TFs in Arabidopsis, Antirrhinum and rice are identified and characterized. However, the complete RR-type MYB-related family in tomato has not been studied to date. Here, a genome-wide identification of tomato RR-type MYB-related TFs (SlMYBR) was performed by bioinformatics analysis, and their expression patterns were analyzed. A total of thirteen SlMYBR genes, which were mainly distributed in the head or tail of the chromosome, were identified from tomato and were divided into three groups. Group II was all MYBR genes from eudicots without genes from monocots. For Group I and Group III, the phylogenetic tree was in accord with the evolutionary relationship of these species. SlMYBR proteins were unstable proteins and located in the nucleus. The promoters of SlMYBR contained multiple important cis-acting elements related to abiotic stress or hormone responses. SlMYBR genes had various temporal and spatial expression patterns. Experiments of spraying exogenous hormone demonstrated that the expression of most genes containing hormone response elements was changed, indicating that the expression patterns were associated with the amount of cis-acting elements. The comprehensive investigation of tomato SlMYBR genes in the present study helps to clearly understand the evolution of RR-type MYB-related TFs and provides a useful reference for the further functional study of SlMYBR genes in tomato.

Improving Shelf Life, Maintaining Quality, and Delaying Microbial Growth of Broccoli in Supply Chain Using Commercial Vacuum Cooling and Package Icing

Poor and inconsistent quality is a major barrier to increasing produce consumption, and the lack of shelf-life after purchase is the quality issue at retail displays of produce. This research aimed to investigate and identify cooling techniques, namely vacuum cooling and package icing used in supply chains, and any resulting extension of broccoli shelf-life, maintenance of physicochemical quality, and delay in microbial growth at retail stores. Broccoli (Brassica oleracea var. italica cv. Montop) sustainably grown in the highlands of northern Thailand, Chiang Mai Province, under the Royal Project Foundation was experimented on vacuum cooling and package icing were selected to precool broccoli to 4 ± 1 °C. The effects of vacuum cooling using a final pressure of 0.6 kPa for 30 min and package icing using liner Styrofoam boxes (the best ratio of broccoli to crushed ice was 1:1 w/w) on physicochemical qualities, microbial growth, and shelf-life in simulated refrigerated retail displays were examined. The results illustrated that the shelf-life and quality of broccoli could be extended using both vacuum cooling and package icing. Both precooling techniques inhibited the yellowing of florets, provided high sensory scores, delayed microbial growth, and could be able to extend the shelf-life of broccoli. However, package icing offered greater potential for maintaining quality, especially retaining bioactive compounds, and extending shelf-life, thereby increasing the produce market window from 5 to 12 days at 8 ± 1 °C with 85% RH. Therefore, package icing was recommended in the supply chain for fresh broccoli cv. Montop grown in northern Thailand.

Effect of Simulated Vibration and Storage on Quality of Tomato

The influence of simulated transport vibration and storage conditions for 10 days on tomato fruits quality (color, weight, firmness, total soluble solids, and headspace gases) were investigated. Better kinetic models for color changes, weight loss, and firmness of stored tomato fruits were selected. Tomato fruits were divided equally into two main groups where the first one was subjected to vibration at a frequency of 2.5 Hz for two hours and the other group was set as a control (with no vibration stress). Both tomato groups were stored for 10 days at 10 °C and 22 °C storage conditions. The results showed a reduction in total soluble solids, yellowness, weight, lightness in the tomato fruits subjected to vibration at 22 °C storage condition. Ethylene and carbon dioxide increased by 124.13% and 83.85% respectively on the same condition (22 °C). However, storage at 10 °C slowed down the investigated quality changes attributes of both tomato groups (vibrated and control) during storage. The weight loss change kinetics of both tomato groups at both storage temperatures were highly fitted with a zero-order kinetic model. Color and firmness kinetic changes of tomato groups stored at both conditions were described well by zero and first order kinetic models. To validate the appropriateness of the selected model, lightness, redness, yellowness, and firmness were taken as an example. The study revealed that the vibration occurrence and increasing storage temperature cause various changes in the quality attributes of tomatoes.

Extending Shelf Life and Maintaining Quality of Tomato Fruit by Calcium Chloride, Hydrogen Peroxide, Chitosan, and Ozonated Water

Tomatoes are perishable fruit that makes them deteriorate rapidly during the post-harvest chain. Therefore, the effect of calcium chloride (CaCl2), chitosan, hydrogen peroxide (H2O2), and ozonated water on the storage abil\ity and quality of tomato fruit (Solanumlycopersicum L. cv. 448) stored at 10 °C for 28 d was studied. Weight loss, firmness, fruit color, total soluble solids (TSS), titratable acidity, total carotenoids, and ascorbic acid content (AsA) of treated tomato fruit were recorded. Our results revealed that all tested treatments significantly extended the shelf-life and maintained quality of tomato fruit compared to the control. Chitosan and CaCl2 were the most effective treatments in maintaining quality attributes. Furthermore, a correlation study suggested that AsA and total carotenoids played a vital role in conserving tomato fruit quality during storage. PC1 had strong positive loading for pH, appearance, firmness, AsA, TSS, carotene, fruit color (L* & b*) and a strong negative loading for lycopene content, color (a), weight loss, and color index. PC2 had high positive loading for total acidity and total sugar content.

Bruise Susceptibility and Impact on Quality Parameters of Pears During Storage

Bruise damage is one of the mechanical injury problems that could appear in fresh produce during the post-harvest supply chain. The study investigated three main effects (drop impact level, storage temperature, and storage duration), which can expand the level of bruising and cause some quality changes that contribute to the damage of pear. Pear fruit samples were purchased from the market and delivered to the post-harvest laboratory. Each pear was impacted by a ball with a known mass at three different drop heights (20, 40, and 60 cm), stored at 22°C with 45 ± 5% RH and 10°C with 85 ± 5% RH for 14 days storage period. Bruise area (BA), bruise volume (BV), and bruise susceptibility (BS) were calculated. Different quality analyses were done like color, firmness, and total soluble solids (TSS). Analysis of variance (ANOVA), regression analysis, and pearson correlation coefficient were performed. With increasing drop height and temperature for 14 days storage, BA, BV, BS, lightness (L*), yellowness (b*), color saturation (Chroma), and total color difference increased. However, firmness was highly reduced (92.82%) due to the increase in drop height (60 cm), storage temperature (22°C), and storage duration (14 days). Color purity (Hue), redness (a*), and TSS were not affected by drop height (impact level). A strong relationship with a strong linear regression (R2) was found between BS and CIE L*, a*, and b* color coordinates. A positive and strong correlation was also found between BS and CIEL*a*b* color parameters with a strong and negative correlation with firmness. Overall, this study can be considered as guideline for horticulture researchers and in fresh produce supply chain during post-harvest operations.